Harmonic percolator Aionfx

[Frankthe14]

Hey, I recently finished le harmonic percolator pedal by aionfx (https://aionfx.com/app/files/docs/particle_documentation.pdf) and it has a really low output, I have to crank up the volume and raise up the the output on the amp. Anybody build this? Any solutions?

[antonis]

Hi & Welcome..

Try to lift CLIP switch middle lug up from GND to see if output is OK with your taste..

If yes, we'll proceed to raise diodes clipping levels..
(although, for switch set position 2-3, output level should be fine..)

[Ben N]

Have you checked Q2 for hfe? Is it oriented correctly? Are the trannies socketed? Maybe try some others.

[Phend]

Hello,
Great topic, I see it is else where on the Forum.
But I also have a question, being that I plan on building one maybe using George Giblets circuit.
See below.
Question is about capacitors, maybe in general when it comes to effects.
Can the Ceramic Disc caps be substituted with a Polyester caps in this circuit.?
The Tantalum cap, can it be substituted with a plane ole Electrolytic cap.?
IN General are there any instances when caps Can't be substituted.?

[mozz]

Sometimes disc caps are microphonic.  Does it call for disc and you want to use poly or the other way around? Can't see the picture. EDIT: picture didn't work on phone, i see it now on home computer.

Poly or other types should work fine in place of disc caps.

[Phend]

Yes the circuit calls for Ceramic Disc and I would like to use Tropical Fish.
Not sure why you can't see the pic.
Google Harmonic Percolator Giblet.

[glops]

Hey, I recently finished le harmonic percolator pedal by aionfx (https://aionfx.com/app/files/docs/particle_documentation.pdf) and it has a really low output, I have to crank up the volume and raise up the the output on the amp. Anybody build this? Any solutions?

I built an "Albini spec" percolator on perfboard over 10 years ago but ended up scrapping it as it just sounded ok. Looks like the Aion board uses the Albini spec values as a default. Had plenty of volume. Measure the transistor voltages and make sure the germanium transistor you are using is at least a PNP transistor. There should should be plenty of volume even with the germanium diode clipping configuration so you def have a problem somewhere. Around 2016, I built the George Giblet version/schematic that Phend posted and that sounded leaps better to me than the Albini spec.

[glops]

Yes the circuit calls for Ceramic Disc and I would like to use Tropical Fish.
Not sure why you can't see the pic.
Google Harmonic Percolator Giblet.

I can see the schematic. I built a bunch of percs off of that one, no need to use ceramic caps as called for as those were just likely what was used in the OG unit that was traced. For me, I found to get the best sound was trying different transistor combinations. I would say the NPN transistor doesn't matter quite as much as the PNP GE transistor. I've built some with 2N404s and some with other PNP models. It's such a simple circuit but an odd one that  in my opinion is worth sticking on a bread board and tweaking to your delight. In the builds I did I stuck a 25K trimpot in place of R4 which allows me to tune the GE transistor by ear.

[PRR]

...The Tantalum cap, can it be substituted with a plane ole Electrolytic cap.?

Today's Al e-caps are much better than the ones in the 1960s. Much lower leakage. Also smaller. Tant had a real advantage back then, but the Al cap people caught-up. Aided by high cost and conflict-status of Tantalum. I absolutely would use good Al (not something salvaged from a 1966 radio) at C4.