Piezo pickup question -- + fuzz content

[midwayfair]

So last night I put together a board for my mandolin. I thought it would be fun to include a fuzz, but everything I tested ... didn't work. Fuzz Faces basically had no output, and in fact any distortion pedal, once it got into distortion land, either had no distortion or the signal would be almost completely lost (massive volume drops).

This would make sense to me if the mandolin was going straight into the fuzz with no intervening buffering etc. The impedance would be way too low for a piezo so I would expect massive signal loss; there could also be complications with the piezo being a voltage instead of current source maybe? But I was running a compressor on in front, and the signal was good and normal passing through that and pretty much any non-distortion pedal into the amp. One of my boosts with a JFET buffer also behaved normally. I run the same compressor with a fuzz all the time using an electric guitar with no problem.

Now, less fuzz overall would make sense to me. There's little bass content in a mandolin and that's where most of the fuzz comes from in a Fuzz Face. But I would have thought an overdrive would behave differently (diodes), and given that a mandolin's frequency response isn't so different from a guitar's, I certainly wouldn't expect any frequency filtering to result in a "lost" signal.

So can anyone explain or venture a guess as to what's going on?

[Mark Hammer]

Well, first thing, you DO realize that wanting to send a mandolin through a fuzz is now classified as a clinical disorder in the current DSM-IV?    ( http://en.wikipedia.org/wiki/Diagnostic_and_Statistical_Manual_of_Mental_Disorders )

Second, mandolins are not exactly widely respected for their astounding sustain and long decay time.  We repeat-pick mandolin strings not just because it sounds nice, but because the note dies pretty darn quick after we pick.  Fuzzes can create the illusion of added sustain by applying lots of gain and a hard ceiling on signal amplitude, but there needs to be something there to start with.  So maybe that has something to do with it.

[midwayfair]

Second, mandolins are not exactly widely respected for their astounding sustain and long decay time.  We repeat-pick mandolin strings not just because it sounds nice, but because the note dies pretty darn quick after we pick.  Fuzzes can create the illusion of added sustain by applying lots of gain and a hard ceiling on signal amplitude, but there needs to be something there to start with.  So maybe that has something to do with it.

Hrm, good point on the sustain. But I wanted blatty, blurty, farty mandolin notes. Like an overdriven microphone or a record cut too deep. :/

Well, first thing, you DO realize that wanting to send a mandolin through a fuzz is now classified as a clinical disorder in the current DSM-IV?    ( http://en.wikipedia.org/wiki/Diagnostic_and_Statistical_Manual_of_Mental_Disorders )

Hardly my most pressing mental health concern!

[Mark Hammer]

I should add that your mention of the near total absence of bass content is quite apropos.  Mandolins certain "cut through", but that doesn't necessarily mean they have the sort of overall amplitude - "heft" accompanying the cutting power - to push diodes or whatnot into conduction.  Perhaps it's that blasted difference between actual/absolute amplitude in millivolts, and perceived loudness?

[pinkjimiphoton]

my brother jeff was avant-garde "slambience" mandolinist "woden thoth", he would just say USE MAGNETIC PICKUPS.

piezos will need a preamp most likely, and cause an impedance problem...they're a lot higher than a regular pickup.
you may need to use some kind of "load" box...try using even a 1meg pot in line, and see if it makes a difference maybe.

jeff was an effects monger, but all he used was his mandobyrds usually.

[midwayfair]

my brother jeff was avant-garde "slambience" mandolinist "woden thoth", he would just say USE MAGNETIC PICKUPS.

piezos will need a preamp most likely, and cause an impedance problem...they're a lot higher than a regular pickup.
you may need to use some kind of "load" box...try using even a 1meg pot in line, and see if it makes a difference maybe.

jeff was an effects monger, but all he used was his mandobyrds usually.

Unfortunately, carving up a $3K mandolin to install a magnetic pickup is not an option. (I bought the back when I could afford such things.)

I was using a compressor with 5M input impedance and <10K output impedance. That's the reason I'm confused ... the actual pickup mechanism should be out of the equation by the time it reaches the fuzz. I think Mark's probably right about the combination of percieved loudness and "plunkyness" rather than there being some sort of weird electronic reason.

[pinkjimiphoton]

well, as a mandolinist as well, i don't really see the sustain being much worse than an accoustic guitar. you can put an accoustic with piezos thru a fuzz, but it sounds pretty horrible..very very bright and nasty. the mando SHOULD do the same, as the high "e" strings are the same pitch on guitar and mandolin.
i think something else is going on. either an impedance mismatch or something else. for all intents, the sonic range of a guitar and a mando is too similar for it to be that different.
do you have an accoustic with a piezo bridge you can try thru the same effect chain? if it does the same thing (probable) then it's gonna be an impedance issue i bet. maybe you've gotta go the opposite way, and get a lower impedance to the fuzz.
i mean...it should work. i've played my ovation thru my pedal board live, including fuzz and overdrives, and it was definitely fuzzed out.