Harmonic Percolator gut shots

[vortex]

I just saw this thread over at Harmony Central. One fine chap has gone to the trouble of shooting some nice pics of his HP.

I can't identify some of the components, there are some odd parts that I haven't seen before, maybe someone here can clarify. Apparently the builder potted the transistors to avoid copying. I read that the transistors are a combo of Germanium and Silicon.

take a boo...:shock:

http://acapella.harmony-central.com/forums/showthread.php?s=744743d30c3b9df98947560e53137ade&threadid=1008997http://acapella.harmony-central.com/forums/showthread.php?s=744743d30c3b9df98947560e53137ade&threadid=1008997 :shock:

[nelson]

what the hell are the strange looking glass thingies(technical term)?


not the germ diodes.....  :?

[vortex]

what the hell are the strange looking glass thingies(technical term)?


not the germ diodes..... Confused

Exactly what I was thinking.... I'm sure someone will chime in with the answer. Mojo parts I think!!! :wink:

[Peter Snowberg]

what the hell are the strange looking glass thingies(technical term)?


not the germ diodes.....  :?

Resistors. Those are probably late 50s / early 60s military surplus.

The transistors are probably in TO-18 cans with those ferrite core looking things glued on top

[vortex]

Thanks Pete.

Watcha figure that lone black component with the green end and the red blob is?

Mojo, I tell ya :wink:

[MartyB]

Pretty sure that's a jumper connecting 1k, 20k and emitter of Q1 to base of Q2.

[jmusser]

Hey Vortex, thanks for the post. It's really detailed, and that enclosure is in excellent shape. Maybe if my Percolator had those vintage parts in it, it would sound decent! My DIY Percolator has been my biggest dissapointment to date.

[Doug_H]

Wow, is the battery really held in by duct tape?? Yikes!...

Doug

[Stevo]

This has been one of the most fun circuits for me   I have had good luck with these a trick is after the circuit put a rat filter circuit and than a 470k resistor and build a mini booster on the end of this ....Really cool now with plenty of sustan and gain and a real nice distortion pedal not really fuzz or overdrive......The trans need to be like pnp needs to be less than the npn trans that I have found out .....I added and extra germanium diode in series with one of the two.....

[MartyB]

Thanks Vortex for the link.  Now if we could only see those component #'s alittle better....

Here's a layout based on the pics:

http://aronnelson.com/gallery/MartyBs/hrmoncprolatr

[Doug_H]

Mine sounds real good as is:

http://home.cfl.rr.com/dbhammond/harm_spec.gif

I can't remember which one of Alf's versions this is. There may be a minor difference but I don't remember what it was. The other version didn't sound right to me. It was more of an "overdrive" than "fuzz" sound. This one gets a pretty heavy fuzz tone when you crank it up. Transistor types are important. I like the 1n46 diodes for stronger output.

Someone who has a real Perc told me mine sounds just like it.

Doug

[PB Wilson]

I like the Harmonic Jerkulator I built from the layout at Home-Wrecker.com. It doesn't have the diodes at the end, but it sounds cool anyway. Mine is pretty brash and bright and somewhere between overdrive and fuzz. Perfect for garage band type stuff. I recall using a Germanium/Silicon pair of transistors, but can't remember which ones offhand.

[jmusser]

Mine wasn't that one. I built mine off an old schematic Alf had on his site back about 4 years ago. If I remember, there were two versions of it, and I built the one that had been proven at the time. I don't remember those transistor types being the ones I used. I'll have to check this schematic against that one I built from to see what the difference was, but I'm not remembering a germanium in there either. The way it sounds now, no mod is going to hurt it, that's for sure!

[Peter Snowberg]

Did everybody see the last guts shot?

http://i14.photobucket.com/albums/a333/mbet/CIMG3335.jpg

That's no ordinary jumper!

[doug deeper]

also the strange glass tubes might be "coils" of some sort...
phillips seems to have made some with the tl XXX names...
just a thought...
i also suspect thats more than a jumper.

[Dan N]

Alfonso Hermida did trace this thing a long time ago. A little reworking of his trace gets us this:

http://users.rio.com/senorris/junk/Percolatorplay.gif

He has the mystery jumper as a 1uf cap.

Looks weird to me...

[vortex]

Did everybody see the last guts shot?

http://i14.photobucket.com/albums/a333/mbet/CIMG3335.jpg

That's no ordinary jumper!

Hey, if the guy goes to the trouble of potting his trannys, he might make his own funky jumpers!

I admire his creative building /design.

You are right though!

[MartyB]

OK!  Thanks Dan.  Looking at your revision of Alfonso's schematic that leaves us with just one unknown resistor value!  

Here's the updated layout:

http://aronnelson.com/gallery/MartyBs/hrmoncprolatr

[Dan N]

Marty, just for fun, if Alfonso had a 220K going from Q1 B to C, maybe it is the value going from B to E in the new look?

I just get really lost in circuits with both PNP and NPN trannies. Even just 2!

[MartyB]

Good idea.  That'd be a good one to try breadboarding.  The markings on the photos from HC Forum are something like Tl 196  ....  Maybe someone will figure it out and share.  OTOH it wouldn't be too hard to just sub till it sounds good.  I have no idea what this thing sounds like. My build of Alfonso's Harmonic Jerkulator always reminded me sound wise of that Joe Walsh song "Life's Been Good To Me So Far".