ok, here it is...after a few months of frustration and breadboarding and getting help from samhay/slacker/merlin/ etc etc...thanks guys. ;)
introducing the ''
CHASM REVERB''
i finally nailed this bugger...and thought it deserved its own thread. get your popcorn ready.... ;)
i was going to release the pdf's only by pm due to being ripped off recently by some brazillian @#$%er (long story)..but i can't be arsed with all that hassle. and goes against my sense of shared community etc.
and seems a shame to not share due to bad apples with no morals at all.....
however, I will seriously re-iterate...this is
NOT FOR COMMERCIAL USE...(as some @#$%ers don't seem to understand this phrase :icon_evil:..you have been warned. :icon_evil:
anyway i have a batch of pcb's for this if people want them, £8.50 GBP each. (includes worldwide post/paypal fees) pm me ok.
here are the files to print off your own pcb too....just don't take the piss ok!!!...you have been warned...seriously. :icon_evil:
verified :
https://dl.dropboxusercontent.com/u/7464107/CHASMREVERBLAYOUT.pdf
https://dl.dropboxusercontent.com/u/7464107/CHASMPCB.pdf
(https://dl.dropboxusercontent.com/u/7464107/WP_20131119_002.jpg)
(https://dl.dropboxusercontent.com/u/7464107/WP_20131119_004.jpg)
(https://dl.dropboxusercontent.com/u/7464107/WP_20131119_003.jpg)
happy building + merry xmas. ;)
Sweet Reverb Rob.
Very nice indeed I love the tails thats great.
I've never used the bricks. Are they fragile? Hard to work with? How and where is it mounted?
Thanks
Rich
BTW wheres the best place to source belton bricks pls? Uk based
Excellent! Can not wait!!
Damn Rob, another "must have"!
Sounds realy cool, thanks for sharing.
But where is the tone poti?
And what´s that Chorus?
Is this true bypass? :P
nope..it has tails ..
being buffered is a good idea anyway imo...as most people will have this at the end /or near end of their chain...
i had this on a TB breadboard so i know the buffered bypass is the same sound as TB when tested... ;)
Quote from: deadastronaut on November 20, 2013, 03:01:49 PM
nope..it has tails ..
being buffered is a good idea anyway imo...as most people will have this at the end /or near end of their chain...
i had this on a TB breadboard so i know the buffered bypass is the same sound as TB when tested... ;)
Just yankin' your chain.. have been following the thread ;)
You're right, buffered at the end of the chain is not a bad thing..
Nice demo Rob - looks like it does everything you set out to do, and I can't hear a hint of pop.
Any chance you could post a schematic of the final version? I have lost track, and can't really face wading back through the other thread.
Now, for a Mk III, shall we aim for some modulation and a kitchen sink switch?
Oh - Rich, the bricks are pretty robust. You can break the pins off then (don't ask), and probably cook them if you try really really hard, but are no worse than any other IC. You can get them from das Musikding (http://www.musikding.de/Accutronics-BTDR-2H-L_1). Postage should take about a week.
Thanks Rob, Sam, Merlin, and all others who contributed to this! :)
Rob, I'll send you a PM for purchasing a couple of boards.
Rob, that´s a great pedal. Etched box, right? If it is, I´ve never seen a tidier etch. Ever!!
Hate to ask, because of what you commented about the ripoff, but: Will you release a schem? Or is it in the other thread? I always like to see a schem when building.
Thanks for sharing.
Looks and sounds great!
Does anyone know where I can get a brick in or near New Zealand? All the websites I've checked work out at around NZ$30 per brick, with about NZ$10 of that being shipping... >:(
Quote from: psychedelicfish on November 20, 2013, 03:34:31 PM
Looks and sounds great!
Does anyone know where I can get a brick in or near New Zealand? All the websites I've checked work out at around NZ$30 per brick, with about NZ$10 of that being shipping... >:(
Try tubesandmore.com They are around $14. I don't know what shipping to NZ would be.
Great looking and sounding pedal.
Any chance of getting a gut shot to see how you stuffed all the goodies in the box?
Just Sweet!!!!!!
Rob...your killing me...im going to have to make another one now :)
Edit: Heres another sound sample for you to critique of the chasm reverb. It was an early iteration (flying saucer reverb) but assume it still sounds much the same as this newer version. I cant praise this reverb enough. I use it ALL THE TIME:
This is incredible! Nicely done, sir ;D
Wowww! Good work on reverb!! Care to share graphics? Its awesome! Im definetely biulding this
Thanks for posting Rob.
Are you going to post the schematic or is it in the other thread?
Could someone please confirm this BOM based on Rob's layout? (https://dl.dropboxusercontent.com/u/7464107/CHASMREVERBLAYOUT.pdf)
Chasm Reverb
Diodes:
Pwr 1N4001x 1
D1-D4 1N4148 x 4
Transistors:
2N5457 (JFET) x 2
2N7000 (MOSFET) x 1
ICs:
IC1 TL074 x 1
VReg LM7805 x 1
Rvb BTDR 2-H L x 1
Caps
100nF x 3
10nF x 1
100pF x 3
470nF x 1
1μF NP X 1
10μF x 6
47μF x 1
100μF x 2
Resistors:
100R x 1
1k x 4
2.2k x 2
5.6k x 1
10k x 4
22K x 5
47k x 1
56k x 1
100k x 1
1M x 1
Pots
B10k x 2
B22k x 1 (sub B25k)
A100k x 1
Jumpers x 3
LED x 1
Switches:
SPDT x 1
DPDT mom x 1
Rob-Also please let me know if you see anything out of whack. Thanks!
Nice work Rob!
Just wondering, no more tails switch?
3 jumpers?
I only see 2...
yep 2 jumpers only.
@john D : latching dpdt .not momentary ;) (you knew that ;)) ...ALPHA is nice.. 8)
@yorick: yeah gave up on tails off/TB option...too much grief
no gut shot at the mo, this one has already gone to a good home,...but because we are only using a dpdt there is room for either putting the brick above the pcb (which i did)
or just above the dpdt..attached by 6 way rbbon wire... i used a card template for laying it out/cutting wire to length etc..
the next build will have gut shots ok... 8)
Oh but I don't mean Tails/TB, just plain ol' buffered/no tails :icon_mrgreen:
I don't always want the reverb to fade out naturally. Is that possible to achieve without grief?
Quote from: Valoosj on November 21, 2013, 07:56:54 AM
Oh but I don't mean Tails/TB, just plain ol' buffered/no tails :icon_mrgreen:
I don't always want the reverb to fade out naturally. Is that possible to achieve without grief?
Define grief. This might be a better question for the other, slightly more epic, thread.
If you want buffered bypass, then one could add another FET switch to kill the wet signal (rather than the dry signal at the moment) on bypass (this could be switchable). It probably won't pop, but it might. It will need more breadboard time...
However, it's in a big enclosure, so you could just add a second true bypass stomp switch.
Wow! That sounds beautiful! 8)
~ Charlie
Board already etched... Hehhe
I don't have any 22k pot... But a 20k should do the job.
Right?? Hehe
Sounds great Rob, a really great sounding circuit I love it. Might just have to build one a s soon as I get the chance. :icon_cool:
Quote from: gtangas on November 21, 2013, 07:02:34 AM
3 jumpers?
I only see 2...
Thanks guys. Mr. Brain wasn't working at full capacity (that's why I like for others to review my work ;)). I missed the two blue jumpers and thought that 3 of the other resistors said 00k and 00Ω . I'll correct the BOM for this and the switch.
...so here is the revised BOM:
See Deadastronaut's BOM below.
Thanks Rob! ;D
Having a go at a pcb... I dislike wiring pots. Like to check that it's right, though, so I'll wait.
I will start on mine tonight... Yeah
At first congratulations for this great design...!!
Now, sorry for the "noobish" question but I am totally inexperienced with fet switching...
Doesn't fet switching requires a momentary switch for the fets to do the latching..?
What type of reverb is this?
Quote from: thanal9999 on November 22, 2013, 05:00:59 AM
Doesn't fet switching requires a momentary switch for the fets to do the latching..?
As a general rule, no.
Quote from: soupbone on November 22, 2013, 05:05:17 AM
What type of reverb is this?
It's a 'Chasm' reverb. Not sure if I understand the question, but The BTDR bricks are digital chips that give a pretty ralistic spring verb sound.
Nice one Rob!
Waiting for my brick, box ready for drilling. This is going to be the last one in my space series as I finally loose my printer on Monday :(
(http://www.stallibrass.com/images/kas/ChasmBox.jpg)
looks great...
vol mix damp decay are reversed from my version..no matter though.
nice one., 8)
Oops! That because I just copied it from the layout and gave no mind to the fact that the view is from below.
Never mind, as you say it matters not..
Re: The parts list. My tired eyes only see one 2.2K resistor and two 1M resistors.
here ya go..
(https://dl.dropboxusercontent.com/u/7464107/chasm%20bom.jpg)
Great work as always, Rob. Love the demo, too. (Especially the epic intro. :D)
Quote from: deadastronaut on November 22, 2013, 08:32:39 AM
here ya go..
(https://dl.dropboxusercontent.com/u/7464107/chasm%20bom.jpg)
This is exactly what i was looking for! :icon_biggrin: I'm gonna have to build me one!and HELL NO it will not be for sale! :icon_evil: Awesome job Rob!
Just finish it... Yeaaaa
I had to temporary replace one of the FETs by an J201... But ok
The off board wiring is consuming but the end result is very very sweet... Thanks Rob
Quote from: gtangas on November 22, 2013, 09:40:56 PM
Just finish it... Yeaaaa
Holy crap, you are faster than me! I've been spending too much time on the bike trail. I MUST etch tonight!
I feel so slow... gotta wait for my board to arrive, first. (Then I have to wait more for the courier to bring my parts.)
Hehe
with all that wires putting this one in the box will be a nice challenge...
i had the parts and a rub a dub that was unboxed so...
Parts ordered
Great movie, Rob. You ever thought of going into pedal-building too? ;D I've not even boxed up the previous version yet - I wish you'd give us mortals a chance to catch up. Oh well, need to go buy another brick, I guess...
BTW, John Martyn would have loved your reverb/delay/chorus combo. :icon_cool:
Quote from: midwayfair on November 22, 2013, 09:13:12 AM
Great work as always, Rob. Love the demo, too. (Especially the epic intro. :D)
I thought it was gonna be a trailer for the next Star Wars movie... :D
I was thinking about two reverbs, one long one middle brick.
Any chance to do this with a switch?
That would be a "one size fits all" reverb
From what I understand, two bricks would draw too much current for the 78L05 reg.
My progress so far:
(http://www.dangerouscreation.com/wp-content/uploads/2012/04/tangled_in_wire.jpg)
Quote from: alanp on November 23, 2013, 07:18:31 PM
From what I understand, two bricks would draw too much current for the 78L05 reg.
Could try a LM7805. Good up to 1 amp ;)
If the idea is to switch between two bricks, then just switch the power too. It might pop, but if you're only going to activate the switch between songs, it's not as much of a problem.
Whoa. This thing is great. Such a lush ambient sound. I'm going to destroy my volume pot on my guitar from all of the swells. :D
On the original reverb you would need the horizontal mount brick, but since it is wired off-board I recommend using a vertical mount with a waffer connector. It makes things a lot easier than soldering directly to the brick's pins.
I'm not done, but I just wanted to hear it. I plan on wiring it with the option of true bypass, hence the 3pdt.
(http://i1267.photobucket.com/albums/jj545/haveyouseenhim/DSC08798_zpsbca51586.jpg)
(http://i1267.photobucket.com/albums/jj545/haveyouseenhim/DSC08799_zps876c67fa.jpg)
Man!!! this reverb sounds good!! congrats you brainiacs!! now I have to try and build this!! its going on my pedalboard!! :icon_wink:
cool glad you guys built/like it... 8)
now to add a delay with lfo... ;)
in fact i think i'll bread up merlins small time delay and tinker with an lfo on it..
kind of mini echobase with tails....it'll go nice with this... 8) 8) 8)
https://www.youtube.com/watch?v=YQyhPSqhxCk
8) nice one mike...sounds lush....
the TB was a pita, that's why we just dropped it ..
in the end i couldn't imagine myself wanting a dead cut off anyway with this...(maybe on another build)
i did ask ian about his echobase tails/boss 4066 setup , but he said he couldn't guarantee it would be silent still....
so i stuck with the fet solution as it is dead silent. (required)
Nice demo Mike.
I'm pretty sure you sure you should get no wet signal (reverb) bleeding through in tails bypass once the feedback has done its thing - Rob can confirm this I guess.
It might be that FET 1 is not closing properly on bypass. You may want to try another FET and also make sure the gate is pulled to ground when bypassed.
hi sam, i think mike means 'decay' ...(feedback)
it is working as it should be.
he was just commenting on the amount of /decayfeedback still at minimum...inherent to the large brick.
but can be tamed better with the damp.
Quote from: samhay on November 25, 2013, 06:32:09 AM
Nice demo Mike.
I'm pretty sure you sure you should get no wet signal (reverb) bleeding through in tails bypass once the feedback has done its thing - Rob can confirm this I guess.
It might be that FET 1 is not closing properly on bypass. You may want to try another FET and also make sure the gate is pulled to ground when bypassed.
I'll give that a try. After I switch it off when it is oscillating It will keep going and not taper off.
Quote from: deadastronaut on November 25, 2013, 06:36:46 AM
hi sam, i think mike means 'decay' ...(feedback)
it is working as it should be.
he was just commenting on the amount of /decayfeedback still at minimum...inherent to the large brick.
but can be tamed better with the damp.
That wasn't what I meant when talking about the tails. I'm ok with the minimum reverb. It's just that after I bypass, it will keep going till i turn the decay down
it shouldn't keep going , especially in non osc mode...sure you have a 47k/100k on that switch?.
non osc mode will fade it off nicely even at max...
Yea. It will fade nicely in non osc. With osc and decay at full it won't taper off when tails is engaged.
thats right then...
it should tail off at around 2'0 clock though in osc mode.......osc mode is for tweakable osc..
i left it at that for osc nutters.. ;D
but had the non osc so it could be maxed without osc..
edit: 100k is non osc / 47k is osc... so you may want to up the 47k to be more controllable in osc mode..depends how crazy or fadey you like it..
Quote from: haveyouseenhim on November 25, 2013, 06:43:35 AM
That wasn't what I meant when talking about the tails. I'm ok with the minimum reverb. It's just that after I bypass, it will keep going till i turn the decay down
gotcha - that's a design feature.
However, if the TBP footswitch ends up being unusable, you could swap it out for a momentary SPST that shorts lugs 1 & 2 of the feedback/decay pot. You could then stomp on it when you want to kill the oscillation and it will momentarily turn the feedback all the way down...
edit - disclaimer: I haven't tried this, and the change in impedance (of the decay pot) may do something funky. Worth a try with an aligator clip though.
^ yeah, good idea. 8)
Quote from: samhay on November 25, 2013, 06:55:36 AM
gotcha - that's a design feature.
However, if the TBP footswitch ends up being unusable, you could swap it out for a momentary SPST that shorts lugs 1 & 2 of the feedback/decay pot. You could then stomp on it when you want to kill the oscillation and it will momentarily turn the feedback all the way down...
edit - disclaimer: I haven't tried this, and the change in impedance (of the decay pot) may do something funky. Worth a try with an aligator clip though.
That's what I was thinking about doing with the huge gaping hole where the TBP switch was. Or even adding the LFO from the shoot the moon trem into an LDR on the volume or damp pot to have a lil tremolo in it too. :icon_cool:
squeeze a delay in there... ;)
Quote from: deadastronaut on November 25, 2013, 07:07:03 AM
squeeze a delay in there... ;)
I could throw pickdropper's smd DBD in there :icon_twisted: But I won't because I took my psych meds today :D
I just did a lil test with adding an LFO. I put an LDR on the volume pot with alligator clips and used the shoot the moon trem LFO into it and it made a pretty cool sound. I'm working on putting the LFO on a piece of vero and squeezing two more pots into it to control depth and speed.
Like.
Jacob
Chasm reverb with added LFO:
https://www.youtube.com/watch?v=8BW7x2XW8NE
@mike: aha you nutter , you did it....and found a way to fill that hole up too :)....nice one man. 8) 8) 8)
Quote from: haveyouseenhim on December 02, 2013, 03:41:23 AM
Chasm reverb with added LFO:
https://www.youtube.com/watch?v=8BW7x2XW8NE
Amazing sounding. Superfuzz wall of sound would go nicely with this thing.
Has anyone managed to fit this into a 1590B enclosure?
Here is my built of The Chasm Reverb...
It works great and it will be for sure on my pedalboard for a loooooong time...
special thanks to deadastronaut an the other guys who helped for this design...
(http://i449.photobucket.com/albums/qq213/TheHumanMole/IMG_1915_zps6eecba55.jpg) (http://s449.photobucket.com/user/TheHumanMole/media/IMG_1915_zps6eecba55.jpg.html)
(http://i449.photobucket.com/albums/qq213/TheHumanMole/IMG_1917_zpsbaf0507d.jpg) (http://s449.photobucket.com/user/TheHumanMole/media/IMG_1917_zpsbaf0507d.jpg.html)
(http://i449.photobucket.com/albums/qq213/TheHumanMole/IMG_1922_zpsb4d32c87.jpg) (http://s449.photobucket.com/user/TheHumanMole/media/IMG_1922_zpsb4d32c87.jpg.html)
Nice art and guts! :)
Cool build man, ... 8)
Quote from: therealfindo on December 20, 2013, 12:34:56 PM
Has anyone managed to fit this into a 1590B enclosure?
Is it doable? The current pcb would fit, theoretically, but the jacks would be problematic... I'm still rubbish at pcb layouts, but does anyone reckon it could be rejigged to a 1590B or 125B friendly size?
Great looking pedal Thanal9999! Is that hand painted artwork? It is hard for me to see if you etched the design in first.
I guess I should post a pic of how my pedal turned out. I have posted gut shots in another thread. I followed on with the theme of the father of the Chasm Reverb, but I stuck to a black on white color scheme. The knobs are aluminum. The odd gold color and the gold shadows are from the crappy flash on my quick and dirty camera.
(http://i44.tinypic.com/2i1l5jq.jpg)
Looks great man, very nice, love the gold knobs on white, classy... :icon_cool:
Oops..they are silver...sorry, my crappy phone... 8)
Quote from: KazooMan on December 28, 2013, 10:16:07 AM
Great looking pedal Thanal9999! Is that hand painted artwork? It is hard for me to see if you etched the design in first.
Thank you...! Yes it is painted by hand... it isn't actually what I wanted it to look in the first place but it was a first time try for painting a pedal... :)
Now that you mention it, the "gold" knobs on the white pedal do look nice. I will have to look around for some to try out. I would still be stuck with the silver stomp switch button.
yep, and jacks too...looks cool as it is. 8)
Been working on something. I like this box of tricks, I just don't like the wiring.
(http://i163.photobucket.com/albums/t282/Gutstwohand/chasmbox_zpscc853ea2.jpg) (http://s163.photobucket.com/user/Gutstwohand/media/chasmbox_zpscc853ea2.jpg.html)
(http://i163.photobucket.com/albums/t282/Gutstwohand/chasmguts_zps8d2d098c.jpg) (http://s163.photobucket.com/user/Gutstwohand/media/chasmguts_zps8d2d098c.jpg.html)
I wound up doing a fair bit of wiring on the back :( but it works now :)
Once I got the board working, it was the easiest build I've done yet in terms of boxing it up, since the stomp was already in the circuit :) just wire the jacks and power!
(Out of respect for Rob, I won't be sharing the pcb at this point in time.)
I DEMAND that you disrespect Rob and share that with me!
Out of respect for Rob.....
You need to add about 12 more LEDs to that build! ::) ;D
Out of respect for Rob, you should jam a burnt weenie inside the enclosure. ;D
Lol....
@alan. Cool, glad you got it sorted man...
excellent etch too :icon_wink:
Finished up my build of 2 units this morning. Both turned out great and sound great, too! No idea what I'll do with the extra but it may come in handy for trade bait or something. I used a couple of blem housings I had lying around and added a momentary footswitch for the oscillation.
(http://i717.photobucket.com/albums/ww172/theehman/DIY%20Stompboxes/chasm1_zps9cea26dc.jpg)
(http://i717.photobucket.com/albums/ww172/theehman/DIY%20Stompboxes/chasm2_zpse0bcf6cf.jpg)
nice build ron, the gap between the switches gives an ideal space for the brick too..
8)
Quote from: deadastronaut on January 02, 2014, 06:52:48 AM
nice build ron, the gap between the switches gives an ideal space for the brick too..
8)
Thanks, Rob. I'd normally put the battery there but I figured this probably isn't too battery friendly. Thanks again for the pcbs!
Help!!!
>@john D : latching dpdt .not momentary (you knew that ) ...ALPHA is nice..
I finally built this sucker and it only works if I hold the latching switch down continuously. When I click it, the LED only lights for a spilt second and I get no effect. I only get clean signal. Suggestions? Bad switch?
that's weird..yes i suspect the switch is shot...
have you another one?..if not wire up a dpdt toggle just to test.
Quote from: Jdansti on January 05, 2014, 03:02:17 PM
Help!!!
>@john D : latching dpdt .not momentary (you knew that ) ...ALPHA is nice..
I finally built this sucker and it only works if I hold the latching switch down continuously. When I click it, the LED only lights for a spilt second and I get no effect. I only get clean signal. Suggestions? Bad switch?
Are you sure it's a standard footswitch and not a momentary?
Thanks, guys. I just checked the resistance across the switch terminals with it still wired up and the power off, and it's acting like a momentary switch. I had ordered a latching switch, and it clicks like a latching switch, but it must not be latching.
Here are my readings:
(http://i1160.photobucket.com/albums/q485/jdansti/B8F26A26-8E11-449F-A37D-72EA785BD22A.png)
Side note: the 5k and 12k readings flip flop when I change the meter lead polarity. Probably due to the diodes in the circuit.
I can't find another DPDT stomp switch in my stuff, but I've got some 3PDTs. I'll try one of those and see how it does. The 3PDT footprint isn't any larger than the DPDT given the DPDT's X-wing terminal configuration.
Thanks for the help. I swapped the switch with a 3PDT and that took care of the bypass problem. All is working now except I get no oscillation. I checked the SPDT osc switch and it is good. I checked the connections to the switch and they're good. I checked the locations of the switch connections to the PCB and they're correct. I'll take a look at the schematic and see if I can figure out where to check next.
john, cool, so it was the footswitch then,..
re the osc: double check the 2 resistor values that the switch goes to...
47k osc
100k non osc
The 47k (Y-V-O) is reading 50k and the 100k (Bn-Bk-Y) is about 105k.
However... The 100nF cap across the two resistors appears to be a 1nF cap. I'll pull it and check.
The correct cap did the trick! I've got oscillation now. Unfortunately the oscillation irritated my wife. :( She told me to stop playing and build something (I can't play while I build). ;)
Anyway, I'll post the results after I get it boxed up.
Thanks Rob and theehman for your help!
next project: build the wife some headphones.. :D
cool glad you got it sorted. ;)
LOL :D
psyched.... my brick came in today... tomorrow, i'll get some rat-shack perf (my first attempt at perf, <shudder>)
and i am gonna build this thing...
thanks rob!! this and jon patten's cardinal trem and i think i'd done for a while. ;)
perf?...brave man.. ;) 8) 8) 8)
cheater perf, the stuff with a pad for every hole!! ;)
isn't your layout on perf?
seems easier than vero, at least this project for some reason. vero's great for simple fuzzes, but sometimes it can be a pia!!
hi jimi, its on pcb...
i only use vero for tiny quickie stuff.
Here's my Chasm Reverb. Thanks for working on this Rob and the others who collaborated. Sounds great!
This was my first epoxy pour-on. Thanks to Mustachio for great Envirotex tips on other threads.
(http://i1160.photobucket.com/albums/q485/jdansti/C17A078F-744D-49A2-BE37-3878DDF950A8.jpg)
(http://i1160.photobucket.com/albums/q485/jdansti/D6941DB9-52BD-41C2-907A-5E5AF3309A06.jpg)
(http://i1160.photobucket.com/albums/q485/jdansti/29836E4E-610B-4218-842E-1F341B4CA2CB.jpg)
(http://i1160.photobucket.com/albums/q485/jdansti/2F34537B-5160-4870-951C-F07E59063A3B.jpg)
Edit: I should add, thanks to some talented person who put the chasm art on the web.
Quote from: deadastronaut on January 09, 2014, 11:01:02 AM
hi jimi, its on pcb...
i only use vero for tiny quickie stuff.
i know i did more than my share of acid, but the pdf in this thread sure looks like it's on perf to me!! ;)
lol
Quote from: pinkjimiphoton on January 09, 2014, 09:45:16 PM
Quote from: deadastronaut on January 09, 2014, 11:01:02 AM
hi jimi, its on pcb...
i only use vero for tiny quickie stuff.
i know i did more than my share of acid, but the pdf in this thread sure looks like it's on perf to me!! ;)
lol
There's a PCB transfer along with it.
https://dl.dropboxusercontent.com/u/7464107/CHASMPCB.pdf
+1
^I think that the spacing on the color image that shows the components is the same as perf board spacing. Even if it's not exact, I'll bet it'll work for ya'.
lets hope so, cuz i can't burn any pcbs!! ;)
if it will fit on the perf layout, i think i can do it. i'm brave AND stupid!! ;)
i think it should work out, as if the stuff fits on the perf layout, it should fit in reality hopefully!! ;)
I did up a pcb to avoid flying wires, and to avoid perf, and to even more avoid having to etch PCB's (dont have the supplies, don't want the headache of disposal.)
Probably would have been less effort doing it point to point :/
honestly, after the clone theory project on vero, everything looks kinda easy now. ;)
Quote from: pinkjimiphoton on January 09, 2014, 10:03:24 PM
lets hope so, cuz i can't burn any pcbs!! ;)
I'll burn one for ya if you would rather use a PCB.
that would be awesome mike, if you could, i'd be grateful...
should probably leave the perf toward something a little easier to start with i get the feeling!!
do you need my addie again?
Quote from: Jdansti on January 09, 2014, 09:42:17 PM
Here's my Chasm Reverb. Thanks for working on this Rob and the others who collaborated. Sounds great!
(http://i1160.photobucket.com/albums/q485/jdansti/29836E4E-610B-4218-842E-1F341B4CA2CB.jpg)
Nice one, John. Looks great. I must get round to building mine...
Quote
Edit: I should add, thanks to some talented person who put the chasm art on the web.
You should have kept quiet and taken all the glory! ;)
Quote from: pinkjimiphoton on January 09, 2014, 11:15:57 PM
that would be awesome mike, if you could, i'd be grateful...
should probably leave the perf toward something a little easier to start with i get the feeling!!
do you need my addie again?
Yeah. PM me your address and I'll have it done within a week.
@john: looks great man, love the led under it too...white on white, classy, 8)
@mike: good man on helping brother jimi out 8),
ive just been too busy to knock up more pcb's... ::)
8)
Thanks Marc and Rob!
Would it be hard to add a BTDR3 instead of the 2? Adds another knob but I can do without the oscillator switch. Or would this not add any real value since the effect is good as is? If so, which BTDR2 is nice? Short, medium or long?
The data sheet for the BTDR3 is pretty similar to the 2
http://www.tubeampdoctor.com/images/File/BTDR-3%20DIGI-LOG%20REVERB%20MODULE.pdf
Or maybe I just need a more simple reverb after all...
Only a fool or a knave would attempt to build this on perf .
Clearly , I am both . I have just completed this , and to my complete amazement ,
IT ACTUALLY WORKED FIRST TIME !!!!!!!!!!!!!!!!!!
Sounds awesome , thanks Rob ! Well worth the effort - I would recommend it to anyone .
BUT - be sensible - buy a PCB from Rob .
I mentionned on the other "cool reverb apart pop issue" topic that I'll have to test your design, and I did it. It was the right move! :D
It sounds lovely.
I hadn't wired the "trail bypass" and the mosfet buffer, because I have other tests in mind (add a kind of slam/hold switch in the feedback loop).
And I don't know if it's because of those changes, but the feedback pot is inactive. Maybe I have to reduce the feedback resistor... As far as I remember, before you have added the fet switching, you had a 33K/22K feedback resistor, hadn't you?
@loylo: yep i think so..i went through so many variations,combinations, its hard to remember now....my brain hurts..i'm still messing with 4 pt's.. ::)
@nick; no pics?. :)
Here we go -
(http://[url=http://s1239.photobucket.com/user/NICKDUNKERLEY/media/CHASM%20reverb/SAM_0420.jpg.html%5D%5BIMG%5Dhttp://i1239.photobucket.com/albums/ff510/NICKDUNKERLEY/CHASM%20reverb/SAM_0420.jpg)[/URL][/img]
(//URL=http://s1239.photobucket.com/user/NICKDUNKERLEY/media/CHASM%20reverb/SAM_0422.jpg.html%5Dhttp://%5BIMG%5Dhttp://i1239.photobucket.com/albums/ff510/NICKDUNKERLEY/CHASM%20reverb/SAM_0422.jpg)[/URL]][/img]
(//URL=http://s1239.photobucket.com/user/NICKDUNKERLEY/media/CHASM%20reverb/SAM_0424.jpg.html%5Dhttp://%5BIMG%5Dhttp://i1239.photobucket.com/albums/ff510/NICKDUNKERLEY/CHASM%20reverb/SAM_0424.jpg)[/URL]][/img]
(//URL=http://s1239.photobucket.com/user/NICKDUNKERLEY/media/CHASM%20reverb/SAM_0425.jpg.html%5Dhttp://%5BIMG%5Dhttp://i1239.photobucket.com/albums/ff510/NICKDUNKERLEY/CHASM%20reverb/SAM_0425.jpg)[/URL]][/img]
Just needs decorating now , but the main thing is it works and works very well ! I've only done a few perf builds ,
and I've NEVER built anything without a schemo to work from , so I am feeling pretty chuffed with myself !
All credit to you , Rob , a great job !
^ cool, your a brave man doing perf.. :icon_eek:
8)
Hi Guys
Need some help. My chasm reverb is given me some troubles!
When the effect is on... UAU!!! Amazing reverb.... but when i disengage it and for a few seconds the chain signal becames distorted.... like overdriven sound... the effect it selfs works lovely and this think started a few days...
i tried to plug guitar>chasm>Amp (maybe another pedal was doing the mess) but same result
any hints?
Hmmm...strange.
not sure what would cause that,
check over your board for values, and orientation etc...
It sounds to be something with the fets (distorting) in the switching. It may be too large value for the caps in the switching circuit (100 µF or higher instead of 10) or whatsoever.
For the dysfunction in the feedback loop of my circuit, it seems to be because of a break within a cable to the feedback pot. It's the first time I encounter this kind of problem, it was pretty hard to find! Now I'll have to try my kind of "slam/hold" swith with a DPDT momentary switch. ;)
@loylo: oh man, been there too...my jumper leads are getting tired now ( just bought a fresh set) but a few in particular were preventing my delay from working,
it took ages to find the culprits.. ::)
: yeah makes sense with the switching i guess with ganstas issue..
i was looking to the diagram and the pf caps that i have on the board are 100pf! but you point to change 10pf to 100pf!
can you point the caps to mess around?
this is my chasm reverb:
the faceplate didnt came out the way it should but i will install a new one (laser engrave)
(http://i775.photobucket.com/albums/yy38/gtangas/20140126_122912_zps3ad35fc6.jpg)
(http://i775.photobucket.com/albums/yy38/gtangas/20140126_123013_zpse29e05c7.jpg)
I was speaking about the caps in the switching part of the circuit, with a value of 10 µF, not pF (the 100 pF are OK).
The switching is essentially the left part of the board on your pic. You should check the value of those components.
ok i will check it, but i am 99% sure that those are the correct values.
the strange think is that i have the pedal working for a few weeks and this start to happen a few days ago...
next build on my bench. on perf. wish me luck!!!! lol
Quote from: deadastronaut on January 26, 2014, 05:12:06 AM
@loylo: oh man, been there too...my jumper leads are getting tired now ( just bought a fresh set) but a few in particular were preventing my delay from working,
it took ages to find the culprits.. ::)
;)
Now it works like a chasm... heu like a charm! :icon_mrgreen:
I have to do some fine tunings with the feedback resistor, because with 62K the reverb goes into oscillations with the feedback pot at only 50%.
I have another question about the mix control. With the pot at 0, my sound is not totaly dry (the reverbation is still audible). At the other end, the sound is perfectly dry. Does it act the same with yours, or should I question my pot?
I also wonder if there is a way to reduce the depth of the reverb below the nominal decay of the BTDR. With the feedback pot we can way over the nominal decay to infinite reverb, so It would be interesting to also be able to decrease the decay under 2 seconds...
when mix is at zero fully left...no reverb at all, as it should be.
@1:50
http://www.youtube.com/user/100roberthenry?feature=mhum
as for time 'limiting' i think thats just down to the brick itself not allowing that. 2:85s..
Thanks Rob.
So the culprit may be the mix pot.
I still have to fine tune my "slam/hold" option, but it sounds promising. Hope to tell you more soon. ;)
Hi Rob,
building it now and I have one question. How can I change the predelay? I want the reverb closer to the signal. More like Holy Grail.
But anyway it sounds cool!
pre delay?.. ???
Pre-delay is usually found on studio reverbs. It's basically the time between the dry signal and the first reflection, usually measured in ms I.E. how long it takes before the wet signal starts.
yep i get that, not sure how it applies to these bricks though...
hi again!
so i check the electros and all are 10uf
as i said the distorted signal fades after as few seconds.... can i swap those for another values?
^ are your electrolytic caps the right way around?...
G morning DA
Yess the caps are ok and for a weeks everything worked ok. The thing start to happen a days ago...
I have to disassemble it and check the transistors and some values.... Not in the mood for it but... AAAAAAAA
morning..
that's a shame, i hope you can identify the problem..
bad mosfet maybe.
Maybe... I had J201 at the beginning of the build... The orders from tayda are taking almost a month to arrive to Portugal... But it was the only thing that I swap...
solved.... bad tranny!! now its running with two J201 and everything ok again!
Cool, glad you got it sorted... 8)
Yeaaaa
Quote from: deadastronaut on January 27, 2014, 06:25:22 AM
when mix is at zero fully left...no reverb at all, as it should be.
@1:50
http://www.youtube.com/user/100roberthenry?feature=mhum
I definitively have a problem with the mix pot. :-\
There is some bit of reverb when the sound is supposed to be dry. It is barely audible when I'm playing at home, but it is noticeable, even more when playing in a band context.
The pot is fine, the mix control acts the same with another pot. And there is no problem such as a soldered jump or a bad component's value.
Whereas in your video, your mix control seems to sound as it is supposed to... ???
Quote from: deadastronaut on January 27, 2014, 06:25:22 AM
as for time 'limiting' i think thats just down to the brick itself not allowing that. 2:85s..
Your are right, the decay could'nt be adjusted, it is preset in the brick (while the BTDR-3 let us dial it). Same for the predelay.
I am close to try to dismantle the brick (like this: http://ada.graudal.dk/bdtr2/bdtr2_top.JPG) and remove some CMS resistor to make them adjustable and have those control, thanks to the russian guys who traced the brick. http://www.freestompboxes.org/viewtopic.php?f=20&t=23706&p=232607&hilit=btdr#p232607
But it is risky! :icon_razz:
Otherwise, I've came by a version of the Tenebrion reverb modded with a "short/long" decay switch.
http://guitar-gear.ru/forum/index.php?app=core&module=attach§ion=attach&attach_rel_module=post&attach_id=29936
I don't know if changing from a 100K to a 1K "verb" pot make the decay shorter as this schematic suggests it.
I should try to add a 100K pot wired as a variable resistor with a 1K fixed resistor at the tail, acting the same as the "verb" pot always at the max setting, as the reverb level is kinda controled by the mix pot.
mad seeing inside the brick... 8)
loylo: i have pm'd you... ;)
So I realize the schematic is a touchy subject because of the Brazilian Incident, but is there an updated schemo to be had? I did find the V1.6 in the other thread, but a lot seems to have transpired since that version. This thing is just too cool not to build.
Thanks,
George
mike/haveyouseenhim burned me a board... populated tonite, wire it tomorrow... wish me luck!!
hey is there a quick easy way to test 5457's? i have a few but i am concerned one may be damaged.. they're slopping around the bottom of my junk drawer.
could i sub 2n5952's ina pinch?
bugger, if i mess with it i get it to switch on, very hissy and no verb, but taking voltage measurements sometimes i can hear the reverb for a split second.
gotta try and debug some. gotta be something stupid!!!
Quote from: pinkjimiphoton on February 08, 2014, 06:15:21 PM
gotta try and debug some. gotta be something stupid!!!
Yea. Like letting some stupid Alabamian etch boards for you. :icon_mrgreen:
betting it's something stupid even for ME.
for a dumb alabamian, you had the proper number of holes in the right spots, so i think it's good old yankee lack of ingenuity. :icon_mrgreen:
Quote from: pinkjimiphoton on February 08, 2014, 07:21:52 PM
you had the proper number of holes in the right spots
That was pure luck. I just shot it with some birdshot :D
ok.... found some bridges and some cold solder... got the thing kinda running.
i baked one chip and one 7805 so far.
got clean signal... and loud... with the volume all the way down. if i turn it up whatsoever, the brick starts motorboating like crazy, sounds like a damn airplane.
the modulation is working. i can hear it on or off. so THAT's good...
any ideas as to where to look to find the motorboating problem? i had a hell of a hum, i thought it may have been from having the 1u cap backwards... i had oriented it with + to the right originally, tried it the other way and lost the hum.
i've tried subbing the 2n5457's, no change at all, so assuming they are working. i haven't tried the 2n7000, do you think that may be the culprit?
funny... yesterday i had reverb. today, i have an airplane synthesizer. ;)
help!!! please ;)
ok.... found some bridges and some cold solder... got the thing kinda running.
i baked one chip and one 7805 so far.
got clean signal... and loud... with the volume all the way down. if i turn it up whatsoever, the brick starts motorboating like crazy, sounds like a damn airplane.
the modulation is working. i can hear it on or off. so THAT's good...
any ideas as to where to look to find the motorboating problem? i had a hell of a hum, i thought it may have been from having the 1u cap backwards... i had oriented it with + to the right originally, tried it the other way and lost the hum.
i've tried subbing the 2n5457's, no change at all, so assuming they are working. i haven't tried the 2n7000, do you think that may be the culprit?
funny... yesterday i had reverb. today, i have an airplane synthesizer. ;)
help!!! please ;)
Quote from: pinkjimiphoton on February 09, 2014, 03:52:44 PM
ok.... found some bridges and . . .
Quote from: pinkjimiphoton on February 09, 2014, 04:00:14 PM
ok.... found some bridges and . . .
So you may not have any reverb, Jimi, but you sure as hell got an echo! ;D
wtf??? weird!!! windows on acid!!
Quote from: pinkjimiphoton on February 09, 2014, 03:52:44 PM
ok.... found some bridges and some cold solder... got the thing kinda running.
i baked one chip and one 7805 so far. ....why, wrong way around?
got clean signal... and loud... with the volume all the way down.( should be the same level as bypass when fully CCW) if i turn it up whatsoever, the brick starts motorboating like crazy, sounds like a damn airplane.
the modulation is working. i can hear it on or off. so THAT's good...(that's not good ;D)
any ideas as to where to look to find the motorboating problem? i had a hell of a hum, i thought it may have been from having the 1u cap backwards... i had oriented it with + to the right originally, tried it the other way and lost the hum.
i've tried subbing the 2n5457's, no change at all, so assuming they are working. i haven't tried the 2n7000, do you think that may be the culprit? (i used a 2n7000 ) and 2 of 5457 or j201 will be ok)
funny... yesterday i had reverb. today, i have an airplane synthesizer. ;) lol..
hi jimi, theres something quite wrong if you have massive volume with it all the way down...theres a lot of wiring on this man, check you haven't got anything crossed, especially the brick wires.
help!!! please ;)
Quote from: deadastronaut on February 09, 2014, 04:21:32 PM
Quote from: pinkjimiphoton on February 09, 2014, 03:52:44 PM
ok.... found some bridges and some cold solder... got the thing kinda running.
i baked one chip and one 7805 so far. ....why, wrong way around?
mayyyyyyyyyyyyyyybe.... i figured better safe and popped a new one in there. the voltage is good.
Quote
got clean signal... and loud... with the volume all the way down.( should be the same level as bypass when fully CCW) if i turn it up whatsoever, the brick starts motorboating like crazy, sounds like a damn airplane.
the modulation is working. i can hear it on or off. so THAT's good...(that's not good ;D)
well, i mean it's unity with the volume fully clockwise, anything above that and the motorboating starts. i meant good, in that obviously it's passing clean signal, the modulation is working, and the reverb must be too, or it couldn't keep making that godawful racket. ;)
Quote
any ideas as to where to look to find the motorboating problem? i had a hell of a hum, i thought it may have been from having the 1u cap backwards... i had oriented it with + to the right originally, tried it the other way and lost the hum.
i've tried subbing the 2n5457's, no change at all, so assuming they are working. i haven't tried the 2n7000, do you think that may be the culprit? (i used a 2n7000 ) and 2 of 5457 or j201 will be ok)
i do have some j201's. i could try them i guess. i don't think that's it tho, i think it's working... but somewhere is a feedback loop.
Quote
funny... yesterday i had reverb. today, i have an airplane synthesizer. ;) lol..
hi jimi, theres something quite wrong if you have massive volume with it all the way down...theres a lot of wiring on this man, check you haven't got anything crossed, especially the brick wires.
help!!! please ;)
[/quote]
hmmmm.... i connected pins 2 and 4 together with a jumper (i mounted my brick on a small piece of vero ) at the brick, it's circuit and signal ground... on the schematic, both are shown being wired to ground... do you think that may be where the problem is?
the motorboating is audible even in bypass. something is wrong somewhere... have checked the damn board and wiring, sucked/reflowed with fresh solder and checked for unwanted continuity AND wanted continuity... something is way weird.
i disconnected the right side of the mix control. if i touch the wire of it, i get a strong reverbed buzz. but... that should be the output of the reverb there, right? or is it the input to the reverb?
if i temporarily connect the wire from this node to the input jack tip, i get a huge swampy reverb.
i HAVE dry signal, and the volume works fine with the wire disconnected.
the dwell and decay knobs make audible difference when turned with said wire jumpered to the input signal.
if connected to the pot, they change the sound of the cacophanous noise. i do not get it... unless somehow i got the wiring wrong, but it matches the layout. i'm thinking it's more likely someplace in the switching part of the circuit, but i'm scratching my head hard on this one. am i right the mosfet is the switch, and the two jfets are for mixing clean and effected signal?
maybe i need to draw a proper schematic up, cuz i'm getting lost on this one i think.
where the hell could a feedback loop be happening that would do this?
i've swapped out the jfets for the j201's you suggested rob, and have changed the 2n7000, the chip, and the regulator.
shorted pot maybe?
i tried to connect pin 4 of the brick to it's own ground, made zero difference.
i'm looking at this really hard, and i've gotta wonder if it's the brick itself that may be defective, but then why would it work hooked up wrong?
dumb question... but rob, we're looking at the back of the pots on the layout, correct? pin 3 would be to the right?
where would be a good spot to try bypassing the switching...wondering if maybe i'm better off just with true bypassing it.
so... good news... all things working. bad news... not working right. ;)
hellllllllllllllllllllllllllp..... it has to be someplace a strong feedback loop would be happening, or somewhere limiting the signal being sent to the reverb i'd think. in a tube amp, it would be a blown cap in the reverb send amp letting dc thru to the springs i'd think, but i don't know if the same would apply here.
jimi: pm'd...
Well, there could be many explanations:
As you fried the 7805, chances are you have also fried the brick.
Maybe, you have a wrong value of resistor, like the feedback resistor at 47R (instead of 47K) or 10R (instead of 100K), explaining why the reverb goes into wild oscillations, sounding like motorboating.
And/or you don't respect DA's layout, with that ground thing with pin 2 and 4 of the brick (I don't understand what you did with your build).
^ fried brick...oh dear.. maybe,
the pots are left to right 3 2 1 btw (looking at the back of pots)..if you are getting motorboating when on/bypass, then the switching might be ok..
but it must be another issue..maybe osc switch wiring?..
Quote from: deadastronaut on February 10, 2014, 03:36:20 AM
^ fried brick...oh dear.. maybe,
I hope it's not that, but the brick may be the culprit.
I suggest to verify everything else first, like component's values, wiring...
well, no, the brick works. if i go directly to the input of it, i get a reverbed signal.
it's happening somewhere in the feedback loop. i'm thinking it's gotta be a hosed chip.
the 805 never fried per se, i just felt it better to try a fresh one.. i've found with them they can be a real bitch.
i've been over the wiring a gazillion times. it matches deadastro's exactly. it has since it was built.
it switches on and off, so i assume the fets are all working.
it passes dry signal.
but as soon as i hook up pin 6 of the brick, it goes @#$%ing batshit. if i turn the volume all the way down, no oscillation. as soon as i crack it open, it starts.
it sounds like a blown reverb transformer blowing dc into some springs almost. wondering if something in the brick internally hosed itself.
noticed lead dress seems to be an issue too... it will start oscillating if the wire is removed from pin 6 of the brick and even put anywhere near pin 1 or 3.
that said... if i remove pin 6, i get no oscillation. so it's gotta be in the stage that goes to the input of the brick, and bugger if i can find the problem. i mean, all that's there is a
couple parts... and i've even disconnected the osc switch, that makes no difference.
if every thing on the board is right, and the wiring is right, i mean, what the hell else can it be? gotta be the brick... but if it WERE the brick, why the hell would it work directly?
also....
i have one HELL of a loud hum if i don't jumper the grounds of the input/output jacks together.
the oscillation is the part i'm not getting... something has to be leaking dc, right? but what the hell is there to leak? and the brick is supposed to be ok for ac coupling...
i'm stumped.. the interweb is no help.
The chip will not operate correctly without a high enough resistance to ground on pin 6. What happens when you put 5-10k from pin 6 to ground?
Brick-not PT2399. Ignore this post. :icon_redface:
i can try that... at the moment, i have the chip hooked up on my breadboard...the brick is working fine.
whats happening is somehow theinput is bleeding into tghe output... i can reproduce it outside the pedal.
i need to take a break and look again. every semi i've swappe4d out still works in other circuits. has to be something with the pcb or the wiring, it melted the 22k pot... @#$%er was smokin
very very very weird. and this was the cleanest build i'd done. WAS. ;)
took all the semis out. checked continuit everywhere, and for shorts. the straight guitar comes thru. the buffered guitar comes thru.
the brick was even working, tho it wasn't really loud. it has a reset, if you unplug it for a few seconds it seems to come back. i'm suspecting something burned out inside... i mean, it is 2399's, right?
what i can't understand tho is why i can plug the guitar right into the input, and take either output to my amp... totally wet, but working like that.
i re-wired the switches and pots, and even put in good jacks. same result.. when all appears to be right, as soon as ya crack the volume knob, all hell breaks loose.
it's a VERY cool airplane simulator, lol... but for the life of me i can't see what the hell i've done wrong.
the ass end is working. the front end is working. the buffered straight thru guitar is working... could the chip short internally between the input and output somehow?
or is it the brick itself? man... what a bitch this one is. ;)
i thought it was a dc hum, but it's definitely a feedback loop happening from the output to the input somewhere.
Do you have another 2399? Sometimes they can become damaged and sometimes they're bad right out of the package. Of course, the problem may lie elsewhere. This wouldn't be fun if it were easy! ;D
Please ignore anything I say. There is no PT2399. I should know-I've built one of these. :icon_redface:
Are those diodes for the fet switching round the right way?
resistor values?...
im not sure what could be giving you grief....
i know the feeling of doing a nice neat and tidy build then having to pull
it all out man, been there too, what a bummer....
soemething is defo wrong with wiring if you smoked a pot....
Let me try to understand:
My understanding is that the sound goes weird as you soon as you connect pin 6 of the brick.
If you don't connect pin 6, do you still have reverb?
Because pin 6 is one of the output of the brick (assuming you have a BTDR-2, not a BTDR-1), the other output is pin 5.
And the circuit is able to function properly with only one of the two outputs connected.
Quote from: Jdansti on February 11, 2014, 01:27:06 AM
Please ignore anything I say. There is no PT2399. I should know-I've built one of these. :icon_redface:
Take the cat off your head, John. It's affecting your brain! ;D
jimi - If you melted the delay pot, then you probably put 9V across it. One of the lugs (#2) connects right next to V+ on Rob's layout. Any chance you have a solder bridge?
sam, thanks... exactly what i'm looking for, cuz it SOUNDS and acts like the power supply and audio are connected somehow.
the pot smoked while i had all the chips and fets taken out, i was afraid i may nuke them doing continuity tests. so i'm wondering if that is where i'm gonna find the problem.
i'm trying to take some time away from it so i can be a bit more objective.. i have it narrowed down to where it's messed up, stage wise... it has to be somewhere either in the audio switching or the stage feeding the input of the brick...
other wise, i can't see how the heck the brick can work on the breadboard.
speaking of..yes, disconnecting pin 6 of the brick (it's the newer 6 pin btdr2hl) will stop the oscillation, but then the reverb doesn't work. the oscillation is always happening, i can turn it down with the volume control soit has to be somewhere between the input (chip a) and output (chip b).... so it's gotta be in or near the feedback circuit. i'm betting sam may have found it, i will check.
could the brick be shorted internally? the original regulator is fine, it's putting out a solid 5.1v, and the brick works fine on my breadboard. i can get the exact same effect as the problem if i connect pin 6 to pin 5 or pin 3 of the brick (out of the circuit, on the breadboard).
i can get reverb out of either side, but pin 5 is definitely wimpier than pin 6.
it's hard to describe and troubleshoot, cuz each power up it seems to do something different.
i hate to buy ANOTHER brick to find it wasn't the problem. but maybe i should. worst case, i can build a verb with this one that doesn't have the fancier accoutrements. ;)
i bet i spelled THAT wrong. ;)
gonna smoke a doobie and guzzle a couple huge cups of coffee and go have a look-see... i am gonna go out on a limb and misquote larry/armednready and pronounce it's something i must have done wrong
i'm wondering if it's a latch up problem? i've had 2399's act like this.. maybe it burned a feedback path inside the chip?
proud to announce the birth of yet one more chasm reverb. despite a long and arduous birth at the hands of a rather inept doctor, the patient has survived the operation and sounds great.
i looked at it again. hard. went over the entire trace side of the pcb and scratched between every trace, every node. plugged the reverb in.
silence...and then the airplanes arrived.
to build the photonic airplane simulator.... details below. it's really cool if you have an azimuth coordinator sound system. i digress.
i was like, @#$%!!!!!!!!!!!!
so i went out and smoked a while. cleared my brain. come back in, now entirely sure the wiring was right, entirely sure there were no bridges, broken traces or dead chips/fets. what the hell could be wrong?
well... i finally start looking at the top side of the board, component by component. that was when i noticed the big mistake. i will take lumps for it. i deserve them, cuz it was stupid. epic stupid.
on either side of rob's layout of the regulator are two 10 k resistors. above them, another that is horizontal. these are in the feedback path of the circuit
i remember pulling out the last of a small bag of 10k resistors, not even looking at them. i generally populate all of each value as i go. these were all definitely in the same bag, that's why i grabbed it.. it had a couple, and i figured cool.
well, 3 of them 10k's were actually 1k's. i'm betting the guy who packed them made the same mistake as i did, cuz man, looking at them and the 1k's they look almost the same. VERY subtle difference.
i replaced those with 10k's, reconnected the long-suffering brick, which was put thru the digital mole station of it's life (digitals as in fingers) and hooked up wrong intentionally and everything, and STILL works.
it sounds great... even the dang smoked pot still works. and it was cool, i got to watch the light show when i let the smoke out of it.
still using the original 805! it's working fine.
so.... if ya want the patented jimi photon airplanes in your head real attrociously @#$%ing loud pedal, change them three resistors to 1k and let 'er rip.
(http://i605.photobucket.com/albums/tt137/pinkjimiphoton/1625646_10202419700006721_175432358_zpse49fc739.jpg)
(http://i605.photobucket.com/albums/tt137/pinkjimiphoton/1925023_10202419700046722_210875787_zpsea84893b.jpg)
anyways, with just THOSE THREE CHANGES, YOU can have YOUR OWN AIRPLANE SIMULATOR PEDAL!!! SO ALL YOU COMERCIAL BUILDERS!!!! TAKE THIS BROTHER MAY IT SERVE YOU WELL!!!
:icon_mrgreen:
seriously nice sounding box rob... thank you so much!!!
and thanks mike for burning me out a board
and all you guys for the support, education, humor and putting up with my idiot self while i found this.
stupid pedal trick of course will be imminent. with fuzz and without. ;)
oh shoot, just noticed too when i was trying to debug, i changed the .47 cap to .047.... guess i gotta fix that too... makes for a nice clear verb, but i bet it's gonna be a big improvement.
<epic facepalm>
cool (the getting it going rather than the face palm and whatnot).
thanks sam!! :icon_smile:
brilliant!...now you can relax and chill a little.. ;)
8)
the 1k mod.. ;D
yes, the "mod"...... :icon_mrgreen:
Glad you sorted this out! 8)
I know that guys who advise to check the components' value may sound like morons when you're convinced the problem lies elsewhere. And then you check for the tenth time, facepalm! Been there so often!!! ;D
In fact, along the two "1K" resistors in the feedback loop, the third "1K", forming the voltage divider for Vref, was certainly another part of the problem as it made Vref way above 1/2 V+ ;)
Quote from: loylo on February 11, 2014, 02:59:35 PM
Glad you sorted this out! 8)
I know that guys who advise to check the components' value may sound like morons when you're convinced the problem lies elsewhere. And then you check for the tenth time, facepalm! Been there so often!!! ;D
In fact, along the two "1K" resistors in the feedback loop, the third "1K", forming the voltage divider for Vref, was certainly another part of the problem as it made Vref way above 1/2 V+ ;)
the funny thing is i was describing exactly what would happen there.... <shakes head>
i was so obsessed with looking for shorts, i forgot to check topside. ;)
Looks like the "pot" wasn't your problem... The "pot" actually helped you solve the problem! ;)
I'm glad you got it sorted Jimi.
I'm really glad it wasn't my boards fault ;D
lol.... the board is good mike, no worries.
i still have two problems...one, i need to find a good tl074 or 84, i have an lm324 in there right now and either it or the brick is a little hissy.
after the abuse they both sufffered, i can't blame them for having PTSD a little.
the other problem, is the volume goes all the way to zilch, which it wasn't doing before. but hey, i can live with that.
i don't wanna have to go back in there again!! lol... trimmed wires as short as possible, some broke off while i was tinkering. that made fixing them difficult.
but that said, nice job rob, this thing sounds wonderful!!
thanks again rob for the circuit, mike for the board, and all you guys who helped me. ;)
(http://i605.photobucket.com/albums/tt137/pinkjimiphoton/1517590_10202421610454481_130676494_zpse1e90be4.jpg)
complete with cool-ass purple ultraviolet led..
(http://i605.photobucket.com/albums/tt137/pinkjimiphoton/1901494_10202421611854516_949459129_zpsdb226b79.jpg)
i opted to make the osc footswitchable, cuz i had some spdt footswitches and didn't feel like buying some pos at rat shack!!
it's cool, tho, no pops or anything. ;)
Nice result, Mr. P. You should call it the "Dreamliner Reverb". Both are aircraft that catch fire! ;D
Has anyone tried an ON/OFF/ON switch for the OSC Switch? I haven't found specifically that an ON/ON is called out, but in reading the thread, that seems to be the default.
I was comparing the Rub-a-Dub Reverb and the Chasm and it looks like the OFF position would make the Chasm similar to the Rub-a-Dub, meaning no feedback loop.
I curious if that would yield a different type of sound, or would the change be negligible.
-George
The feedback pot shunt the feedback signal to the ground, so the feedback pot at 0 is similar to the Rub a Dub. There is no need of an on/off/on switch.
Quote from: loylo on February 24, 2014, 03:06:47 AM
The feedback pot shunt the feedback signal to the ground, so the feedback pot at 0 is similar to the Rub a Dub. There is no need of an on/off/on switch.
Ugh, should have seen that. Got too distracted by the shiny object.....
Thanks!
George
Ready now!
Thanks Rob
https://app.box.com/s/176c4lunl1te0mjbyewg
https://app.box.com/s/39sayal2fud0ewu4bqzr
^ ;D
cool, nice one maik. ;)
I was so excited by my latest build that I wanted to share it with you guys.
Thanks, Deadastronaut!(http://img.tapatalk.com/d/14/03/13/epygyra9.jpg)
(http://img.tapatalk.com/d/14/03/13/4ybusu8a.jpg)
(http://img.tapatalk.com/d/14/03/13/7y9e7u8u.jpg)
8)
nice one man. 8) 8) 8)
+1!
Might have been answered. But what are the two black components. Rectangle one with numbers backward and the other one with nothing on it up right and bottom left hand corners?
Those are little patches of copper when the PCB is made.
Or at least I assume they are, as one has some text in it.
They are nothing but good spots for standoffs; I only used one since the brick worked as one for me
Does anybody have the build doc for the fabbed board?
PCB and layout on this post:
http://www.diystompboxes.com/smfforum/index.php?topic=105109.msg945587#msg945587
BOM on here:
http://www.diystompboxes.com/smfforum/index.php?topic=105109.msg945841#msg945841
Finally had the time to complete this and I'm really pleased with the sound. No build issues apart from a jack socket shorting on a pot. Loadsa wires so hit them under the board. Finding a difference in the tails depending on the OSC setting. On bypass with OSC off, the tails linger until I mute the strings or hit another note on that string. With OSC on, the tails linger over the new notes of that makes sense.
Rob, if this was by design then my hat off to you. If I've made a mistake somewhere, I'm not changing it as it's really effective :icon_biggrin:
Am finding that on short, muted staccato notes, the delay repeats are very obvious though that's disguised during normal playing. Using a long delay brick, wondering if a short one would help
(http://www.stallibrass.com/images/kas/chasm1.jpg)
Guts
(http://www.stallibrass.com/images/kas/chasm2.jpg)
WOW. That's great.
How did mine turn out looking like a spilled bowl of spaghetti? No one else seems to have a problem with getting the wiring neat.
Thanks Mike. Trust me, if you saw under the board... Bit of a rats nest held in place with a loose cable tie. Just had to leave enough length on the wires to allow the board to be lifted if necessary.
Beautifully done, Kevin!
+1. Really nice job, Kevin. And cool that you included Rob on the front, too. :icon_cool:
Mine is still at the completely-unbuilt stage. I'm concerned that mine will be nowhere as neat, with all that wiring to do (great concealment, btw!). More likely to be like Mike's spaghetti, or worse... some kind of alien autopsy... :o
Quote from: bluebunny on April 15, 2014, 03:19:19 AM
More likely to be like Mike's spaghetti, or worse... some kind of alien autopsy... :o
Or worse.... A spaghetti autopsy. :icon_eek:
nice one kevin, looks great, and really tidy too...
no that wasn't a deliberate design btw, but if it works for you then even better.. ;D call it a 'feature' ;D
cool.
...
btw guys i should be getting boards fabbed pretty soon. for onboard pots , brick, switch ....no more spaghetti. ::)
as soon as they are available i will test build and post up ok. ;)
Quote from: deadastronaut on April 15, 2014, 05:11:58 PM
btw guys i should be getting boards fabbed pretty soon. for onboard pots , brick, switch ....no more spaghetti. ::)
as soon as they are available i will test build and post up ok. ;)
ah.. in that case...
I was bracing myself to try and fit it on a 125B sized board!
just waiting on postman.. ;)
Quote from: deadastronaut on April 29, 2014, 05:25:24 AM
just waiting on postman.. ;)
Eeeeek! I can't wait. I'm ready for another. Can we get a teaser?
1590bb
heres a teaser: ;D
(https://dl.dropboxusercontent.com/u/7464107/Plain%20Pork%20Chipolata%20prize.jpg)
onboard brick, pots, switch...
in the uk its impossible to get onboard pots, so i will be wiring mine anyway... ::)
Quote from: deadastronaut on April 29, 2014, 05:44:27 AM
1590bb
heres a teaser: ;D
(https://dl.dropboxusercontent.com/u/7464107/Plain%20Pork%20Chipolata%20prize.jpg)
onboard brick, pots, switch...
in the uk its impossible to get onboard pots, so i will be wiring mine anyway... ::)
well.. maybe I'll stick with my ambition to stick it in a smaller box then ;)
oh and onboard brick...neato!.
aha...guess what the postman just brought me... 8) 8) 8) 8) 8) 8) 8) 8) 8)
excellent quality...plush!!!!!.. 8)..love the corners too.. 8)
(https://dl.dropboxusercontent.com/u/7464107/chasmpcb1.jpg)
(https://dl.dropboxusercontent.com/u/7464107/chasmpcb2.jpg)
these were actually designed by chi boy (george) a member here, thanks for all your help with this man. 8)
next up is the abductor fabbed pcbs. ;)
How many did your order? Are they the same board on the upper left hand corner?
hi armando, yep the same.. i ordered up 10, but you get 11, result. 8)
i'll populate one to verify as soon as i get time...should be cool though.
pukka quality, and nice traditional green 8)
Finally got mine finished. The "L" modules were unavailable, so I used an "M". It sounds great, thanks for a superb design.
How do you post photos?
Rob,
This project was a lot of fun and I'm glad you're happy with the boards. Thanks for letting me in on the fun!
Well, I'm not the best photographer, but this is a little tease of how the boards look populated.
This is my first etched enclosure and I still need to work out the kinks, but I wasn't going to trash the enclosure because of a few pits. Gives it character, right?
Anyway, this is how she looks.
Cheers,
George
(http://home.comcast.net/~gprause/IMG_5761.JPG)
(http://home.comcast.net/~gprause/IMG_5763.JPG)
(http://home.comcast.net/~gprause/IMG_5766.JPG)
(http://home.comcast.net/~gprause/IMG_5767.JPG)
Quote from: Cozybuilder on April 29, 2014, 09:14:56 PM
Finally got mine finished. The "L" modules were unavailable, so I used an "M". It sounds great, thanks for a superb design.
How do you post photos?
You need a photo host website to store your photos (photobucket and many others). Once you upload your photos, copy the direct URLs for them. Hit the photo icon above the posting window here in the forum and paste each URL between the image commands. It's easier than it sounds. Your post should look something like this, except with
square brackets [ ].
{img}yourphotoURL{/img}
You can see an example by going to any post that has a photo and clicking "Quote".
This really looks great George. It looks like a fantastic layout.
BTW, Steve at Small Bear has the long reverb modules back
In stock.
hi george, man that looks lovely and neat inside...no more spaghetti yay!.. 8)
the etch is fine man, you should've seen my first attempts..they either got painted and turned into other projects , or i flipped the box over and re tried it... ;)
either way i used them.. 8)
i'll pop a board as soon as i get a chance...
i got my bricks from musikding in germany btw they were the cheapest i could find for UK/europe post etc..
@cozy: i got your message man about a 1590a :icon_eek: but cant see pics... try dropbox.
Wow, that looks a lot nicer than my pcb :)
Thank you Jdansti for the photo instructions. Here is proof of my lunacy
Main board
(http://i1362.photobucket.com/albums/r688/russrutledge/DSCN1900_zps662e801f.jpg)
Main & daughter boards
(http://i1362.photobucket.com/albums/r688/russrutledge/DSCN1897_zps4d45bb12.jpg)
Jacks, switch, LED, regulator, daughterboard and plug installed
(http://i1362.photobucket.com/albums/r688/russrutledge/DSCN1907_zpsdff2263e.jpg)
Complete gut shot- its all there
(http://i1362.photobucket.com/albums/r688/russrutledge/DSCN1908_zps7a30da1e.jpg)
With apologies for my clearly underwhelming artistic abilities.
(http://i1362.photobucket.com/albums/r688/russrutledge/DSCN1909_zps3b0642e8.jpg)
:icon_eek:
you nutter..i'm always amazed at the lengths you micro 1590a'ers go to ;D
8)
Cozybuilder - that is astonishing, especially seeing as you used perf! I like the use of the Millennium bypass daughter board and the header pins.
Any chance you could share the layout?
Rob / George - nice boards.
Here is the pencil drawing of the layout that I worked from. Both sides of the board are used in fitting components and wiring. C1 is 100μF
(http://i1362.photobucket.com/albums/r688/russrutledge/DSCN1866_zps4432f35c.jpg)
Quote from: Cozybuilder on April 30, 2014, 08:20:07 AM
Thank you Jdansti for the photo instructions. Here is proof of my lunacy
Main board
(http://i1362.photobucket.com/albums/r688/russrutledge/DSCN1900_zps662e801f.jpg)
Main & daughter boards
(http://i1362.photobucket.com/albums/r688/russrutledge/DSCN1897_zps4d45bb12.jpg)
Jacks, switch, LED, regulator, daughterboard and plug installed
(http://i1362.photobucket.com/albums/r688/russrutledge/DSCN1907_zpsdff2263e.jpg)
Complete gut shot- its all there
(http://i1362.photobucket.com/albums/r688/russrutledge/DSCN1908_zps7a30da1e.jpg)
With apologies for my clearly underwhelming artistic abilities.
(http://i1362.photobucket.com/albums/r688/russrutledge/DSCN1909_zps3b0642e8.jpg)
:icon_eek:
Amazing!
Now... take my money and make me one ;D
@Cozy- that's simply amazing!!! :o
Clearer photos of wiring diagrams
(http://i1362.photobucket.com/albums/r688/russrutledge/DSCN1916_zps076355af.jpg)
(http://i1362.photobucket.com/albums/r688/russrutledge/6dbfd273-a609-4566-abb9-42810a163921_zpsedc8888b.jpg)
How are you crazy people fitting this into a 1590a!
I need a hell of a lot of room, hence I used an old pie tin. You know one of those grim chicken and mushroom ones in the blue tin. After eating the contents (an unpleasant task) I sanded it down and due to the shape I couldn't help but make a homage to Robs whole space theme. I say homage, but I've actually just done a bit of a rip off of his design for the flying saucer reverb. I've also added colour changing LEDs (probably a bad decision as a get a little background noise buzz as they change, but its only faint so I've decided to stick with style over substance)
So here it is
(https://farm6.staticflickr.com/5553/13903857249_bdba5e336b_z_d.jpg)
(https://farm3.staticflickr.com/2916/14087358012_330a1f6df8_z_d.jpg)
(https://farm8.staticflickr.com/7178/13903882860_c083d05540_z_d.jpg)
Anyway enough about pretty lights and pie tins. This pedal also sounds awesome! I've built a few different pedals before and each time have had to do loads of fault finding after, so to make things a little harder for myself I thought I would try and etch my own pcb for the first time. I used 1:1:1 mix of Hydrochloric acid (32%), hydrogen peroxide (40%) and water and just drew the design on the copper with a permanent marker. a few seconds and it was done! and to my utter surprise after populating the PCB it worked first time!!! and it sounds great. Thanks for sharing this Rob. I'd been looking for a worth while DIY reverb and this really is worth the while!
Brilliant, absolutely love the abduction graphic...very cool. Cheers . Rob. 8)
I'm serious @Cozybuilder - this reverb sits on my small board always on, so a 1590A version would be suh-weet!
Nice one 9aul, and you hit on some of Rob's favorite themes- space, aliens, and LEDs! Maybe even grim chicken and mushrooms! ;)
@9aul:
just remembered , re: your colour changing led noise, i remember tinkering with those and the noise problem..
IIRC i put a 220uf in parallel with the colour changer and it cured it...worth a go. 8)
watch the skies!!!! ;)
i'll be populating the new pcb today...i haven't any onboard pots, but hey...
while i'm here actually, any tips for making a pcb mount pot into an onboard?...led legs?..
Quote from: deadastronaut on May 06, 2014, 03:25:25 AM
while i'm here actually, any tips for making a pcb mount pot into an onboard?...led legs?..
I guess LED legs would work well, but I've just used plain ol' resistor offcuts. No one said it had to be pretty, but it works!
I like rectifier diode legs (1N400x) as they are a bit sturdier.
I think Stephen Giles has suggested using paper clips before.
ahh yes, 1n4001's should be fine..cool, cheers guys. 8)
will have to wait for my dpdts to arrive to finish it off..
Ah thanks Rob! nice tip, I'll try that out.
populated: i must say these pcb's are a dream to solder up..very nice... 8)
just waiting on my toggle switch now..should be here saturday ::)
(https://dl.dropboxusercontent.com/u/7464107/chasmpukka.jpg)
i'll crack on with my box while i'm wating..... ;)
Beautiful! :)
Quote from: deadastronaut on May 08, 2014, 07:14:02 AM
(https://dl.dropboxusercontent.com/u/7464107/chasmpukka.jpg)
Nice one, Rob.
Quote
just waiting on my toggle switch now..should be here saturday ::)
Swap you a toggle for a board! :icon_biggrin:
yay!!!!...got all my bits to finish this off now,
busy this weekend, but should have it all done on monday... 8)
Sweet!
PCB looks amazing !!
Which is the manufacturing suppier of these ?
Quote from: bluebunny on May 06, 2014, 03:42:39 AM
Quote from: deadastronaut on May 06, 2014, 03:25:25 AM
while i'm here actually, any tips for making a pcb mount pot into an onboard?...led legs?..
I guess LED legs would work well, but I've just used plain ol' resistor offcuts. No one said it had to be pretty, but it works!
I've done that with much success. I actually soldered 2 together side by side, which didn't take very long and was oddly relaxing.
Passing the solder tip along the two legs repeatedly got a very nice, shiny, strong a smooth solder connection.
YAY!!!!...GREAT NEWS: finished it off today.
the fabbed boards are now verified, works lovely... , 8) 8) 8)
i have some chasm reverb boards available at £11.00 GBP which includes p+p worldwide ok..
pm me for paypal details if interested ok.
: i used off board pots, as onboard pots are rare as hens teeth in the UK.. but still a nice clean easy build,. 8)
Here is a way to emulate "on board" pots with a bit of vero and a few right angle header pins.
The images depict the long pin pots but can be made shorter as needed.
The pots used are the 90 degree board mount type that are fairly common.
(https://dl.dropboxusercontent.com/u/53299166/DIYstompboxes/pots%20pins.jpg)
(https://dl.dropboxusercontent.com/u/53299166/DIYstompboxes/pots%20top.jpg)
nifty mod, nice one larry... 8)
Cool idea. It's cool how the dimension are the same
Yes...it was mechanically engineered over the course of many minutes to work out that way. :icon_wink:
It's good in a pinch because some values are a bit hard to find in the right angle pot department.
Especially reverse taper!
Ok, I've had a good crack at this pedal. I'm a bit of a newbie to DIY pedal making and maybe I bit off a little too much with this as my third build but I am determined to get it working!
I'm not to far away, I have quite a lot of it working but some things not working as expected. I've made myself an audio probe now so I've been able to probe in and test for signals at any point in the circuit ( should have
done this ages ago!!!).
So, with the foot switch on I have a signal (an decent output). The volume, mix and damp pots are working perfectly. I'm really pleased with the initial results and i think I'm tantalisingly close to completing it.
The problems: the decay knob and osc switch are currently doing nothing, they don't effect the sound at all. I've done all the obvious checks (component values, reflowed, checked for bridges) . If you could give me any pointers as to what I should be expecting to find at the pins on the decay knob it would be most appreciated, infact any clue of the signal flow of the circuit would really help as I don't really understand how it works and that would allow me to check through methodically rather than randomly which is what I am currently doing. I see that the one pin is connected to ground.
My other problem is that in one position the footwswitch engages the circuit and led. In the other position (bypassed) I get no signal through at all. I would like to get the other bits sorted first, unless you think this is related?
Cheers
Hi , just built mine, with one little problem.
There is a constant whine along with the wet signal, high pitched tone ?
The only changes I made were using 1n914 diodes instead of the 1n418 is it?
Any thoughts please?
Is this thread still alive?
JZA
^ not sure if the diodes will matter that much,
which layout did you use?..the diy pdf, or did you buy a pcb.?
have you checked around the oscillation on/off switch...?
I used the PDF and etched, I will be able to get and retest in an hour, just hoping for an easy fix if you had encountered similar issue at some point.
It doesn't occur during bypass .
I will have a check around the osc switch first, otherwise works fine .
Nice t know there is still life in this thread.
Thanks JZA
it's alive... :icon_twisted:
yeah have a checkup with the osc switch, and check the wiring on the brick too...(theres a LOT of wiring in the pdf layout version, ..and easy to make a wrong connection...been there.)
the layout is very verified, so it will be ok....
It's alive,
After checking many things I tried with a battery and it worked perfect, I assume its the dc socket, was brand new but since I 1st connected it something wasn't right with the socket, the plug wouldn't sit right and was popping, u forgot about that , either it has a slight short or the rapid popping and clicking has messed up my power supply!
I will find out for sure tomorrow as It's getting really late.
One thing is for sure the build is perfect, just need a better supply of dc sockets in the future.
I will make up an enclosure for it tomorrow.
I wonder how many hours I can get out of the battery, I know reverbs generally eat batteries for breakfast. Will be interesting though.
Thanks deadastronaught, for your help and design, I wonder if you know of or are working on another pedal that makes use of that other brick, the one with many preset options?
JZA
****TYPO******
Where my post says " u forgot about that" should read "I forgot"
****************
It was getting very late, and my phone spell check is decidedly arrogant it seems.
Thanks again.
JZA
I play a lot of keyboards and would love a stereo version, especially as these bricks have 2 channels.
Not having the schematic for this circuit makes it difficult to establish how or your design works, are we controlling the parameters inside the brick or the actual sound path with these pots.
Do you think this design is adaptable or would this be a complete redesign...?
I found this thread when searching for a feedback circuit to use with the Belton brick. I was really happy to discover the added bonus of oscillation feature too. Please let me know if stereo is an easy adaption or a complex affair.
.. thanks
JZA
The brick has two outputs, but they are not stereo - just two independent mono outputs.
right , I will take time to read up on the datasheets soon , just my over excited assumption.
Also I need to read up on Power supply and mixing negative ground / positive ground pedals and their supplies , I just connected a new dc connector socket to my chasm to find that motorboating sound again, however when i touched my (G4 Metal casing) laptop to type to you guys i noticed the metal had a mild fuzziness electric feeling !!!!
this is something i try to read up on but can't get a definitive answer too.
I am assuming now that this pedal is POSITIVELY GROUNDED??
(here i go assuming again)
I read a lot about some fuzz pedals being positive grounded (can i just abbreviate to PG/NG for this post)
I know this is not a fuzz pedal but it does make use of JFET and MOSfet ???
I have never used or owned fuzz with external ac/dc adapter , just my fuzzwah morley ... but it seems these pedals are the first build projects for most DIY pedal builders , giving them an early understanding in this topic of NPN PNP Germanium transistors etc..
I have built many pedals , I'm pretty sure most of them are PG except this CHASM and the LPB-1/2 I have ... there are maybe some EHX pedals I have that are NG but I have used batteries in those .
I am slowly getting a pedal board/rack together in my mind and will soon be buying a power supply / supplies for it , so i need to conquer the theory of this before I go any further .
As there was no schematic available for this build I hadn't really thought about this till now, but I am pretty sure that this is the reason for my Noises on this build , you see i am using the same 240v multi plug adapter for the pedals i am testing , some PG , some NG..
I am sorry to take this thread way off topic , If someone could link me to a good thread on this or a good read somewhere, I would be grateful .
and if you could clarify the grounding on this build to ease my weary logic.
The new DC socket is plastic mounted type which is new for me so just getting to grips with the terminals etc... having said that the metal one I used was motorboating before I mounted it into an enclosure.
it seems the more I write this post, the more questions I have on this topic as a whole and the motorboating issue as a whole ..
So I will stop here.
JZA
So just to clarify my last post if you havnt read all my questions regarding this build so far...
***Works fine with BATTERY.
***Motorboats with DC adapter (PG)
***Reverbs eat batteries for breakfast :)
***how to / where to plug in dc adapters (wall warts) to use both PG and NG pedals in the same studio / pedal board.
***which power supply (if any) can power both NG PG pedals at same time with individual isolation and multi voltage.
***can you even chain NG and PG pedals in same signal path ?
*** if not can we modify this CHASM build using to be NG (or vice versa if I'm getting confused what it actually is).
I especially like my last question as that seems to make a lot of sense to my problems,,,,
sorry for so many questions , but I'm sure this will help many DIY noobs out , if you can help.
JZA
Quote from: JZA on June 10, 2014, 09:23:14 PM
I am assuming now that this pedal is POSITIVELY GROUNDED??
Nooooooo! :icon_eek: Sorry, "no": the CHASM is most definitely negative ground. Like the majority of other pedal designs you'll see around here. This is a
gross over-simplification, but you tend to find that builds involving Ge PNPs are positive ground, but they're in a minority.
^ yep..
IT IS NOT POSITIVE GROUND!!!!!!!! i never build pos ground pedals, i can't be arsed with that lark...
you should be using a tip negative 9v psu.....(get a good one) being cheap on a 9v psu is just not worth it....
the chasm has a reverse polarity protection diode, ....going by the sound of it , it needed it.. :)
@JZA: You may be confusing positive ground and positive sleeve on the DC jack.
We use plastic DC jacks that are wired with the positive on the sleeve and the negative on the tip. This is because most pedals and pedal wall warts are wired this way. The positive sleeve is insulated from the enclosure because the jack is plastic. The enclosure and board are wired such that they have a negative ground.
(http://i1160.photobucket.com/albums/q485/jdansti/DBBBE22C-114A-4DF2-9CE3-42F1890C8575.jpg)
JZA: You may be confusing positive ground and positive sleeve on the DC jack.
Yes that's exactly what one of my confusions are.
I find most my pedals are negative ground but nearly all use the positive tip method.
However that is pretty trvial as these circuits will only work one way, I just flip polarity on the adapter and make sure the 9v always meets the 1n4001, so even without schematic its pretty obvious.
I fail to figure why it doesn't motorboat with battery????? So you see now why I have to doubt y most basic understanding of electric logic!!!
So if someone has an idea on that ?
It should be stated that my dc adapter works fine with all my pedals and I had the same issue before I enclosed the build.
This is strange. Are you connecting the battery and adapter to the exact same points?
Quote from: Jdansti on June 11, 2014, 03:16:30 PM
This is strange. Are you connecting the battery and adapter to the exact same points?
Yes , the same solder points ... Not using the 3rd lug at all on dc socket... Not using battery in the build other than to test !
It works fine with battery and technically fine with DC except for the whining motorboating tone ????
You're damn right its strange !!!
Thats why I was doubting my setup and other things using power sources.. and finally got to doubting the grounding , which i knew people would jump on me for ;))
Still as a wise man once said " I Don't Honestly Know" what it could be.
I do know that this is my 1st digital build, and that wasn't on ourpose , I originally was looking for a spring reverb tank circuit etc... and got this far down the rabbit hole to find that digital can have Noise issues ;)))))))
Hey , thanks for thinking for me, let me know if you have any ideas , no matter how silly ... I have bought another Voltage regulator, as this a new component for me to be working with , I can't tell how to test it and it is possible (my only guess) that the regulator is drawing too much current through ???? obviously the battery can only give so much current so is possible that the dc could be allowing the voltage regulator more current than battery.
let me just try this new regulator... at least its a TO92 this time ... just reading up on its datasheet though before fitting it
Thanks JD!
JZA
Voltage readings during your testing would help.
Quote from: JZA on June 11, 2014, 08:30:36 PM
. . . its a TO92 this time ...
If you had a TO220 package last time (7805), this one (78L05) "faces the other way".
BTW, what DC PSU are you using?
new batch of pcbs just in, if anyone wants one..or two...etc
£11.00 GBP posted worldwide. pm me ok.
(https://dl.dropboxusercontent.com/u/7464107/chasmpcb2.jpg)
Can i sub J201s for the 5457?
yep...i used 5457's in my last build IIRC.
A few quick questions. Sorry for my noobyness on this.
1) I have been unable to find a 22k Lin pot anywhere to use for the Decay knob. Can I just use a 25k in place of it or do you know of a place I can order one in the US?
2) I was also unable to find a LM7805 voltage regulator on Mouser, Mammoth or Small Bear Elec. To my knowledge/understanding a LM78L05ACZ would work fine correct? If so is the orientation the same as the 7805?
3) Was there an offboard wiring diagram anywhere? I might have missed it but I didn't see one anywhere as to how the jacks should be wired up.
4) I'm assuming it uses Mono/Mono jacks on the input and outputs?
5) What size enclosure is the PCB layout meant for? Assuming 125B should work fine...looks like most builds are 1590BB anyone fit it in anything smaller (excluding crazy stuff like 1590A)?
Thanks in advance!
Great looking boards Rob, love the little heavy metal little stick spaceman. :icon_cool:
Quote from: 0ron124 on July 10, 2014, 06:29:31 PM
A few quick questions. Sorry for my noobyness on this.
1) I have been unable to find a 22k Lin pot anywhere to use for the Decay knob. Can I just use a 25k in place of it or do you know of a place I can order one in the US?
2) I was also unable to find a LM7805 voltage regulator on Mouser, Mammoth or Small Bear Elec. To my knowledge/understanding a LM78L05ACZ would work fine correct? If so is the orientation the same as the 7805?
Thanks in advance!
1) 25k linear is fine...
2) LM7805...? You can't find at mouser? :icon_confused:
http://www.mouser.com/Search/Refine.aspx?Keyword=LM7805&gclid=CjwKEAjw8_idBRCExfC15My3owwSJACSDX_WjKTRRzpEfGgCAD0swiNWc6w9jb_Ms6BdY2s-ZzthRxoCMBTw_wcB
or
http://www.mouser.com/ProductDetail/Fairchild-Semiconductor/LM7805CT/?qs=sGAEpiMZZMtdAabcSkQOlwJydEoyhc9b
or
http://www.taydaelectronics.com/lm7805-l7805-7805-voltage-regulator-ic-5v-1-5a.html
or
probably a LM2940
Quote from: 0ron124 on July 10, 2014, 06:29:31 PM
4) I'm assuming it uses Mono/Mono jacks on the input and outputs?
5) What size enclosure is the PCB layout meant for? Assuming 125B should work fine...looks like most builds are 1590BB anyone fit it in anything smaller (excluding crazy stuff like 1590A)?
4) That would be fine, since you're unlikely to be using a battery for this build.
5) The board shows four pots in a line, plus a switch, so this isn't going to fit in a 125B. Not unless you smash it into tiny pieces with a large hammer. :icon_twisted: I'd go for the BB.
Thanks for the replies guys!
I guess I'll just do that and go for the BB and after looking at the specs for the Belton I think that the LM78L05ACZ would work fine which is the only thing that Small Bear and Mammoth have in stock and since I usually order everything there I'll just try that out instead. If it doesn't work I'll get the LM7805 from Mouser thanks for finding it, for some reason it wasn't coming up :icon_confused:
As for #3, I went back and looked at the Schematic and I'm stupid...the wiring is there thanks guys!
Tayda has the LM7805 for $0.23.
http://www.taydaelectronics.com/catalogsearch/result/?q=Lm7805
Hi guys! I have a problem with my build: also if not engaged, the pedal make a very bad, very loud noise (perfectly tuned in A), something like self oscillation... The volume pot works fine (if i turn it down, the motorboating stops), the mix pot works fine (if the pedal is engaged and i turn up the mix pot i can hear, under the oscillation, the instrument i'm playing), the damp pot works fine (i notice a variation in tone turning it). The decay doesnt' probably works. Any idea?
@gg... I take i it you made your own pcb?...
there is a lot of off board wiring in the diy pcb layout..
triple check it over...its easy to get distracted and put wire in the wrong place.
many others have built from the diy pcb layout with success
..ok..
Yeah, i made my own pcb from your layout and double, triple checked the wiring... all in the right place... What part of the circuit can be related to motorboating?
Take a really good look at your 78L05. Check the datasheet and compare the pinout to the schematic. Don't just look at the flat spot and assume it's all good. Make absolutely sure the pins are oriented correctly.
I had a very similar problem with my first reverb build and traced it to the regulator.
Mmmm, it shouldn't be a problem if i used a 7805 in place of the 78L05, right? Pins are oriented correctly, input, ground, output... don't know... however i'll try to re-control all the traces! Could it be a short? :icon_confused:
you want 9v at the top of the reg, and 5v at the bottom... 7805/78l05 have different pin outs...
7805:
https://www.google.co.uk/search?q=7805&client=opera&hs=chY&tbm=isch&imgil=gNku2Al1T4jp_M%253A%253Bhttps%253A%252F%252Fencrypted-tbn2.gstatic.com%252Fimages%253Fq%253Dtbn%253AANd9GcTCQ8xpW5cX8T7eW5ILO0nPGOa0LfZ0AQS02OLX-pjNLF6gWngd%253B305%253B242%253B4w70rj_UNgIfdM%253Bhttps%25253A%25252F%25252Fwiki.techinc.nl%25252Findex.php%25252F78xx_power_supply&source=iu&usg=__iHAt4VAtR5sw60_jTYxNJY_NQZ0%3D&sa=X&ei=OFbaU534JtGv7AaB5oHgCA&ved=0CDEQ9QEwAg&biw=1871&bih=955#facrc=_&imgdii=_&imgrc=gNku2Al1T4jp_M%253A%3B4w70rj_UNgIfdM%3Bhttps%253A%252F%252Fwiki.techinc.nl%252Fimages%252F5%252F54%252FLm7805-pinout-diagram.gif%3Bhttps%253A%252F%252Fwiki.techinc.nl%252Findex.php%252F78xx_power_supply%3B305%3B242
78l05
https://www.google.co.uk/search?q=78l05&client=opera&hs=0Nt&source=lnms&tbm=isch&sa=X&ei=e1baU7XvH47y7Aa72oDYCQ&ved=0CAYQ_AUoAQ&biw=1871&bih=955#facrc=_&imgdii=_&imgrc=XHpOVAlDj4OV7M%253A%3BtlGHvXy-2BCUQM%3Bhttp%253A%252F%252Fwww.piclist.com%252Fimages%252Fwww%252Fhobby_elec%252Fgif%252F78l05e.gif%3Bhttp%253A%252F%252Fwww.piclist.com%252Fimages%252Fwww%252Fhobby_elec%252Fe_oscillo7.htm%3B200%3B200
Confirmed: pins oriented correctly; now i'm re-wiring all the offboard cables!
Might be time for some voltages, pictures, and a proper debugging thread.
Just finished building mine up last night (posted in the pictures thread). This thing is loads of fun.
I want to increase the overall level of the thing though as I'm finding I'm only using the last quarter of the 'Level' control, all dry mix means unity at around 3 o'clock, would like to get it around 12 o'clock. Am I right in thinking altering R16 (currently 22k) should achieve this...? ... or is it R15 (15k).
Cheers,
Marcus
There aren't any 15k resistor in this build (this might be the problem; I'm going by this layout: https://dl.dropboxusercontent.com/u/7464107/CHASMREVERBLAYOUT.pdf).
If you want to keep the bypassed signal at unity gain, then you need to reduce the value of the resistor connected to lug 2 of the volume pot. This will increase the maximum wet/non-bypassed signal. This is 5.6k in Rob's build and should give you a max gain of ~4 and unity roughly at noon.
ha, I did mean to write 5.6k but as it was R15, I wrote 15 again....
Cheers Samhay, I'll have a look around that area.
If it is 5k6, try dropping it to 3k3.
Hey there
Just wondering if anyone has a BOM for Rob's PCB of this circuit that they wouldn't mind sharing? I don't trust myself using the schematic!
Cheers guys!
here ya go.. ;)
(https://dl.dropboxusercontent.com/u/7464107/CHASMBOM.jpg)
Perfect! Thank you, greatly appreciated.
Will this work for the regulator? http://www.musikding.de/7805CKC_1
The geulators in all the build reports I've seen don't have the metal tab.
Thanks again Rob
too bulky...use the 78L05
a to92 version.. 8)
https://www.google.co.uk/search?q=7805&client=opera&hs=xDc&source=lnms&tbm=isch&sa=X&ei=GfDtU6fQKbSv7AbEuYGYBA&ved=0CAgQ_AUoAQ&biw=1920&bih=975#q=78l05&tbm=isch&facrc=_&imgdii=_&imgrc=XHpOVAlDj4OV7M%253A%3BtlGHvXy-2BCUQM%3Bhttp%253A%252F%252Fwww.piclist.com%252Fimages%252Fwww%252Fhobby_elec%252Fgif%252F78l05e.gif%3Bhttp%253A%252F%252Fwww.piclist.com%252Fimages%252Fwww%252Fhobby_elec%252Fe_oscillo7.htm%3B200%3B200
Cheers Rob. You're a gent.
For anyone that likes BOM's in table format I put this together. Fingers crossed it's correct. Please note this is for ROB's PCB of this circuit (not sure if there are differences between the PCB version components and the vero version components).
(http://i.imgur.com/6kq2I9N.jpg) (http://imgur.com/6kq2I9N)
Thanks
Sorry for all the posts. Can I sub the 22k Lin pot for a 25k? The place I get my parts from doesn't stock 22K. Grrr.
Yep...22k is a uk value...we are just awkward... ::)
Ha ha. I'm in the UK!
I currently order from http://www.musikding.de/ in Germany. Can you suggest anywhere closer to home?
Cheers!
Bitsbox (http://www.bitsbox.co.uk).
BTW, super-fast too. I ordered some stuff yesterday afternoon and it's just popped through the door!
Bitsbox and Dr Tweek (http://www.doctortweek.co.uk/) cover most bases in the UK and are both excellent. If you can stomach wading through large catalogues, then RS and Farnell are excellent too, but have minimum order requirements. You will still need das musikding for the odd thing like reverb bricks.
found this guy recently...whilst hunting for toggles..
http://shop.pedalparts.co.uk
UK, newcastle based (i'll be up there next week, long drive ::))...excellent service too.
even wrote 'nice work DA '' on my envelope.. 8) ....whoever this elusive guy is, thanks. 8)
I think this is Poodle, post-revamp? Now doing the Belton brick! +1 on Dr Tweek - Steve's a top bloke.
@ Threepwood- a 7805 will work, check my build report on page 12, also the additional shot here:
(http://i1362.photobucket.com/albums/r688/russrutledge/ad6bda55-5e23-4765-bc28-5d2dd692167d_zps7bb79733.jpg)
Its a bit of work though
yes it will work...i just prefer the tiny to92..
check pinouts though... ;)
@cozy: :icon_eek:
Quote from: deadastronaut on August 17, 2014, 06:11:25 AM
check pinouts though... ;)
Yep, Rob's right. If you have a 78xx "facing you", i.e. writing towards you and tab behind, then the 78
Lxx will face
away.
(Note that the negative - 7
9Lxx - versions don't suffer this need for rotation.)
Cheers for the replies, all greatly appreciated. I'll have a look at all the stores mentioned.
Also thanks for the 7805 tips!
Anyone know a good source for 22k pots?
Quote from: shrike88 on August 23, 2014, 08:21:37 AM
Anyone know a good source for 22k pots?
Nvm, I just saw the post above. Must be early morning before my coffee
Sorry if this is a daft question but what does the Damp control do?
it acts as a tone really...takes the top end off or not..
Quote from: deadastronaut on August 16, 2014, 12:12:11 PM
found this guy recently...whilst hunting for toggles..
http://shop.pedalparts.co.uk
UK, newcastle based (i'll be up there next week, long drive ::))...excellent service too.
even wrote 'nice work DA '' on my envelope.. 8) ....whoever this elusive guy is, thanks. 8)
Thanks for that link Rob, Newcastle is my neck of the woods so I will have to get in touch, I much prefer to buy stuff locally if I can, support you local area so to speak.
yeah i agree, he's cool, i just came back from benton wednesday...been up there for 2 weeks. :)
Quote from: deadastronaut on September 05, 2014, 02:25:01 PM
yeah i agree, he's cool, i just came back from benton wednesday...been up there for 2 weeks. :)
I wished I had known Rob we could of had a meet up and a few pints , there's been some good local bands on up here over the last two weeks as well.
yeah that would've been cool...unfortunately i was up for a funeral at st marys lighthouse way...
no doubt i'll be up again sometime under better circumstances though man.. 8)
Quote from: deadastronaut on September 05, 2014, 03:11:59 PM
yeah that would've been cool...unfortunately i was up for a funeral at st marys lighthouse way...
no doubt i'll be up again sometime under better circumstances though man.. 8)
Ah ! Sorry to hear that , funerals aren't the best of days, I've been to far too many this year.
Hey again
Just getting the bits ordered for the circuit and have been looking for the TL072P chips. The site I am using has TL072 or TL072IP. Will either of these fit the bill?
http://www.musikding.de/TL072_1
http://www.musikding.de/TL072IP_1
And finally, is the SPDT On-On ?
Thanks!
@Threepwood
either of the TL072's you referenced will work.
yes, the SPDT is on-on
hi guys..i got fed up with typing untold messages back n forth, so decided to add a page to my site to make life simpler for me, and you... 8)
http://deadastronaut.wix.com/index#!__build-your-own-pedal
Cheers Rob that's great! Good work.
I hope this doesn't sound rude but would there be any way you could provide Build Docs for the pedals? I find it almost impossible to collate all the build tips that come up through the threads here on DIYSB. A Build Doc with a BIM and build notes would help immensely.
Keep up the good work!
hi man, yep i'm working on that, trying to suss pdf's.. :)
mrs astro's office skills will probably help with that.. ;)
You're a gent!
Thanks Rob.
Quote from: deadastronaut on September 17, 2014, 12:50:57 PM
hi man, yep i'm working on that, trying to suss pdf's.. :)
You wanna create PDFs, Rob? I think the latest versions of Microshaft Orifice will do it, or else OpenOffice does it out of the box and fer free.
ahhh cool, cheers marc, i have an old 2003 orifice prog...mrs astro knows how to do all that stuff apparently..
i'll email her the gumf at work and see what she comes up with.. 8)
Thanks for all the hard work Rob.
I might hold off putting my PCB together until the build doc is up. I'm sure I'll screw it up otherwise. Ha.
Quote from: threepwood on September 19, 2014, 06:34:21 AM
Thanks for all the hard work Rob.
I might hold off putting my PCB together until the build doc is up. I'm sure I'll screw it up otherwise. Ha.
This will get you going:
http://home.comcast.net/~gprause/BuildDocs/Chasm_Reverb_V2.1.pdf (http://home.comcast.net/~gprause/BuildDocs/Chasm_Reverb_V2.1.pdf)
The only difference between this build doc and the final boards is that the silk screen error was fixed. Any board that is greater than V2.1 was fixed and doesn't require REG1 or Q3 to be rotated.
Cheers,
George
Thank you. Greatly appreciated!
should have a build pdf up later if mrs astro gets time ... :)
pretty crude CHASM build pdf. courtesy of mrs astro.... 8)
board design courtesy of chi boy 8)
https://dl.dropboxusercontent.com/u/7464107/Chasm%20Reverb.pdf
Thank you to Mr and Mrs Astro and Chi Boy! ;D
;)
Would anyone be kind enough to spell out how to connect an LED to this? I've not used DPDT switches before so I'm not familiar with how to do it.
Also, is it possible to hook this up to a test rig with a 3pdt so I can make sure the board is all working before connecting the jacks and foot switch?
Cheers guys.
@ threepwood
If space in the pedal enclosure is not an issue, just use a 3PDT, thats the easiest way to include an LED.
There are many methods of wiring a DPDT switch for a pedal. This is what I use to include an LED:
(http://i1362.photobucket.com/albums/r688/russrutledge/DSCN2135_zps132266e0.jpg)
@threpwood: here ya go...sorry guys should have put this in the pdf..(which i will update ok)
(https://dl.dropboxusercontent.com/u/7464107/chasm%20switching.jpg)
R25 and D6, right?
Yep... 8)
Doesn't seem to have the ground trace?
hmmm...i see...
out of curiosity i just wired up a dpdt as above with an unboxed populated working chasm ( plugged into breadboard for testing)...with led ground going to ground pad on main pcb..
led works on/off...but i still get a little verb on bypass...hmmmm....
@george: how did you wire yours?..
for reference.
(https://dl.dropboxusercontent.com/u/7464107/chasmverb.jpg)
Maybe simplifying to something like this would be worth a try (2N7000 or other MOSFET):
(http://i1362.photobucket.com/albums/r688/russrutledge/DSCN2144_zpsdcb3a46b.jpg)
@cozy: we shouldn't need to add anything at all....
me and sam worked on the switching to be totally silent so it didn't bleed /pop when bypassed/on etc...which it did perfectly on my diy pcb prototype...
and chi boy said his fabbed pcb build was fine too...so am curious to see how chi boy wired his switch/led too.....chi boy?...are you out there?..
i have it working ok now, no verb on bypass...
however i get a thump when switching...so am desperate to see chi boys fs/led setup :)
I did mine like this and haven't had any issues.
(http://img.tapatalk.com/d/14/08/07/etejurud.jpg)
CLR off SW2 - CLR to Anode LED - Cathode LED to SW3
Looks pretty much the same as your PCB at the top of this page
ok, cheers man, cool. 8)
i guess its because mine isn't boxed then...
i'll get it boxed up ;)
My finished Chasm. Really love how this sounds Rob. Thanks for a great PCB
Keep up the good work!
(http://tapatalk.imageshack.com/v2/14/11/01/fcfa30f6379ee11aa529c2d6ea455ebe.jpg)
Finished mine yesterday, sounds realy cool but it has a loud whistle.
And with decay full up it sounds nearly like a slapback echo (but with reverb sound).
The whistle didn´t change when I tunr the pots.
With osc on the whistle is incredible loud.
Hi maik..
Something don't sound right with that...
Never had that issue...
check regulator, pot wiring etc, values..
Hi Rob
will do.
i'm boxing a chasm up today..
so if you need voltages etc ....
yes please
will be later ok....just had to repaint my etch... ::)
finished my latest chasm reverb ... the 'CELTIC CHASM'
(https://dl.dropboxusercontent.com/u/7464107/WP_20141105_012.jpg)
(https://dl.dropboxusercontent.com/u/7464107/WP_20141105_003.jpg)
(https://dl.dropboxusercontent.com/u/7464107/WP_20141105_006.jpg)
(https://dl.dropboxusercontent.com/u/7464107/WP_20141105_008.jpg)
(https://dl.dropboxusercontent.com/u/7464107/WP_20141105_011.jpg)
(https://dl.dropboxusercontent.com/u/7464107/WP_20141105_014.jpg)
Damn Rob, that baby looks realy cool!
Cheers man....yea i'm pleased with how this one came out.. :icon_cool:
have you sorted yours yet?...
Sweet. :icon_cool:
cheers marc... 8)
Aw come on Rob, you're making us mere mortals look incompetent ;)
:D ;)
Yes Rob, sorted it nearly.
The power supply sucks! Tried it with battery and its quiet.
Now only a little prob with the osc. But I had no time to look yesterday...
ok cool...
having a 'pop' issue with my build...hmmmmm
the fets/mosfet switching should eliminate any noise whatsoever, that's why its there ......(as it did in my diy pcb)
i'll poke around with grounds etc today....
How to wire the osc switch WITH led?
use a dpdt..
one side for switch , other side for led/s red on/green off maybe..
_ led+.....
_ 9v
_led+.....
join both - of leds to a resistor...then gnd. 8)
or stick your resistor from 9v to middle of switch...
or do it the other way with gnd going to centre lug...with leds reversed..up to you man.. :)
Thanks Rob.
I can only do paint by number... ;)
me too.. :)
LOL :icon_mrgreen:
sorted my pop issue... 8)
swapped the fets, silent as a mouse now..back to lush verb.. 8) 8) 8)
here's a drill template for the CHASM in case anyone needs/wants it to make life just that little bit easier.. 8)
SVG. file (inkscape)
https://dl.dropboxusercontent.com/u/7464107/CHASMTEMPLATE.svg
Nice, what about a drill template for the delay and trem? ;D
Ahhh, forgot, there is no pro pcb for the delay. Perhaps some day???
yeah, one day.... :)
i'll sort the trem one out ... ;)
Yep, I know, the delay thing was realy cheap... ;D
nice nice nice. now to make it work with btd-3h and stereo output... :icon_twisted:
How much mA needs the reverb? Could 100mA go?
Quote from: Maik on December 05, 2014, 12:07:52 PM
How much mA needs the reverb? Could 100mA go?
Probably. I think Rob uses a 100 mA regulator (78L05?) in his builds.
^ yep,
Thanks
Quote from: Maik on November 11, 2014, 08:59:05 AM
Nice, what about a drill template for the delay and trem? ;D
Ahhh, forgot, there is no pro pcb for the delay. Perhaps some day???
trem template is done.. ;)
I have a problem. I wonder if anyone can help.
I've built two pedals and the circuits have worked fine outside the enclosure but as soon as the jacks touch the enclosure the signal cuts out.
As I said , I've had the exact same problem with two DIY builds.
As you can imagine, I have no idea when it comes to electronics but I imagine there is a grounding issue, ye ?
BTW. I live in Spain, I don't know whether that makes a difference.
Matt.
Any chance you are using a metal DC jack? As pedals live in an alternative 'negative tip' world, these won't work and you end up grounding your V+.
+1...
Just answered your email. :)
just for the record:
matts problem was a tip pos supply... :)
How would I wire the OSC to a footswitch instead of a toggle? Do you think it would be more fun to have it be a momentary switch or latching? I can't decide :icon_wink:
I'm also slightly confused about how to wire the main on/off footswitch as well... I was thinking about using a little Millenium Bypass daughter board for the LED. Does anyone have a fairly straight-forward way to explain? I'm fairly new to all of this, so please excuse my noob questions. Thanks so much (in advance)!
Btw, I'm using v. 2.4 PCB (04/15/14)
@aiesha..,, give me a bit and ill knock up a drawing ok....
here ya go..
(https://dl.dropboxusercontent.com/u/7464107/chsw.jpg)
you could use a momentary or latching for the osc..,
connect 2 lugs on a dpdt (red)
/ /
/ /
/ /
Thank you, man! I really appreciate it. ;D
Btw, since there are pads for both foot switch and toggle... Would it be possible to connect both a toggle and the momentary switch? Or does one cancel the other out?
i would think they would cancel out..
Quote from: chi_boy on April 29, 2014, 10:50:25 PM
Rob,
This project was a lot of fun and I'm glad you're happy with the boards. Thanks for letting me in on the fun!
Well, I'm not the best photographer, but this is a little tease of how the boards look populated.
This is my first etched enclosure and I still need to work out the kinks, but I wasn't going to trash the enclosure because of a few pits. Gives it character, right?
Anyway, this is how she looks.
Cheers,
George
(http://home.comcast.net/~gprause/IMG_5761.JPG)
(http://home.comcast.net/~gprause/IMG_5763.JPG)
(http://home.comcast.net/~gprause/IMG_5766.JPG)
(http://home.comcast.net/~gprause/IMG_5767.JPG)
Quick question: I populated the PCB and I'm about to solder in the pots. However, I noticed that they have metal on them, and it would be a bad idea to do that without anything in between the back of the pot and the board! What do you guys use to isolate the two?
Quote from: SnoopKatt on February 11, 2015, 12:52:59 PM
Quick question: I populated the PCB and I'm about to solder in the pots. However, I noticed that they have metal on them, and it would be a bad idea to do that without anything in between the back of the pot and the board! What do you guys use to isolate the two?
EDIT: Re-read the question. It shouldn't be an issue if the back of the pots touch the board as the board has a solder mask, so as long as they aren't actually touching any leads it shouldn't be a problem. Another option is to get pots that have "pot condoms" on them that prevent any contact.
the toggle switch generally acts as a spacer too...
and like nathan said, pots with those plastic condoms are cool..
if your really worried about it touching though, and you haven't got condom pots
slip a strip of non conductive stuff behind there...ive used cut up vinyl cd covers, old tupperware tub cut up..
or a bit of packing foam. but really the toggle should leave an adequate gap.. ;)
Cool, I just gotta drill the holes and fit them. Thanks! My other pots have those condoms, but the 22k didn't :/
Cool, your fine then... 8)
Hello people!
I built a Chasm using Robs PCB, and I think it's working... I mean, is acting strange, but I get a nice reverb out of it....
What happens is this: when the MIX pot is about 75% to 100% CW, the dry signal is attenuated and the processed signal takes over more and more... that's normal. But it's lags behind the input signal for about 100ms, I reckon.
Here is a demo of what is happening:
I checked all the soldering, all the values of each position. They are ok.
Then I probed the signal and I found that the signal is OK until it hits on Beltons. It's output (pins 5 and 6) is a lagged signal, regarding the input.
Then I measured the voltages, and these are the results:
Quote
(https://dl.dropboxusercontent.com/u/7464107/chasmverb.jpg)
Voltages measured with
- circuit powered ON on footswitch
- OSC Off
- All pots @ max
V+: 9.17v
Va: 4.94v
Vb: 3.33v
Vc: 6.65v
Note: "~" means oscillating reading
Q1
D: 3.33v
G: 0.12v
S: 3.32v
Q2
D: 3.34v
G: -0.33v ~
S: 3.20v ~
Q3
D: 6.65v
G: 3.31v
S: 2.00v ~
IC1
1: 3.34v
2: 3.34v
3: 3.03v
4: 0v
5: 3.34v
6: 3.47v ~
7: 3.47v ~
8: 6.65v
IC2
1: 3.34v
2: 3.34v
3: 3.34v
4: 0v
5: 3.34v
6: 3.34v
7: 3.34v ~
8: 6.65v
Belton BTDR2H-L
1: 4.93v
2: 0v
3: 3.34v
4: 0v
5: 3.35v ~
6: 3.34v ~
I think something's wrong, but the only thing I can think of is that it's caused by a faulty brick.
But really, im not sure. Could you guys help me out??
thank you!!!
^when the MIX pot is about 75% to 100% CW, the dry signal is attenuated and the processed signal takes over more and more... that's normal.
Correct
^But it's lags behind the input signal for about 100ms, I reckon.
Also normal. That's what the brick sounds like without the dry signal mixed back in.
If you don't like it, add a 4k7 - 10k resistor in series with lug 3 of the mix pot, or replace the mix pot with a log 10k pot so that this only happens at the very extreme.
Edit - lug 3, not 1 of the mix pot (Fixed).
Thank you samhay!!!
So everything is working as it should.
Just out of curiosity, whan I was probbing I noticed that after R9 (and on pin 6 of IC2) there was no sound/signal, but on IC2 pin 7 (output) I got signal again.
Although this must be correct, could you be so kind and explain why that is happening?
Tks
Quote from: samhay on March 03, 2015, 02:52:14 PM
If you don't like it, add a 4k7 - 10k resistor in series with lug 1 of the mix pot, or replace the mix pot with a log 10k pot so that this only happens at the very extreme.
lug 1? not lug 3?
Good catch - sorry, that should be lug 3. Will update post, but the log pot recommendation still holds.
As far as the audio probe goes, here is half of the answer: the op-amp's inverting input (pin 2 and 6 in the TL072 package) has very low impedance and will try be be at the same voltage as the non-inverting input if DC feedback in applied (as it is here). The inverting inputs in IC1B, IC2A and IC2B can be considered to be at virtual ground as the non-inverting inputs here are grounded (well connected to VB). If you audio probe VB, you won't hear anything either.
Quote from: samhay on March 03, 2015, 03:19:23 PM
Good catch - sorry, that should be lug 3. Will update post, but the log pot recommendation still holds.
As far as the audio probe goes, here is half of the answer: the op-amp's inverting input (pin 2 and 6 in the TL072 package) has very low impedance and will try be be at the same voltage as the non-inverting input if DC feedback in applied (as it is here). The inverting inputs in IC1B, IC2A and IC2B can be considered to be at virtual ground as the non-inverting inputs here are grounded (well connected to VB). If you audio probe VB, you won't hear anything either.
Thank you so much for your time explaining this. Really appreciate it. :)
Now for some good news: I just soldered a 5K resistor to MIX pot lug3, and it works flawlessly!! So gooood!!!! :icon_lol:
Thanks again samhay!!
hi all, I have little knowledge of electronics and is the first pedal I'm trying to build, but unfortunately has pop when I press the button and the oscillation does not work.
thank anyone who can help me.
greetings .
Hi, for the pop issue, i had this on one build only, and i changed the fets and it cured it instantly
Hence why we always suggest socketing fets/IC's etc...
which switch did you use for the oscillation switch?... 2 lug spst?...3 lug spdt?
hello,
Thanks for the reply, I will try to put sockets on the board and I'll tell you if the pop disappears.
about the oscillator I'm using 3lug spdt .
sorry for my bad English , best regards .
Hi everyone.
First I wanna thank Deadastronaut for his incredible job. This reverb is just great and I can't wait to build it and most of all... use it!!. Actually this is my first diy project so I wanna ask you something:
- I read something about the bypassing of the signal when the pedal is off. Is this dude true bypass? If not, is it a big deal?
- What kind of wire should i use for the signals? The differences between shielded ones and not shielded are relevant for this project?
- Should I connect the entire enclosure to GND or just let it float?
- I read in your pdf that there is the opportunity of replacing the osc/off switch with a footswitch. How do i wire it? how can i add a led to it? I won't thank you enogh if you will be so patient to draw me a little sketch of the wiring diagram ::)
- About the BOM. Do you have any suggestion for the passives? Is there any filter cap?
I think that I asked everything i had to :D Thank you again and sorry for my bad english ;)
Quote from: toziano on April 22, 2015, 07:02:00 AM
Hi everyone.
First I wanna thank Deadastronaut for his incredible job. This reverb is just great and I can't wait to build it and most of all... use it!!. Actually this is my first diy project so I wanna ask you something:
- I read something about the bypassing of the signal when the pedal is off. Is this dude true bypass? If not, is it a big deal?
hi, this is a buffered bypass reverb, this allows you to have ''tails'' when bypassed, if it were true bypass it would stop abruptly...which imo is nasty ad not very 'live' friendly..
buffered v's true bypass is a bit of a weird purist thing really, myself i quite like buffered bypass , especially at or near the end of my chain..
others may not...but to me its fine..no big deal at all..
- What kind of wire should i use for the signals? The differences between shielded ones and not shielded are relevant for this project?
no need for sheilded wire, sheilded is mainly used in high gain circuits...distortions etc
- Should I connect the entire enclosure to GND or just let it float?
it will be grounded through the jacks etc...
- I read in your pdf that there is the opportunity of replacing the osc/off switch with a footswitch. How do i wire it? how can i add a led to it? I won't thank you enogh if you will be so patient to draw me a little sketch of the wiring diagram ::)
- About the BOM. Do you have any suggestion for the passives? Is there any filter cap?
the filter caps (electrolytics) are in the design..
[/list]
I think that I asked everything i had to :D Thank you again and sorry for my bad english ;)
your english is fine man...no worries.as this is your first project i would keep it simple for now, get it working and tested out of the box first and we will go from there
with the ''optional footswitch ok.....rob.
Thank you rob, i'll follow your lead ;D
I'm doing the bom right now.. so excited!!
cool.. yeah its a great reverb man.. 8)
Hi everyone,
New here and I'm still working my way through reading the thread but figured I'd ask anyway. Not sure if this has been answered.
First off I know there is a lot going on inside the box (4 pots, switches, the brick and the board itself) but has anyone tried running this off a battery / tried fitting one in the enclosure?
Thanks for the help!
It will work with a battery for a little while - perhaps 1-10 hours depending on the type of battery.
Thanks Sam! I didn't really doubt that it would work just wondering on battery life and if anyone had any experience with it. Personal preference but I like building both options into my pedals. So just curious.
Quote from: deadastronaut on March 28, 2015, 03:11:04 PM
Hi, for the pop issue, i had this on one build only, and i changed the fets and it cured it instantly
Hence why we always suggest socketing fets/IC's etc...
which switch did you use for the oscillation switch?... 2 lug spst?...3 lug spdt?
thank you very much deadstronaut the pedal works very well , it is true change the FETs remove the pop so I take this into consideration in the next pedal job , besides this pedal is a awwesome project i am very happy bye.
Cool..glad it got it sorted man... 8)
I built the pedal and it sounds great! But on the second day the OSC switch stopped creating feedback and instead shortened the decay time to 0% (which stopped the decay pot from moving.) The pedal still works fine when the OSC is off, but are there any ideas on what could be wrong?
Ive followed the schematic with a Multimeter and it all seems to be fine, and double checked the values of R11, R12 & C8. But still no dice! Any tips?
I guess the obvious would be to check the switch....
if it worked , then it suddenly didn,t, it may be that...
or a short out somewhere...
Hello everyone! I am new one this forum, but i have been reader over one year. Ok now I have litlebit problem whith Chasm reverb. Out signal is very low to amp. Pedal is working As It shud be. I have TL074CN on IC1 problem? Great pedal very Nice reverb but so quiet :icon_biggrin:
Spring is finaly in Finland.
you made a diy pcb then?...
Got my pedal working by the way rob! Just had a crappy soldering job on R11. Thanks for you help, sounds great!
cool...glad you got it sorted man.. 8)
Jep I make diy pcb.
howdy! the pedal was sounding awesome but now the signal when bypassed (and when on) sounds overly distorted in a nasty way. could this be one of the ICs/transistors?
>howdy! the pedal was sounding awesome but now the signal when bypassed (and when on) sounds overly distorted in a nasty way. could this be one of the ICs/transistors?
Yes - it's not true bypass so there are a couple of op-amps and a MOSFET in the dry signal path. Did something happen to it / change before this problem started. Is it still getting 9V?
Thanks sam! I only finished assembling it today and it dropped in and out of the distorted sound (from a normal operation) and eventually stayed distorted after a few minutes! I'll check voltages on the op amps. Is there an easy way to test the Transistors with a multimeter?
Cheers
Are you powering it with a battery?
If so, this won't work for very long and you need to find a power supply.
If you are running from a power supply and it died after a few minutes, check the orientation of your electrolytic capacitors and look for a broken wire or cold solder joint.
I have a volume drop when engaging the pedal ??? I have checked the polarity of capacitors, diodes, solder bridges etc...
I have used TL072BCN instead of TL072P, is this causing it?
Just finished mine up this morning. Thanks for the GREAT circuit!! I love it.
(http://img.photobucket.com/albums/v215/SlaveUnit/20160205_101115_zpsvpntfbz7.jpg)
(http://img.photobucket.com/albums/v215/SlaveUnit/20160205_101202_zpslatrrhpx.jpg)
(http://img.photobucket.com/albums/v215/SlaveUnit/20160205_101221_zpshzskiqmt.jpg)
awesome....love the ufo design.... 8) 8) 8)1
Nice build.
i built this, awesome reverb :D But my 78l05 is kinda warm, should i concerned about it? Maybe i can change it to 7805? Also how much current chasm reverb uses? İ don't want to destroy my belton, its quite expensive for me, thanks :)
The Belton brick has 3 PT2399s in it. The data sheet for the PT2399 shows typical current draw of 30mA, and max of 40mA. Based on that, the brick could be expected to draw 90mA, and up to 120mA would not be out of specification. The 78L05 regulator is rated for 100mA. IMHO, it would be better to use the device with a higher current rating (the LM7805), which has a current rating of 1.5A. Many have built Belton brick based reverbs using the 78L05, perhaps the Belton brick draws significantly less current than the 3 PT2399s it is constructed of would lead you to believe, or lady luck has been smiling on them, or they haven't burned a finger on their regulator yet.
Quote from: Cozybuilder on April 01, 2016, 07:03:44 PM
The Belton brick has 3 PT2399s in it. The data sheet for the PT2399 shows typical current draw of 30mA, and max of 40mA. Based on that, the brick could be expected to draw 90mA, and up to 120mA would not be out of specification. The 78L05 regulator is rated for 100mA. IMHO, it would be better to use the device with a higher current rating (the LM7805), which has a current rating of 1.5A. Many have built Belton brick based reverbs using the 78L05, perhaps the Belton brick draws significantly less current than the 3 PT2399s it is constructed of would lead you to believe, or lady luck has been smiling on them, or they haven't burned a finger on their regulator yet.
İ played like 1 hour today , ver slightly warm, i think my hands were too cold last night, but i should give any chance that regulator to get hot, its time to make a space for that big ass regulator, any body ekese had that kinda suspicion? Or 78l05 is just good forever? Thanks btw mate :)
Quote from: Cozybuilder on April 01, 2016, 07:03:44 PM
The data sheet for the PT2399 shows typical current draw of 30mA, and max of 40ma.
This Princeton Technologies PT2399 data sheet lists supply current as:
typ max
15ma 30ma
http://www.princeton.com.tw/Portals/0/Product/PT2399_1.pdf
The Belton BTDR-2 & 3 data sheets list the supply current at:
typ max
60ma 100ma
Also of note:
The BTDR-2 is comprised of 3 PT2399s, a TS321, (single op amp) and a 74HC14, (Schmitt trigger)
The last two ICs draw current in the µA.
It seems there is more than one data sheet for the PT2399. I took my data from the full data sheet from June 1998, the table on p.6.
http://www.diyaudiocircuits.com/wp-content/uploads/2012/09/2399.pdf (http://www.diyaudiocircuits.com/wp-content/uploads/2012/09/2399.pdf)
Still, from an engineering view do you want to use a regulator that has a 100mA rating to power a chip that has a 100mA spec? If cost were a consideration, the LM7805 is currently $0.23, while the 78L05 is $0.09. My pedal and peace of mind knowing that the regulator will perform on a hot day is worth spending the extra 14 cents. Size? I fit it all in a 1590A, including the LM7805. Surely it will fit in a larger enclosure.
I wonder if the IC was redesigned for better efficiency over the span of 12 years from 1998 to 2010. :icon_question:
Quote from: armdnrdy on April 02, 2016, 10:22:25 AM
I wonder if the IC was redesigned for better efficiency over the span of 12 years from 1998 to 2010. :icon_question:
Probably.
Still, the Brick specs 100mA.
Looking into this a bit further...
I took a measurement of one of my reverb builds.
The draw was 89ma! (unboxed, no LED yet)
This circuit used a BTDR-3 and was fashioned after the BYOC reverb 2. (with a tone control)
Thanks Cozy for bringing this to our attention.
All of the reverb brick projects use a 78L05. :icon_eek:
>All of the reverb brick projects use a 78L05.
Not mine, but then I only use the TO-220 regulators these days.
But to muddy the water, I have measured current draw by BTDR-2s in the 60's mA, which is pretty safe for a 'L' model regulator. This is also the 'typical' value in this data sheet: http://www.accutronicsreverb.com/main/?skin=sub01_05_1.html
Also, your build will also have a couple of dual op-amps and associated gubbins that will be eating maybe 10 mA that isn't going through the voltage regulator, so you're not flying that close to the sun.
my regulator 78l05 stays cool...no issue there....hmmmm...
Quote from: deadastronaut on April 03, 2016, 10:14:32 AM
my regulator 78l05 stays cool...no issue there....hmmmm...
Maybe my regulator is not rated 100mA, i have 7805 brand is Kia, it says it's rated 500mA, i think it should be okay, i'm using layout v1.6 btw. You sir, you are awesome, i played 5 hours of Pink Floyd with that pedal :D Cheers.
cool, glad you enjoy it..
thank the guys on here too...particularly samhay..
he helped a great deal on it...and prevented my usual 1000 page thread ;) 8) 8) 8)
Quote from: deadastronaut on April 03, 2016, 01:01:19 PM
and prevented my usual 1000 page thread ;) 8) 8) 8)
I saw what you did there, Rob! You started a new page! ;D
ha ha.... got ya!!!... ;D
977 to go... :icon_rolleyes:
we could always post 12,789 pictures of sausages... :icon_idea:
Or one sausage with loads of Chasm reverb :)
Not sure how I feel about standing between Rob and another 1k page thread, so I will join in to...
Quote from: deadastronaut on April 03, 2016, 04:34:32 PM
we could always post 12,789 pictures of sausages... :icon_idea:
Now you're talking. :icon_cool:
Hello again, can you explain to me what "damp" control actually does :D Sorry for noob question, half deaf here :D
hi, it acts as a tone control....cutting highs, etc....
Quote from: deadastronaut on April 04, 2016, 11:40:51 AM
hi, it acts as a tone control....cutting highs, etc....
Thanks mate, btw i put "kia 7805" regulator, its still kinda warm, not hot to not touch but its warm, maybe its because of it has more metal area to give away heat? My chasm reverb draws about 60mA, 65 with all pots full with bright white led, is that normal? İ don't have any short circuits in my pcb, i checked it 10 times, all voltages are normal, tl074's legs about 4,3-4,5v, when i swtich to osc, leg 3 is 1.87 volts same as j201's source, drain is same as the tl074's voltages, everthing works perfectly but i dont want to destroy my belton :D
Thanks.
>My chasm reverb draws about 60mA, 65 with all pots full with bright white led, is that normal?
That sounds about right.
Quote from: samhay on April 04, 2016, 03:00:26 PM
>My chasm reverb draws about 60mA, 65 with all pots full with bright white led, is that normal?
That sounds about right.
Yeah its normal but its kinda weird that my 7805 gets warm :D warmer than 78l05 :S
You did put it in the opposite direction to the 78L05? The pinouts are mirrored: 78L05 = OGI, 7805 = IGO.
(http://i1160.photobucket.com/albums/q485/jdansti/B0AC3708-D77E-44E2-A685-F6DD132DA63C.png)
(http://i1160.photobucket.com/albums/q485/jdansti/8EDA05DA-1640-41E9-93E7-283A47AEB976.gif)
Quote from: bluebunny on April 04, 2016, 04:29:58 PM
You did put it in the opposite direction to the 78L05? The pinouts are mirrored: 78L05 = OGI, 7805 = IGO.
Yeah reversr Pinout, i put in reverse, got warm, i tried the iç before putting into thr pedal, have me around 5.06 v without load, then i put it on the pedal, i get thre same values, pedal working awesome as always , but it was warm @65mA i put thr 78L05 again,
The 7805 still has to dissipate as much heat as the 78L05. However, you may notice this more with the 7805 if you touch the heat sink - the metal will likely feel warmer than the plastic.
use it to keep warm... ;D
Does it warm up the sound?
If it gets hot enough, will it produce mojo smoke? Or glow enough to replace the LED?
I've got my coat.. ;D
Feel the "Bern"! :o
Hand me mine too, stallik...
Hello again folks, i'm having some problems again :( My friend wanted chasm reverb to use it on a record, everything is good till this point. He send me a soundclip : http://s000.tinyupload.com/index.php?file_id=07927315184193377675 and he told me when he open up the reverb knob that sound appears. Also he told me he watied fo 2 hours and plugged the pedal in , played a little then that sound again :( İm suspacting about regulator (78L05) , hope he didn't destroyed the brick. Any ideas? Btw, when i made the pedal i checked every value, every voltage, every polarity before running it for the first time, we can be sure there is no solder joints etc. pots wired correctly. Also there is no straching noise, like brick clipping. Maybe he used the pedal with ossilation swtich on all the time? Mayve pt2399's locked up? Thanks.
First post, novice here:
Before I start, thank you for the design! It's my 6th pedal so far, and my most ambitious to date.
I'm curious if anyone has used a btdr-3 with this circuit. I have, and I'm getting a lot of noise with the depth control. If I increase the depth (dual 10k pot), a white noise creeps in. If I crank the damp control, that reduces it, but my understanding is that it's just bleeding off some highs. Keeping the depth low gets rid of most of the noise. Has anyone encountered this? Further this noise comes through even if the circuit is being bypassed, and if I've got the depth set to max with the osc on, it will start to feedback even when if the circuit is disengaged. I've tried battery power to no avail (was hoping it was just a dirty power supply).
Otherwise, I think I have the full thing working. All knobs and switches function as advertised. It's a vero board build, so no gut shots because it's hideous in there.
Thank you,
DK1
(http://i.imgur.com/SIeAkLCh.jpg)
im about to start on this one, can somebody give me a size reference as im using a plotter to cut a vinyl mask for the pcb and want to check that i have scaled it right.
Quote from: DK1 on May 28, 2016, 06:57:52 PM
I'm curious if anyone has used a btdr-3 with this circuit. I have, and I'm getting a lot of noise with the depth control.
As a follow up, I checked in with Belton, and received this (edited) response.
"With the BTDR-3, it is normal for the noise level to increase with an increase in the depth control. If the noise is too high, the circuit may have too much gain in the recovery circuit for the reverb. /Hyun Park"
Helped me feel a little better about the issue, and perhaps helpful if anyone else tries the BTDR-3.
DK1
I have a reverb on the breadboard that uses a BTDR-3 and dual 100k pot driving the brick's depth control. I hear no significant white noise at any point on the depth setting.
The depth control of the BTDR-3 appears to set the amount of feedback around the brick - i.e. from somewhere near the outputs back to the input. There is no such feedback in the BTDR-2 brick, so this is part of the circuit in the CHASM and other BTDR-1/2 designs - via the feedback/decay control. If you turn this fully ccw, does that help with the noise as you turn the brick's depth control up?
Quote from: samhay on June 01, 2016, 03:00:43 PMIf you turn this fully ccw, does that help with the noise as you turn the brick's depth control up?
No. It doesn't really interact with the decay control. The decay control seems to be very subtle. I really only notice it when I've got the osc on, where it really impacts the feedback. I'll recheck that part of the circuit to make sure I have no errors.
Thank you,
DK1
I did notice like a white noise "blow" as well, but only with headphones; when playing straight to my amp I can´t hear that noise, so no complaint.
My problem with it happens when the chasm is off...
It works great: The reverb is lush and versatile, the buffer is completely transparent to my ears, and I´ve got trails. The strange thing happens when the chasm reverb is off and then I turn my naga viper booster on in front of it. The booster is set so there is a bump in volume, and when that happens, that increase in volume level seems to trigger the reverb for a while, (when the chasm is off as I said before...).
It didn´t happen all the time, only when I´ve got the boost on and I hit the guitar really hard...
Any idea?
Quote from: DK1 on May 28, 2016, 06:57:52 PM
(http://i.imgur.com/SIeAkLCh.jpg)
Maybe I missed something on earlier posts, but what is that depht knob about? My chasm build only have 4 knobs, (level, mix decay, and damp), and the oscillation switch...
Quote from: traktop on June 02, 2016, 09:14:53 PM
I did notice like a white noise "blow" as well, but only with headphones; when playing straight to my amp I can´t hear that noise, so no complaint.
My problem with it happens when the chasm is off...
It works great: The reverb is lush and versatile, the buffer is completely transparent to my ears, and I´ve got trails. The strange thing happens when the chasm reverb is off and then I turn my naga viper booster on in front of it. The booster is set so there is a bump in volume, and when that happens, that increase in volume level seems to trigger the reverb for a while, (when the chasm is off as I said before...).
It didn´t happen all the time, only when I´ve got the boost on and I hit the guitar really hard...
Any idea?
I've noticed something similar. I think that's just a side effect of having tails instead of hard bypass. With my white-noise issue, I can get feedback from the OSC loop even when the effect is "off". If I flip the OSC switch, it goes away... again, even with the effect off.
Quote from: traktop on June 02, 2016, 09:18:41 PM
Maybe I missed something on earlier posts, but what is that depht knob about? My chasm build only have 4 knobs, (level, mix decay, and damp), and the oscillation switch...
Yup. I used a BTDR-3, which has 4 extra pins compared to the BTDR-2. Those are wired to a dual gang 10k pot to control depth within the brick itself, so it requires no modifications to the pedal circuit otherwise. After doing it, I think it's not worth the trouble, but I wanted to give it a shot for fun. Pure speculation: I think probably adjusting the value of the dual pot or the OSC resistors might be required to make it play well in the circuit. With both the Decay and Depth knobs as I have them, the Decay only varies the "echoes" slightly and the strength of the OSC feedback in my pedal. Most of the effect control comes via the Depth knob. YMMV, and I'm square out of my knowledge depth discussing such things. I just used the 10k dual gang suggested in the Belton datasheet.
Another follow-up from Belton, re the BTDR-3 here:
QuoteA feedback loop has been added around it to increase the depth, but it can also lead to instability and unpredictable behavior. This module was not designed for this application. The TL074 (DK1 note: I used a TL074 rather than two TL072s) is a bit noisy, and the resistor values chosen will increase the noise as well.
Having two TL074s in the feedback loop will increase the noise as the depth control is increased.
That said, the simplest suggestions I can offer are:
-Try replacing (with a) the BTDR-2. Some are quieter than others.
-Try replacing the TL074 with a TLC2274.
I hope it is helped for you.
Have a wonderful day.
Best regards/Hyun Park
So,yeah, the BTDR-3 is probably not worth it. I might eventually fiddle with it to see if tweaking the Depth pot value(s) helps, but mine works well enough for now and still sounds good.
Thanks,
DK1
I was wondering if there is a way of turning the pedal switching system to true bypass like the prismatic/allstar reverb, I mean, bypassing the buffer completely.
Just finished and tested my first board worked first time :icon_mrgreen: sounds great, built as per pdf build doc only change is a 25k pot replacing the 22k, just got to design box and fit up, great work deadastronaut !!!!
excellente'... 8)
look forward to seeing your build...
uk is 22k / usa 25k... not a lot in it.. 8)
Reverb is all boxed up working well,
Have found an a slight thing ... Get it all set and playing away through amp only in a clean channel, if you then switch to dirty with the amp over drive the reverb becomes too much and needs adjusting down but then go back to clean and the reverb is non existent can't seem to find a happy medium.
On a side note can some one confirm the Spdt toggle I'm supposed to be using is it (on - on) or (on - off)
Thanks dan
on off IIRC....
thats a weird issue.....
the output should be the same regardless....
have you tried it in your amp loop?
Thought you were gonna say that :-[ I'll change the toggle for the right on then.
I was running it guitar to pedal into amp combo as I say clean is perfect but switch to dirty on amp and it is too much I'll try and get a clip of the two if I can a post it
your pushing reverb into a distorted channel...
thats like putting delay before distortion...it will be more boosted.
have you got an fx send return on your amp? try it through that.
before you swap the switch..
I'll check tonight, just looked for the toggle can you link to the right one somewhere all on off ones only have 2 pins and there's 3 on the pcb sorry still learning :)
my signal : guitar-dist-reverb-delay....amp clean channel.
your signal: guitar reverb/delay ....dist on amp channel.
it will sound weird..
heres mr wampler demoing that very issue...around 4:50.
https://www.youtube.com/watch?v=dAWxd2bES_s
you want on/off SPDT. (3 lugs) Double throw
not SPST. (2 lugs) single throw.
Ok just watched, makes sense now I'll re locate the pedal, one other check point the I have wired the foot switch as per your build doc, for wiring the led does it matter if I connect ground to lug on Dpdt and live to the fs1 point on the pcb as I have more room to connect there
yep should be ok... 8)
another vid: using fx send/return..
https://www.youtube.com/watch?v=r9BrW9AGrJ4&t=0s
No problem, :) tbh I'm surprised I've built this as my first ever pedal and these are the only issues! I'm am now feeling that I'm either being really stupid or ....
With the toggle I cant see an on off only, these are what I'm looking at
https://flic.kr/p/JCGNqE
oops...on off on... ;) middle one 'll do ya,..
youve done well for a first pedal man... cool.
a baptism of fire,. :icon_twisted:
Ahhh.. And the penny drops lol, to any noobs chasm is a cool first project and with amazing results I am proof anyone can build, roll on graphics
So atm I'm using the top one (on-on) what difference is this going to make cant work out the trace on the pcb
Let´s see if you can help me on this one.
My chasm reverb is working beautifully.
My problem started when I hooked it to one of the boss es-8 loops. Every time I insert the chasm reverb loop on the signal chain, (the effect itself remain on all the time), I hear a loud pop followed by its own reverb trail, (without even playing the guitar), thing that don´t happen even with my cranked big muff and my other drive pedals. I tried in different loops, (and different cables of course), and every time I insert the chasm, that pop sound appears.
Any Idea?
Cheers, Gilberto.
hmmmm....
it stays on all the time? in a loop...
but its working fine on its own, or not in a loop?
Quote from: deadastronaut on July 13, 2016, 04:35:52 AM
hmmmm....
it stays on all the time? in a loop...
but its working fine on its own, or not in a loop?
The pedal remains on all the time when I use it inside a boss es-8 loop. The pop sound appears when I turn the chasm loop on, (thing that don´t happen with any of my other pedals).
On the other side, the chasm switch is working fine on its own. The dpdt on/off switch works smooth without any kind of noise or "pop" sound that others experienced due a faulty 2n7000. The only strange thing I experienced lately, (inside a es-8 looper or by itself), is that being the Chasm reverb off, when I increase the signal level of my guitar with a booster for soloing, (in front of the Chasm), that rising in level seems to trigger reverb splashes on the hardest picking parts. All this happens with the chasm reverb disengaged... So Time for a 2n7000 swapping maybe...?
(The reason I didn´t do it yet is because my transistor shockets wear way fast, so I wanted to consult what to try first).
Cheers, Gilberto.
Replaced like ten 2n7000s, with same result.
One thing I noticed is that I used 2n5458s instead 2n5457s, but made a research and seemed that they are pretty much interchangeables.
im not sure whats going on there with the boss es8..
i just had a quick browse at it..
apparently it has switchable buffers on/off...not that it should make a difference
but have you tried it with the internal buffer on and off?...just curious
so your chasm is working fine without this es8 loopy thing?.
I use to have the output buffer on, but I tried without buffers with same result.
I tried the chasm in all es-8 loops and every time I introduce the chasm reverb on the signal path, (when the es-8 is feeding the chasm with the guitar signal), the pedal makes a loud "pop" sound.
By itself, the chasm works smoothly outside the es-8, with no noises related with the switching system. The only problem that persists, (even outside the es-8), is that when the chasm reverb is off, if I throw a booster or any other pedal with a volume boost, (about 4dbs), before the chasm, this increase in signal volume triggers splashes of reverb when reaches certain threshold. This issue is inherent to the pedal, (by itself, or inside a es-8 loop), and happens even after I replacing a bunch of 2n7000 and 2n5458s.
hmmmm...
all i can suggest is maybe a wrong value on the chasm board maybe...
this might be the issue,
I will take a deep look at it.
Cheers, Gilberto.
I checked the board and everything seemed ok.
The only thing that differs is that I used 2n5458s since I didn´t have 2n5457s available as I mentioned before. I thought they were pretty much interchangeables, but a deeper research showed a difference on average Vp's of 2.5V vs 1.5V respectively, (I really don´t know what that means though...), so maybe that could be the cause of wet path fet don´t switching properly with a higher than average signal voltage coming from my booster¿?
A different option could be trying a 3pdt switch, using the third pole to dump the wet signal to ground just before going into the 2n7000, (for example).
I´ve been thinking about the pop sound when into a es-8 loop. Do you think that circuit behaviour could be improved with a pulldown resistor on this specific scenario?, (and where to insert it).
Cheers, Gilberto.
I found a schematic that shows no pull-downs on in or out. I would add some.
Fit from 2M2 to 10M (highest in that range that you have) from PCB signal in to ground. 100k from PCB signal out to ground. Depends on your build where it's easiest to fit them - on the pcb or the jacks.
Higher FET threshold could be causing bleed thru grief at the switches when signal level is high. Check your 9V supply and +UB voltages first.
Thanks.
I will add pulldown resistors, but don´t 100k resistor to ground at the output would be too low of a value?
My 9v supply reads exactly 8.98v.
I don´t know what are +UB voltages. You mean fets and tl074 IC?
100k would be fine. The output op-amp can drive a low impedance and the output cap is large. 1M will work too.
Do you have access to the schematic? +UB is the reference voltage used by the op-amps and also the bias for the FET's. The difference between +UB and the FET gate control from the footswitch determines how well the FET switches are turned on or off.
+UB is I believe, produced at the junction of 2 10k resistors close to the +9V input before the 5volt regulator. You should get close to 4.5V there. You can also check for a similar voltage on the drain and source of the FET's and on the outputs of the TL074 amps (corner pins).
I found some info on this page...
http://www.coda-effects.com/2016/02/dead-astronaut-fx-chasm-reverb.html
R23 & R24 junction is UB.
Also check FET gate control voltage across C14 & C15. It should be very close to +9v or 0v depending on footswitch.
Pulldown resitors were not included in this build as it is not designed to be true bypass. As Jim said, 100k or 1M on the output would be a good idea to stop popping when you switch it on/off and if that doesn't help, try 1-10M on the input too.
I would guess that the Q1 JFET is the problem regarding signal bleed-through. A better choice (and cheaper) than 2N5457 here would be a J112 or similar (N channel switch rather than amplifier). But as Jim said, make sure the FET switch is working properly and pulling the gate to 9V and ground.
I had an idea to help us use high pinch off JFETs as signal switches.
What if, assuming N-channel, the signal input to the switch also drove a negative voltage diode charge pump. This supplies the gate "off" switching instead of 0V. When the signal swings down towards 0V, the pump charges the gate control more negative, maintaining the off state. Would that work? Has it been done anywhere?
Sorry, I´ve been out for a while.
I´ve just measured Q1 and Q2 gates at their respective electrolitic caps, and this is what I´ve found:
Q1: Sw.On: 8.98v---Sw.Off: 0.08v
Q2: Sw.On: 0.08v---Sw.Off: 8.98v
Measured the output of the transformer and reads 5.00v.
Readings seemed ok, right?
Yes, those gates are ok.
hi everyone, I have decided to wire OSC selector to a foot switch and I would like to have some sort of indicator (LED light) to show me that I am in the oscilator mode. How can I make it? Cheers and big thanx to Dead Astronaut for a great reverb pedal!
hi, use a dpdt footswitch,
one half switches the osc..on/off
the other half used for led...
8)
(https://dl.dropboxusercontent.com/u/7464107/ledswitch.jpg)
thank You so much Sir ;)
your very welcome....have fun. 8)
once again BIG BIG thanks, thing is fixed now, and works like a charm! During Saturday band session we will fly up on the Moon ;) ;D
cheers, have a great flight....watch out for a little russian dog floating about... ;D
Hey. New on the board and not sure if anyone is still on this thread at all but figured I'd check. Currently putting a chasm together (super excited to get playing on it) and just thought I'd see if anyone has a wiring diagram. I'm sure I'll figure it out just seeing if could save myself a little headache as I always seem to mess something up while wiring. Thanks!
Hi, yes were still alive.. ;D
there is a pdf on my site with switch wiring...
Look below ...
rob
Thanks rob! Can I be needy (I'm obviously a novice at this) and ask to see if you or anyone else out there has a diagram or detailed gut shot of the full wiring including jacks and power? Sorry to be a pain in the butt. Thanks!
Quote from: Mrchroni on March 04, 2017, 01:43:04 AM
Thanks rob! Can I be needy (I'm obviously a novice at this) and ask to see if you or anyone else out there has a diagram or detailed gut shot of the full wiring including jacks and power? Sorry to be a pain in the butt. Thanks!
Here's one on page 4 of this thread: http://www.diystompboxes.com/smfforum/index.php?topic=105109.msg950530#msg950530
There may be other examples within this thread.
Cheers john, 8)
if i get a mo later i,ll knock something up too ok......you needy bugger ;D
wiring guide. a little late, but dropbox changed the way they let you link ...the bstds. :icon_rolleyes:
(https://s5.postimg.org/cyr72t24n/CHASMWIRING.jpg)
I just finished building my chasm reverb and it worked for about 5 minutes then all of a sudden it started making this really loud, distorted noise that was so loud I had to turn the amp off. Any ideas on why this might be happening?
Check your 5v reg is around the right way...
voltages, and pictures will help.
https://www.dropbox.com/s/on5fhhjvzarrzld/IMG_6558.JPG?dl=0
https://www.dropbox.com/s/97j4pg56v0u0j5w/IMG_6559.JPG?dl=0
Add your toggle switch....
its soldered in with these cables
https://www.dropbox.com/s/7cj556sh9y37w56/IMG_6560.JPG?dl=0
Yep thought so, flip that reg around...
the 7805 is opposite to a 78l05.
edit:hopefully you haven't damaged the brick...fingers crossed
shit :/
I flipped it round and the light still comes on but sounds the same, just like a really overloaded sound that increases when I turn the volume pot up. Sound doesn't change when I turn up any of the other pots though...
hmmmm....shit indeed. :-\
basically you have fed 9v into a 5v brick...oops!!!. not good..
do you have 5v going to brick pin 1 now then?.
Yea I pulled out the REG1 and soldered it back in the right way but worried I might have fried the brick :(
lets have a look at your board...
full pic of all components please...
https://www.dropbox.com/s/kuqe1m7knxtn052/IMG_6563.JPG?dl=0
EDIT; one of the legs of the REG1 snapped so i just soldered them to the board with wiring
any pics of the underside?
Is an etchable pcb still available? I got one of DA tremshifters a while back,,,i messed it up real good lol,, little later i was able to solder messed up joints to the traces..sadly it cuts in and out. I need some reverb bad now
why not just buy a fabbed board
moneys to tight with the cost of the brick, plus enclosure etc...i support DA, i bought a tremshifter from him even though theres an etchable layout on effectslayout site. Think im just gonna grab this used beheringer digial reverb locally off craigslist for 20 bucks. When i have more money ill order one a pcb, did u buy one?
ye i got 1, cool board
Was just thinking on gcols problem,
if you feed 9v into the 5v side of a 7805 what comes out of the 9v side ? ...hmmm..
just thinking about his brick
Quote from: deadastronaut on May 13, 2017, 04:37:35 AM
Was just thinking on gcols problem,
if you feed 9v into the 5v side of a 7805 what comes out of the 9v side ? ...hmmm..
just thinking about his brick
I think that will probably just fry the 7805. They can be rather fragile voltage wise.
cheers nathan, yeah thought it wouldnt be good, but you never know eh..
so he is best off replacing it..and may have fried his brick then??....
Quote from: deadastronaut on May 13, 2017, 01:16:40 PM
so he is best off replacing it..and may have fried his brick then??....
Unfortunately yes. Regulators are cheap but when they go the brick often follows. In my experience if you hit the wrong pin of the 7805 with 9V in the regulator shorts and basically turns into a wire, which means you're getting 9V to the supply of the Belton brick, which can quickly turn a reverb brick into a literal brick :-\ And yes, this is from experience :-[
oops!..from the horse's mouth then...cheers nathan,
i'll prob sacrifice a 78l05 just for the laugh...n test..
Quote from: deadastronaut on May 13, 2017, 04:09:24 PM
i'll prob sacrifice a 78l05 just for the laugh...n test..
Video please, Rob. With all the post-production trimmings, of course. :D
Hi all,
Can someone please confirm the oscillation switch is either a:
a) on-off-on SPDT, and if so, is there a funciotnal difference between to the two "on" settings; or
b) on-off SPDT.
thanks
hi philty,
i used an SPDT ''on off on''
but you can use an on/on..
there are no functional differences.
If I wanted to wire the Chasm permanently on, do I need to do anything with the fs1 and fs2 pads? eg: jumper them
You need to wire one to 9V and the other to ground (in order to turn on and off the respective JFETs). I'm on my work PC, so I don't have access to any schematics or diagrams, so I can't say which is which. But Rob will be along shortly to clarify. But don't short just short FS1 and FS2 - it won't do anything.
I think I worked it out from the schematic - fs1 to 9v and fs2 to ground. Appreciate confirmation of this Rob.
The decay control in osc-off doesn't change anything, but changes a lot in osc-on, where it really impacts the feedback. How should I fix it? Thanks.
I'll be starting a Chasm Reverb build in a few weeks, but I'm wanting to add a 'Hold' feature to the circuit in order to play bypassed notes on top of the trailing reverb effect (essentially have the reverb effect continue (pedal still switched 'on'), but play clean notes that bypass the reverb effect while a momentary switch is depressed). Is this possible with the addition of SPDT momentary switch at the beginning of the effect circuit or should another method be utilized?
Any insights or suggestions on how to achieve the above are appreciated!
The Chasm already does "tails", so when you hit the bypass switch, whatever's "in there" will reverb away naturally while anything you play subsequently won't be affected. If you really want it to "hold", then I guess you could make the OSC switch stomp-able - stomp OSC to set it going, then stomp bypass so you can play over it.
And welcome. :)
...in fact, Rob does exactly this (albeit using the normal toggle switch) about six minutes into his demo on page 1.
Quote from: bluebunny on November 09, 2017, 12:48:04 PM
The Chasm already does "tails", so when you hit the bypass switch, whatever's "in there" will reverb away naturally while anything you play subsequently won't be affected. If you really want it to "hold", then I guess you could make the OSC switch stomp-able - stomp OSC to set it going, then stomp bypass so you can play over it.
And welcome. :)
Thank you bluebunny. Yes, the example Rob plays at the 6min mark in the demo is exactly what I'm looking to achieve, but with the addition of a second footswitch (momentary) to temporarily bypass the reverb instead of using the ON/OFF switch. If I understand you correctly, it sounds like this would be possible to achieve with a Normally Closed switch wired into the OSC switch (toggle OSC switch + NC momentary footswitch).
(and apologies in advance for any comments that may seem rhetorical... I'm a novice and trying to learn more about pedal schematics)
> it sounds like this would be possible to achieve with a Normally Closed switch wired into the OSC switch (toggle OSC switch + NC momentary footswitch).
No, that won't do what you want. It will just reduce the depth of the wet effect.
Because of the slight peculiarity of the switching, paralleling a second momentary switch won't work.
You could replace the footswitch with a DPDT relay and switch this with any combination of momentary or latching switches.
Or, if you wanted to make it true bypass, you could use a latching switch for true bypass and a momentary switch to do the (momentary) tails bypass.
Quote from: samhay on November 09, 2017, 03:32:58 PM
Or, if you wanted to make it true bypass, you could use a latching switch for true bypass and a momentary switch to do the (momentary) tails bypass.
samhay,
Can you help me understand how to appropriately implement the true bypass option? I've been staring at the chasm switch and circuit diagrams as well as 3PDT true bypass examples all day and I'm starting to go cross-eyed... ???
^
Treat 'IN' and 'OUT' as any other circuit input and output and wire to a 3PDT (or DPDT with e.g. Millenium bypass) as per usual. You then wire the standard Chasm on/off switch, which will switch in wet signal when you depress. If this is momentary, I would have thought it will be a PITA for most applications as you will only get reverb when you hold down the switch.
True bypass may also cause switch popping as you don't have pull down resistors on the input or output - you can probably tack these on somewhere though.
(https://2.bp.blogspot.com/--3OmPq2sxS8/VfVFZp69n6I/AAAAAAAABoU/V6IYQHmS1Pc/s640/chasmreverb.gif)
Another option is to use a DPDT toggle switch to select between a latching OR momentary switch
I may have done a poor job explaining what I'm looking to achieve, so below are a couple of videos that demonstrate the 'HOLD' functionality I'm looking to add to the chasm. Instead of "only get reverb when you hold down the switch", I'm looking to bypass the OSC reverb when holding down the momentary switch.
https://youtu.be/6iDHTTImBS4?t=11m13s (https://youtu.be/6iDHTTImBS4?t=11m13s)
https://youtu.be/Jfrfz4n1jE8?t=3m56s (https://youtu.be/Jfrfz4n1jE8?t=3m56s)
^
That's achieved the same way as above, but now I can see how that could be useful.
You need a DPDT footswitch regardless, so you can choose to wire it either way - i.e. effect 'on' when switch up or switch down.
I'm a visual learner, so I've attempted to sketch up what you've described. The initial issue I see with this diagram is that when the momentary is engaged, then the reverb tails coming for the Chasm Board will end abruptly. Is there any way to have the signal from the chasm circuit continue to be sent to the output when the momentary is engaged?
(https://s18.postimg.org/i8kkkyy7p/CHASM_WIRING_W_MOMENTARY_v1.jpg) (https://postimg.org/image/i8kkkyy7p/)
^ other way round - swap the 2 stomp switches.
Of course! Thank you samhay for helping me think through a solution here.
I'm hoping someone can help me troubleshoot my modification on the chasm reverb. The pedal has been built to have two footswitches. One latching footswitch turns the effect on/off and a second momentary footswitch temporarily bypasses the effects when depressed. Here are the current scenarios:
1. With the pedal bypassed (off), I get a good guitar signal
2. With the pedal active, I don't get any guitar signal (there is also a loud pop when the pedal is turned on/off)
3. With the pedal active and the momentary switch depressed, I get a clean guitar signal (this is the desired effect of the momentary switch)
When looking at the attached picture of the circuit, the switch on the right is the Bypass footswitch and the switch on the left is the Momentary (hold) switch.
(https://uploads.tapatalk-cdn.com/20171125/4dcb1c2e1446d028a9773d7eed37550c.jpg)
Sent from my iPhone using Tapatalk
Did the circuit work before you wired up the footswitches?
I failed to test before wiring the footswitches, so I just re-wired to the original design (one footswitch) and I still fail to get a signal with the footswitch engaged (the loud pop has gone away though when engaging the effect). There is a little bit of high pitched whine sound with the OSC switch active and the effect pedal engaged.
I also checked the voltage and I get 9V into the IN pin of REG1 and 5V into pin 1 of the BTDR-2H.
Sent from my iPhone using Tapatalk
I believe I traced the problem to a bad connection with the volume pot to the PCB... Will update once re-wired
Sent from my iPhone using Tapatalk
The bad connection from the volume pot to the PCB was the culprit. Everything seems to be working with the two switch system now. Here is the final pedal:
(https://uploads.tapatalk-cdn.com/20171125/11bf3016e61d371a89372608af437728.jpg)
Sent from my iPhone using Tapatalk
Excellent.
Has it stopped popping other the bypass switch?
Quote from: samhay on November 26, 2017, 06:06:16 AM
Excellent.
Has it stopped popping other the bypass switch?
I still have a pop when depressing the BYPASS (on/off) footswitch. Any thoughts on how to fix this?
Sent from my iPhone using Tapatalk
You probably need to add pull-down resistors on both the input and output.
You may be able to tack these onto the PCB, but it may be easier to do this on the footswitch.
I've attempted to add pull-down resistors (1M), but the only thing that still seems to fix the 'pop' is cycling the BYPASS footswitch 25x or so. Is there is a correct way of wiring the pull-down resistors into the circuit? I have researched and tried a few different ways, but I don't feel confident that I've come across the proper way.
They need to be wired so that they're permanently connected to the input (and output) of the circuit on the PCB. If they're the "other" side of the footswitch, then they have no effect.
^ yep..
try adding the 1M's across your jacks.
note: the chasm was designed to have silent switching. i cant stand pops on trails/delays..
but you have managed to bring back the pop... ;D
Just to make sure I understand correctly, I would place a 1M resistor into the 'G' and 'IN' and a second 1M resistor into the 'G' and 'OUT' holes of the PCB (with the pre-existing wires remaining in the 'IN' and 'OUT' holes)
Sent from my iPhone using Tapatalk
Yes.
Yup. Worth a try...
The pull down resistors placed at the input and output of the PCB resolved the pedal pop. Thank you samhay, deadastronaut, and bluebunny for the help and guidance
Sent from my iPhone using Tapatalk
Excellent, and you are most welcome.
Hi, I'm looking foward to build this pedal but i can't acces to the PDF's of the pcb and layout on the first page :(
Am i the only one with this problem? i would be so grateful if someone could post those pdf's again. Thanks
same on the no access... i get a 404 error page with those links.
with that said,
good info here (https://www.coda-effects.com/2016/02/dead-astronaut-fx-chasm-reverb.html)
edit
o, and here u also go (https://effectslayouts.blogspot.com/2017/07/deadastronaut-chasm-reverb.html)
The documentation is available on Rob's website - the link is in his .sig above. The Chasm page is here (https://deadastronaut.wixsite.com/effects/chasm-reverb).
Hi! I've just built Chasm reverb, it sounds great, everything is fine, every pot is doing what it is supposed to do. But problem is when i turn my effect off. It doesn't shut effect off, it keeps reverberating my signal even when i turn effect off. Could you help me with this please? I built it on etched PCB from page effectslayouts, before soldering i checked every trace, every pin, if everything's alright. Next i checked every component's value. I double checked wiring. I've used 3PDT switch, but just 6 out of 9 pins.
Here are some photos:
(https://i.postimg.cc/wtjBntj8/IMG-20210203-182500.jpg) (https://postimg.cc/wtjBntj8)
(https://i.postimg.cc/mcnTq8nC/IMG-20210203-174656.jpg) (https://postimg.cc/mcnTq8nC)
And there are readings when effect should be off (LED is off):
9,20 V power supply
Q1 (J112):
D. 3,40
S. 3,40
G. -1,70
Q2 (J112):
D. 3,40
S. 3,40
G. -1,15
Q3 (2N7000):
S. 1,90
G. 3,40
D. 6,80
REG (7805):
I. 6,80
G. 0,00
O. 4,98
IC1 (TL072):
1. 3,41
2. 3,41
3. 3,08
4. 0,00
5. 3,41
6. 3,41
7. 3,41
8. 6,82
IC2 (TL072):
1. 3,41
2. 3,41
3. 3,41
4. 0,00
5. 3,41
6. 3,41
7. 3,41
8. 6,82
Readings when effect is on (led is on):
9,20 V power supply
Q1 (J112):
D. 3,40
S. 3,40
G. -1,12
Q2 (J112):
D. 3,40
S. 3,40
G. -2,48
Q3 (2N7000):
S. 2,22
G. 3,64
D. 6,70
REG (7805):
I. 6,80
G. 0,00
O. 4,98
IC1 (TL072):
1. 3,60
2. 3,40
3. 3,06
4. 0,00
5. 3,40
6. 3,40
7. 3,40
8. 6,80
IC2 (TL072):
1. 3,40
2. 3,40
3. 3,40
4. 0,00
5. 3,40
6. 3,40
7. 3,40
8. 6,80
Thank you for any reply, I really appreciate that!
Hi sargeras611! Welcome to the forums!
I think your 'issue' might be a feature! What happens in the Chasm is that the input signal to the reverb circuitry is cut-off, not the output! In some pedals this is called the 'TAILS' option :)
Can you verify that new notes aren't reverberated when in bypass? :)
Thanks for kind welcome! And thanks for quick respond. I know about this feature of "Tails", for reverb it's great feature, but in my case, also new notes after switching to bypass mode are reverberated. Also all pots are reacting in bypass mode.
Hi, 6.8v from a 9v supply... something wrong there...
Check over your values...trace through and see where the 9v is dropping if you cant see any obvious wrong value.
Hi deadastronaut, thanks for your respond! I checked it from power supply, after diode 1N5817 I'm reading 8,88 V, and after 33 Ohm resistor i'm reading just 6,8 V. Please do you have any idea what could be wrong? Or what should I check next??
Thanks to deadastronaut my problem is solved, it was bad mosfet transistor... I just replaced it and now it's working perfectly, thank you! It's great sounding reverb. Here is photo of my build
(https://i.postimg.cc/Wq8m1Bb3/PSX-20210304-201829.jpg) (https://postimg.cc/Wq8m1Bb3)
Excellent, nice easy fix.....thought it was that.
Nice build man.... 8) 8) 8) enjoy.