Why is the Harmonic Peculator So Microphonic?

[replaceablehead]

Why is the Harmonic Perculator so microphonic?

I've got other germanium fuzzes that are a tiny bit microphonic, but nothing like the Perculator. It's the same on both my Perculators, I hit the foot switch and you can hear the whole mechanism of the switch and case vibrating. Then if I poke at the pickups or tap my tail piece you can here it echo clear as day through the speakers even at low volume. I can sing into my pickups at low volumes and hear myself when my Perculator is on. Both of my pickups are potted, but only lightly.

I've played around with other pedals and found some of my other germanium fuzzes and boosts have the slightest microphonics and if I boost the heck out of my signal you can start to here a little bit more noise from the strings, body and bridge. I also plugged in my Teisco that has very microphonic pickups and was astounded to find the effect produced by the Perculator was far more microphonic than the Teisco pickups through my Timmy.

The Perculators something else, it really does make the entire rig noticeably microphonic.

Am I crazy, is it just gain? Is it that the Ge tranny is microphonic, but not everything else. Is there a scientific explaination.

[Rob Strand]

In the case of the guitar.  The microphonics cannot be from the unit.   It can only be the unit boosting the microphonics of the guitar itself.

How much a pedal boosts microphonics not only depends on the gain but also at what frequencies the gain is high.  If you have a high gain pedal that cuts the high frequencies it will sound like high gain for guitar signal but not for higher frequency 'taps'.    The Percolator doesn't use much EQ so perhaps the fact it has more high frequency gain is making  the microphonics sound louder than other pedals.

Another issue is when play the guitar through a pedal, is very small signals get full gain and don't get clipped, whereas larger signals get clipped.   For the percolator the point where the signal gets clipped is quite low so that means it starts squashing the guitar signal quite early.  When you squash asignal it starts to sound softer (the distortion also goes up which is the whole point of the pedal)    The thing is the percolator could have high gain for tiny tiny signals but you don't perceive the high gain in terms of the a high level of the signal when using a guitar.    What the high gain for tiny tiny signal does it is makes the background noise and microphonics sound louder - basically it makes all the stuff you don't want to be loud louder.

What I can't explain the physics of why a switch pings with no DC across it.   There's some some bounce but I'm not sure how much ping will get through.   If if was oscillating then while the switch contacts changed over then maybe you would get a ping.

 

[John Lyons]

More likely ceramic or tantalum caps or microphonic foot switch.
Sometimes even a solid core wire can be microphonic. Tap around
the board, switch or wires to the switch and you'll find the offender.

[replaceablehead]

Maybe, but, I've built three of these, boxed two, different components each time, different schematics too. It's definitely the circuit. I'm not the only person who's noticed this. If you google Harmonic Peculator and "microphonic", it comes up quite a lot. But no one ever satisfactorily explains just why it is so profoundly microphonic.

Yes it makes a difference if the pickups are microphonic to begin with, but I've tried all my guitars with it, and even with my well potted and normally silent SD humbuckers, I still get a noticeable effect.

I have a few theories, to begin with I thought it was obvious that only the pedal was microphonic and the case was picking up sympathetic vibrations. You only have to touch the case to hear it's very microphonic. Both builds are like this, both were made years apart using different types of caps and other components, different foot switches etc, both contain the same low hfe Russian transistor.

After many years I've noticed more and more that my Peculators give my guitars a ghostly sewer pipe reverb. I thought it was related to sub octave thing that mine do during cold weather. In fact the colder the weather the stranger the effects. Eventually I started playing around by singing into the pickups and finally the other day I compared it to my Teisco and that's when I made this thread. I believe gain is a big part of it, the eq thing seems remote, all my gain pedals do increase the microphonic qualities of my more microphonic pickups, but I feel like there is much more going on.

I remember the first time I plugged into my Peculator, my very first impression was that the feedback at low volumes was supernatural, almost like using an E-bow. The ease with which feedback can be generated is beyond a normal gain pedal. You can stack as many pedals as you like and you'll never get close. It's not dissimilar to playing with a cheap hollow body, although it reminds me more of feedback spring reverb tank with the reverb way up. It's more like that, you hear the sub octave swell and then the whole pedal starts humming like a drain pipe.

 

[duck_arse]

is the Harmonic Peculator the same/similar to the harmonic percolator we are all familiar with? can you show us the circuit diagram you built to?