big muff... loudness?

[adapt]

hi guys, i've been laboring over this big muff vero for a while, it's the russian one at its base but i've been experimenting with some slightly modified values (none really outside the range of regular muff pedals), and when i fire it up, it sounds good, but it's really quiet. which component(s) could have such a drastic effect on the volume? all the transistors are socketed and i even removed the first set of clipping diodes and the accompanying ceramic cap (i'm using two 1nf film in series = 500pf) and it's still at unity gain at 3 o'clock on the volume knob!

any ideas?

[tjdracz]

That's weird. I've got my Civil War Russian one and it's LOUD. Unity at 12 o clock or even before that. Which values did you change?
http://www.kitrae.net/music/big_muff_guts.html - have you seen that?

Baiscally, experiment with values of emitter resistors. Smaller value = more gain, try Q4 first. Also you can change collector resistor at Q4.
Besides that it Base-Collector resistors at Q1, 2 an 3 that influence gain. But I would first play around with volume recovery stage at Q4 to see what happens.
Maybe there;'s something wrong with tone stack? Try to bypass that and see what's the change in volume. Normally there is some volume loss there but that should be remedied by Q4 stage.

[Jopn]

Definitely check the pinout of your transistors against the pins marked in the layout.  If I remember correctly, a few of the Big Muff layouts had transistor icons facing the opposite way from what you'd expect from the common transistors called for.  I remember having the exact same issue (sounded great, but quiet) and the issue was that I had followed the pictures and not the pinouts.

[adapt]

well guys. turns out the input resistor is 290k (stock value is 39k). i am looking at the pics i took from work and that's definitely the case. i am sure this would be the culprit, yeah?

[tjdracz]

Makes sense as that limits ammount of signal. I haven't seen them larger than 39K. Actually, think one version had it as small as 3K3

[Silver Blues]

Yeah that'd be it. Muffs are extremely loud circuits by nature, and the initial input resistor has a lot to do with the amount of signal that gets into the preamp and clipping sections. 39K is the stock value for the Green Russians, I believe, and 290K is definitely waaaaay too high.