Interfax - Harmonic Percolator

Greg · Post by **Greg** » 04 Dec 2007, 11:56

Would some pics help this thread ?
Here's some guts shots of the Chuck Collins repro which is supposed to be true to the original design:-

sosodef · Post by **sosodef** » 04 Dec 2007, 12:22

I just want to know
where you can get those
diodes and trans like chuck
is using.

Is there nothing modern equivalent?

snail · Post by **snail** » 04 Dec 2007, 14:21

Cool

Thanks!

Meanderthal · Post by **Meanderthal** » 05 Dec 2007, 01:24

2N404a- look for those on evilbay. I picked up a big sack of em for $20.00, pulled from an ancient room size computer circuit board. Pretty much any good PNP germanium should do the trick though, provided the gain and leakage are within shooting range of whatever it is that works for this circuit.

2n3565- smallbear has 'em(I think). I recall ordering some of those for (I think) a foxx tone machine. Equivalent- 2N3904 maybe? 2N5133 look the same and are also npn, but probably cost more. Check the pinouts if yer gonna sub this one out.

1N34a- I think those would work ok for the diodes... those are still pretty common.

spiffy chap · Post by **spiffy chap** » 26 Jan 2008, 09:16

Any schem on this?

kusi · Post by **kusi** » 26 Jan 2008, 10:28

30seconds on goolge...
http://www.bargeconcepts.com/bp/largeschem.bmp

barge concets has a improved clone of it:
http://www.bargeconcepts.com/bp.html

here some nice guts from the original on discofrequs;
http://filters.muziq.be/model/interfax/ ... percolator

i think this topic is better located in the vintage-corner

regards, kusi

Greg · Post by **Greg** » 26 Jan 2008, 10:36

Or a quick search here:-

http://www.phpbbserver.com/freestompbox ... oxes#13731

The first part of the thread seems to be missing though ?

spiffy chap · Post by **spiffy chap** » 26 Jan 2008, 11:39

Sorry. Newb

soulsonic · Post by **soulsonic** » 27 Jan 2008, 20:54

Anyone else here notice the story on the Barge site about the "true" HP-1 using two identical NPN transistors instead of the NPN/PNP mixed pair that you see in every other schematic?
Interesting.
Anyone here ever build one with two identical NPNs?

RLBJR65 · Post by **RLBJR65** » 27 Jan 2008, 23:00

Good info in this thread including another schematic.
https://www.diystompboxes.com/smfforum/ ... c=55987.80

Greg · Post by **Greg** » 27 Jan 2008, 23:44

soulsonic wrote:Anyone else here notice the story on the Barge site about the "true" HP-1 using two identical NPN transistors instead of the NPN/PNP mixed pair that you see in every other schematic?
Interesting.
Anyone here ever build one with two identical NPNs?

There's a rebuttal to that claim on the Chuck Collins site, and it's generally regarded that the Barge version doesn't sound or behave like the original.

soulsonic · Post by **soulsonic** » 28 Jan 2008, 01:11

Greg_G wrote:
soulsonic wrote:Anyone else here notice the story on the Barge site about the "true" HP-1 using two identical NPN transistors instead of the NPN/PNP mixed pair that you see in every other schematic?
Interesting.
Anyone here ever build one with two identical NPNs?
There's a rebuttal to that claim on the Chuck Collins site, and it's generally regarded that the Barge version doesn't sound or behave like the original.

This is ridiculous - you know, all someone would have to do is carefully remove the transistors from an original and then test them with an Atlas DCA55 semiconductor analyser and we'd know exactly what sort of transistors are in there! You don't even need an Atlas tester, anyone with a brain could do a simple battery of tests to determine the polarity of the things and whether they have any leakage (a sure sign of a germanium device).
And if Bruce has indeed done this... why isn't anyone sharing the info about the correct transistor part #s?
Does anyone here have one of Bruce Collins' remakes that we might see the guts of, or perhaps at least share the model numbers of the transistors used?
I honestly don't care which of the two parties is correct in this issue - or even if either of them are correct - I just want to lay the mystery to rest. That's what this forum is all about: studying unique circuits and uncovering the truths behind the mysteries which enshroud them.

Greg · Post by **Greg** » 28 Jan 2008, 01:26

soulsonic wrote:
Greg_G wrote: There's a rebuttal to that claim on the Chuck Collins site, and it's generally regarded that the Barge version doesn't sound or behave like the original.
This is ridiculous - you know, all someone would have to do is carefully remove the transistors from an original and then test them with an Atlas DCA55 semiconductor analyser and we'd know exactly what sort of transistors are in there! You don't even need an Atlas tester, anyone with a brain could do a simple battery of tests to determine the polarity of the things and whether they have any leakage (a sure sign of a germanium device).
And if Bruce has indeed done this... why isn't anyone sharing the info about the correct transistor part #s?
Does anyone here have one of Bruce Collins' remakes that we might see the guts of, or perhaps at least share the model numbers of the transistors used?
I honestly don't care which of the two parties is correct in this issue - or even if either of them are correct - I just want to lay the mystery to rest. That's what this forum is all about: studying unique circuits and uncovering the truths behind the mysteries which enshroud them.

I've already posted gut shots of the Chuck Collins pedal.

http://www.phpbbserver.com/freestompbox ... oxes#13731

Collins says he's had the opportunity to study a couple of originals, but there's not many out there, so i doubt many others have had that opportunity.
As far as i'm concerned, the Collins repro is right and the Barge isn't.

soulsonic · Post by **soulsonic** » 28 Jan 2008, 01:41

Okay, I see now. Thanks for sharing that - I must have not been paying attention, because now I remember seeing it.

Those gutshots should be presented together with a schematic so people will correctly connect the two, instead of getting stuck on false notions like I did.
This is a good example of how the disorganized aspect of the DIY community has led to confusion over the years.
Thanks for sharing, and I'm sorry I didn't pay closer attention.

Greg · Post by **Greg** » 28 Jan 2008, 01:57

soulsonic wrote:Okay, I see now. Thanks for sharing that - I must have not been paying attention, because now I remember seeing it.
Those gutshots should be presented together with a schematic so people will correctly connect the two, instead of getting stuck on false notions like I did.
This is a good example of how the disorganized aspect of the DIY community has led to confusion over the years.
Thanks for sharing, and I'm sorry I didn't pay closer attention.

True soulsonic.
There are a some threads on this forum that have become disjointed by the practice of taking "parts" of a thread and moving it to another section because it's gone off topic temporarily.
It might seem logical, but I think it just creates confusion in the end.

It seems that Barge Concepts design came from schems. they found on the internet, and they decided that the circuit couldn't work with mixed transistors... so they changed it.

Maybe the gut shots can be mated with a schematic and put on to the "white list" ?

noelgrassy · Post by **noelgrassy** » 29 Jan 2008, 03:27

You guys must have seen that comparison of the Barge[Bilge

] Concepts vs the HP "made by the crazy guy"[his comment, not mine]. IMO the Barge Concepts' product can be totally eliminated from the discussion. It sounds like a $hitty distortion box compared to the dynamic original. The video I refer to is performed by[god, I'm so bad with names] the guitarist/producer of Shellac. He's been a speaker at a few TapeOpCons in the past, so his opinion seems to matter. Oh yeah, his first band was Big Black. Killer guitar in my opinion.

soulsonic · Post by **soulsonic** » 29 Jan 2008, 04:07

Yeah, Steve Albini wasn't too impressed with the Barge one... oh well. I like the sound of the albums he's done (Jesus Lizard's Down comes to mind as a really good-sounding one), but I don't worship him the way some folks do. I think his tone with Shellac sounds damn nice, but his tone with Big Black was intentionally awful, there's no doubt about that. There's no way you can listen to Songs About F*cking and think that's a sweet guitar sound, cuz it ain't, and it's not supposed to be. I like that kind of stuff, so I like Big Black; I like how they sound intentionally bad just to mess with people and be offensive. Those guys from Barge were foolish to think that he'd give a straight opinion of their pedal.

noelgrassy · Post by **noelgrassy** » 29 Jan 2008, 08:42

Steve Albini[hits head]Yeah. I mean just using your own ears [while watching that video] you can hear that the Barge pedal isn't happening in the slightest. I did mean his playing with Shellac specifically. The Big Black sound is righteous but in no way tipifies "killer guitar tone". There have been a few others whose guitar tone was just plain wrong and their "cohesive whole" makes me like 'em despite that. A couple on AAD label for example. God knows a few on early Roadrunner Records can join this fraternity.

soulsonic · Post by **soulsonic** » 29 Jan 2008, 09:23

Yeah, the Barge isn't giving up the goods in that video at all; sounds weak. I think it sounds like total junk in their official demo video as well. In that vid, they have it sounding vaguely like a weak HP, but then the guy tweaks the controls and the (confusing!) footswitches and gets it sounding like some total garbage fuzz box. It's like they were so in love with that awful fuzz sound they got it to do that they completely forgot about bothering to make it sound like a real HP. They should just market it as some kind of oddball gritchy fuzz box and stop comparing it to the HP.

But back to the schematics. The pics of the inside of the Chuck Collins one don't match the gutshots of the original at DiscFreq's site. But, the one on DiscoFreq's does match the schematic on the Barge website. People have mentioned that there were two different "official" versions that were made. While Chuck Collins did a remake of the Si NPN/Ge PNP one, Barge traced the Si NPN/Si NPN one... but then proceeded to mess it up by adding a bunch of extra junk to the circuit that kills the Harmonic Percolator's "soul".
So, now my question is: Has anyone built the NPN/NPN one true to the original spec? What I'm wondering how similar it sounds to the NPN/PNP one. Though I can imagine him wanting to improve it, I don't think the original maker would have wanted to drastically change the sound that much from one version to the next. I wouldn't be surprised if they sounded very similar, though it would be a shock to me if they sounded the same.
Hmmm.... I think I have an idea for the next experiment to be published on my site...

noelgrassy · Post by **noelgrassy** » 01 Feb 2008, 22:04

This just in!https://cgi.ebay.com/Harmonic-Percolato ... dZViewItem I'm very tempted to pony up and see what they've got. I should at least be able to roll it at TGP if I don't dig it. After I give a report here of course.

Interfax - Harmonic Percolator [schematic]