Dunlop - JBF-3 Joe Bonamassa Fuzz Face

Tonetweaker · Post by **Tonetweaker** » 27 Mar 2011, 08:33

Well... it finally came in the other day.

It's very pretty... but pretty much a standard Fuzz Face.

Pretty good sound. Here's a review with a couple of sound clips:

Premier Guitar Review

Here's the same image with some component values added:

More to follow...

Tonetweaker · Post by **Tonetweaker** » 27 Mar 2011, 08:55

Here's the undercarriage... where I found a couple of SMD components hiding out...

I wasn't sure about the transistors... The military spec equipment I always worked on was very clearly labeled, so I'm always a little wary when it comes to identifying commercial grade components. They're definitely PNP though (I measured them, plus it makes sense with the power conections). They are pretty well marked, so I took several pics to show all the markings around them...

I found the backwards "C" with the dot in it on an IC logo identification page... It was listed as "Planeta."

Rough schematic to follow...

fosnal1950 · Post by **fosnal1950** » 27 Mar 2011, 08:58

But remember it's just an endorsement , it doesn't make you play and sound like him straight away.
Practising is what you need or maybe one of those talent boosters.

This isn't meant personally

Tonetweaker · Post by **Tonetweaker** » 27 Mar 2011, 09:11

Here's my rough draft of the schematic...

I'm a bit unsure of the transistors (as I mentioned above), and the resistors and SMD components. Some of the resistor values struck me as a little odd (332 Ohms?, 3.16 kOhms?)... Perhaps I'm misreading the color codes?

The little SMD trimpots are obviously nearly impossible to identify (no markings that I could see), so I took a reading across them with my Fluke to at least provide an idea of what mine were set at. I would assume these are being used to trim the collector voltages, so I would imagine that you could drop 10k trimpots in and simply tweak to taste.

The SMD cap (C5) is a bit of a mystery, since I couldn't find the damn thing.

As you can see in one of the pics, C5 is labeled on the far left of the board... and even has traces and leads, but it's directly under R1, so I don't know where it is? Perhaps its a multi-layered board or something? I've never really worked with SMD components or multi-layered boards, so I'll have to plead ignorance on this one. Since it appears to be forming a simple filter with R1, I would think that any small value cap would do the trick.

Anyway, if you guys could give me a hand with a few of these questions, I'll be happy to spruce up the schematic with the missing info and repost. At that point, I'd say you could use any standard FF board (with a couple of trace side components) and build away for a lot less than I paid for this beast.

Cheers...
Steve

Tonetweaker · Post by **Tonetweaker** » 27 Mar 2011, 09:14

fosnal1950 wrote:But remember it's just an endorsement , it doesn't make you play and sound like him straight away.
Practising is what you need or maybe one of those talent boosters.

This isn't meant personally

Still right on the money, though...

If only it were that easy to capture killer tone like his in a box. It's still a pretty good-sounding little beast, but certainly no miracle cure for my half-assed playing.

Cheers...
Steve

JEM · Post by **JEM** » 27 Mar 2011, 11:15

Hello friends, the transistors are the Russians MP39B Hfe with a range of between 20-60, and IT308B (possibly the military equivalent of GT308B) the you can find on ebay without any problems at an affordable price.
I left some shots of the Datasheet for if you can lend a hand.

Greetings from Spain.

RnFR · Post by **RnFR** » 27 Mar 2011, 13:25

hey you beat me to it! yes, the transistors are Russian Ge. I was wondering when we were going to start seeing these transistors in commercial boxes. I guess the secret's out!

btw- those smd trimmers on the trackside are slick! I wonder if mr. tripps is behind this one?

also, my guess is that c5 was removed or was never placed on the board due to schematic revisions.

Tonetweaker · Post by **Tonetweaker** » 27 Mar 2011, 18:49

JEM wrote:Hello friends, the transistors are the Russians MP39B Hfe with a range of between 20-60, and IT308B (possibly the military equivalent of GT308B) the you can find on ebay without any problems at an affordable price.
I left some shots of the Datasheet for if you can lend a hand.

Awesome! Thanks for the info!

I had a feeling they were germaniums based upon the sound, although admittedly I'm far from an expert on identifying the difference purely on sound quality. It's good to know that they are readily available too... They really do produce a pretty sweet sound, so it'll be nice to be able to reproduce it... especially since it's such a relatively simple circuit.

RnFR wrote:hey you beat me to it! yes, the transistors are Russian Ge. I was wondering when we were going to start seeing these transistors in commercial boxes. I guess the secret's out!

btw- those smd trimmers on the trackside are slick! I wonder if mr. tripps is behind this one?

also, my guess is that c5 was removed or was never placed on the board due to schematic revisions.

I thought the trimpots were a pretty cool addition as well. I don't think I've ever seen trimpots that small.

As far as C5 goes, that was my first inclination too... except that some solder has been applied to the lead areas, so I wasn't 100% sure. I have limited experience with multi-layer boards and some of the newer SMD construction techniques, so I wasn't really sure if there might be a slim SMD component in there underneath the surface.

I probably sound pretty ignorant in this regard, but the vast majority of my electronics experience was with much older military equipment (certainly pre-SMD), most of which worked at much higher voltages. I just didn't want to miss anything.

It is also worth noting that there are other mistakes on the printed layout on the underside of the board. If you look closely, you'll see that the electrolytic cap polarities are backwards on the labeling. I'd suspect that they dabbled with an NPN version of the circuit at one time, or are recycling boards from an NPN FF variant. I never bothered to look inside my Dunlop Dallas Arbiter FF reissue, but I may pull it out of the footlocker for a look at some point to see if the board was the same.

Cheers...
Steve

PS ~ I'd be interested to hear opinions on this is anyone decides to breadboard it or build a copy. I think it's a pretty good-sounding fuzz, but probably not worth the heavy duty price tag attached. I bought it in part to be able to contribute the info to the forum since I learn so much from you folks, so I'll be pretty happy if some of you find it useful.

Steven_M · Post by **Steven_M** » 27 Mar 2011, 23:51

I can tell just from looking, but isnt it common for folks to use a low value capacitor in fuzz face builds between the legs of the transistors to stop oscillations and such? Just a guess, but perhaps C5 is there for that reason and is added/removed when the circuit is tested.

prehistoric · Post by **prehistoric** » 28 Mar 2011, 06:30

not so fast , guys. looks like dunlop has already released revision 1B:

johnnyg · Post by **johnnyg** » 28 Mar 2011, 11:49

Tonetweaker wrote: It is also worth noting that there are other mistakes on the printed layout on the underside of the board. If you look closely, you'll see that the electrolytic cap polarities are backwards on the labeling. I'd suspect that they dabbled with an NPN version of the circuit at one time, or are recycling boards from an NPN FF variant. I never bothered to look inside my Dunlop Dallas Arbiter FF reissue, but I may pull it out of the footlocker for a look at some point to see if the board was the same.

Cheers...
Steve

PS ~ I'd be interested to hear opinions on this is anyone decides to breadboard it or build a copy. I think it's a pretty good-sounding fuzz, but probably not worth the heavy duty price tag attached. I bought it in part to be able to contribute the info to the forum since I learn so much from you folks, so I'll be pretty happy if some of you find it useful.

Thanks Steve

- the copper finish is just a paint then on these?

The hfe of those Russian Transistors is probably the key here for anyone wanting to build a traditional sounding Ge fuzz face - so you're generosity is likely to be a lot more useful than you might have realised

I believe that board is exactly the same as the one found in the most recent blue Jimi Hendrix Dunlop FF - that uses BC108 NPN transistors and was developed by Jorge Tripps. So they are recycling the pcbs there. He's done a really good job I think - the earlier Dunlop FFs I've encountered (just two of them admittedly) were shit sounding.

Not sure what's going on inside the unit posted by prehistoric - is that for real?

Tonetweaker · Post by **Tonetweaker** » 29 Mar 2011, 02:41

prehistoric wrote:not so fast , guys. looks like dunlop has already released revision 1B:

For some reason, I can't seem to get the full-sized image in your post, but even at the forum size, I can see that it looks NOTHING like mine.

I wish I could see that damn image.

Could someone re-post please?

I pre-ordered mine direct from JB's site within a few days of receiving the fan club notification... I can't imagine why they'd already be tinkering with the guts. Folks have barely had a chance to plug it in yet.

johnnyg wrote:Thanks Steve - the copper finish is just a paint then on these?

Happy to share, Johnny.

Actually, it's either copper or a pretty decent alloy of some sort. The pedal is pretty heavy, and a look at the edges makes me think it's actually a polished surface. If it's some sort of paint or laminate, I'd be very impressed.

johnnyg wrote:The hfe of those Russian Transistors is probably the key here for anyone wanting to build a traditional sounding Ge fuzz face - so you're generosity is likely to be a lot more useful than you might have realised

That's very true. If these turn out to be readily available and can be had for a good price, I'd say that these will be quite popular for FF builds. I can certainly vouch for the fact that these sound pretty darn good.

johnnyg wrote:I believe that board is exactly the same as the one found in the most recent blue Jimi Hendrix Dunlop FF - that uses BC108 NPN transistors and was developed by Jorge Tripps. So they are recycling the pcbs there. He's done a really good job I think - the earlier Dunlop FFs I've encountered (just two of them admittedly) were shit sounding.

I have a red Dallas Arbiter reissue by Dunlop. I wasn't particularly impressed with it, so I know what you mean there. I was pleasantly surprised at how good this one sounds, though, so things have definitely improved at Mr. D's factory.

johnnyg wrote:Not sure what's going on inside the unit posted by prehistoric - is that for real?

I was thinking the same thing. Even in the forum-sized pic, it looks drastically different. I hope he didn't buy it used... The first thing that came to mind is that someone pulled the old switch and dropped some cheap distortion board. Considering the big price tag on this beast, I could see someone rehousing the JBFF guts and then reselling the rest with a generic fuzz or distortion. I sincerely hope that's not the case, though.

Cheers...
Steve

prehistoric · Post by **prehistoric** » 29 Mar 2011, 13:25

turns out the one i posted was a prototype from my photoshop lab

Hides-His-Eyes · Post by **Hides-His-Eyes** » 29 Mar 2011, 13:59

Love the design on that prototype with the vintage components on top and the modern additions underneath. Looks really slick.

GuitarlCarl · Post by **GuitarlCarl** » 29 Mar 2011, 16:54

prehistoric wrote:turns out the one i posted was a prototype from my photoshop lab

Hahaha. Couple of days early man that would have been a sweet April Fool's Day pic...
maybe put it on TGP on 4-1!!! see how many orders ya get...

prehistoric · Post by **prehistoric** » 30 Mar 2011, 01:09

i agree, that is a new level of boutiquism in modern major mfgr world. has the stamp of mr tripps all over it. making it look totally vintage (inside) yet having a few hotrod tricks under the hood is very slick indeed.

RnFR · Post by **RnFR** » 30 Mar 2011, 02:02

the only thing slicker would be to put a charge pump trackside for use with a standard dc jack. I do enjoy the whole SMD trackside thing, it's something I've been meaning to get into. of course, it means buying even more parts.

DrNomis · Post by **DrNomis** » 30 Mar 2011, 02:16

I had a listen to the two audio demo clips, my two Fuzz Faces sound nothing like the Joe Bonamassa signature model.....

Maybe those Russian Ge transistors are the secret?....

Hides-His-Eyes · Post by **Hides-His-Eyes** » 30 Mar 2011, 04:16

RnFR wrote:the only thing slicker would be to put a charge pump trackside for use with a standard dc jack. I do enjoy the whole SMD trackside thing, it's something I've been meaning to get into. of course, it means buying even more parts.

Gawd, I know. I can't stand the thought of having to keep a full stock of 1206 as well as standard resistors. Something like this demonstrates the real possibilities though.

johnnyg · Post by **johnnyg** » 30 Mar 2011, 15:18

DrNomis wrote:I had a listen to the two audio demo clips, my two Fuzz Faces sound nothing like the Joe Bonamassa signature model.....

Maybe those Russian Ge transistors are the secret?....

Different transistors certainly have their own sound (or maybe frequency response is a better term) as you'll know more than me I'm sure DrNomis

So I've no doubt those Russian ones have their own thing going on (and evidently do a great job for Mr Tripps and Mr Bonamassa to be happy with them).

But the hfe range of those types is possibly more interesting than the actual type - if you want to tinker or look through transistors you've already got instead of buying more... no doubt those Russian ones will jump up in price now the words out!

What are they?.. 20-60hfe on average... think I've a couple of Russian ones that look like that, can't remember the type - they had very little leakage, and that perhaps is a reason Mr Tripps/Dunlop have picked theirs (in addition to cost/availability).

The original NKT275 had a nominal range of 30-90hfe.

The Denis Cornell 90s Arbiter Reissue I took apart had a pair of AC128s with hfe c.50.

You get the idea!

Good chance Denis Cornell and Jorge Tripps have measured original units I would suspect. Electric Warrior has said somewhere that lower gain is the way to go with the ge fuzz face - David Main has also said that somewhere on his site. You don't have to stick to low gain of course - but if you want the traditional kind of sound then it's the way to go I guess.

Dunlop - JBF-3 Joe Bonamassa Fuzz Face [schematic]