More volume out of Ibanez wh10 wah

[JebemMajke]

Here is the schematic

http://www.dirk-hendrik.com/wh10.pdf

I've made this amazing wah ... it's a killer.

But it does have a volume drop.

Do you have some advice how to fix this?

Sincerely

[lungdart]

You could add gain to the active stages but this will most likely change the filtering characteristics without careful engineering if it's possible at all. All the discreet stages are common collector topology which means they should only be able to achieve unity gain, so there's not much tinkering you can do there.

R31/R32 set up a voltage divider which looks like it's designed to set the output impedance, and possibly limit the current. Reducing the output impedance from ~100k to something smaller would cause more signal to make it to your next stage, try lowering R31, and see if that helps. You might be able to short R32 completely, but i doubt you will increase your gains very much by removing that voltage drop.

An other option is to add an output buffer after the fact with some gain to compensate, of course.

[JebemMajke]

It drops volume to about 90% of the original.

I don't need it to give me more volume than the bypassed volume.

So the increase in the overall gain doesn't necessarily has to be big.

I've considered lowering r30 to 15k or 10k. Because I am using bc 550's and not 2sc1815's.

[lungdart]

It drops volume to about 90% of the original.

Wow, that doesn't sound correct. I highly doubt the original Ibanez had that much attenuation. I would double check your connections and pinouts to the schematic if you haven't already. Does the volume drop appear in simulation as well?

[JebemMajke]

Not by 90% but to 90%.

It's a 10 percent drop of volume. Maybe a bit less.

Double checked a couple of times. I've used 1458 as a opamp ( i really like the sound of this thing, ever since i've cloned ts 8, love the mids in it ), bc 550's and bc 560. Everything is ok,

[Quackzed]

I've considered lowering r30 to 15k or 10k

thats what i'd try first... easy enough to clip another 22k in parallel and see...