Tonefiend Forum

Just for fun, I hooked up my Fiendmaster to a frequency generator (sine wave) and measured the frequency response. I thought I was crazy thinking that my open chords sounded like they were missing the low strings. After seeing the low-frequency roll-off, I realize what's up. The graph is plotted as a percentage of the highest output voltage I observed (above 6 kHz, the response is basically flat) since we only really care about the relative frequency response here.

Obviously, the Fiendmaster is well-suited to lead playing; open chords, not as much. I suspect that someone with more engineering knowledge than me could have looked at the circuit and my component values and predicted this behavior without doing the experiment. 🙂

Fascinating! What size input cap did you use?

Yeah, a .033 usually sounds pretty good. The originals used a teensy, bass-nixing input cap — a .0047, I think.

Don't forget that audio amplitude is usually calculated in deciBels (dB) which are logarithmic. So 50% on a linear scale is just 6 dB down. It's still noticeable and I'm not disputing your sonic observations. The only real point is that you can hear things which are 40 dB down, even though that's only 1% of the full-scale. 40 dB down would be fairly quiet though.

Yours pedantically,

DL

Fair enough. I didn't mean to imply that you couldn't hear the low strings at all, but the balance is definitely different when played through the Tonefiend, even with a pretty large input capacitor. That being said, this was a really good first start on building my own guitar effect box and one that's whet my appetite for more projects.

Got the basic part on the breadboard and it really doesn't change the sound much at all, volume but nothing really exciting? Might have something to do with my little awful SS Marshall bench amp and the horrid epi I was using too.