Guyatone PS-021

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Guyatone PS-021

Alex
There's a schematic now available here: https://aionelectronics.com/schem/guyatone_ps-021.png
I want to draw a layout but I'm not 100% sure which components you'll need to eliminate to completely get rid of the flip flop switching system.
I was thinking: Q9, Q10, Q11, R15, R16, R20, R41, R69 and C10.
Any help would be appreciated.
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Re: Guyatone PS-021

rocket88
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Re: Guyatone PS-021

Alex
This post was updated on .
Cool Zach!
Would you remove the Input buffer too?
Is this what you've meant?
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Re: Guyatone PS-021

rocket88
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Yea. That looks like what I was thinking. Isn't the input buffer removed in the schematic you just posted?
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Re: Guyatone PS-021

Alex
It is.
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Re: Guyatone PS-021

aion
The output buffer is safe to remove, but I would probably not remove the input buffer. I've never seen a Ross/Dyna circuit without it, and I'd be a little wary of connecting the CA3080 directly to the inputs.
A BJT input buffer is very resilient, but a CA3080 can be fried very easily by static and the like.
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Re: Guyatone PS-021

Sergio
Hallo aion, your pcbs will be using lm13700 instead? Easier to get. Thank you!
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Re: Guyatone PS-021

GrooveChampion
Theres a conversion daughterboard for that
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Re: Guyatone PS-021

reddesert
The CA3080 is well out of production and fake ones are such a problem that I think people should design for LM13700 in future. I understand the desire to keep vero layout size down, but for PCBs, designing for CA3080 is designing in obsolescence. Using a daughterboard works but then you're not keeping the size down anymore.
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Re: Guyatone PS-021

Alex
Added the input buffer back and an LM13700 version.
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Re: Guyatone PS-021

reddesert
Cool!  I really appreciate how responsive you and the other designers on this blog are to suggestions.
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Re: Guyatone PS-021

R O Tiree
In reply to this post by aion
Hi, aion,

If you have an original schem to hand, I'd really like to see the flip-flop switching system. I get Q10/Q11 switching between "dry" and "wet" for the output buffer, but I can't see what Q9 brings to the party. Was this pedal an all-or-nothing system? In other words, when you switched it on, you got both the Dynacomp and the exciter? Or could you get Dynacomp on its own, Exciter on its own or both together?  If it's the latter case, then I can't see how the "dry" signal gets to the exciter on its own, or how the "wet" signal gets from the output of the Dynacomp to the output buffer on its own.

Thanks.