Jim Dunlop JD-F2 Germanium to Silicon BC108C transistor conversion.

[Bakersdozen]

I had one of those, olive drab, big assed knobs and heavy and dirty as all get out. Loved that thing.

Yep that's the one mate. With the cool timber box it came in. There more I think of it, it's bringing back more and more memories of lugging it round to jams and gigs .. so so cool

[Marcel]

Many many moons ago I had the need on my workshop test bench for a multi isolated outlet 9VDC supply. Found one on Fleabay by Viloos for AU$34. It came with leads, 8x9V plus a 12V and 18V outlets, and a 1.5A 18VDC AU plug pack to power it.

After a few months I found it worked so well on my bench that I bought 2 more for my rig, one for the input jack pedals and one intended for the effects loop pedals thus dispensing any need for a bucket load of 9V batteries. It's not exactly as how things are today as the 2nd supply intended for the effects loop is in my travel case for those times where I want to play away from home. Other than the bright Blue LED's on each output jack when a 9V lead is plugged in I've never had an issue, so I'm reluctant to spend the huge money on upper end 9V distribution gear like the MXR power brick.

FYI, the 'other 5' on my current 'home board' are a Poly tune 3, TCE Helix, NUX Time core, Catalinbread Echorec and a Behringer NR300 gate..... so many hours of fun, noodling and writing...

[DrNomis_44]

You can't go wrong with a good Fuzz pedal on your pedal board, one of the very first FX pedals made for the electric guitar, way back in the early 60's, and it all started with a faulty Langevin mixer preamp when Marty Robbins was in the studio recording the song "Don't Worry".


Bit of trivia there for you.

[DrNomis_44]

Gave my red Fuzz Face a test-out to see if it's still working, cause I'm going to use it at an up-and-coming gig at the Nirvana club on Thursday next week, fortunately it is still working perfect.


It's a surprisingly simple circuit, but what a raw tone it produces, very vintage-sounding, definitely nothing like what you get from plugging straight into an overdriven tube amp, but definitely thick and smooth like a typical Fuzz should be, it does tend to sound a bit woolly in the low end, but I think that's a good thing since it compensates for pickups that tend to be a bit ice-picky in the high end, one thing I will say is that it is very sensitive to how you set the volume control on the guitar, you can get various shades of Fuzz from a slight breakup to full-on psychedelic Fuzz just by turning the volume up or down, it also responds to your picking-dynamics too, pick softly and you get a slight smokey breakup, pick harder and it gets more saturated, if you turn the Fuzz control up to full and pick hard, you get a sort-of compression effect on your pick attack and then a blooming effect when you sustain a note.

Note: It does tend to sound smoother and better through a tube amp.


And for those interested in building a Fuzz Face pedal for themselves, I'll post a hand-drawn circuit diagram tomorrow, based on what is currently in my red Jim Dunlop JD-F2 Fuzz Face pedal, and what's on the replacement circuit board I installed, including voltage measurements......stay tuned.

[DrNomis_44]

Here's the latest revision of the wiring in my red JD F2 Fuzz Face, the reason why I did the wiring revision is mostly because I found that the wire I had used previously was prone to breaking at the solder-joints due to how thin the inner conductors are, so I decided to replace all the existing wire to improve reliability, here's a pic so you can see how it all turned-out, I used a photo of the insides of a vintage NKT275 Germanium transistor Fuzz Face as a guide:




This is pretty close to what you would see if you looked inside a vintage BC108C Silicon transistor Fuzz Face pedal.

[Marcel]

Lol... you said "vintage BC108C".... First time I had my hands on and was soldering in BC108's was back in 1973... Yeah, that was more than the vintage spec 25y ago.... LMAO & ROFL ...

[DrNomis_44]

Lol... you said "vintage BC108C".... First time I had my hands on and was soldering in BC108's was back in 1973... Yeah, that was more than the vintage spec 25y ago.... LMAO & ROFL ...

Yeah I know, but nowadays an original silicon transistor Fuzz Face from the late 60's to early 70's would be considered vintage, apparently Jimi Hendrix used one of the early turquoise silicon transistor Fuzz Faces at the original Woodstock music festival, which started on the 15th August 1969, the exact same month and year that I was born (I was born 16 days later how cool is that?), which makes it about 51 years ago, since I'm 51 years old now, and the early silicon Fuzz Faces used the BC108C.

My guess is that the reason why Dallas Arbiter chose the BC108C was not only that it was far less temperature-sensitive than the AC128 or NKT275, it was probably a fairly cheap and readily available transistor as well, who knows.


Here's an interesting webpage article on the history of the Woodstock music festival:

https://www.history.com/topics/1960s/woodstock

[DrNomis_44]

Hey Everyone,

Just thought I'd do an update on this forum thread I started, so here goes........


Earlier this year I ordered two new Issue 2 Fuzz Face pcbs online from Pigeon FX in the UK, I used one of them to replace the original Issue 1 Fuzz Face pcb I had in my red JD-F2 Fuzz Face pedal because I noticed that the copper pads on the undersize were starting to lift, last year I bought a set of 8 CDIL BC108C NPN transistors on eBay and I went through them and picked two of them with the highest gain of the lot, one had a gain of 635 which I used for Q1, the other had a gain of 660 which I used for Q2, I paid a visit to my local Jaycar Electronics shop and bought packets of 1W/5% Carbon Film resistors containing two resistors of the following values, 330 Ohms, 470 Ohms, 8k2, 33k, and 100k.

Using a 330 Ohm, 8k2, 33k, and a 100k 1W/5% Carbon resistor, the three capacitors on the old Issue 1 pcb, and the two selected CDIL BC108C transistors, plus an extra 1nF/100V greencap I soldered to the underside of the new Issue 2 pcb in parallel with the 100k resistor, I re-built the Fuzz Face circuit, I used some short pieces of clear heatshrink to insulate the base leads of the two transistors so they wouldn't short-out against the other transistor leads, this was necessary because the solder pads for the transistors on an Issue 2 pcb are configured for BCE transistor lead layouts rather than CBE.

Just recently I ordered a set of two new TRS Cliff Jacks from Evatco, they arrived in the post yesterday and I installed them in my red JD-F2 Fuzz Face pedal.

So, now, my red JD-F2 Fuzz Face is as close as I can possibly get it to a vintage Silicon Transistor Fuzz Face, once my mobile phone has finished charging I'll take a couple of pics of the insides and post them here.....stay tuned....


Here we go....

[DrNomis_44]

Last year, or maybe the previous year, I managed to buy a second-hand Fuzz Face pcb on eBay, it originally came out of a Jim Dunlop JD-F1 Jimi Hendrix Fuzz Face, the turquoise one, and I installed it in my red Jim Dunlop JD-F2 Fuzz Face, the JD-F1 Fuzz Face pcb uses two BC108B NPN silicon transistors, it also includes a couple of surface mount trimpots, and some other surface mount components on the underside of the board, I'll post a pic of the insides shortly.


Okay, here we go:



And, a closeup of the Jimi Hendrix JD-F1 Turquoise Fuzz face pcb I bought on eBay: