Rat Debug. Are these substitutions a problem...

[Evad Nomenclature]

Hey guys.

Sooo... I built a Rat on a tonepad PCB and had *almost* all of the parts needed, however I did make what I thought would be a couple of "minor" subs.  If anyone has a sec, could you take a look at this layout at TP and see if you spot a problem?  BTW, the pedal works, it just doesn't work right, which is why I am thinking my subs might be off... basically, it's really nasally sounding (I know a Rat kind of sounds like this, but it almost sounds like there is an envelope filter on there at all times.. weird) as well as there is a bit of a volume drop (not that much) with all the pedal cranked, in opposition to the volume of my amp when the pedal is off..

Here's the layout

http://www.tonepad.com/getFile.asp?id=89

Here's what I subbed...

Volume pot-I used 1 Meg (other pots are the 100k's) Figured this was fine....
The 4.7 electro cap off of the dist pot- I used a 3.3 instead (ran out of the 4.7's used the last one in the other 4.7 spot on the schem)
The 30 pf cap above the IC I used a 51 PF... (a little sketchy on that one)
Diode 3... I used a 914 instead of a 4002.
and last but not least, on the tranny I used a 5457 instead of a 5458 (I read these were interchangable, just different gain levels for them...)

So... I'm not at home now, so I don't have the pedal on me to test any voltage or anything like that...
But for starters if anyone has any idea if any of these subs are bad it would be appreciated...

thanks!

P.S.  I socketed all the parts in question ^_^  That's the good news... I just still don't have a huge parts stash from futurlec that I'm waiting for =/

[Evad Nomenclature]

I think I'm an idiot...
(most likely...)
Tranny?
NPN vs Jfet... congrats on answering my own question by using my brain?

Edit: Just changed to a couple different trannies... same problem... so it's not that I dont think

[earthtonesaudio]

Both the 2n5457 and 2n5458 are n-channel JFETs.

None of those part substitutions seem likely to have caused the problem.  Go through the general debugging procedures to make sure there's no construction/setup error.

The 4.7uF cap you changed, is that the one that goes to lug 3 or lug 1 of the distortion pot?  If you changed the one going to lug 3, I'd switch 'em.  If that doesn't help, maybe take the 1M gate resistor and put it to the 1/2 voltage reference instead of ground.  Might not make much difference unless you have a particularly bad JFET, in which case you might just want to replace the JFET anyway.

[Evad Nomenclature]

Swapped out the J-fet for a few different ones... still the same... changed the Op-amp... still the same.
That 4.7 uf cap is the one from the 3rd lug, so I'll swap that when I have a sec and see if it makes a difference. 
I was pretty much assuming that the pF caps are such a small rating that changing something like 10 pF won't do much of anything.