Ersatz Verben - PT2399 pseudo reverb

allesz · Post by **allesz** » 16 Mar 2012, 22:11

[quote="audioguy"]just finished this one and its a little dark, rolls off a lot of high ends. I swapped C7 and C1 for .047, not much help. Should I try smaller, or is this just going to be dark?

I think this is the limit of this architecture... my crap-fi delay has got the same problem.

Smaller input and output caps won't cure this; you can add an input buffer, I am working on it for the delay and it seem to get better, but I have not boxed it yet (just breadboarded once with good results).

Try increasing R3 to 100K; you will get a strongher signal and probably some (unwanted?)distortion. I had somewat better results with a 50K mix pot, nothing to scream about but a little better.

Post by **audioguy** » 16 Mar 2012, 22:39

Changed values again, C1 to .022 and C7 to .01 and its usable now. Still rounds the highs off a bit, but no longer in an un-natural way.

allesz · Post by **allesz** » 16 Mar 2012, 22:46

Hey, you are on the breadboard right now, aren't you?

I will try those values as soon as I can.

culturejam · Post by **culturejam** » 16 Mar 2012, 23:54

I don't think it's all that dark with the stock values, but maybe it's my gear.

Since the the second low-pass filter in the chip isn't being used, the wet signal needs some pretty heavy low-pass filtering to keep it from sounding all "low-fi". If you like that kind of sound, you can reduce all the filter caps' values.

Specifically, C6 sets the "minimum" roll-off when the delay time pot is at minimum. C4 starts to kick in as the Delay pot resistance increases. So you can also lower the value of that to make it less dark.

allesz · Post by **allesz** » 17 Mar 2012, 09:23

Well, tonite I tried a 22nF input cap and I liked it. Maybe it was a little too light, 33nF? A positive effect of the smaller input cap is that it does not distort even if you hit hard on the strings (but I use single coils).
I left the standard 100nF output cap by the way.
Anyway I plan to continue testing using the secon Opamp as input buffer because the effect seem to be more forgiving for other effect placement... right now I put it first in the fx chain because with some (unbuffered) dirt boxes I experience some weird behaviour; but I will try lower input caps too, it seem to be a good (and unexpected to me) way to move.

ThePastRecedes · Post by **ThePastRecedes** » 23 Mar 2012, 18:40

Hey,

I'm planning to build this too. I've done a perfboard layout.

I think it should be okay but anyone else care to check it before I go ahead?

thanks!

Troll_face · Post by **Troll_face** » 24 Mar 2012, 08:09

culturejam wrote:My 2-sided layout is now verified.

Attached is a photo taken with my iPhone. Big camera batteries mysteriously died.

cheapverb_pcb1.jpg

Wow, Culturejam, that pcb looks awesome. Where did you buy it from?

andregarcia57 · Post by **andregarcia57** » 20 Oct 2012, 17:01

I think there's a loss of volume.
Anyone know any way or if this buffer can help?

grateful

andregarcia57 · Post by **andregarcia57** » 20 Oct 2012, 17:15

This also has another buffer of IvIark

andregarcia57 · Post by **andregarcia57** » 20 Oct 2012, 18:07

I just did some tests and amz worked well before effect

friedtransistor · Post by **friedtransistor** » 26 Mar 2013, 00:44

Excuse me, but could you please post a schematic that I can copy to Word? The pic is either blank or just shows the link to it...

Oddball · Post by **Oddball** » 24 Jul 2013, 23:12

Apologies for bumping an old thread, but I figured it would be better for help than a new one.

I just built an Ersatz, but opted for a higher delay time pot (100k).

It's working fine, sounds interesting and all of that.... but I'm only getting one, single repeat. No matter where the feedback knob is, it's just one single repeat.

Anyone have any suggestions on how to solve that to get the full feedback/repeats? I've followed the vero layouts posted, and like I said, it's working entirely otherwise - delay time works fine, as does mix. It's just the feedback that seems ineffective.

I'd appreciate any suggestions on how to get feedback working!