hi guys, gotta red ross flanger on fleabay in great shape for no money...30 bux shipped or so.
they said it passed signal, but no effect
(cue the audience going <siiiiiiiigh>)
so, i figured i'd open the dang thing up and see what's what.
i took some voltage readings, everything seems to be in the ballpark...modulating things are modulating, i can hear a faint clock in the background.
tried "laying of hands" and reseated the sad1024 chip. no dice. i'll get to voltages in a minute, but pretty sure it's the sad1024 chip that's toast.
no idea really how to check it other than to replace. i HAVE ONE. i've been saving it to build an mxr flanger, but this is almost the same thing from the research i've done so far.
i WILL post voltages...not gonna bother with the opamps, they're all 4558's, and all about right...there's a 20v transformer, and the reg is working it's magic..b+ is about 14.41v or so on the output of the regulator.
but...my question is...is it safe to plug the unused SAD chip in and see if i get flange, or can i damage it doing so? it's unused in the original blister pack still.
if it works, it would seem the next step would be to keep this thing, in which case if some of you brothers out there can guide my dumb newb ass thru it, i won't waste the sad1024, but hopefully convert it to a pair of MN3007's, of which i still have probably 10 or 12.
i'm gonna post this, then come back with the voltages i wrote down in the other room... i'm a newb, but to me, they seem to be about reasonable, and not matching necessarily the kinda voltages i've seen others post with a dead sad chip...so i'm thinking it may be something else stopping the effected circuit from working.
i just don't wanna f it up doing something stupid. i'm sure it will need to be dialed in, as all the trimmers were pegged. :(
thanks for any and all help.
not sure which parts correspond to what yet on the mxr flanger, so i'll start with the sad and the clock... but i think everything is gonna be fine except the bbd, unfortunately.
i hope to be able to work up a vero daughterboard that will plug right into the existing socket...do you think that would be possible?
lotta questions...sorry!!
http://www.diystompboxes.com/smfforum/index.php?topic=55292.0
Dork with the trimmers if they have been "dimed". I had the same issue with an 18v EHX EM and was able to get it back.
Luck!
voltages...like i said, i won't post the OA's, they're all seemingly doing their thing...amplifying or modulating, etc..
sad1024
1 0.0
2 4.68
3 7.23
4 0.00
5 4.91
6 4.91
7 14.48
8 7.25
9 14.48
10 7.24
11 8.3 - 8.20 (modulating?)
12 8.4 - 8.21
13 0.0
14 7.24
15 4.82
16 0.00
the cd4013be
1 7.25
2 7.24
3 12.52
4 0
5 7.23
6 0
7 0
8 14.48
9 14.48
10 11.25
11 14.49
12 12.40 - 12.85 (modulating)
13 14.48
14 14.48
thanks tony for the help... i will play with the trimmers a little bit, but i am getting ZERO effected sound.
the voltages on the sad chip seem good, from what i can tell.. so i assume the bbd may have survived? i CAN hear - barely - what seems to be a slight "delay" sound on a couple of the pins..it's hard to really tell tho.
i'm gonna go try and mess with the trimmers a little bit.
i am getting ZERO hum.
wondering...do you think maybe one of the tants blew out somewhere between the output of the chip and the mixer stage or something?
i have a way steeper learning curve here than you may think.;)
Audio probe it yet?
nope dave, not yet... i had a lesson that just left, and g's making chow. after everybody goes to bed, i'll break out the audio probe and see what's what.
i take it from the voltages *MAYBE* the sad chip survived? i'm hoping that's what i'm reading into this?
seems to me, if i'm passing signal thru dry, it's gotta be a problem somewhere in the output or mixer stage of the wet signal. i gotta print up the data sheet too so i can look...this is way over my head, i'm afraid. ;)
so i'm imagining i shouldn't sacrifice a virgin at the reticon altar yet? :icon_mrgreen:
CMOS chips are "cheap like borscht". Don't abandon hope for the BBD until you've verified that it's NOT the 4013. Keep in mind that if the 4013 is fried, you ain't gettin no delay no how no way. Should we assume that the modulation of the 4013 corresponds to the LFO rate?
Assuming, for the moment, that the Ross schematic corresponds at least 95% to the MXR 117 schematic, there should be 3 trimpots: a pair of 20k and a single 500k. The 500k sets the clock range, one of the 20k (connected to BBD pins 11 and 12) sets the BBD output level, and the other 20k sets the input bias voltage. For the moment, you can just dime the BBD output level trimpot, and set the 500k unit to its midpoint until you get the bias voltage right.
Assuming that all the other things one might normally attend to in a dysfunctional pedal check out OK, like the stompswitch, the wiring of the jacks, continuity within the pots, etc., you would futz with the bias trimpot by setting Manual to minimum, depth and regen to max or near max, and the speed at about 2:00 (or as close close to 1-2hz as you can). This would provide the most obvious in-your-face flange sound if you DO manage to hit a sweet spot on the bias trimpot. Once you have that sweet spot roughly identified, you can back off the regen so that it does not smudge the sound so much, and allows you to aim the trimpot more precisely for audio quality, rather than just obvious delay.
Should wet signal be resurrected, and quality maximized, you will then want to aim for the overall delay range using that 500k trimpot. For that, you may want to slow down the LFO to hear how it sweeps. You may also want to futz with the manual control at this point, since one does not want the manual control and clock trim to work against each other. Remember that the depth control works such that manual has the most impact on delay time when depth is at minimum, and has negligible impact on delay time when depth is at max.
@jimi: +1 on everything Mark said. :icon_cool:
And... I will open up my properly functioning ROSS tomorrow and post some V's. Hope you have it sorted out by then. If not, you will have something as a reference.
Does your multi meter have a frequency counter function?
hi guys,
i understood some of what mark said dave,
i set the controls up as he suggested, and used my original readings to kinda tune it back in...or close.
no delay. but... i can hear clock and sweep, so i'm thinking it's gonna be a bad cap or something. i'm a mite too burnt to scree any schematics tonite,
tho i did print them out and start looking at it. it is indeed pretty close, the mxr is more adjustable i think.
with the sad chip up top, the 2nd 4558 from the right on the board has MUCH lower voltages than the other three, but it's pretty premlinary of an assumption..
i've gotta go and actually match up which chips go where in the schematic, and i'm better off doing that stuff with a fresh set of eyes.
still betting it's somewhere between the output of the sad, and the mixer stage, probably that opamp. all the others are reading voltages around 14.5v at pin 8, that one's reading i think more like 4.5v or so.
i don't know what i'm doing, so yes, it's a 10,000 monkeys situation.
dave, yes, i do have a frequency counter on my meter.
also noticed slight discoloration on the socket for the sad , pins 12-15.. looks like it might have gotten hot.
tomorrow, i think i'll start by just replacing all the electros and see if that helps. next, the tants..
can i replace them with regular electros?
dave, if you can make out the values, i'd be indebted.. too small for me to see even with my glasses. glaucoma sucks.
so smoke lotsa funny vegetables to prevent it if so inclined. ;)
just kidding. flux inhalation is all ya need.
it's like being an oracle, or something. ;)
mark, i don't know really how to tell if the cd4012 is working, but the voltages seem to indicate it's doing something...unless i'm mistaking the changing voltages on the pins for the oscillators...but i thought the clock was the oscillator?
my brain hurts. ;)
more tomorrow...thanks my brothers. ;)
The pics I have seen online show both the SAD1024 and CD4013 in the Ross units soldered in place.
It's not Jimi's fault, obviously, but let this be a lesson to folks to spend a few extra pennies for the sockets. Being able to pop either or both chips out and test them in a different pedal to confirm functionality can save LOTS of time and headaches in troubleshooting.
Of course, I can't really blame Ross either. How could they know back in 1980-whatever that there'd come a time when it was easier to find the wreck of the Titanic than find another SAD1024?
The Ross I have open and sitting in front of me as I type this has the 4013 soldered and the SAD1024 is in a socket.
I will take those V readings later. Now I have to go on a job interview. Bills to pay and all that other stuff. :P
mark,
they all have just the sad chip socketed, at least the ones i've seen...i've owned 3-4 of these over the last 30 years or so, i never tend to keep them very long.
i have a pearl flanger that just blows these things away!! does the through zero point thing, too.
dave, this one has only the 1024 socketed. i will if necessary socket everything. but i really don't think it's the clock. i think it's either the bbd or a bad cap that's not passing audio.
good luck break a leg at the interview today bro!
QuoteOf course, I can't really blame Ross either. How could they know back in 1980-whatever that there'd come a time when it was easier to find the wreck of the Titanic than find another SAD1024?
Eye popping story;
I recently repair a pedal for a gentleman down in the States. He asked if I could also clone said pedal, since the original is a rare collector, and he didn't want to gig with it. I said "OK". He then asks me if I could also create a clone of the the Mutron Flanger. He had one in the past, sold it, but missed it, and wouldn't mind having a clone. Not being familiar with it, I told him I would look into it. Checking out the circuit, and seeing the need for said SAD1024, I told him the dilemma concerning cost/availablity of said chip. He replies, "No problem. My buddy worked at Musitronics back in the day, and when they closed up shop, he gave me a tube of 25 of them. Just let me know if or when you're ready to build it, I'll send you what you need."
:icon_eek:
Of course, I did also advise him that the price that tube of chips could fetch, he can probably get himself a nice bevy of pedals.
Go figure.
BTW. I found a copy of the Mutron Flanger circuit, although the writing (values and such) was tough to read. Still, it was a hi-rez pic, so I blew it up to 3 feet to 5 feet size, which allows me to decipher pretty much all of the writing. Eventually, I'll get it cleaned up, and post it. That's one I wouldn't mind cloning.
:icon_eek: :icon_eek: :icon_eek: :icon_eek:
Give me a sec while I try to get them back in their sockets.....there, better now.
The Mu-Tron Flanger is one of those exceedingly rare birds.....like SAD1024s. I'd be very interested in the schematic once you have it deciphered, as I'm sure many would. Of particular interst is the way in which the sweep range is defined, and the switchover from LFO to pedal control. Interesting feature.
Speaking of which, I should probably ponder whether it is worthwhile to adapt the Anderton pedal-flanger circuit ( http://hammer.ampage.org/files/Anderflange1.PDF ) to something more available, like an MN3207 or similar.
That's on my to-do list. I really need to get a bunch of work of my bench right now. I told the gentleman that IF I took it on, I wouldn't be able to tackle it before early next year.
I will do my best to clean up the schematic, and post it in the next few weeks.
It's a circuit that would fit nicely into the Hen's Tooth Cafe.
There's been some write up on it over at "you know where", including some posturing on replacing the SAD with and MN. Nothing concrete though, and ("out of my league here" alert) timing issues (?) with using a different chip? That's more up your alley Mark.
I just copy them. Analysis is still baby steps for me. :icon_lol:
ok guys,
i bit the pickle.
yes, it's the sad chip. i broke down and in a fit of impulsivity, took the pristine brand new unused one out... . <cue the whole forum shrieking NO~~~!!!!!>
AND I STUFFED IT IN.
the new one, after a couple minutes tweaking, runs and flanges and delays and damn near phase shifts at some extreme settings... i swear i heard some of that yoyoyoyoyoy we all love so much.
but any signal going thru it is distorting no matter how i set the trimmers. turning the knobs generates crackle (not ok) so i'm assuming all new electros are in order, and i wanna replace all the tants, too. i don't have them.. and frankly, where i have room, i think i'd prefer the electros anyways. tants always seem to lead to probs for me, anyways.
so i'm gonna carefully take the new chip out, seal it back in it's package, and set out on the herculean task of figuring out how to adapt an mn3007 or two to the circuit. i mean...dumb newb here... a 1024 bbd should be interchangeable i would imagine, right?
thinking daughterboard with any necessary components. i know peeps have done this..
or should i just bite the bullet and use the 1024 in this thing? when dialed in right, pretty sure it'll be an amazing sounding flanger.
if i added a couple more trimmers, could i get all the functions in the mxr do you think?
obviously, if i install the 1024, it's a done deal, and i'm keeping it....so i have no issue modding the sucker. but i believe it's gonna be way the heck over my head.
i've compared the two chips data sheets, and the pinout is alot different, as is the function. i'm more than willing to try to do the work to reason it out, but some aspects i know i'm gonna get stuck on.
dumb newbe is learning. slightly.
it would seem to me, that the 1024 and 3007 are NOT gonna be able to be used.. the 1024 is two 512 bbd chips in one, the mn is one 1024 bbd.
so...this ain't gonna happen. guess the dream of building the mxr flanger is gonna go the way of the dodo byrd.
time to bite the bullet. ;)
unless someone infinitely smarter (which could mean just barely to genius ) than me can figure out a way to do it.
i know folks have done it, or claimed to do it, but the visual evidence a newb like me would need doesn't seem to have survived.
At least you know a 37 year old chip works ;)
With a small daughterboard you can easily build/repair either flanger w/the MN3007. ;)
Voltage readings coming soon.
And... you only need one 3007 for the job.
I'm confused.
Are you saying that installation of a NOS Reticon chip results in all the expected "tricks", except with unacceptable audio quality?
If I understood you correctly, then your problem lies outside the SAD1024. I honestly can't think of a single instance in 30 years, whether in my own experience, or something someone else posted, where one of those chips could perform all the expected functions, but just do a crummy job at it.
Straighten me out here, bro.
Probably needs to be biased correctly.
To my simple mind turning the pots and getting "crackle" is usually indicative of pots that need cleaning.
Aside from that; consider using the SAD1024 in the MXR117 clone. That board fits in a much smaller box than the Ross. There is plenty of room in the Ross for a daughterboard without having to cram things in and getting stressed in the process.
hi mark,
i believe what happened is and electro or a tant cap leaked enough dc to fry the original chip.
pop in the new chip, and the think comes to life, with a good bit of "sweet spot" on the 3 trimmers. but...there is distortion, a muffled crackle i've associated with leaking blocking caps.
so yes, you are right...the problem lay outside the chip. unfortunately, i don't think the chip survived. putting the original chip in with the same settings that make the known good one sing it does nothing. seems to me it would be the chip.
so...i'm off to rat shack, the only big electros i have atm are 1000u @10v...not enough nads to handle the 22 volts coming from the power supply.
gonna start by putting something huge in there...maybe 1000-4700u @ 35 or 50v in first for the filter, then replacing all the 10u electros.
from that point, i'll check it out and see if the crackle remains. if it does, i'm betting on one or more of the tants being open and letting dc thru.
i'll check back shortly...sorry for the confusion.
the weird thing is, the bad sad and the good sad both read about the same, voltage wise.
and mis-clocking the sad? there's a spot at the extreme of the clock adjust where it starts phase shifting. it does a thru zero i never knew these things could do, and could probably be tweaked just a little to self oscillate. i think it's gonna be cool.
dave...thanks bro...
i would like to retrofit this thing and save the sad for a proper project. ;)
dave. the crackle isn't like a dirty pot, it sounds like the crackle from a SHO more..
rat shack here blows...no more metal boxes (good news for small bear, as all the db!!FX pedals to come once my stock runs out will come from there)...no pot cleaner.
sheesh.
hope they have some decent caps..otherwise, i'll have to series/parallel a couple with some resistors so i can use them 1000u ones.
tony...amazing, isn't it?
;)
thanks bro!!! ;)
Dave, I thought the Ross and the MXR-117, like so many of the Ross and MXR pedals, were - but for the odd mod here and there - essentially interchangeable.
Folks, I have one question:
Before you close your nice Ross Flangers, would it be possible that someone takes a picture of the solder side so that this little baby can be traced ? :icon_wink:
analogguru
hell,yah, analog guru.,,
bur you have traces on both sides i thiink,,,
i already changed the filter cap, but other than that is stock.
i have no way to get a macro pic unfortunately. all i got is my sh***y phone or an ANCIENT digital camera.
video shortly, too
dunno if these are useful, unfortunately...probably too small
(http://i605.photobucket.com/albums/tt137/pinkjimiphoton/382120_4522201786024_443012938_n.jpg)
(http://i605.photobucket.com/albums/tt137/pinkjimiphoton/598403_4522198465941_34146496_n.jpg)
(http://i605.photobucket.com/albums/tt137/pinkjimiphoton/248894_4522193985829_757792224_n.jpg)
(http://i605.photobucket.com/albums/tt137/pinkjimiphoton/542679_4522181065506_771682788_n.jpg)
If the last picture would have the same size as the others it would be a it easier.....
Anyhow, you have the last version of the Ross Flanger (same pcb as in the black one) and what can be seen from the pictures the schematic of the MXR Flanger (M-117) should match pretty well:
http://www.shredaholic.com/mxrflanger.html
The BBD-bias trimmer (R49) is the upper middle (between the pots), the trimmer beside the recycle pot is the "trim level" (R 48) and the trimmer beside the transistors is the "trim clock" (R43).
analogguru
damn phone pix, bro. they suck.
;)
i'll try and get another...never know what size the dang things will be.
yah, had a "made in taiwan" sticker on the bottom, definitely the same as the black ones.
very nice, liquid...did ya check the video, analog guru?
ok, took it out last nite, worked brilliantly.
like i said, i never knew these to be capable of thru zero flanging, but it's definitely doing it, and is way more intense (probably due to my intentionally miss-setting the trimmers til it sounds the way i like it) than any of the ross flangers i've had previously...perhaps the chips were tired in them, or they were just set up to be "more polite" at the ross factory.
i like the mix trimmer full tilt boogie.
the sweet spot on the other 20k is gonna be different i'd imagine from chip to chip. around 1:30-2:00 on it (with half way as 12:00) seems to be best..by careful adjustment, you can really dial it in.
the clock trimmer was the most interesting. you can dial in the whole effect right there, and that's where i discovered i could do the thru zero trick. full blast makes some interesting sounds!!! depending on the settings of the front panel knobs, you can get everything from chorused sounds to bending rubber bands.. even a bit of yoy. pretty cool. i think i'll keep it.
so...next phase...
adapting an mn3007 to work in this circuit. i read thru a bunch of the threads, but it's a little (a lot) over my head still..
I started to disassemble mine to provide the trace side photos as AG requested, but I don't have a deep enough socket to remove the pot nuts. Sorry!
Technically, it can't do TZF, and neither can the MXR. There is certainly an interesting "turnaround" in your demo, that has a similar feel, but it's not TZF. Here's an example: http://www.youtube.com/watch?v=y94SFk3CID0 As one reaches the through-zero point, the signal appears to get "sucked away" and then return.
In theory, an SAD1024 could be used for TZF, since it is configurable as two independent 512-stage sections. But that would mean a separate fixed clock for one section and a variable one for the other, which is not found on either the Ross or MXR. There is also no delay imposed on the dry signal.
Haing said that, one of the reasons why the Reticon chip is loved for flanging is because it is very easy to get it to clock so high that it is very very close to the zero point (though as a delay chip, it would always lag behind an untampered clean signal by some amount). The PAiA Hyperflange gets it down to 170usec (i.e., 0.17msec), and the A/DA is somewhere in that neighbourhood as well, a few more octaves of upward sweep than the BF-2.
Not intended as a dressing down, bro. Merely a friendly reminder that there are still new worlds to conquer. As always, if it sounds good, it IS good.
far out, thanks mark, no dis taken, it helps me learn.
so to actually do true "thru zero" you have to start with a delayed signal, correct? so you can move the two side independently and make them cross over, right?
it sure sounds pretty close...the ones i had before never sounded like this.
i've gotta check back later...shower and gig...early tonite, downbeat for 8. ugh.
Quote from: Mark Hammer on November 21, 2012, 04:21:17 PM
Technically, it can't do TZF, and neither can the MXR. There is certainly an interesting "turnaround" in your demo, that has a similar feel, but it's not TZF. Here's an example: http://www.youtube.com/watch?v=y94SFk3CID0 As one reaches the through-zero point, the signal appears to get "sucked away" and then return.
In theory, an SAD1024 could be used for TZF, since it is configurable as two independent 512-stage sections. But that would mean a separate fixed clock for one section and a variable one for the other, which is not found on either the Ross or MXR. There is also no delay imposed on the dry signal.
Haing said that, one of the reasons why the Reticon chip is loved for flanging is because it is very easy to get it to clock so high that it is very very close to the zero point (though as a delay chip, it would always lag behind an untampered clean signal by some amount). The PAiA Hyperflange gets it down to 170usec (i.e., 0.17msec), and the A/DA is somewhere in that neighbourhood as well, a few more octaves of upward sweep than the BF-2.
Was going to mention how it comes close to TZF, but cannot go through the null with a single delay line. I wonder how much trouble there would be if using two different clocks on an SAD1024A or MN3010? Given the close proximity of the delay sections, I would suspect that aliasing between the two clocks would be a major concern. Of course, the static delay could be set rather short, so the static BBD clock could be well above the audio range (> 100 kHz). But it would seem that the two clocks would interfere, especially near the through-zero point.
FWIW, my A/DA clone is presently set for a minimum delays of of around 0.45 ms - much shorter than that and there's not much audible flanging, even on full-bandwidth signals. That would put the first notch of the comb filter around 2200 Hz. 0.4 ms results in the first notch at 2500 Hz. Also, I've found that the SAD1024A's gain is reduced by a couple of decibels when it pushes up close to 1 MHz, which results in shallower comb filtering, and less intense flanging. I would suspect that the signal loss at 0.17 ms would be even greater. On mine, I've set the dry/delay mix for maximum cancellation through the critical midrange, say from 200 Hz to 1 kHz, which roughly corresponds to the 5 ms to 1 ms range, or a clock rate of 51.2 kHz to 256 kHz respectively. The BBD gain stays relatively linear through this range.
Also, the Ross sample and a few others have a pronounced "boingy rubber band" effect at the bottom of the sweep that I don't hear from my A/DA. I wonder if the LFO waveform is somewhat different?
Oh, and I'm wondering if there might still be some faint hope for that old Reticon chip. If you're lucky, it might work if the rest of the circuit is brought back to spec.
It is possible one side of the "bad" SAD1024 is still good. That'll give you a 512 stage BBD which is still very useful. Don't toss it yet!
@ 12Bass: When I finally get some free time to do some meaningful work I plan on trying to clock the 2 sides of an MN3010 (I have plenty of them) differently. This will require a lot of careful layout planning, ground planes, etc. This has been on the "to do" list for waaaay too long. Just need to get my life back first. :P
Dave,
MN3010s? I have plenty of them?
Okay boys.....Get Him!!!
Quote from: armdnrdy on November 21, 2012, 07:51:35 PM
Okay boys.....Get Him!!!
Get in line. There's lots of "get him" directed at me lately. :icon_lol: :icon_lol: :icon_lol:
Quote from: 12Bass on November 21, 2012, 07:02:07 PM
Was going to mention how it comes close to TZF, but cannot go through the null with a single delay line. I wonder how much trouble there would be if using two different clocks on an SAD1024A or MN3010? Given the close proximity of the delay sections, I would suspect that aliasing between the two clocks would be a major concern. Of course, the static delay could be set rather short, so the static BBD clock could be well above the audio range (> 100 kHz). But it would seem that the two clocks would interfere, especially near the through-zero point.
FWIW, my A/DA clone is presently set for a minimum delays of of around 0.45 ms - much shorter than that and there's not much audible flanging, even on full-bandwidth signals. That would put the first notch of the comb filter around 2200 Hz. 0.4 ms results in the first notch at 2500 Hz. Also, I've found that the SAD1024A's gain is reduced by a couple of decibels when it pushes up close to 1 MHz, which results in shallower comb filtering, and less intense flanging. I would suspect that the signal loss at 0.17 ms would be even greater. On mine, I've set the dry/delay mix for maximum cancellation through the critical midrange, say from 200 Hz to 1 kHz, which roughly corresponds to the 5 ms to 1 ms range, or a clock rate of 51.2 kHz to 256 kHz respectively. The BBD gain stays relatively linear through this range.
Also, the Ross sample and a few others have a pronounced "boingy rubber band" effect at the bottom of the sweep that I don't hear from my A/DA. I wonder if the LFO waveform is somewhat different?
Oh, and I'm wondering if there might still be some faint hope for that old Reticon chip. If you're lucky, it might work if the rest of the circuit is brought back to spec.
One way to get around the potential heterodyning of clocks might be to use different capacity BBDs for which the required clocks would be so different as to yield inaudible sideband products. So, something like a 2048-stage BBD used to produce a 2msec fixed delay, and a 512-stage unit to provide the swept delay, that wouldn't have to go much lower than 1.5msec to produce a robust through-zero effect. The clock for the 2048 stage unit would be VERY high, such that adding or subtracting the clock from the swept delay would still ikely yield something out of hearing range.
The starting point in the spectrum for comb notches is often inaudible at the high part of the sweep. Particularly with guitar, the signal bandwidth does not extend upwards all that far, so there may well be no audible notches at the top end of the sweep. As I'm fond of reminding people, the benchmark flanging sounds that send all of us running to buy or make one, or at least try one out, are frequently flanging applied post-production to multi-source mixed-down tracks that cover an enormous chunk of the spectrum. Under those conditions, the comb filtering is more obvious, because there is more content to filter. When you throw a rather spectrally-limited guitar at a flanger, there can be big chunks of the spectrum where the flanger is producing
potential notches, but there's nobody home at that address. The result is that it tends to disappoint us.
Nothing wrong with the flanger, just with the program material.
The same, incidentally, is true about phasers as well. Sixteen-stage phasers will sound pretty dang fine with a full drum kit or white noise, but won't deliver much more sonic bang on a guitar than a 6 or 8-stager will, despite what seems like it oughta be fabulous in theory. Again, if a notch is hypothetically created i the spectrum, and there is no source material there to be affected, was a notch truly produced?
Steve Giles has intermittently waxed eloquent about the "bounce" circuits found in some flangers. This is a circuit intended to emulate the little momentary tug that a tape take-up reel would provide as one took one's thumb off the flange. The old Eventide Instant Flanger had this feature, and the late and greatly missed Jurgen Haible incoroporated it into his Storm-ide and Son of Storm-Tide flanger designs. I don't know enough about the inner workings of the MXR/Ross LFO circuit to know whether anything sort of like that is being produced. It could simply be an asymmetrical waveform that has a jarringly quick turnaround at one end of the sweep.
Good morning, I'll dig out the bounce circuit tonight in case anyone needs it.
so.... in summary...
this flanger isn't worth modding, better to mod something else. it may not be TZF, but it appears to be close enough for rocknroll.
i'm sure i don't have it adjusted as per factory, but i've had like 10 of these over the years, and they all sounded pretty much the same.
this one is MUCH more intense..
and yes, that rubber band thing at the bottom of the sweep i REALLY like.
the reticon may indeed have one good side.. i believe i can pop it in the sad512 socket of my full double tracking effect maybe to see... it's gotta weird chip, it's the same length as the 1024 but only has i think 8 pins or so...i'd have to look.
i won't trash the reticon...but i really do want to save the brand new one for the mxr 117 project dave hooked me up with.
i hate to ask, but i've looked thru pages upon pages of threads about the substitution of a mn3007 (which i have a bunch of...line up, guys, when you're done with dave, lol) but i haven't seen anything graphic that newbs like me can decipher.
does anyone have a conversion they can hip me to? i can work out a vero daughter board, but i don't understand really what's what in terms of trying to make two (to me, anyways) completely different things substitute.
a schematic would be freekin' awesome...or did i miss something? it seems a lot of stuff that used to be linked to some of the older threads is gone now.
Hey Jimi- as oldschoolanalog said, don't give up on that SAD yet. In you posted voltages, it looked like there was voltage present at the outputs of both sides; I had a prob with an SAD in an MXR build and was getting 0 volts at the output of the bad side...worth looking into. If it does end up being the chip, a single-sided SAD can still be used- check out this thread, especially page 3: http://www.diystompboxes.com/smfforum/index.php?topic=93646.40 (http://www.diystompboxes.com/smfforum/index.php?topic=93646.40). Federico (Fender3D) turned me on to a mod for the MXR that uses (in my case) an SAD512 and works beautifully- practically indistinguishable from a full 1024. You might consider poppin' yer good SAD into the Ross and doing the MXR build anyway, using either the bad 1024 or the MN3007 daughterboard, which also sounds good...good luck either way, dude!
thanks john,
who knows? i've kept the "bad" chip, but i'm pretty sure it's hosed. the voltages all stay the same with the good chip and the bad one, but only one works.
we'll see what happens..
for now, the sad chip will live in the ross...it sounds so nice, i can live with that. but i STILL wanna work up the daughterboard for this..i've found the threads, i've found the layouts etc...but it's way, i mean WAY over my head still.;)
Swapping in an MN3007 is not that complicated. The big differences are that the power and ground lines have to be swapped and that the clock rate has to be doubled to compensate for the doubling of BBD stages. The rest is just working out the details.
The 2 sections of the SAD1024 are in series in the Ross (and MXR117). No need to double the clock f in these pedals. The A/DA & EM are a different story...
However; I do agree. The devil is in the details.
@jimi: I'm on the case. ;)
thanks guys.
i'm trying to begin to see the light...so would you simply reverse the power supply to the chips like you would going between a pnp and npn version fuzzface?
i don't really "get" what all the connections are, seems the "details" between them are part of what is rendering what little brain i have null and voider.
voided?
voidoid? ;)
so like, would you then sum the inputs and outputs? doesn't it still need a half power supply as well?
too many questions... ;)
dave...you will achieve godlyke status for pulling this off. you could probably make a living selling conversion chips to guys with dead sad pedals. ;)
I'm just a hack with a soldering iron, 'scope, test gear and very limited knowledge.
My only strong point is a willingness to take on and try ideas that are talked about but little R&D has been done on.
That pretty much sums it up.
lol...well., let's put it this way...if i had 10,000 typewriters, you could probably replace peter tork with me. :icon_rolleyes:
:icon_mrgreen:
Quote from: analogguru on November 20, 2012, 03:55:42 PM
Folks, I have one question:
Before you close your nice Ross Flangers, would it be possible that someone takes a picture of the solder side so that this little baby can be traced ? :icon_wink:
analogguru
It took some time to find a deep socket to remove the pot mounting nuts, but I finally did and took some photos. Here are the small versions, larger ones are available at the home-wrecker.com Ross Flanger page (http://home-wrecker.com/ross2.html)
(http://home-wrecker.com/flanger-comptn.jpg)
(http://home-wrecker.com/flanger-tracetn.jpg)
(http://home-wrecker.com/flanger-xraytn.jpg)
brian, that's awesome bro...sorry, all i have is a crummy phone to take pix with, these look great..
mine tho, the sad chip was socketed...wonder if there's any other diff? i think yours is an older one, mine was made in taiwan, even tho it's that lovely shade of purple red..
Thank you for the nice photos Brian! :icon_cool:
The BBD chip is socketed in mine. It is a USA-built model and the date code on the pots indicates it was produced no earlier than May 1979.
Jimi, I love you just a little more for making a Richard Hell joke, don't think it went unnoticed.
Quote from: wavley on November 27, 2012, 12:58:51 PM
Jimi, I love you just a little more for making a Richard Hell joke, don't think it went unnoticed.
:D
Quote from: B Tremblay on November 27, 2012, 12:15:09 PM
The BBD chip is socketed in mine. It is a USA-built model and the date code on the pots indicates it was produced no earlier than May 1979.
ah, diggit.. i see that now. on mine, the socket is white, not black!
i used this thing live again last nite...and have decided i'm gonna sacrifice the new sad chip and leave it in there. this thing sounds amazing now. i highly reccomend playing with the trimmers, the stock ross settings are pretty mild... obviously the bias doesn't leave you much room to work, as the flanging only takes place over maybe 20% of the trimmer's range.. but the wet/dry trim and especially the clock can make an unbelievable difference.
i'm getting real close to the same kinda sounds charlie gets in his set up videos for the mxr 117. stock, the ross doesn't do that. a couple minutes with the trimmers, and a completely different animal. i don't think it can be hurt by messing with it, but i may be wrong so of course be careful. but i am pretty sure once you mess with it and get some of the capabilities out of this you can't stock, you may find this simplest of "mods" is worthy.
Just in case I feel experimental before putting the back plate on again, which is which trimpot?
Thanks for the pictures, I can compare the rest now easier.
Quote from: B Tremblay on November 29, 2012, 10:46:02 AM
Just in case I feel experimental before putting the back plate on again, which is which trimpot?
As I wrote earlier:
Quote from: analogguru
Anyhow, you have the last version of the Ross Flanger (same pcb as in the black one) and what can be seen from the pictures the schematic of the MXR Flanger (M-117) should match pretty well:
http://www.shredaholic.com/mxrflanger.html
The BBD-bias trimmer (R49 in the MXR-schematic) is the upper middle (between the pots), the trimmer beside the recycle pot is the "trim level" (R 48) and the trimmer (down in the middle) beside the transistors is the "trim clock" (R43).
analogguru
yep. my suggestion is (with it open and upside down, knobs away from you) crank the top left trimmer full blast, then hit the bottom one closest to you to adjust the clock. start with it all the way up, and you should hear a very phasey sounding flange. back it off until it sounds good to you, then play with the upper right trimmer and get it to where it sounds best...relatively small window. back off the clock a little bit, and play with the two until you find a nice balance. i have mine set so that the bottom and top of the sweep are about the same time, and backed off just to the point where it starts to sound like a metallic rubber band at the bottom. that way, can still get all the same sounds of the original ross a little earlier with the recycle control, or crank it up into jet territory. you still can find the killer chorusy and mild flanges, but can take it way beyond the stock sounds. i've had about 6 of these over the last 43 years, and this one is the best sounding of the bunch. all of them from the factory are pretty tame compared to what you can get out of it. you may find some settings of the bbd bias/clock give almost a formant kinda phasing sound. it's pretty hip.
and worst case? turn the trims back to where they were, and it's stock. but i think you'll appreciate the diff, brian.
analog guru...thank you so much for the help and insites!!
Thanks to both of you for the info and tips. I have never played it that much and maybe if I can tweak it a little, that will change.
i had a pearl and a dano flanger on my board for years now, both just got retired in favor of the ross, if that says anything. the only dif really is the pearl can self oscillate, like an echoplex..
but i gotta pair of plexes for that if i need 'em.
i think you'll like it a lot more...did ya see the SPT i put in this thread? happy tweaking brother!
I knew that chip would find a good home.
I love it when hard to find ICs are used to keep vintage stuff up and alive. :icon_cool:
Well played jimi!
Quote from: Tony Forestiere on November 30, 2012, 09:23:51 AM
I knew that chip would find a good home.
thanks again, tony, this thing is not only happy and healthy, but sounds freekin' awesome!!!
i will still probably build the flanger, but i think i'll do THAT with a 3007 instead. makes more sense.
the ross sounds sooooo good now...thanks!!
i hope brian checks in, lets us know his opinions after having a play with his one. ;)
Quote from: oldschoolanalog on November 30, 2012, 10:23:37 AM
I love it when hard to find ICs are used to keep vintage stuff up and alive. :icon_cool:
Well played jimi!
well, dave, ya know... i am blessed to have good friends like you and tony that make stuff like this possible!! ;
;)