Harmonic Percolater

[RCZ53]

Wondering if anyone has built the Harmonic Percolater drawn by Alfonso Hermida on this site? It doesn't look like a terribly difficult build and the originals are pretty rare. I have noticed some missing component values but that could make things "interesting". Ideas ..... thoughts?
Thanks for a great forum everyone!!
Roger

[nightingale]

if i recall correctly,
i think it sounds good, but the volume/ouput is barely past unity.
hope this helps ,

[Gladmarr]

'tis true.  I've built one of these (well, two of these really) and it doesn't get very loud.   I also bought one from Chuck Collins, the guy who claims he's got the accurate, real schematic and he's making re-issues.  The volume issue is mostly because the Ge clipping diodes really cut the output down.  Resistors or diodes in series with the diodes in the circuit to ground would bring the volume up, but there may a tonal price to pay....

... oh yeah, my build wasn't very pretty either.

[MartyB]

Gladmarr,  How would you compare Alfonso's version in sound to the Collins copies?

MartyB

[jmusser]

There was a recent post on this, where someone was trying to decide between the percolator, and the Easy Face for a build, so you may want to loook around for that one. I built Alfonso's several years ago, so I must have all the component values if you can't find them. I don't like this thing at all, and consider it a paperweight, but other people like it. This is probably one of those cases where you're going to have to see what kind of equipment they're playing through if they are the ones who like it. For me personally, it's been my most dissapointing build to date.

[RCZ53]

Thanks for the feedback . I found that thread on The Easy Face or Percolator dilema and there is a Harmonic Jerkulator for Veroboard by Tim Escobedo. However I don't see any diodes on his schemo. Am I missing something?

[PB Wilson]

No, you aren't missing anything. Tim left them out and monkeyed with the part values. http://home-wrecker.com/harmonic.html has Tim's version with a perf layout. I built one last year (without the diodes) and used a Ge/Si transistor combo. It's bright, harsh and cutting. It's definitely an aquired taste, but I like it for some brash punk rock sounds as it cuts through well.

I was actually going to add a diode pair and use a switch to add or subtract them from the circuit, but didn't because of the volume difference.

[Gladmarr]

Hey MartyB,

I actually had an original Harmonic Percolator years ago, and I returned it because I didn't like it.  Everything on the circuit board was potted, so you couldn't see anything.

The Collins copy is really thin and nasaly.  I got it the same week I got my first Orange amp, and I was not impressed by the combination.   However, with a lot of tweaking and massaging, it can sound good as a gritty clean boost.

The one I built was actually from AMZ I think.  It's been years... but I know I tweaked all of the coupling caps and the diode/resistor clipping dealie at the tail end of it to make things thicker and dirtier.  It's a great platform to start with, but modify it to your own taste.

[Dragonfly]

Thanks for the feedback . I found that thread on The Easy Face or Percolator dilema and there is a Harmonic Jerkulator for Veroboard by Tim Escobedo. However I don't see any diodes on his schemo. Am I missing something?

Actually, youre probably referring to the veroboard layout i did ...its Tims circuit, in which he omitted the diodes (they can easily be added at the end of the circuit)...i decided to do the layout as his schematic showed, so i wouldnt confuse anyone...

andy
dragonfly fx

[RCZ53]

Nice work Andy. I actually can't remember seeing veroboard. Is there a good source that you know of? thanks,  Roger

[Dragonfly]

Nice work Andy. I actually can't remember seeing veroboard. Is there a good source that you know of? thanks,  Roger

I know a lot of people order it from www.futurlec.com ....Aron might be carrying it soon as well...

i guess most well stocked electronics supply places should have it....

andy

[Dragonfly]

Nice work Andy.

BTW... Thank you !!![/b]

[RCZ53]

Andy what are the 3 red squares on the board? thanks

[Dragonfly]

Andy what are the 3 red squares on the board? thanks

the little red squares with the dot in the middle are the places you need to cut away the copper strip...the easiest way ive found is to take a small drill bit (5mm or so), insert the point in the whole (that sounded dirty....) on the copper side, and twist...the copper should get removed in a nice neat circle....

hope this helps,
 andy

[RCZ53]

I see. I wonder if an exacto would help? Thanks, Roger

[Dragonfly]

I see. I wonder if an exacto would help? Thanks, Roger

you can definitely use an exacto...i just find that a drill bit is easier to use, works better, and is safer...

my $.02  

andy


btw...in case i didnt make clear..no *drill* is needed...just the bit...you turn the bit by hand....

[Doug_H]

Here's my perc clone:







I think my schem is pretty close to Alf's. Use 1n46 diodes for hotter output. They are Ge and will give that soft clip it needs, but at higher threshold voltage.

I like it. Nice semi-clean with guitar vol rolloff and a nice fuzztone when dimed. Reminds me a little of a "rangemaster driving an amp sound", a little... Nice upper harmonics and octave blooms.

I've got a soundclip around here somewhere... I'll put it up when I find it.

Doug

[Jason Stout]

Welcome back Doug!

[MartyMart]

Welcome back Mr Hammond  
Hope you'll be around now and then, thanks for posting your schemo !

Regards,
Marty.

[Dragonfly]

Nice work Doug ! Welcome back !

Andy