Harmonic Perculator gets great Gilmour tone

[ragtime8922]

I've been tearing up the breadboard on my recent quest for David Gilmour's "Shine on you crazy diamond" tone. I finally nailed it with the harmonic perculator. Specifically Doug H's harmonic speculator schematic. I didn't have the trannies listed so I subbed in a 2N3904 and one of Jack Orman's Ge AC128/01's. By throwing the Ross Compressor in front then the perculator while running the a cheap digitech phaser in the loop all running through my amps clean channel with the pre-gain at about 3:00.

I don't know if it's the trannies I'm using but to acheive this tone I have the circuit's gain knob ("Harmonics") in the barely cracked to 9:00ish range. Probably the AC128 is at fault. The schems 2N404A Ge has an hfe of 50 and the AC128 is around 100. The schems Si tranny is supposed to have an hfe of 150-600 so the 3904's 100-300 range is in the ballpark.

This tone needs a low gain Ge style edge and mainly in the mid-higher frequncy range for my rig. The rangemaster just wasn't right. Jack Orman's GPB was damn close to the right tone but no quite there.

Any suggestions/mods from previous builders? I tried the input cap but increasing it provides a path to mud. I used si diodes so I'll try Ge and then no diodes at all.

[MartyB]

Check this out from the layouts gallery and this thread from harmonycentral:

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

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

[Coriolis]

Hmm, I breadboarded a Jerkulator using all Si (3904) lately, and no diodes I think. Didn't like it. Maybe I'll try it with Ge, then?

C

[Ben N]

That sounds like a great tip.  I'll have to try it--but I can't find the Speculator schem.  How close is it to the Jerkulator?  The rep of that pedal is that it is touch and volume knob sensitive, with a bright edge, which should be perfect.

BTW, not a DIY thing, but I have used a Boss Blues Driver with the gain and tone about half for "Shine On"--I assume you are talking about the part with the singing part, which stands out with its lack of compression.  I always found that very dynamic tone refreshing after all of the heavy compression on pretty much the rest of the  record.  I came across the BD-2 tip on a pretty neat Gilmour-tone site, http://www.gilmourish.com/.  The guy has been in a Floyd cover band forever, and has done his homework, so he has researched Gilmour settings, but then also gives his own, more practical (for most people not using Cornish pedalboards and stacks of Hiwatts) suggestions for how to nail the sounds.
Ben

[ragtime8922]

That sounds like a great tip.  I'll have to try it--but I can't find the Speculator schem.  How close is it to the Jerkulator?  The rep of that pedal is that it is touch and volume knob sensitive, with a bright edge, which should be perfect.

BTW, not a DIY thing, but I have used a Boss Blues Driver with the gain and tone about half for "Shine On"--I assume you are talking about the part with the singing part, which stands out with its lack of compression.  I always found that very dynamic tone refreshing after all of the heavy compression on pretty much the rest of the  record.  I came across the BD-2 tip on a pretty neat Gilmour-tone site, http://www.gilmourish.com/.  The guy has been in a Floyd cover band forever, and has done his homework, so he has researched Gilmour settings, but then also gives his own, more practical (for most people not using Cornish pedalboards and stacks of Hiwatts) suggestions for how to nail the sounds.
Ben

Cool site! I haven't seen that one. Thanks. Also, if you don't find the Speculator schem I'll e-mail it to you. Doug posted it here in an old thread so I don't think it will be a problem.

Coriolis, I don't like the circuit too much when the gain "harmonics" knob is in the mid to high positions. Even above 10:00! But I was using an audio taper pot just cause it was laying right beside my breadboard. I plan to mod it to get that incredibly usable range from off to around 11:00. Also, the Ge is VERY important tone-wise to this circuit IMO. I did more than 10 circuits while searching for this tone and I modded each of them probably 10 times. This one just naiils it. Specifically the 2nd solo but everything else as well.

MartyB, thanks for links/layouts!

[Ben N]

Thanks, Rags.  Google came up with a thumbnail, but the link was dead.
It is ben_dot_law_at_verizon_dot_net.

[Doug_H]

Here's the "Brick" I built for myself:

http://home.cfl.rr.com/dbhammond/doug.htm#brick

There is a short clip there too.

The HC thread is interesting. Mine doesn't sound anything like the guy's who posted there. But when you dime the "balance" (volume) control it will drive the amp. So his has some amp sound in it too. Mine sounds like a nice Ge fuzz with an upper harmonic that sounds a little like a Rangemaster. I used 1n46 diodes for a hotter output which I really like. If I dime the volume control it will drive the amp pretty good. I suppose if you max out both controls it will get pretty wild but we know there's nothin' special about that. It's a nice unique sound though, cleans up really nice with guitar vol. Rollng down the vol on a single coil neck pup will sound kind of "fendery".

Transistor types and hfe matter. Experiment to find your sound.

Doug

[psst]

if you don't find the Speculator schem I'll e-mail it to you. Doug posted it here in an old thread so I don't think it will be a problem.

Here it is:
http://aronnelson.com/gallery/Richard-Boop-RLBJR65/Speculator

Interesting.
I'll give it a try.
Thanks!

[Doug_H]

Man, you guys don't read the threads do you? Just check my last post and you'll see I posted it on my site...

Doug

[ragtime8922]

I switched to Ge 1N34 diodes and no diodes. Both had great results for the tone I was seeking. Also, I changed to a CV7003 transistor (OC44 military version) that I tested (RG-style test) to have a gain of 89 with low leakage. Nice tone with a bit less gain.

This is a loud pedal. I am barely cracking the harmonics knob and a tad more on the output knob and it's better than unity volume. beyond that it's just too much and the tonal attributes get lost. This circuit, IMO, is way better, tone wise, when used as a treble booster.....Well, let's call it a "rangemaster plus" type of tone. Now to mod it a bit to get a more useful range out of those knobs....

[rockgardenlove]

Looks pretty cool, and simple.  I think I'll give this one a try.