First Build - ROG Big Daddy - Master Volume Problem?

[bigp7099]

I've been a lurker here for a bit and I have tried building my first pedal a Run Off Groove Big Daddy http://runoffgroove.com/grace.html

I have a problem similar to a lot of the other posts, the sound fizzles out after the initial attack, but a couple of things

1) I can't find a thread where anybody has solved the fizzling problem, even by starting over

2) when i turn down the master volume a bit (maybe down to 8.5) the fizzle goes away and i get the overdrive i'm looking for, but i also get some hum and radio interference, this happens with both pots that i tried

3) 1 and 2 happen when using a 2N5457, i have also tried an MPF102 and 2N5458 (can't find a J201) and i get no fizzle, hum or radio interference at all, but the overdrive is way too mild

4) I tried a battery that was a little run down (about 5v) and with the 2N5457 i got more drive than i did with the other 2 transistor types, but still not enough, and no fizzling or hum

So 2 questions i guess

A) Should i try a trimpot  or bigger value resistor on the battery to see if i can find a voltage a little more backed off that gets me the sound i want?

B) What is going on with the master volume?  from my limited understanding of electronics, the master volume in this circuit really shouldn't have the kind of effect on the sound that is produced

[artsinbloodshed]

having built a couple of these, I like to go with mpf 102's. the sound is powerfull enough to drive any amp and the distortion sweet enough not to be harsh...
-your problem of master volume seems a little weird but you should try with a brand new pot. it happens that sometimes, pots are defectuous and doesn't conduct the signal as they're meant to do...
turning your pot all the way to the right should "let the signal pass"...if it fizzlesmeéans that there's some kind of bad contact inside just like it were dirty...
-the hum and hiss is probably due to radio freq that are "on air"...turning the pot acts as setting a radio station...usually,i get rid of them by putting a RC filter at the input (or at least a resistor in serie for a good dissipation).also try to put a cap on the dc source...it somehow cleans the thing...
As the lm386 pump quite of a gain it enhances radio freq quite well at times,moreover when you're in a "radio friendly  zone"
-if you want more distortion,I suggest you to build the big daddy schemo which is more gain oriented as opposed as the grace one....

[artsinbloodshed]

By the way...is your circuit already inside a box? 3PDT? millenium bypass? shielded?

[Curtis]

What kind of grounding are you using?

[artsinbloodshed]

I'm using the box as a ground (ground soldered to jack's shield)...it helps preventing radio freq to interfere (but you have to use a rc filter anyway when the induced radio signal is strong).