TH CUSTOM Re-Verb Volume Boost Help!

[mickeybellinello]

Hi to all!

I made a Re-Verb reverb kit from musikding.

It works perfectly but i noticed a slight volume boost when it's engaged.

I use it with bass guitar.

I tried with reverb and feedback at 0 so I got only the dry sound out and I get a volume boost when it's engaged.

Are there and way to decrease the output volume?

Here's the schematic


Thanks

[Fender3D]

Lower R11 value

[intripped]

if you can, connect pin3 of IC1A to VB (not to GND).
that's how to properly connect an unused opamp when you use virtual ground (VB)

note: this has nothing to do with the volume boost issue. it's just a little error in that schematic

[samhay]

Lower R11 value

This will lower the wet signal too. If you only want to decrease the dry signal, make R10 smaller - 10k will give you almost no gain.

[mickeybellinello]

Lower R11 value

Tried it, seems to works! Thanks!

if you can, connect pin3 of IC1A to VB (not to GND).
that's how to properly connect an unused opamp when you use virtual ground (VB)

I'll take a look thanks! But...what does it change if i connect pin3 to VB?

This will lower the wet signal too. If you only want to decrease the dry signal, make R10 smaller - 10k will give you almost no gain.

The r11 decrease seems to works right. I noticed also the drop of wet volume but it's not a bad thing. I mean, with bass I don't need tons of reverb so in a certain way the reverb and feedback pot seems to works better.

I haven't tried it in a band situation so I keep in mind what you told me and In case I have another way to improve this pedal!

So thanks really!

[intripped]

if you can, connect pin3 of IC1A to VB (not to GND).
that's how to properly connect an unused opamp when you use virtual ground (VB)

I'll take a look thanks! But...what does it change if i connect pin3 to VB?

nothing sonically changes, but the unused opamp just feels better 

PS:
here some more informations: https://www.maximintegrated.com/en/app-notes/index.mvp/id/1957

[PRR]

I vote for R10 at 12K or so.

The dry gain varies with wet return mix impedance.

A truly non-interactive plan probably needs another opamp. (Yes, IC1A is idle, but can you hack it into use? That's a tight PCB.)

A truly musical plan probably keeps dry gain at 1.05 until reverb is 50%, then drops dry gain so reverb predominates. We do this by connecting the wet pot "backward" and passive-mixing into the dry signal. Again this may be difficult on that PCB.

[mickeybellinello]

PS:
here some more informations: https://www.maximintegrated.com/en/app-notes/index.mvp/id/1957

Thanks So Much! I'll read as soon as I can!

I vote for R10 at 12K or so.

The dry gain varies with wet return mix impedance.

A truly non-interactive plan probably needs another opamp. (Yes, IC1A is idle, but can you hack it into use? That's a tight PCB.)

A truly musical plan probably keeps dry gain at 1.05 until reverb is 50%, then drops dry gain so reverb predominates. We do this by connecting the wet pot "backward" and passive-mixing into the dry signal. Again this may be difficult on that PCB.

Thanks So much!
Unfortunately there's no room for adding another opamp etc...
With "I vote for R10 at 12K or so. The dry gain varies with wet return mix impedance." what do You mean?

[antonis]

With "I vote for R10 at 12K or so. The dry gain varies with wet return mix impedance." what do You mean?

Dry signal gain is 1 + R11/R10, when Reverb pot set all the way down (wiper to lug1) or 1 + R11/{R10 + (pot right side resistance in parallel with pot left side resistance + the parallel combination of R7 & R13 PLUS OUT 1 & 2 impedance ..}
R9 & R10 form a voltage divider so IC1D non-inverting input signal voltage is IC1B (V_out*R10)/(R9+R10)
Lowering R10 results in less incoming signal for the specific gain setting hence less dry signal amplification (in the mean of output voltage..)

[mickeybellinello]

With "I vote for R10 at 12K or so. The dry gain varies with wet return mix impedance." what do You mean?

Dry signal gain is 1 + R11/R10, when Reverb pot set all the way down (wiper to lug1) or 1 + R11/{R10 + (pot right side resistance in parallel with pot left side resistance + the parallel combination of R7 & R13 PLUS OUT 1 & 2 impedance ..}
R9 & R10 form a voltage divider so IC1D non-inverting input signal voltage is IC1B (V_out*R10)/(R9+R10)
Lowering R10 results in less incoming signal for the specific gain setting hence less dry signal amplification (in the mean of output voltage..)

Thanks So Much! Now all is clear! Thanks for the precious explanation!

[mickeybellinello]

Here I am! I tried the r10 mod.
I used a parallel resistor and I have 13k value.
Super fast try but it seems better than r11 mod.
More updates in few days.

Last Thing. regarding of

if you can, connect pin3 of IC1A to VB (not to GND).
that's how to properly connect an unused opamp when you use virtual ground (VB)

If I cut the pin3 trace that goes to GND and I make a bridge across pin 3 and pin 10... is it a good idea?