This is a library of perfboard and single-sided PCB effect layouts for guitar and bass. I'm not an electrical engineer by any stretch of the imagination, just a DIY'er who likes drawing layouts. It is meant for the hobbyist (so commercial use of any of these layout is not allowed without permission) and as a way to give back to the online DIY community.

Tuesday, June 25, 2019

1981 Inventions DRV

There's been a lot of hype about the DRV and it's a very cool pedal from a very cool builder too. At it's heart is a tweaked RAT surrounded by 2 opamp gain stages and buffered bypass, all running on 18 volts (schematic below). Originals have soft touch relay switching, which has been omitted here. It can be wired either for true bypass or buffered bypass like the original (see wiring diagram below). If you want to use a MAX1044 chip for the charge pump instead of the LT1054, I've added 2 additional pads on the PCB to connect pin 1 to 8. Should squeeze into a 1590B nicely.






Wire In Jack to In pad on the board.

49 comments:

  1. cheaper substitution for LT1054 - 7660S?

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  2. Apart from the 1044 chip you'd have to do a different voltage doubler off board.

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  3. Well thanks a lot, that's killer! I assume the 1N4148 diodes are for clipping duty? So we can test whatever we want?

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    1. Yep. Already wishing I'd used some sockets in my build to try out some BAT41s.

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  4. On the psb diagram it is indicated to connect for 1044 1 and 8 contacts, will this be enough?

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  5. To wire it as true bypass it is enough to ignore bufor in and out? Or I have to do something else?

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    1. Just ignore the buffer out pad. Or better yet, you could cut the trace between pin 3 and 5 of IC1 (the left TL072) and connect pin 3 to the Vref (half supply, yellow trace). Then omit the 4.7µ cap and the 100k and 470Ω resistors right above IC1. That would properly terminate the unused section of IC1.

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    2. Thanks. Will try it next week :D

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  6. hi everybody!
    what a great project! ( i,ve been looking for this one since a few month!)
    build it, with the 1044 charche pump, and it works from the first time!
    im not really sure about the gain factor?? mine has a little less gain......
    but with a booster in front, it works great!
    i have the chance to compare it with an original the next days,
    as always: great job, really cool project! thank you
    ( maby i try out some different opamps, and replace the charge pump...)

    greetings from austria

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    1. Something might be off there, because it can get pretty nasty with the gain after 12:00

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    2. boa tarde Blues, usei o max1044 também, ainda não coloquei na 1590b, no entanto o meu gera um ruido/microfonia muito alto a partir das 12:00 que incomoda, o seu funcionou direitinho ou também possui o ruido?

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  7. This looks awesome - do I need to make any jumpers/new traces if using a 1044?

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    1. If you're building on perf you'll need to add a jumper to connect pins 1 and 8 of the 1044, but if you're etching, there are pads already for the jumper.

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  8. If I want to run it at 9V can I just omit the 1054 section completely and connect the 9V+ to R3,R9 and R14?

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    1. Yes, just omit the 1054, the 2 extra 10uF caps connected to it (C14 and 15), and the 2 extra 1N5817 diodes (D4 and 5, to the left of the 1054), the jump the anode of the lower left diode (D4) to the cathode of the upper left diode (D5).

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  9. I can not find pcb in Transfer Image Library. Could you share the link?

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  10. Hi! I am new to the blog so first things first, hello everyone hope to have a great time and fun with this community!!!! Secondly, Thank you so much for the project! I had a lot of fun building it on a perf board! I managed to squeeze it into a 1590B, very challenging but it worked. It sounds amazing!!!! I used the 1044 and did a TBP output. The sound is just exquisite! Thank you!!!!

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  11. hello! this set up is not passing a dry signal for me. i'm thinking it's the FS wiring. i wired it like the diagram above. any tips? i do get sound when it engaged, and it sounds rad. any help would be appreciated. thanks!

    chuck

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    1. actually, i think it's more likely that i'm not getting any buffered signal out. i have to do some further inspection...

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  12. Just plugged this in - I originally mindlessly plugged in a 7660 and wired the pots backwards. I replaced it with the 1044 (don't use the 7660). This thing rips. Thanks!

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    1. If you use a 7660 you must link terminals 1 and 8. Enough.

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  13. boa tarde pessoal, montei esse pedal o drive funciona mto bem, no entanto ele gera um ruido como se fosse uma microfonia e não consegui corrigir alguém pode me ajudar?? usei o max1044.

    ABRAÇOS

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    1. Você conectou o pino 1 ao pino 8 do 1044?

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    2. Conectei, fiz um teste desviando totalmente do max ligando direto em 18v e funcionou sem ruido, o meu MAX que não funcionou devidamente vou precisar comprar novos CI's .
      obrigado pedal muito bom!

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    3. Desta forma e ligando direto em 18v eu estaria perdendo qualidade no pedal ou ele estaria funcionando normalmente??

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  14. Hey! Are you selling a pcb for this design? thanks

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    1. Not on the store, but shoot me an email and I'll hook you up.

      gehringcustomguitars@gmail.com

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  15. Just built this as well and it works great. I attempted the true bypass build instead of the buffered bypass as detailed in another comment and it worked properly.

    Just wanted to note I was getting weird grounding issues when I connected it into the daisy chain power supply on my pedalboard, but only when the 1/4" cables were connected. I'm using non board-mounted pots and the perf was floating and happened to touch the ground of the signal jack...kind of a weird situation that's totally my fault but be cognizant that it's a tight build

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  16. Is there any sound difference running 9V instead of 18V?

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    1. There's a little less headroom, but it's not super noticeable IMHO...

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  17. if i use 1044 only need a jump wire between 1 and 8 pins?

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  18. First of all thanks for all the contributions. Second, I apologize if my question is a bit silly. If I supplied 18v directly from a source right in the space between the D5 and R18, would it work without the need for the voltage doubler (LT1045)? Thanks

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  19. All my 7606 are whistling, so i built whithout them! I like this 1981! Nice sound!

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  20. Hi, how many volts are the polarized capacitors? thanks

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    1. I'd go 35 or 50v. You should be fine with 25v, but I've seen a couple of them blow on a 9v supply so better to err on the side of caution

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    2. Thanks for answering .. I am from Argentina and I use a translator haha, I have another question, can I omit tl1054? in that case what are the connections? or what replacement does the tl1054 have?
      by the way, this is my first project

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    3. You can use a MAX1044 or ICL7660 chip to get 18v. You'll need to jump pin 1 to 8 if you're using those chips. It will also run off 9v just with a little less headroom. Just replace D4-5 with jumpers and omit IC3, C14-15. Hope that helps

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    4. hola.! arme todo pero me esta saliendo un ruido bastante feo, será que me puedo comunicar con vos? para manadrte fotos y videos y me ayudas por favor

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    5. mételo en una caja de aluminio y revisa que haya tierra en todos los lugares donde debe de haber tierra y que haya continuidad entre la caja y la tierra. Eso suele resolver los problemas de ruido. Sino se resuelven puede ser cuestión de deficiencia en el filtrado de los 9v.

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  21. Boa Tarde!!! Sou Brasileiro e vou tirar esse Buffer e deixá-lo True Bypass!!! E vou usar o Setor do CI para Buffer de Tensão para filtrar o ruído!!!

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  22. Acredito que assim, não fará diferença no Timbre!!!

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  23. Hello there! Thank you for this amazing site. I just don't understand what to do if to use 7660 instead of 1054 (except jumping pin 1 to 8). Thank you in advance.

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  24. Real late to the party here, but has anybody here built this from the etched circuit? I’ve etched two boards and both ground out as soon as the signal hits R12. Both the clipping diodes ground out, and all the lugs on the cut knob but only when plugged into 9v. Any ideas?

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    1. Is it grounding out between C8 and R12 or after R12? I'm wondering if you've got some bad diodes that are just acting as jumpers.

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    2. Seems like the diodes were the culprits! I'd already switched them out once, but doing it again did the trick. That was a new one for me. Thanks for the tip. Much appreciated.

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  25. Really an excellent sounding circuit, I built one last year and it worked right from the get go. Now I'm on to round two and some modifications!

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