"added master volume to amp"-pedal

[cedric]

i remember i've seen this here and on ebay as well (pre-made).
like taking the speaker-out from the amp to the "pedal" (ie. two jacks, a pot and some wire), controlling the master volume with the "pedal", and sending the signal from the pedal to the speakers.

it should just be an insert between the speaker-out and the speakers.

where's the schem?
is it just a 500k linear pot?

- ced

[Peter Snowberg]

When you want to reduce the volume from the speaker, you want an "attenuator". These come in two main types.... resistive and inductive. Resistive attenuators are also called "L Pads".

Depending on the amp, you can cause damage by using the wrong values in your attenuator and many amp people will say all kinds of bad things about various types or brands of attenuators.

Search the forums for "L and pad" and "mass and motor" for some examples of each type.

Some commercial devices include the Marshall "power soak", the "Air Brake" designed by Ken Fischer (I don't recall who makes it), and the "MASS" by Weber VST. http://www.webervst.com/mass.html

Happy hunting.

Take care,
-Peter

[Ansil]

i remember i've seen this here and on ebay as well (pre-made).
like taking the speaker-out from the amp to the "pedal" (ie. two jacks, a pot and some wire), controlling the master volume with the "pedal", and sending the signal from the pedal to the speakers.

it should just be an insert between the speaker-out and the speakers.

where's the schem?
is it just a 500k linear pot?

- ced

question do you have an fxloop man,,  i used to do this with my fx loop  as it was completely wet,  and since it shunts signal to ground all the way down is silent  best volume pedal i ever had..

bespeco

[cedric]

thanks for your answers. but something easily doable must be out there.
how about build a master volume pot into the amp (which is a '64 Selmer T'Bird 50)?
someone once did this on the exact same amp, but then later on it was removed. so i've already got the hole for the pot there..

- ced

[danelectro]

the thing is most master volumes arent after the output transformer.. theyre normally after the PI and before the power tubes.

so your idea migth work, but it still wont emulate a real MV

[Ben N]

I don't think there is an easy way to do this with a pedal, and you shold beware of trying, since if you don't get it right you run the risk of frying your output transformer--not a good thing at all.  You might want to ask about this at Ampage, since it is more an amp issue than anything else.  However, there are some interesting attenuator circuits out there, including a couple in patents by Tom Scholz--yeah, that Tom Scholz.  If I'm not mistaken, there are links to them at Randall Aiken's site, or you can just do a patent search.  I've never seen a pedal attenuator.
Ben