Is a Klon a must build for a diystompboxes junkie?

[Beo]

I'm a basement guitarist, solder monkey. For all the pedals I've built, I've never put together a Klon. I feel like I got into this hobby a decade after the Klon's heyday... sort of like a teenager rejecting the last generation. Just another OD right? The OCD was nice, and I love the Timmy, and I've done lots of TS variants... why build the Klon...

Even if not a keeper, should every diy'er try a Klon at some point, or is it just another OD?

[Ben N]

A question only you can answer. It's more complex than the ODs you've built, so you may enjoy the challenge. OTOH, with EHX cloning them for dirt cheap, it's probably not worth the trouble of building it just to try it out.

[mremic01]

A question only you can answer. It's more complex than the ODs you've built, so you may enjoy the challenge. OTOH, with EHX cloning them for dirt cheap, it's probably not worth the trouble of building it just to try it out.

The Soul Food is not a straight up klone, at the very least it needs a diode swap: https://manticorefx.files.wordpress.com/2014/09/soulfoodschem2.png. It would be awesome if someone more knowledgeable than me could explain some of those changes from the Klon circuit. I'm particularly curious about all the unnecessary parallel caps.

To answer the original question, I'd have to say that that's up to you. Do you want a Klon? Do you think you can build one that's more accurate than EHX? Then go for it. If you're not interested in the thing, there's no reason to build it just because it's a 'must build'.

[Digital Larry]

Parallel caps could simply be a way of cheaply fine tuning the frequency response.

[nate77]

Even though it's unpopular with some, I love the klon. But as others have said (and always do), only you can be the judge. I came into this behind the klon's "time", but it is one of the few pedals that never leaves my board. Also, it is about twice as many components as you're other pedals you've mentioned, which can really be a problem when it comes to debugging, but there are a few killer quality PCB's out there to make it a bit easier, as well as some great verified vero layouts if you want a larger challenge. For a 1:1 board, aion effects has a great board that I've used a number of times, guitar pcb and madbean have great klon based PCB's also that are a little different than the original. Anyway, I recommend the build, but it's your choice!

[mremic01]

Parallel caps could simply be a way of cheaply fine tuning the frequency response.

That would make sense if the two cap values added up to what was in the Klon circuit, or to a value that made sense in spots where fine-tuning mattered. Instead, the Soul Food has a 27nF cap in parallel with the already correct 390nF for a total of 417nF. I've put this cap on a switch and found no audible difference between 330nF and 390nF, so it seems bizarre that not only would EHX use the correct value rather than the easier to find nearest value, but that they'd also add an extra cap. Especially when altering that value doesn't have much impact on the tone. That's a few cents more per unit when they already had the correct part. And then they subbed 330k for the 392k resistor. That makes sense if it's cheaper to use the more common resistor, so I can understand this substitution. I can also understand using two SMDs in parallel if it's cheaper than using just one for 390pF or 3n9, but then there's an 82nF where the Klon has a 68nF. But we all know that the Klon has to have two 68nFs, so one of the 1uF electros is subbed out for a second 68nF. Now there are two. So someone who just takes a quick look at the board can see that all the values look right, but once you start tracing the circuit, the right values are in the wrong places.

If EHX wanted to tweak the thing, I'd expect the resistors around the tone pot to be changed. The treble response on klones is one of the most common complaint about them, yet EHX has left the stock values. We also might expect the 82nF cap to be increased to thicken things up, but they left that the same as well. The differences mostly seem like things that would not be audible rather than things that are fine-tuned.

The Klon circuit has been well known for years, and the market for them isn't into tweaked klones quiet yet. TGPers still want things as dead-on accurate as possible. And it's not like the circuit itself is copyrighted. If anything, explicitly mentioning the Klon in their marketing is more of a no-no than recreating the circuit down to the most obscure component value.

The only explanations for what I'm seeing on the SF's PCB are that those extra caps may be really tiny and don't change the equivalent capacitance much, with some electrical engineering reason that makes their presence advantageous, or that EHX thinks it's hilarious to muddy the thing up with all these extraneous parts. Because it's a Klon and Klon-hype is hilarious. Or something.

I get the impression that they put some effort into hiding things. The diodes are underneath the board so that the whole thing has to be taken out of the enclosure to see that they're not germanium. The through-hole caps with readable values are the correct values, but not always in the correct places. So at a glance it looks like a part-for-part klone when it's not quite part-for-part.

And then there's the Turnip Greens, which seems so niche that I can't understand why a manufacturer would bother with it.  

I get the feeling EHX is just pranking Klon-hypsters.

[slacker]

How many Klons have been traced? As far as I know there's one schematic from one unit, maybe they weren't all the same.

[mremic01]

How many Klons have been traced? As far as I know there's one schematic from one unit, maybe they weren't all the same.

There are 3 revisions to the PCB. Rev2 ads R1B, R14B, and a ground pour. Rev3 (which is used in over 80% of all Centaurs) adds R1C and reorients a few resistors near the output. Bill has explicitly mentioned the changes for Rev2 in the Premier Guitar interview, but not rev3. The unit that was traced was S698 and had a rev3 board. There were claims that an even later serial Silver was traced, but those claims were... well, let's just say they were problematic and unsubstantiated. I've confirmed Martin Chittum's S698 tracing over and over. The changes made from the Klon circuit to the Soul Food don't indicate that it was based on anything other than the Rev3 board, if they even looked at a real unit at all and not soulsonic/Chittum's schematic. The SF has R1B and R1C, but not R14B. If they were going for the sound of the earlier Centaurs by excluded R14B, but left R1B and R1C in for pop-prevention, you'd think EHX would want to advertise that with something like "sounds like the earliest version of the Centaur circuit". There's also the perpetual misconception that there are separate Gold/Silver specs, when the specs depend on the PCB version and not the color. Silver was optional when the Golds were standard, and then the Silvers became standard when Bill decided that he didn't want to paint the things anymore. Both got whatever PCB Bill was using at the time, and there are more Golds with Rev2 PCBs and only a few Silvers, simply because he was selling fewer Silvers at the time. The first 300 or so Golds have a Rev1 board, but the lowest serial Silver I know of is S027 and has a Rev2 board. So if there are Rev1 Silvers, there have to be about 20 or less.

[mremic01]

Edit: dup post

[Beo]

Thanks guys. With lots of other projects on my to-do list, maybe I'll test drive an EHX soul food sometime.

[Mark Hammer]

If you bought your original Centaur from Bill (Finnegan), you had a half-hour conversation with him.  During the course of that conversation, Bill would enquire about your amp, your preferred tone, your guitar, and make a judgment call regarding whether his pedal was right for your needs.  If he deemed it a mismatch, he would recommend against purchase, even if you really wanted one.

Unfortunately, that took a lot of time, and partly accounted for the order backlog.  People would spend large sums on e-bayed Klons, under the mistaken assumption that it had some magical sound that would supersede everything else in their rig.  It doesn't.  Disappointed that their purchase didn't make them sound like gods, they would e-bay it, where there was a willing clientele, and neither buyer nor seller would have had the benefit of Bill's thoughtful assessment.

So it goes.

[Blitz Krieg]

I've confirmed Martin Chittum's S698 tracing over and over.

with de-gooped specimens?

[mremic01]

I've confirmed Martin Chittum's S698 tracing over and over.

with de-gooped specimens?

The KTR isn't gooped. I've traced three of them. There are four differences from the Chittum schematic. R1 is 2M instead of 1M and R1D (a 2M drop down resistor) has been added. Bill has talked about this change publicly, even mentioning the values explicitly. The other two differences are minor. The 12k and 5k1 resistors are actually 12k1 and 5k11.

What are some other values in question? If we have reason to doubt Bill's claim that he hasn't changed the circuit after adding R1B, R14B, then we would have a reason to think there are other Centaurs that differ from the Chittum schematic. But we don't. Bill has been open about the addition of R1B, R14B, and R1D, but failed to mention R1C. So most of his story checks out, and R1C is pretty insignificant. I have photos of two degooped Centaurs, two KTRs, my own KTR on hand, my own still gooped Centaur (that I have no reason to think is different from S 698 despite being a Gold), and have scrutinized gutshots of over 250 units looking for things that might be noteworthy. I don't have a single reason to think there are other versions of the Centaur out there that were part of the thing's regular production.

These are the versions of the circuit:

Rev1 - The first 300 or so Golds
Rev2 - Adds R1B and R14B, used in Golds ~300-800 and Silvers ~S001-S200 and reissues sold by boxing_rabbit
Rev3 - Adds R1C, used in Golds ~800-3900 and Silvers ~S200-S3900 and reissues sold by boxing_rabbit (this is the only change Bill hasn't talked about)
KTR - Adds R1D and doubles value of R1, used in all KTRs
Bass - No one knows what values Bill changed in the bass units or how many exist
Mod - Each of these is going to have unique specs geared towards customer request, only known unit is MOD 2
Gold Centaur 309 - Has a zero ohm resistor for R1B on a Rev2 PCB, may or may not have R14B

If we really want to get anal retentive about changes, I can tell you that Bill switched from SU series electrolytic to M series somewhere after S 698. And that some PCBs in the middle of the Centaur's run have the number 3102 screened on them for some reason. Maybe I'll discover some other changes. But for the time being, there's no information that suggest additional versions exist. And the things that make them different are mostly very very minor.

How many Centaurs do we really need to degoop before people start believing Bill? We have more than enough information about the thing. The things I want to see are a degooped bass unit, some closed-tail Silver horsies with their serials, and some very very low serial Silvers (to see if the earliest use the Rev1 PCB).

[upspoon12]

what is that goop thats covering all the components anyways?

[kimelopidaer]

plastidip?