Add-Verb distortion

[Matt]

Good evening- I finished up the Add-Verb and got it into an enclosure. I’ll have pics tomorrow but for now I’m getting distortion on the tails of the verb if I hit it too hard. Clean signal going in and individual notes sound ok, but if I hold a chord the slap back is overdriven. Has anyone experienced that before? I’m on my way to go check components again but wondered if anyone had an idea in the meantime. Thanks!

[Matt]

 

I also have a video. I’ll upload it to the tube and put a link in.

 

[Matt]

https://youtu.be/ydmi2KbVp80

I think that worked.

[Anonymous]

If you are experiencing some distortion in the tails of the signal, you may be over driving the reverb brick.  This may be most noticeable with the decay pot at full CW rotation.  First, try sending a lower signal to the circuit.  If the distortion goes away, you can work with that level or you could reduce the gain of the first stage by lowering the value of R3.  AT 200K, the gain is 7.4 for the first stage. (200/27).  The build doc also suggested using a shorter decay by changing the Decay pot to a 10K dual pot.

The limitation is a function of the brick itself.  If you reduce the signal, you can clean this up and then regain your level further downstream.

[Matt]

I’ll try digging out that R3 first. I’ve tried running the pots at a reduced level and I just get quieter distortion. I definitely don’t want shorter decay, so I’m hoping this will help. Thank you.

[Cybercow]

Matt – Taking a stab it this issue . . . .   C5 (based on the photo provided) looks a little large for 100pF. (Could just be the camera lens\angle.) Double check that value. I’d also dbl-check the value of R7 at 6K8Ω

Mark

[Matt]

Thanks Mark. I’ll look when I get home. Got called into a gig today. The resistor looks right to me, blue, grey, black, brown but I’ll look in person. The cap I’ll have to check in person. I appreciate you looking. I’ll also try lowering the input volume.

[Author]

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