tonal change when engaged

For the Voluum™ Digitally-Controlled Analogue Volume Effects Pedal

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bowser111
Posts: 12
Joined: Mon Nov 30, 2015 6:29 pm

tonal change when engaged

Post by bowser111 »

Hi i've just received my voluum and it seems great, the only problem is it seems to increase the highs or boost the signal when engaged. I tried it first on its own and thought i might be imagining it but then i put it in front of a fuzz pedal and it totally changed the sound, in a similar way to putting a buffer in front of it.
I bought the voluum to use with a midi looper so i can switch fuzzes/drives while changing to different volumes/presets at the same time and alter gain levels of different pedals, so i need it before them. I'm using preset F00 with a strat, voluum (in true bypass), danelctro french toast to a 5 watt valve amp and im powering it with a separate 670ma 9volt if that helps. Is there a way to change this?

cheers
martin
jdbenge
Posts: 8
Joined: Wed Feb 01, 2017 11:03 pm

Re: tonal change when engaged

Post by jdbenge »

I think you are correct that the volume is changing your tone like a buffer does. I am pretty sure it's an active volume circuit (otherwise it would need a pot, thus could get scratchy) but the side effect is it affects the output impedance of what is in front of it. You're recovering the highs you would lose from a high impedance signal through your capacitive cable.

I don't think there's a way to change this. You could try to eq the signal after the voluum to tame the highs. Personally, I just eq the amp to compensate, but I've got a buffer in my boss es5 on all the time anyway.

What fuzz circuit are you using? I'd guess it's a fuzz face. Those are sensitive to input and output impedances. I love the way they sound but pretty much stopped using them.
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james
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Re: tonal change when engaged

Post by james »

I am pretty sure it's an active volume circuit (otherwise it would need a pot, thus could get scratchy) but the side effect is it affects the output impedance of what is in front of it.
Yes, it is active.

The output impedance is not super-low (just over 1k), but that is low enough to let you drive long cables without loosing the highs.

A guitar pickup has both inductance (a lot of it) and resistance. Both of these combine with the cables to create an L-C-R circuit that will affect the tone. Effects like the Fuzz Face are designed to interact with this, and that's why adding buffers or even different pickups and cables make a big difference to the tone.

Some simple EQ (after the Voluum, or on the amp) is probably the best thing to do; it gives you some flexibility to adjust the tone (rather than modifying the Voluum to increase it's output impedance).
bowser111
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Joined: Mon Nov 30, 2015 6:29 pm

Re: tonal change when engaged

Post by bowser111 »

Thanks for the replies, I've had a go at Eq at the amp end but it still leaves the fuzz sounding strange no matter where I set it, I'll have a go with an eq pedal when I get in see if I can sort it. I'm ok with a normal vol pedals tone loss as i just have it in a loop but the voluum's features are amazing and would rather have it if I can. Would it be possible to alter it if I can't get rid of the sound?

Cheers
Martin
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james
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Re: tonal change when engaged

Post by james »

Hi Martin,

Certainly it's easy enough to change the output resistance of the Voluum (only one resistor needs to be replaced). The question is what resistance should be used? That might take a bit of experimenting in your setup. I'm sure you could test by wiring a variable resistor (2 legs of a pot) to the output and seeing if that helps the sound.
bowser111
Posts: 12
Joined: Mon Nov 30, 2015 6:29 pm

Re: tonal change when engaged

Post by bowser111 »

hi again ive tried the eq pedal now and i still can't get it to sound right, the closest i got was putting my guitar tone knob down to 2-3 but even that wasn't perfect and then im left with an unusable clean tone when i switch the fuzz off. I dont really want to play around with the insides of a brand new pedal either, if id had it ages i would but i dont want to void my warranty or destroy anything.
canbaz
Posts: 31
Joined: Sat Dec 13, 2014 10:33 pm

Re: tonal change when engaged

Post by canbaz »

If you have passive pickups and use the Voluum in true bypass mode without any active pedal and circuitry engaged in front of it, you will have a tonal difference between the Voluum engaged and bypassed. I would put the Voluum in buffered bypass mode so that it acts like a buffer and put it after fuzz pedals. You can also use a specific buffer just after fuzz pedals before the Voluum, so there would not be any noticeable difference between the Voluum in buffered bypass and in true bypass modes.
bowser111
Posts: 12
Joined: Mon Nov 30, 2015 6:29 pm

Re: tonal change when engaged

Post by bowser111 »

hi canbaz thanks for your help. Unfortunately i need the voluum before my fuzz/drives as i want to use it to control the gain of them.

cheers
martin
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