Untested. Note cut traces under R2
(http://www.diystompboxes.com/pedals/pcb/diodecompress.gif)
Layout looks alright here.
What kind of circuit is this ?
Quote from: HOTTUBES on February 27, 2011, 12:17:04 AM
What kind of circuit is this ?
its a discrete op-amp. You connect it in place of a LM741/TL071 single op-amp chip.
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Aron,
The only thing thats missing IMO is a trimpot in place of R1, so if you use germanium transistors for Q1 and Q2 or change D1 for other types (germanium or schottky), you can bias the circuit correctly. I've done that in protoboard (I even tried a Mosfet and a Darlington for Q3).
Germanium op-amp eh?
Is there a benefit to building this , and using it in place of a regular opamp ,in terms of sound quality ?
Quote from: HOTTUBES on February 28, 2011, 04:31:07 PM
Is there a benefit to building this , and using it in place of a regular opamp ,in terms of sound quality ?
here's a post talking of how the circuit works, just some lines below this one on this forum's main page:
http://www.diystompboxes.com/smfforum/index.php?topic=79132.0
and I like this circuit because you can actually tweak the sound of your op-amp, instead of just changing it by another model and hope there's a difference in sound.
Just try it in a Distortion+ or Rat circuit, use a 25k trimpot in place of R1 (adjust it to get 1/2 Vcc in the "out" pointed in the picture), and play with the transistors.
Try different models of transistors (as I said before, you can use germaniums for Q1 and Q2, and a Mosfet for Q3, or whatever combo you want), different betas, different diodes (schottky, germanium, silicon, even try LEDs if you want!).
I don't know about you, but I LOVE to play around with these circuits.
Has anyone done a vero layout for a dual varient of this?
If not I can probably work out enough to bash one together for the other newbies... just need to check over the op amp theory and work out the +/- In's lol :icon_biggrin: