DIYstompboxes.com

Hi guys,  i' ve looked around for a diy 'stompbox' bass preamp schematic to tinker with...but have no idea of how they might sound!..

i have a 5 STRING BASS, into DI box into mixer,but sounds flat and lifeless still,  i just need something to lift it up and stay clean, and have a bit of tone control too maybe.......

as its a 5 string i'd like something that can cope with the low end well..

which diy bass preamps do any of you guys use?.....or have used....and would recommend?..(not onboard)

cheers in advance.. :)

Fet version of bassman 135 and or sunn 200's. AMT type of conversion, with schottky diode. Both are killer.

cheers, have you a schematic?...for either.

Here is a thread about a circuit I simmed.  I have not built it yet.  Input at C6
http://www.diystompboxes.com/smfforum/index.php?topic=96621.0 (http://www.diystompboxes.com/smfforum/index.php?topic=96621.0)

Note the 39K collector resistor at the first stage and the controlled gain for 9VDC operation.
Bootstrapped gain stage inputs and a Fender type tone section

hi gus, cheers man, looks nice and simple to breadboard..

where are the lug 2's of bass/mid?..or are they wired 2-1 connected?

Quote from: deadastronaut on March 17, 2013, 12:22:42 PM
cheers, have you a schematic?...for either.

No, but i can draw them. :)
You ll have them both tonight.

cool, nice one misa :icon_cool:

i'llbreadboard it/them and have a tinker.. ;)

Top one is bassman
(http://i1249.photobucket.com/albums/hh505/JebemMajke/Basssmansunn_zpsa193a5db.png)

The late Albert Kreutzer was a bass player and musical electronics enthusiast.  His website is still up, and he had a number of fully-fledged original designs, with layouts.  Do it for Albert.

http://www.albertkreuzer.com/electronics.htm

His preamp is really great.

Someone should mirror that site, as long as it's online...

@misa:  thanks man, but is it just me or is it really hard to read.... :)

i'll be using 3pdt bypass too.

@mark: looks great thanks, but i'd like to keep it to 9v.  :)

Fair enough.  Just keep in mind that bass can generate some serious peaks, necessitating the sort of headroom that the Kreutzer preamp amps for.

Mark brings up a very good point about bass pickup peak to peak voltage.

You can turn down the volume control on a passive bass but you lose the high end resonance of the passive bass and cable capacitance and input resistance of the preamp when you add enough series resistance with the input.  NOW this can be what you want.
 
Think about the passive bass volume control as it is turned down the wiper is the output so you have the resistance of the wiper to the input of the volume control in series with the input of the preamp.

I set the gain of each stage in the sim at about X10 inverting as a compromise for the 9VDC power supply and the output of a passive bass.  You could increase the output gain if needed.

@gus: 

hmmm , well i'll give yours a go on breadboard and see how i get on. i like the idea of 9v as i'll have it in my chain (but just used for bass)

i'm only looking for something to use for home playing/recording bass, so anything has got to be better than just DI /mixer.

was  i right about those bass/mid lug 2' pots on your schematic?..


i also found this..any thoughts?..
http://www.diystompboxes.com/smfforum/index.php?topic=73173.0

JebemMajke circuits look interesting. 

deadastronaut
I have not built the simmed circuit I posted.  The cool thing is you could build tone volume sections and try the different gain stages

The 9VDC supply and the input gain stage vs the passive bass output is what need the most attention,  Do you want to stay "clean" at all settings of the bass and get distortion latter in the circuit or do you want distortion from the first stage?

You could build a circuit with a Jfet input dual opamp and a tone section volume control between gain stages.

 

@gus:   i'd  like it to be clean really,

going from warm non toppy  to spanky/slappy

and maybe a little 'optional'  grit/drive to it...but mostly clean.

ok i re-drew the bottom one of jebem's preamps, just a bit easier on the eye..

are the bat 85's essential in this...or is there an alternative?...if not i'll just order a couple..no probs.   (edit just got some bat85's ;))

@gus: i couldn't get that scheme to work...it was late and i was tired though...so probably human error on my part. :)

(https://dl.dropbox.com/u/7464107/bassmanpreamp.jpg)


i redrew the bassman schematc as well, but for the life of me i couldn't see some values with my x ray eyes.. :icon_eek: ;D...could someone fill those in for me?..  R5/C4/C5

i think the rest is right?....(apart from ground on 1M pot)  ???

(https://dl.dropbox.com/u/7464107/bassmanpreamp2.jpg)

oh man, just breaded the bassman (bottom)...guessed the values

my bass is finally alive after all this time.....brilliant. kicks ass.....more tinkering to do...but yep it kicks properly now!! :icon_twisted:

I've used bat 85, bat 42, bat 43, bat 41 ... pretty much stays the same. Fets that I;ve used on bassman were q1 bf245b and q2 2sk30 and on the sunn ( the bottom one xD ) q1 2sk30 and q2 bf245c. Now the b version of bf 245 provides really nice, glassy kind of sound. More highs and mids. But also more distortion and more noise. The C version is low gain, low noise but lots of bass. 2sk30 is somewhere in between. If you find that it has more gain than you would like than remove the D1.

On bassman values are
R5 10k
C4 and C5 are 0.47 uF
Also vol pot on bassman should be connected to the ground.
Bassman is great for slap and all that jazz bass madness. That fat switch is for a bit more bass sound. It's a nice option to have. There used to be a bright switch, but I've found it to be useless. Both with bass and guitar.

It's a killer isn't it? :)

ahh nice one jebem, brilliant. thanks man,

i used 2n5457's on both Q's...sounds sweet, goes from nice n bright, but still with a thump to it too...which i love.

to warm soft rounded bass.....lots of output level on this too....my mid isn't working at the mo, but i quickly breaded it...i'll check it over in a bit,

if i wanted a bit of 'grit' in there too, are there any mods i can do to it, but still retain the original too?.

anyway,  what a difference, when i bypass it, it sounds so dull and lifeless, god knows how i put up with that since i bought it........i highly recommend this build,  :icon_cool: :icon_cool: :icon_cool:

thanks again man, you brought my bass to life.. ;).....yep got the 1M pot to ground.. ;)....



when ive finished tinkering i'll knock up a pcb/layout for those interested too. :)

Um, tonestack should be similar to the marshall one from duncan tone stack. Different values though. That should fix your mid pot issue.
You can add another stage to make it distort. Or you can use both preamps in one box and than run one into another. Also if you want more dirt use 2sk117's.

PCB layout would rock, especially both preamps on one pcb. I'm still learning how to use eagle's pcb part.

gotcha!..i'll try some other fets in there....experimenting time.. 8)

i only use diylc, but i'll be able to knock up a 1590b for this mutha no probs. ;)

man , i can't stop playing my bass now....its just so nice to hear my bass properly..even my tone controls on the bass are have come into fruition...wish i'd looked into bass preamps before...brilliant!.. 8)

CMOS opamps can get really close to the rails no problem. there are lots of CMOS opamp products that are new with excellent specs. maybe now is a good time to design something around one of these new parts? as a bonus, it will probably be really good on low power/long life battery operation. has anyone thought about a small signal transformer to attenuate and balance the input?

Quote from: deadastronaut on March 18, 2013, 02:27:55 PM
gotcha!..i'll try some other fets in there....experimenting time.. 8)

i only use diylc, but i'll be able to knock up a 1590b for this mutha no probs. ;)

man , i can't stop playing my bass now....its just so nice to hear my bass properly..even my tone controls on the bass are have come into fruition...wish i'd looked into bass preamps before...brilliant!.. 8)

I know, i couldn;t make myself to turn it off when I;ve first built one. I've even sold my old yamaha tbx 170 with three years old strings thanks to this preamp. Guy loved the tone. And he didn't believe that tone came from this little preamp :).
You can add some silicon diodes sym and asym clipping. That would add some dirt. Even lowering values of R 5 and 4 would introduce some dirt.

This is really cool!

Rob, did you get the tone stack sorted yet?

Edit: Hey Rob, I found this Alembic F2B schematic and layout... Looks a lot like the bassman, no? Maybe some subtle differences...

(http://dl.dropbox.com/u/11178619/Bass_pre/Alembic%20F2B.png)

@jebem:  cliipping diodes of course....i'll slap myself now. :)...my bass strings are the same ones on it since i bought it years ago...ive boiled them a few times ;D, but they sound great on this for old strings. :icon_cool:

BASS:  I love how this preamp has  'compression' to it too, without it my bass is all over the place level wise and just feels 'flabby'...but when this is on it tightens it up and i can whack the hell out of it

with no massive peaks n troughs...superb.

heres a clip of my lame ass bass without preamp, then with...and my lame ass playing.. ::)

https://dl.dropbox.com/u/7464107/bass.mp3

now.....

GUITAR: man, out of curiosity, i stuck my guitar in it, sounds really nice and full..

but get this....i stuck my distortion (spitfire v3) into it....DI then mixer...

and @#$%ING HELL FIRE it kicks some serious thrashy , chunky as hell butt..

its like an AMP and CAB SIM all in one...totally awesome.

here's  a rough as hell  clip up of the difference between bypass and on....you'll be shocked...i was,. :icon_twisted:
https://dl.dropbox.com/u/7464107/guitarbass%20preamp%201.mp3


jim: you gotta try this man...you'll love it!!!..\m/ :icon_twisted:\m/

(yep looks the same-ish to me, cool) 8)


anyway, i was thinking last night, due to the excellent sound of both guitar and bass...i fancy it'll be great , and ideal to have a nice ALL IN ONE bass/guitar preamp..

might just be a case of cap switching....might not, but definately worth investigating...., a very happy bunny....i'm on it today.


is there a guitar version of this?...so we can splice the 2..? :icon_idea:

or what values would make it ideal for guitar?....

i just got my bat85's...didn't seem to make any noticable difference with or without..hmmm..

In my opinion definition is better with bat's but you know, it's up to you weather you use them or not.
I use it both for guitar and bass. And i love to stack them or to run my supercollider clone into them ... damn isntant doom/sludge sound.

Quote from: J0K3RX on March 18, 2013, 09:26:05 PM
This is really cool!

Rob, did you get the tone stack sorted yet?

Edit: Hey Rob, I found this Alembic F2B schematic and layout... Looks a lot like the bassman, no? Maybe some subtle differences...

(http://dl.dropbox.com/u/11178619/Bass_pre/Alembic%20F2B.png)

Ofc it looks a lot like bassman. Alembic f2b is based on fender bassman preamp. I just like to use that extra deep switch on it. And tonestack is scaled on mine.

look ok?....not sure of that switch though?..
(https://dl.dropbox.com/u/7464107/bassmanlayout1.jpg)

Ps i my suggestion is to use log for bass and maybe even for treble. SW is fine.

cool, cheers jebem..

one thing i can't get to work on breadboard is that switch...

the C5 coming off C4...Has a 100k to ground, when i lift the 100k from ground , its no different....hmmm

I should change my username. I would like to use my real name. I can't get used to you calling me Jebem :).

That tonestack was nicked from bassman 135. Especially the deep/fat switch.
(http://www.thevintagesound.com/ffg/schem/bassman_135_schem.jpg)

misa then?. ;D

so the switch is the same as this...
(https://dl.dropbox.com/u/7464107/switcher.jpg)

btw i stuck a 680k after the 1M pot (which is now 100k pot) , as it was way too loud...just didn't want to blow my jbl's.. :D

Quote from: deadastronaut on March 19, 2013, 01:49:39 PM
misa then?. ;D

so the switch is the same as this...
(https://dl.dropbox.com/u/7464107/switcher.jpg)

btw i stuck a 680k after the 1M pot (which is now 100k pot) , as it was way too loud...just didn't want to blow my jbl's.. :D

Yes, Misa :)
It is loud as @#$%. I loved that about it.
yes that's the way to wire sw. Like i said i'm new to eagle and I make mistakes. Sorry for the confusing schem :)

So Rob, what would make this a good guitar clean channel? How is the tone stack?

@misa,   so what does jebem mean?...i'm curious now ;D

@jim:  the bass and treble are fine,plenty of bass,  the mid is a little weak but is there, ...still can't get that switch to do anything as yet though. ::).,

i have my family coming up for a few days, then my anniversary at weekend, so i'm gona be too busy to crack on with this till sunday probably... ::)

my old bass player is also going to try this out on breadboard  too...be interesting to see what he comes up with, he knows his shit much more than i do...and plays bass for real. :icon_twisted:

as for being a guitar channel, i'll swap caps in the tonestack to be more 'marshall' 'fender' values and see how i get on....thats the general idea anyway...

Well my whole nickname means motherf***er, and it wasn't supposed to be offending as it sounds. I am a big Frank Zappa fan :D. But Jebem on it's own is a verb, when translated to English it means "I f**k". For it to be just "F**k", one must say "Jebati" instead of Jebem. :) There you go a short class in Serbian dirty words :)
If you want more mids ( which I didn't want ) you should use marshallesque type of tonestack and/or bandaxall one. Because fenders tonestacks are deprived of mids. This tonestack is scaled. Hence those big and low values.

I don't understand how the sw isn't doing anything. You should have massive bass boost with it. You are sure that you've wired it to ground, and that mid pot is wired to ground as well?

ha ha ha...no wonder you was getting p....ed off  with me...  that's funny... ;D

that'll teach ya for using naughty usernames... ;D :D ;)

anyway..

yeah the stack as it is is great for bass anyway..does me fine, i'll have a poke around if i get time , and sort that sw out...i like the idea of a bass boost, even though its nice as it is for bass...just a good option to have too eh. 8)

then i'll have a tnker with the stack to see if i can come up with a guitar/bass stack-ish.. 8)

cheers jebem...erm.... misa.    rob. ;)

 ;D
Cheers
How about that Sunn emulation? The first one? Which one do you like better?

haven't tried the 'sunn' one with the stack on the end yet...

Than you should have nice od. Because without tonestack mine had some nice od tones. With a little boost from voodoo labs overdrive it was like a high gain distortion.

Edit

I;ve forgot to mention in the last build I've used 2sk30gr's in both q1 and q2.

Have you checked out Ginger (http://runoffgroove.com/ginger.html)?

^ yeah that looks cool too..

i'm quite happy with this at the mo, ...still no joy on that switch btw.. ::)

anyway heres a demo of what i have so far...

I'll make one tonight. I'm wondering wtf is wrong with the sw.

hi misa, me too...ive tried it several possible ways...

have you a layout of the one you've built...then i can see whats going on with it.

Not really. I'm always using raster board for my designs. I'll do one tonight and I'll post some ugly looking pictures of it  :icon_redface:

okey dokey...cool. 8)

Looks like you're missing a cap on that deep switch.

Rob, have you wired it this way. Mid pot to the ground and sw to the ground
(http://i1249.photobucket.com/albums/hh505/JebemMajke/switcher_zps7099655e.jpg)

i'll give it a go in a bit, ... :)

nope, if you lift the mid pots ground there is a  massive boost in level.

but not a bass boost. ...i'll see what you come up with...

What do you mean "lift the mid ground"? Just check if that 100k resistor is connected to the ground. Ofc leave mid pot connected to the ground.

1k mid pot always stays grounded. The way it is, switch open takes the path of R6 / switch closed takes the path of least resistance to ground... right?

^ yep.. :)


@misa: i was just trying various ways of switching it... ;D


heres a clip of how that is wired as in the diagram...first clip is how i had it...second is with switch

does this sound right?/the same as yours?...bit of a level diiference?

https://dl.dropbox.com/u/7464107/bass%20sw%20test1.wav

You might have another look at the original bassman schematic... I see some differences. :icon_confused:

Well for me without sw it sounds like jazz bass. Slap is great, it's nasal and great for lead and jazz, blues, 80's. With sw it's ... well it's very close to Korn type of sound ... it's very modern and almost ghetto type bass. But, again my usual eq settings are mids at 8 o'clock, treble at 12 o'clock, bass 3 o'clock. Maybe you've wired that sw the wrong way. When you think it's on it's actually off, and vice versa. The second part of the clip should be similar to mine with sw off. That's how alembic FB-2, fet version, sounds. You can take the sw out and place the jumper there. And it will always be on. Also there is another mod with the tonestack. I'll post it soon.

@jim: which differences?...which schemo?

@misa: yeah i like the sound of both, but does yours have that difference in levels?

Quote from: deadastronaut on March 26, 2013, 05:46:09 PM
@jim: which differences?...which schemo?

For one, the tone stack values (caps, resistors etc.) are different? Maybe it's scaled, I dunno? Might try the original values to get more tonal control?

Quote from: deadastronaut on March 26, 2013, 05:46:09 PM
@jim: which differences?...which schemo?

@misa: yeah i like the sound of both, but does yours have that difference in levels?

Yes, but not that big.

@Jim
Yes it's scaled, ten times. To try and lower the overall noise issue.

Quote from: JebemMajke on March 26, 2013, 06:22:08 PM

Yes, but not that big.

hmmmm i'll wait till you knock up yours and copy that then... :)

dooby dooby dooobyyyy ahhhh ahhhh ahhh ahhh ahh ahhhhhhhhhh... ;D

any news?

How about removing that 680k resistor after the vol pot, and using 1m pot for the volume. Because that's what you've changed from the original. Maybe that's your issue.

ahhh yes... :icon_idea:

i'll try that.

If it hits the top too soon, use log for volume. I mean in reality that's gain pot. You could add master vol at the end. And than place sym/asym sili/germ diodes on the first vol pot, thus making that gain pot. :)

going to try the other preamp today....see how that compares ;)


btw swapped that sw 100k for a 5k pot...gives a nice choice of range'.  8)


edit:
ok tried the other version, nice but i prefer the roundness of the bassman actually...both versions are @#$%ing loud...would these drive a speaker? just curious

i'll put the bassman back on breadboard... ;)

Not sure if they would drive a speaker. The "sunn" is great for that lower kind of bass sound.  I've played in Santana/Clapton tribute band with it and it was great. And bassman was used in metal/rock situations.

I'm building ggg TDA20x0 amp. With Tda2040 and 1x12 cabinet. And I'll use one of these two ( or both ) as preamp. Just need that 4.7r 1/2w resistor, and that's the reason why this project is on hold till Monday / Tuesday.
Nice mod, why only 5k?

5k seemed best i tried all from 1k to 100k...but i'll probably just keep it simple without the switch etc..

been trying to get a bit more mid control though....

another nice mod is switching caps on the tonestack...

switching between 2.2n as normal, and a 1nf...the 1nf makes it great for soft rounded bass.  ;)...and the rest of the stack responds nicely too.

i think i'll go with this for a build...seems nice to me, and no jump in levels either.

i left the bat85's off as they didn't seem to bring anything to the party, put the 680k on out to 'tame' the overall level to be acceptable to me, but still have enough as a boost on the overall volume if needed.

(https://dl.dropbox.com/u/7464107/bassmanmodded.jpg)

here's the layout and pcb files for anyone interested...checked over, all looks fine. 8)

https://dl.dropbox.com/u/7464107/bassmanlayout.pdf

https://dl.dropbox.com/u/7464107/bassman%20pcb.pdf

making a few pcb's today...

btw i put the pads in for the bat85's if you really want them in...(optional) ;)

pcb populated, layout tested+verified.

should have made more room for the 1uf /470n caps..but i squeezed em in ok...

now to design my etch... ;)

sounds nice with that switching caps, warm to bright...suits my taste. :)...great preamp.

cheers guys!..  8)

Looks nice and clean and simple! I like it!!

deadastronaut, i like how alive the bassman sounds in your clip - just what my bass has been missing too!

btw: do you have an active or passive bass?

hi jp,

i have a passive 5 string, sounds great now, when i listen to it without it , i understand why i never really played it much...massive difference. 8)

re: the layout:

i'm adjusting the layout to fit small trimmers and shifting a few caps to fit better, i'll post the layout/pcb up when done, soon  ok.

cheers rob.


just finished etching my box, waiting for paint to dry...building today.  ;)

ok heres the better spaced version. ;)

https://dl.dropbox.com/u/7464107/bassmanlayout.pdf

https://dl.dropbox.com/u/7464107/bassman%20pcb.pdf

DONE!... 8)

(https://dl.dropbox.com/u/7464107/P100413_16.56.jpg)

(https://dl.dropbox.com/u/7464107/P100413_16.57.jpg)

(https://dl.dropbox.com/u/7464107/P100413_17.00.jpg)

(https://dl.dropbox.com/u/7464107/P100413_16.59.jpg)

Once again you blow my mind with your design!

cheers jim,  my missus actually chimed in on this design...as i kept ''fannying around'' too much in her opinion....  ;D

That's gorgeous, Rob.  Much kudos to Mrs. Astronaut for the design.

Quote from: bluebunny on April 10, 2013, 02:06:28 PM
That's gorgeous, Rob.  Much kudos to Mrs. Astronaut for the design.

Mrs astronaut said '' thankyou.......beep........................beep...........very much.......beep........................beep...................... ;D

Cool pedal man. I really hope i get that good at it.

Rob this looks @#$%in awesome. Sick one.

cheers guys.. 8)

i just re-jiggled the bass layout/pcb. the cap switch was popping too much ...one of those irritating things that needed ironing out..

and yes, i 'm quite anal about such things... ;)

very quiet now. 8)


https://dl.dropboxusercontent.com/u/7464107/bassmanlayout.pdf

https://dl.dropboxusercontent.com/u/7464107/bassman%20pcb.pdf

etching a new pcb for it now... ::)

Where abouts are the BAT85.s Rob ?
I'm not familiar with the schematic and I want to build this tonight
thanks
Rich

hi rich, the bat85's are the 'orange diodes'..

i left the pads for those in as 'optional' i didn't use them, they made no audible difference imo.

the 1n4001 'black diode' is optional too (power protection)

^ use the layout above ok. :)

use small trimmers too.

have fun, i'm just drilling my new pcb. :)

I am using the above layout.
for some reason i thought it ddint have a protection diode so im putting mine next to the top left trimmer. oops
It sounds amazing.
What is the foot note about the switch resistors 1M-10M ? was there a problem ?
It's such a low parts its amazing it sounds so good.
i think i might use it in a Bass box. If thats ok with you?
I'd like to incorporate a Pre/Di compressor and distortion with blend.
I intend to have fun mate. I love the smell of flux in the early hours.

hi rich,   i rebreaded it as its small just to get rid of a 'pop' when switching caps...its ok now.  stick 1M to 10M in there (where the 2 paralell 1M's are...)

yeah no problemo help yourself man, , i'd like to knock up a compressor to go with it too, but i want a compressor to serve bass and a guitar..probably just cap switching again.

as i just record at home now..

Just one thing be careful with dirt boxes and this thing together. It hates big muffs, loves Fuzz Face, Loves light overdrives ( zendrive, tubescreamer ). Chorus, delay, phaser ... it all works great with it. But you should be careful when choosing dirt boxes for this preamp. I remember that last summer I've been on a quest for right kind of muff for my bass. And supercollider was the best, and still is. But this preamp ( both of them ) hated it. Especially with the drive knob over 11 o clock. It would turn into gated, over compressed muddy kind of a fuzz.

On the other hand it loved my sili-germ hybrid FF. So it's not on a war path with fuzz boxes. Just with muff's :).

I built a 3 knob seymour duncan fuzz when i first started building that i think will go well with this bass pre if thats the case.

Heres a link to the schematic

http://www.seymourduncan.com/tonefiend/wp-content/uploads/DIY-Club-Project-2-v02.pdf

Do you think this would sound good with Bass and play well (interact) well with the Bassman pre JebemMajke?

Don't know bro. You should try it and see for your self. But always be prepared to make alternations.

will do then buddy
thanks
The main board is now populated and ready for some pots in the morning.

Ok its built but it needs a debugg
i ommited the bat 85 as suggested.Not a peep.
Do i have to set the trimmers somehow?If so how and to what.
Im going to need 3 pairs of hands
First i'm going to go over the board with my DMM.

OK since i missed out the bat 85 does the + side of the 47uf cap (bottom left of layout)go to the 1k or 1m resistor?

- to the ground. And plus touches 1k. Yes.

Trim both to 4.5 or 6 if you please. Or even better trim to your liking.

Trim both to 4.5 or 6 if you please. Or even better trim to your liking.


Kilohms or volts?

im getting there now the probe says signal is getting as far as the volume pot and all the tone pots but struggling to go further. Some how i've got mains type hum on the 680k output resistor.

I had made a wrong connection from Q2.
It's all working fine now.
It sounds sharp and quite (no pedal noise) but with lots of headroom.
The tone stack is amazing as usual with Robs designs.
I even tried it on guitar and it has such a wide variety of tones its amazing on that too.
Thanks guys
Rich

cool glad you got it going man...

yeah masses of headroom...i put the 680k there to tame it back a little as it was way over the top level wise otherwise.

the cap switch is nice eh...2 tones in 1. for hard/soft.

on guitar with distortion in front its really chunky as f..., i'm going to mess around with this stack to make it suitable for guitar too...and add a presence too.

finishing up today too. :)

I've played it with bandaxall, with mid shift and it was really good sounding. For guitar that is.

Its a cool low parts well designed circuit mate.
I'd be intrested to see what you work out for the guitar mods.
I should also say I prefer how it sounds through a solid state amp rather than tube.


I think i will put the compressor infront of the pre in my idea for an all in Bass pre/DI
then the distortion with buff and blender.
Is there a way i can make the blender without the buffer?
The Schematics half way down the page.
http://www.beavisaudio.com/techpages/BlocksFragments/


Any help or comments on this order of things is welcome
Rich

Just cause i'm curious. I tried using it as a DI straight into the sound card to record.
It maybe loud through an amp but its definitly not line level.
I bypassed the 680k on the output and voila just the right level for recording so' i'll have to put a switch in the Bass box to change between Amp and DI levels.

strange, my setup is the same....but with mixer

bass-DI-mixer-soundcard.

plenty of level this way...more than enough, my bass preamp at 10oclock on level

and 10 oclock on my mixer trim...


finished my build#2

layout/pcb verified. ;)



blend buffer:  whenever ive tied the blend buffer there is a point at 12oclock where the 'level' drops...very annoying.

a really simple way is to just use a pot..

out of bass preamp to lug 3

out of comp to lug 1

lug 2 overall out...crude, but its the most basic mixer i can think of. :)

i'm struggling to make the preamp work well with almost any distortion i've made.
It works best with the boss sd1 (genuine)
next up is the yjm 308 and the thunder drive although i dont hold much hope with the thunder drive.
I still have a few to go
ocd3
vlo
Gus   GCS o/d
the ts808
wish me luck

In my set up i use the mixer for routing on back of soundcard.
My set up is modest but capable of good sound i think.

demo  :)

Very cool.
Superbe mate.

Finally I've found some spare time to rebuild my bass preamps. So today I've completed Sunn, Bassy  as @#$%. And big vol boost :D. Which is always great. Especially because we ( my band ) are being forced to play on these little 30w amps. So until i finish that TDA 100w amp I will be using this in front of my 30w amp for boost, and in general to get that sweet sweet sound. Tomorrow I'll do bassman.

30W?....awwwww.... ;D

are you building both into a box then?.. 8)

Quote from: deadastronaut on April 23, 2013, 03:50:12 AM
30W?....awwwww.... ;D

are you building both into a box then?.. 8)

Yes :D

cool. :icon_twisted: :D

Nice work, gentlemen. Has anyone tried it at higher voltages? 18/24V, etc.

nope!..not me anyway.

I've tried 18v. Works just as well. Maybe more dynamics and less distortion/compression. I've finished layout for both ( sunn 300 and bassman ) on a single board. But those lines are too thin. I'm a newbie to eagle. How can I make those lines a bit thicker?

Throwing dastronauts design in mah shopping cart.  Bad ass, man!

Quote from: deadastronaut on April 10, 2013, 12:30:15 PM
DONE!... 8)

(https://dl.dropbox.com/u/7464107/P100413_16.56.jpg)

(https://dl.dropbox.com/u/7464107/P100413_16.57.jpg)

(https://dl.dropbox.com/u/7464107/P100413_17.00.jpg)

(https://dl.dropbox.com/u/7464107/P100413_16.59.jpg)

Hi there. i'm planning on building this preamp. I wanted to ask you two things. Why did you use 2n5457 instead of j201's. and why did you go from 1M to 100k on volume pot? Does the 100k let it distort less?

I am a bit confused, what's the exact bill of materials for  deadastronaut 's bass preamp pedal?  :icon_question:

I have done Taylor's tiny giant 20watt amp , but the bass explodes my speaker  :(  Is this preamp circuit suitable for smoothing the bass signal?

hi fatecasino...

use this layout..same as i used.

http://www.diystompboxes.com/smfforum/index.php?topic=101898.msg905776#msg905776

Hi!
I just built it, it sounds really nice (I am not a bass player, but I will get a detailed feedback from an actual bass player :) )
Technically I had 2 small problems,
1. I think I have to change the value of both trimpots because they only work for a pretty narrow range, something like 7 and 8 o'clock, just 1mm of rotation, after 8 o'clock the sound disappears through all the way to the right.
2. The 680k just kills all the signal. I get 100% of sound before that and 0% after that. I omitted (?) it and the sound came back.

Do you think that these problems have to do with the build itself or with the design? I guess this exact design has worked perfectly for tens of times :)
If anyone here had the same problems could s/he post any suggestions?

Deadastronaut, do you have a list of components for this build ?

thanks

docs on page 4....

Hello! Has the DeadAstronaut project documents been removed? The link does not work !!! ::) :-\
Can someone post again?...tks!!!!

hi they got lost when dropbox decided to change the way they deal with ''public'' pictures..

:icon_sad:

Resurrecting this thread briefly - just to say I finished building this recently:

(http://www.bouron.org.uk/marc/bp399.JPG)

And after finding and removing a track short (:icon_rolleyes:), it sounds bloody good!  Nice one, Rob.  :icon_cool:

yay you got there in the end ...

look great man, even added the 5 string........ 8) 8) 8)

Thanks, Rob.  I didn't have a good face-on picture of my own bass:

(http://i.imgur.com/qSq1Tlj.jpg)

...so I nicked one that looks similar from Martin Petersen's gallery (http://seibass.com/origpics1.html) (this one (http://seibass.com/seioriginal5hl.html), in fact).

nice looking bass man.... 8)

i have an old yamaha 5 string...

have you a diy bass comp?...

Kinda ironically, I'm mostly a straight-into-the-amp kinda guy!  I've used the Bear Hug for bass - it's not too obvious (which I prefer).  But I don't often compress.  Sometimes I'll gig with just a Small Clone (my build, of course).  Or recently I've been using a SY-300 for fun.

BTW, found some other pics of my baby:   ;D

(http://i.imgur.com/7JGTJ21.jpg) (http://i.imgur.com/3Ty2Bcf.jpg)

All Files are gone :(

I had a similar Schack Carbon 4-string.

here you go, made a new 'public ' link.

hopefully it works.  ::)


https://www.dropbox.com/s/eblob0lrr3bmwjt/bassmanlayout.pdf?dl=0

https://www.dropbox.com/s/a14p16c08rp9u1v/bassman%20pcb.pdf?dl=0

 :icon_biggrin:  :icon_lol: 

 ;) 8)

i changed the mid pot to a B2K and used an A25K for the bass pot. it sounds great now.

Hmmm... pretty sure my middle control does something.  I have it tilted to the right in my picture above coz it sounded good there.   ???    I'll have to dig it out tomorrow and give it another listen...  Got pictures of your build (the board) in the meantime?

don't bother to look at it. it's solved. there's nothing wrong with it. i had a tiny solder bridge on my mid pot to ground on my etched PCB. thanks for the circuit!

Quote from: johnk on December 19, 2018, 06:19:32 PM
i had a tiny solder bridge

Well, whadaya know?  Me too!   ;D                             (Scroll up...)

 :)

Quote from: roseblood11 on March 17, 2013, 05:01:23 PM
His preamp is really great.

Someone should mirror that site, as long as it's online...

you were absolutely right...
now it is not no longer online....
BUT it has been mirrored :)
https://web.archive.org/web/20100616023918fw_/http://www.albertkreuzer.com/

Quote from: deadastronaut on November 29, 2018, 09:49:25 AM
here you go, made a new 'public ' link.

hopefully it works.  ::)


https://www.dropbox.com/s/eblob0lrr3bmwjt/bassmanlayout.pdf?dl=0

https://www.dropbox.com/s/a14p16c08rp9u1v/bassman%20pcb.pdf?dl=0

Could you repost the schematic for this if you still have it? I want to try breadboarding it and it would be easier with a normal schematic.

hi , this is it if i remember correctly....

https://www.dropbox.com/s/4mysdj0w7mi3cwt/bassmanpreamp.jpg?dl=0

Ressurrecting this topic again.

Today I got a request from a fried for a bass preamp, and this one was the very first thing that come to mind. I built a similar one to use with guitar and I know it sounds great, so it should sounds great for bass too. And this one have almost all features my friend is looking for.

The only thing my friend asked for and this one doesn't have is a "mid shift" pot. I mean, a pot to shift the center frequency of the mid pot. I know it can be done by switching the caps, but for some reason my friend prefers it as a pot rather than a switch. Any way this can be done?

My idea would be something like this...

(https://i.postimg.cc/0z3sNFWq/21-B9-C72-A-C40-C-44-F6-A44-B-521-C156-F7-C8-B.jpg) (https://postimg.cc/0z3sNFWq)

A midshift pot would act as some sort of capacitance control... i don't know the exact values that would work but i guess trial and error would be needed as I didn't test this or calculate anything at all... :icon_lol:

Again, untested, but just my idea...

Quote from: 11-90-an on December 28, 2020, 11:50:42 AM
My idea would be something like this...

(https://i.postimg.cc/0z3sNFWq/21-B9-C72-A-C40-C-44-F6-A44-B-521-C156-F7-C8-B.jpg) (https://postimg.cc/0z3sNFWq)

A midshift pot would act as some sort of capacitance control... i don't know the exact values that would work but i guess trial and error would be needed as I didn't test this or calculate anything at all... :icon_lol:

Again, untested, but just my idea...

i doubt that pot will do what you want it to do...
injecting more resistance in an already high impedance circuit ducks up more than the frequency you want to target.

change the treble pot to 1M
and place parallel to the treble pot a 1M pot wired as a variable resistance in series with a 100k resistor, this will sweep the mid frequency, and have about the same degree of interaction with other pots as the other pots have on each other.

cheers, Iain

Didn't came to mind I'd have to play around the treble pot to get a midshift. Just to be sure, like that?
(https://i.postimg.cc/V5mpy4D5/tonestack.jpg) (https://postimg.cc/V5mpy4D5)

Quote from: Marcos - Munky on December 29, 2020, 12:59:23 PM
Didn't came to mind I'd have to play around the treble pot to get a midshift. Just to be sure, like that?
(https://i.postimg.cc/V5mpy4D5/tonestack.jpg) (https://postimg.cc/V5mpy4D5)

yup!
you might want to add a buffer since it has really high output impedance now.

cheers, Iain

Sure, I'll add a jfet buffer. Just another question, should I still use 470K for the volume pot with this high output impedance?

Quotei doubt that pot will do what you want it to do...
injecting more resistance in an already high impedance circuit ducks up more than the frequency you want to target.

A better way to implement the intent of the idea would be to have the 100nF permanent and have a pot in series with the 220nF in parallel with 100nF.    Would need to test to see if it's worth a pot.

There's many ways to bend tone controls like that.  Often the result is quite subtle.    Maybe look at the Blackstar.

I did a quick search and found another possibility: to make the resistor variable, like this: https://i.imgur.com/iYkXZqK.jpg. It'll affect the highs and lows, but the results seems to be interesting.

Quote from: Marcos - Munky on December 29, 2020, 06:42:43 PM
Sure, I'll add a jfet buffer. Just another question, should I still use 470K for the volume pot with this high output impedance?

i recommend placing the volume pot after the Jfet buffer as to not load down the tone stack. or if you don't mind crackle while turning, use it as the Jfet pull down resistor, in that case, 10k is fine.

cheers, Iain

QuoteI did a quick search and found another possibility: to make the resistor variable, like this: https://i.imgur.com/iYkXZqK.jpg. It'll affect the highs and lows, but the results seems to be interesting.

Do a search on "slope resistor".

Found this page while searching for slope resistor: https://robrobinette.com/How_The_TMB_Tone_Stack_Works.htm.

To be honest, the friend could just set with switchable caps and we were good to go lol. But I think the preamp will end up very versatile. Now, just have to set a few details with the friend and etch the board.