K so I worked for the CM that made the reissue. I signed an NDA and out of respect, I won't disclose the actual part number but I will say you're basically spot on. Average Vf is/was approx. 270mV when these were manually tested. As for a replacement, it's a ton of hype folks. The original has PLENTY of alternatives that will work just fine. A 1n34a is plenty close enough. I know this because I fooled the test set up we used by substituting 1n34a's in it. This is as far as I will say about this.

I was a moderator on FSB at that time and yes I was in the group of folks that were in the project to degoop the Klon. It’s great to see my buddy Martin/Soulsonic get his due. Thanks for putting this record out there. It really means a lot to see this info out there.

I have NONE of the requisite technical electronics knowledge to understand these videos. Yet, as a lifelong gear and pedal nerd, I cannot look away. You are doing God's work, my friend. Thank you.

In 2007, I received a cold call from Bill, and a request to see if I could coax the pedal into doing something that several customers had requested, *without* changing the basic design or necessitating a change o the board layout. Bill sent me two ungooped boards, one of which had every single component socketed, and a schematic. The idea was that I could sub different component values and compare the modded board to a stock unit. I made myself an enclosure with stompswitch for instant A/B-ing. Have to say I was impressed with the build quality AND the precision of the pots. We had many long chats about the design and his business practices. The schematic (which was returned, along with the boards), had a number of resistors scratched out and subbed with other nearby 1% values. Bill is no electronic engineer (neither am I, for that matter) but he has great ears, and tweaks until he hears what he's aiming for. I did not measure anything about the diodes, but I think several aspects bear noting: 1) The Klon is intended to coax a tube amp into breaking up in a pleasing manner, and was never designed/intended to be an overdrive pedal, producing an overdrive sound itself (i.e., it's *not* a "really really good Tube Screamer", that you could easily recognize by tone, independent of amp being used). 2) It's modus operandi is to provide a *blend* of clean and clipped signals in a certain proportion, that is adjusted as one rotates the Gain control. While the Treble control has both boost and cut, Bill told me he really intended it primarily for cut, to essentially "de-fizz" the signal fed to the amp. 3) While I am a hard agnostic on the differences between diodes, apart from their forward voltage differences, one needs to remember that forward voltage is largely fixed. So if one is intending to blend X amount of clipping with Y amount of clean, the diodes' forward voltage will determine both how hard that clipping is AND what the resulting clipped amplitude is going to be coming out of that path. In the same way that any issue of the Big Muff Pi can be coaxed into sounding like any other by leaving the transistors as is and playing around with the surrounding component values, I would imagine the Klon and KTR could also be coaxed into sound the same, with a change in diode. *BUT* it would necessitate hand-selecting the diodes from a batch, and changing other aspects of the design such that the clipped/clean balance at each Gain-control setting and the hardness of clipping is also preserved. The easier path to pursue is simply to use the same diodes for each unit. If the unit ONLY used clipped signal, without any attempt to blend, then one diode is pretty much as good as another, and adjusting the Gain to push them into the clipping you want is all you really need from them. But it is the strategic *blending* of clean and clipped (using a dual-ganged pot for the two paths) that is fundamental to the Klon, so diode selection, without any other changes to the design or calibration requirements, is critical. It bears noting that pretty much all diodes have a *range* of possible Vf. If I go through my bin of 1N914/4148s, some are in the range of 510mv and others up around 650. Similarly, germaniums can be anywhere from 250mv up to maybe 380mv. So, having a consistent supply of Ge diodes from the same manufacturer can assure (to some extent) that they are all very close to each other in specs, especially if from the same batch. Again, if the pedal was ONLY a distortion unit with diodes to ground, like the MXR Distortion+, batch-to-batch differences in Vf wouldn't matter. You just adjust the Gain control, and Bob's your uncle. Personally, I think far too much is made of the "knee" in diodes. Keep in mind that diodes' principle historical use is in switching circuits, with distortion/drive pedals way way down the list. Is the point at which a diode goes into full conduction important? Sure, but for speeds/frequencies well outside of what musicians, and especially guitarists, would find relevant. As a player, conducting in 200nsec vs 100nsec is meaningless. ALL specs always need to be considered in-context.

This has been in my 'watch later' list for ages (because, you know, run time...). I have to say that It was superb and well worth the watch. I knew various bits of the story around Bill and the FSB de-gooping, and had fallen into the diode rabbit-hole when I built my own clone (1N5711 anybody?) but seeing it all laid out as a coherent presentation was fantastic. Congratulations on putting this together in such a complete way - I don't see how you could have made it any shorter.

Facts on (germanium) diodes I learned the hard way: 1 - germanium diodes of 1 batch can vary in Vf from 0.3 all the way up to 1.9V (had authentic looking 1N34A and 1N60) lots of them were dead as I got them. 2 - not all multimeters measure at 1mA. I have one that does but also another one does at 2mA. Always check! 3 - shottky diodes usually have Vf of about 0.25V at 1mA, but there are higher Vf ones, up to above 0.3 as well. I could not tell the difference between shottky and germanium by the sound of my hm2 clone at similar Vf. Ugly sound at higher Vf silicon. 4 - the clipping circuit of my Marshall jcm900 preamp clone accepts 1N4007 diodes specifically. Every other diode sound crap. No clue why.

This video is beyond amazing, man. Thanks a lot for all the work!

Watched it all the way through. I appreciate the work you did hear. I already knew all the history and drama, but the technicals analysis was what kept me watching. Thanks, cool video.

Can't believe I made it all the way through the video, very, captivating, informative and very good run through on the Klon pedal, with significance or not on those diodes and what the real run down is with them. Thank you.

Fun fact: I once e-mailed Geoff Farina from Karate in the late 00's about his setup on their live album 595, it's a really beautiful tone; he told me that he used a Klon and that he actually worked for Bill at one point putting them together! He also said he got his for the "right" price.

I can't believe your videos only have as many views as they do. Your page is the perfect source of information for my level of knowledge. Thank you!

Good to see magic pedal component speculation cleared up with actual testing. Thanks - great channel for us pedal nerds.

This was incredible, thank you! I didn't know a single thing about these diodes going in, but I learned a lot. Thanks for the great content.

This was a brilliant viewing experience. Thank you ! You're a boss.

Such an underrated channel. Looking forward for more of these! Thanks

I worked on a similar project from 2001 thru 2004. We didn't try to duplicate the circuit. We just analyzed input vs. output and made something that did the same thing. The takeaway was that its all about the gain vs. the voltage drop from the clipping diodes. We ended up using a TL082 and 1n34a combo.

This is awesome. SUPER clear with al the details. Thank you man. Cheers. Nico

Great video Bro! I'm not sure how it took me 2 years to see it, but I'm glad I did. Nicely done!

Thanks for making this video. I really like the way you explain ideas that are beyond my current level of understanding. So yeah, I subscribed and I'll check to see what else you can teach me.

Thanks for putting this issue to rest with your thorough analysis.

Just watched the hour long video, liked and subscribed. Also Five Watt World did a good video on the history of the Klon. I look forward to seeing more of your videos.

Somewhat on topic: The MXR Sugar Drive is an excellent “klone” and seems to get overlooked because they didn’t go for the imagery associated with Klons like everyone else. Switchable buffer, inexpensive, great sound everywhere in the sweep of the gain, and one of my favorite tone knobs for coaxing exactly what I want from different guitars. If you aren’t caught up in having ponies and silver or gold on an oversized enclosure, look at Sugar Drive demo videos or try one out. I went from 4-5 “drive” pedals in rotation to just the Sugar Drive and a RAT. Excellent video, I made it to the end!

This was so well done and well taught. Thanks for doing this, Mr Gray Bench!

Watched the whole thing. You rock bro. Liked and subscribed!!

I just want to comment on the impressive amount of editing done to remove all pauses in your speech. That’s a lotta edit points! I’ve never played a centaur myself but I still found it interesting. Thanks.

Excellent presentation. The use of the white board and oscilloscope was the best explanation I've seen on this platform. I lived down the street from Finnegan in Brookline, MA in the 90s. I never bought one as it was expensive back in day. I saw friends perform with them, Suke Cerulo being one in the 90s. I have the J.Rocket Gold, and the Mythos versions. My JHS Double Barrel is more flexible.

The current edition of the Chellee Ponyboy has a diode switch and even at full gain you’d have to have the ears of a bat to hear the difference between the shotkys and the germanium. The fellow at Chellee basically says as much in his description of the pedal but because of the requests he got he put the option in. As Josh at JHS says, it’s not the individual parts, it’s the circuit as a whole and how those parts are used in the circuit. As someone who’s owned way too many klones (currently it’s an Emerson Golden Face, but I’ve also had the Sugar Drive, the Conspiracy Theory, the Archer, the Archer IKON, the Soul Food, the Ponyboy, v2 and v3 of the Architect, and probably a few more than that), I can tell anyone who will listen that they’re basically all the same. Some of the extra features on the ones with more than 3 knobs are nice to have, but they all sound like Klons.

This was so educational and so well plotted. Thank you for the effort

Really nice informative video. Realizing theses diodes are harder to get or more expensive now, I ran to my stash of parts and found about 20 germanium diodes i paid probably almost nothing a while ago :)

Thanks, this was a super informative video. Im always intrigued about the science behind the scenes, and this didn't disappoint. In the real world, the Klon is just so juicy. Once its dialed in, its hard to resist.

Great video. Love the effort you put into this. Thanks.

Excellent work, I'm building a klone from stewmac at the moment and have a prebuilt mjolnir Klone too so nice to know the real technicalities behind the diodes

Very interesting video! Really cool to see the oscilloscope analysis at the end.

I've read a paper about using Schottky diodes with a low value tail resistor to get something very close to the waveform produced by germanium diodes; perhaps this is one of the tweaks that Finnegan is considering. In the end, it's all about the harmonic content produced at the design voltage and current, and this can be easily analyzed with a hobbyist-grade DSO with a FFT spectrum analyzer function.

It's so refreshing to hear and see an explanation of an electric circuit from an electrical engineer! Thank you so much for making this video. It would be interesting to see the effects that different types of silicon and germanium diodes have on the circuit via the oscilloscope.

This was a great ride! Thanks for doing the testing at the end. I'd like to see more of that. The general lesson I get is that we don't really know if it's the diodes that makes the Klon attractive.... So what else could it be... get into that! Thanks!

You’re awesome man! Keep up the great work!!

Love this. Only gripe I have is I’ve never seen the klon as transparent. It has to be the most midrange heavy drive in history

Great dive! Thanks for providing this. The lowest forward voltage thing I have ever discovered was using jfets as diodes and tying the "wrong" legs together. Got a forward voltage of about 0.1 on some of them. This was only on some of them. Others didn't work that way at all if I recall correctly. Probably @ 1 ma as I was using a MM

Outstanding video…and points proven. I enjoy these topics and I think it’s great fun to search and find the tone one wants- it’s human nature. In the end, the whole Klon hype is fun to watch as a bystander - I learned a long time ago that one can take a well setup Fender Squire Telecaster to a gig with an SX300 solid state amp and get the job done with great tone….I have used that Carvin SX300 at my biggest gigs with a $600 LTD guitar and no pedals ….guitar, cable volume knob and have had some of my best fun. Still, I enjoy the hype and search and playing with these things. Again, very well done!

Interesting. Thanks for the video and proper testing.

Great video. I built a klon clone with 1N34A and love it. However like all pedals I’ve built as clones I modified it to my liking making it more versatile. I like this circuit a lot and in some guitar/amp/other gear combinations it works perfect but in some cases I felt it cut too much low end. Mine has a bass knob(pot) among other features. I like the clean boost thing but I like much more how it sounds at higher gain settings.

Fantastic overview - and made me laugh when I looked at the video duration ;-) I'm about to build a Klon clone myself, and this was perfect timing!

Fantastic analysis and history lesson - thank you!

Very interesting and well presented video! I too have a Ceriatone Centura and find that it sounds exactly like my friend's "real" late 90's Klon Centaur, for about 1/20th the price!

I didn’t know that I had such an interest in diodes. You successfully made what should have been boring very interesting.

This video is truly epic. Thank you greatly

This was very informative. Thank you for such a great video!

Fascinating. The 52 minutes flew by. If by some chance you’re in New England, I have a KTR with the old diodes if you want to test them.

i have old boxes full of parts as i used to build pedals. i am confident i have these diodes . i remember buying all kinds of germanium diodes years ago. one day i'll go through all the boxes

Interesting stuff, I don't play but I have an interest in solid state and tube electronics and putting the before/after signal on the scope was interesting. I wonder if folk have successfully used other devices to clip the audio signal and generate the harmonics, way out stuff like neon bulbs or devices with other gases in them that may give the desired non-linear effect. There is so much lore attached to a given diode part number or even an op amp in pedals - how much is just lore and how much is fact we will likely never know but it is always interesting diving in to these circuits to explore them. Your video explained things quite well IMHO and I envy your tidy, spacious bench.

That was extremely interesting, thank you!

Seems like the real magic is in the pre amp… Thanks for the amazing and thorough video!

Super nerdy and cool info!! Just as with debating tonewoods in acoustic guitars, or any number of such “sonic” debates, much bigger factors are the touch of the player, the precise compression/harmonics of the amp you are playing through, pickup frequency response, etc That is, what so many people get fixated on are really very small contributors to tone. If you took for example, a great electric guitar through the ideal original Klon pedal, into a really nice amp on the edge of break up and hand that guitar to two different players - the difference in the resulting tone would be greater than any diode swap, variation on any particular Klon or Klone specimen could contribute! The substantially larger factor in how you sound is the note you play imprecisely how you play them! I own an early KTR and it’s a cool pedal, but there’s nothing magical in it. It’s just a particular kind of boost with a certain freq Response and type of harmonics. What I do with it is way more important than the sound it imparts on the signal.

Good video as always. I would love to see a teardown on a Harmonic Percolator or the Burns Buzzaround. I always really dug those circuits.

Great video, thanks!

ive been building klons for myself and friends for the past 5 years or so that i mod to have a two channel type set up. I came up with all the mods on my own except the initial gain increase that allows the second mode/boost to work. Its something i would have done anyways but ive seen it on some diy pedal kits as an optional mod so Idont want to take credit for that part lol. Anyways the way i do it is i use a second footswitch that switches four parameters simultaneously to give the klon a boost mode (which includes a boost gain and boost volume pot). But the boost isnt adding any extra circuits before or after the klon circuit its just piggybacking on existing components. I came up with this mod because most people like to use Klons as a clean boost and miss out on the great overdriven Klon tone. So by having a boost/channel 2 type option you can have both. The boost also incorporates a boost gain and boost volume pot that i put slightly above and in between the stock pots/knobs. Because of the way i get the extra gain (10K resistor in place of the 47k R16 if youre looking at the electro-smash schematic) there is enough extra gain that you can get the klon to be even more versatile with single coils. So it can do clean boost to high gain and everything in between. The klon really has much more grunt to offer that just is wasted in its stock configuration. It really makes the Klon circuit so much better in my opinion. The other important part of the mod is adding a minimum gain resistor to the op amp gain stage half of the dual gang pot. Without the minimum gain resistor in place when the boost is active you wont get a boost unless you turn up the stock gain pot a little bit. But with the minimum gain resistor you can have the stock gain at zero for a clean boost then hit the boost footswitch and get a great overdriven klon tone. The stock gain pot and the boost gain and volume are all very interactive with one another since they are reacting just as the stock circuit does. Anyways i might not be doing it justice with my explanation but the modded pedal is really great and id love to built a few extras so more people can experience it. With the boost not engaged its just a typical stock klon because my modification moto is "only add functionality/versatility but never take stock functionality away" so all my pedal builds that ive modded retain their stock functionality via switches etc.. Ive even used some of those cheap klon kits as a base for my modded klons to keep the price down for a couple friends who wanted one but are generally as broke as i am most of the time lol. I keep meaning to put together a complete pcb of the klon circuit with my mods on express pcb so i can post it and other people can build this version of the klon themselves. Anyways i just saw this an figured maybe a fellow klon enthusiast might see this and want to build a Klon with these mods also. If anyone wants to know the full scope of the mods so they can build one or mod an existing klon just let me know and id be happy to answer questions and explain more in depth how to do the mods!

great work on this video

Most excellent. I like the idea of building a circuit to measure actual output. Subscribed. Thanks.

This was a great video. I’d love to hear more about the nuts and bolts of the components of pedals

awesome video, as a fellow music engineering nerd i appreciate the extensive detail

Great video. Thanks ever so much!

Amazing video! Thanks a lot.

This was really informative, thank you! Somebody buy this man a klon.

It was the tube screamer, the Rat, Boss DS-1 and the Boss SD-1 as the most popukar. There were plenty of others, but those were the big four in 1990. Around that time I was using the TC Electronics boost/overdrive which was and is an excellent pedal. Too bad those are also absurdly expensive now.

Thanks 😊 for a wonderful 👍 video that has demistyfied the Klon. It's great to get educational info from genuine honest people like yourself. Some others wrap fluff around Scientific concepts calling them nerdy. Thanks very much. Best regards 😸.John.

Fantastic Video! I enjoyed it a lot! ...I built 2 Centura kits that I purchased from Ceriatone, so I am quite familiar with the circuit, and now I know a lot more thanks to your video. Sub'd!

Very good 3 part series on the Klon circuit. I forgot I was was a tech who used an O-scope in my early years. I wonder if used O-scopes can be picked up cheap? I'm finding the "Tech" in me is coming back after watching this video and the JHS video on his Pedal building where he used an Atlas tester. I just ordered GM328A transistor/diode/capacitor/freq meter/volt meter from a Chinese company dirt cheap . I'll have to read up on what test milliamps it uses. I just retired and finding more hobbies than I years left. Basement is full of benches for guitar setup/repair/electronics testing/Cad computers/toolmakers scope/microscope with video . Garage is a full machine shop . Might have start a business. Looking forward to your next series.

yep i just tested a 1n34a diode with my multimeter I got .21 and with my peak I got .35 i never even thought about this. very cool video. im subscribing to your channel and recommended you to my buddy who builds also.

You're not an expert ? You realy are . I love listening to you, your so enthusiastic :) and really knowledgeable. Thank you for posting

as you know the gain knob is a blend between the a clean and fixed gain amount. there is a resistor you can swap with a pot and then youll have control over the actual amount of gain. when i made a run of klones like 7 years ago i used separate pots for the dual gang pot. so with those 2 mods you got independent controls for clean volume gain amount and gain volume. it made for a pretty cool pedal.

Very interesting video!!

Great video, enjoyed every minute of it! Good inspiration for opening up my Mosky Silver Horse to see if an interesting mod would be possible.

excellent work....as always

Do you think about ever creating "lessons" on guitar pedal building? You're extremely helpful in explaining a lot of the material, super methodical and thought what a killer series you could create on the subject! Your videos are killer and I learned a lot watching this!

Great video! I was around FSB during this time [2007] (still am) and all this information on the tracing, and who made it happen, is correct. In my view, if someone wants a clean boost they’d be better of with a super hard on…or even better, a self built one. My take away from this Klon business is what I’ve always known about each and every hobby or field I’ve been involved in; that is that 99% of its content and “must have” mojo is hype and nonsense disseminated by people who know very little about the fundamental elements of their chosen hobby or whatever. How many “Klon experts” could actually build a nice overdrive if you threw a handful of parts on a bench for them? Very few, I would say. This is the way of the world and always has been. Great show anyways, man! Edited to add: You should maybe start a “GBE Videos” thread on FSB and every time you do a new video post a new reply with it in your thread. It might well get you some more exposure; which would be great and inline with what FSB is all about: the free exchange of truthful information.

Thank you for this amazing video

My DSE Q-1804 20MHz Dual-Trace Oscilloscope has a built-in component tester, one day out of curiosity, I built a very simple diode-clipper circuit on my solderless breadboard, applied a signal to it using a Function Generator and observed the resultant waveform on my scope, I found that the clipping characteristics between silicon and germanium diodes to be quite different, silicon diodes clip the signal sharply, whereas germanium diodes clip the signal softly and the resultant waveform is more rounded than what you get with silicon diodes, I've also tried the same experiment using a couple of Schottky Diodes, Schottky diodes are silicon diodes which are designed to exhibit a forward-voltage very similar to germanium diodes, they also exhibit a very similar soft-clipping characteristic too, so, if you're building a Klon Centaur clone and you're unable to buy any good/usable small-signal germanium diodes, like the 1N34A, try using a couple of small-signal Schottky diodes instead, they should work fine.

Nice video. Thank you for demystifying Klon Centaur. Your description of diode selection was new to me. While I appreciate some features of Klon Centaur, that other pedal doesn't have, I feel that hype around it, is only for bumping price up. I value high the work of Bill Finnegan and his ideas, but at the end final circuit isn't that complicated, anybody with medium electronic skills is able to build a copy, play with it, tweak it to his taste ;-)

I find OD mythology so hilarious. I changed Si for stacked Ge diodes in many pedals and nobody could EVER hear the difference. I can hear and I'm now a producer for majors. Distortion masks TONS of stuff that people CANNOT hear. The EQ manipulation and sequence is all that matters in a "stock" gain unit derived from the classic ODs.

I might be a masochist. This is the second time I watched this video. Really well done!

Great video - and really well explained. So when we talk about the qualities/properties of ANY drive/boost pedal - and the small differences in operating characteristics between Si and Ge diodes, and their manufacturing tolerances, and their operation in the context of the whole circuit (which is full of other components with manufacturing tolerances) - which you then connect to a guitar with different strings, pickup types, pickup output levels - into a huge range of amplifiers with different preamp and power amp topologies - through many different types of speaker in different enclosures - in different acoustic spaces - at a wide range of different volumes - in a band context alongside other instruments - then into your personal and highly individual listening equipment (i.e. ears) - can anybody really tell the difference? Having said that, I'm a sucker for drive/boost pedals - and I love buying and trying them! The most important thing is what sounds good to YOU and inspires you to play/practice/learn : ) Great channel and great content - thank you, and keep up the good work!

i remember when the group bought the pedal i wasn't one of them but i was reading that thread as ive been building pedals since 2003 or so.

Great video

Great video, a lot of information

You can also use Leds as diode clippers as well, Leds do exhibit a higher forward voltage than small signal germanium or silicon diodes, but, they also exhibit a slow/soft turn-on as well.

Thanks for showing the pot cutout and the switch keyway. I suspect the enclosure is laser cut due to that keyway size. Thanks for the video.

If you want to get closer to the original response of a germanium diode with a silicon diode you just add a small resistor in series to reduce the sharpness of the current curve.

Great job man

I'm no musician at all. This might make me sound dumb, but the sound from the diodes I perceived as being "wetter" and without them as "more dry." So I did notice a perceptable difference. I guess I would call it watery. Odd the words that we choose.

The Klon is one of the craziest anomalies in the history of the music industry. Im glad there seems to be something measurable there. I convinced myself i could hear a difference.

Great video.

I adore this channel so much oh my god yes.

This is fantastic geakery!!!

Ahh, when one person’s personal efforts in soldering away the days building that one pedal suddenly becomes less than enough to keep up with his business - but wait!?? Why didn’t this gentleman, Mr. Bill, hire one or two electronics hobbyist friends to better keep up with the demand that was overwhelming him? There are a few business administration epiphanies wrapped up in this story. Really interesting, THANKS!! Edit: ¡¿¡DAMN!?! Also, there are a few EE Eurekas surrounding the finer datasheets points of DIODES! ¡Absolutely comprehensive, very good and insightful presentation, THANKS again!

Wow man it is so interesting, thanks for share

Great video. Really good, clear, and understandable presentation. I appreciate you taking the time to go into so much detail. So the Ceriatone does not use the Bill Finigan "special" diodes, BUT does the Ceriatone use germanium diodes with the correct forward voltage measured at 5ma (or at least the corrected 1ma Vf)? What diodes does Ceriatone use?

Great in depth info .. amazing work thanks Have you checked out the swap out of the ceriatone centura diodes used to nos IIT 1n34a diodes then tested against both a ktr & original klon you tube vid ?

Mannnn, this is great! Loads of info and entertaining for us nerds out here. Lol

A work of scholarship - thanks!