Schematic for a Rocktron Nitro pedal

[Mark Hammer]

Well, I can't explain it either. It defies everything I know, and what has worked precisely as predicted for years, but what the hell, you did what you did and heard what you heard, right?

I don't have a reason to assume otherwise, but both of us are assuming the legending on the board and the schematic we're working from are accurate. Maybe that's what's at the heart of this.

Forty years ago, I was at home in my bedroom and had a turntable on one side of the room and an amp on the other. The cables from each were just long enough to meet in the middle, but I couldn't reach the turntable cable so I asked my dad to pop in and hand it to me. In a sort of manual Spoonerism, he picked up the end of the cable with the wrong hand, and stretched out the empty hand to me, clasping my open hand. The turntable signal came through loud and clear. Indeed it was louder than with the wires directly connected. So I called in my kid sister. She held my dad's hand and mine, and the signal got even louder with three people connecting the two cables.

I still can't explain it, but it happened. It's a nutty world, my friend.

[TWANG]

I pulled C7 out
no difference

I was told.. probably that would cut the highs.
not a bit of difference I could hear.

Maybe it's something to do with how far you crank it up.. because I don't push barely past 9:00.. about the same volume the guitar would have straight in.

and I set it. then I unplug and use just the guitar. and the guitar is always warmer.

And yeah .. others have also been telling me the same stuff you were, so I dunno what to say.
One thing is for sure. I'M no expert!
and I had a lot of fun.

[Mark Hammer]

What we've never established is what you're plugging into the box (i.e., guitar/pickups/settings), and what you're plugging the box into (subsequent pedals and amp). Quite conceivable that what you're calling "treble" is what others might call midrange, and what we're dicking around with here is actually outside spectrum of either the guitar itself, the amp settings and speaker characteristics, or both.

Not sure if you've ever used an "aural exciter/enhancer" effect, but they're great for adding snap and sizzle to miked-up acoustic instruments, and also to single-coil pickups. Numerous companies - Boss, DOD, BBE, et al - have marketed stompbox versions of the effect, and you'll be hard-pressed to find them in stores. Why? Because the range where they have any audibility is well outside of what you get playing P90s or humbuckers into a Marshall, and when people try them out in the store, they aren't sure the effect is on when they see the LED light up. Maybe we're dealing with a similar thing? Just wondering.

[J M Fahey]

Well, I can't explain it either. It defies everything I know, and what has worked precisely as predicted for years, but what the hell, you did what you did and heard what you heard, right?

Placebo effect.
People hears (reads) so much that "silver micas are brighter", that when they use one, they definitely (want to) hear more highs.
Funny thing is, in this particular case one capacitor was in a feedback loop, and the other one was grounding highs, so the effect in both cases is to *lower* highs.
Personal opinion: in this particular case since the possible effect was happening over 10kHz, where there is no guitar signal, (not to mention that speakers have a 24dB per octave filter above 4/5KHz), I think there was no real audible change.
As to the pedal "muddying sound when off", fact is, this is a buffer: when "on" signal travels better through long wires; when "off" it's out of the circuit and *those wires* are the ones which muddy the signal.
Twang has accurately detected that it's better to leave the pedal on, even if not boosting. Way to go.