Build Your Own Clone Message Board

Hey guys I've noticed that E.S.V. fuzz kit in the byoc store ran out of the NOS ac127 germanium transistors. I wouldn't mind getting the silicon version of the kit, but does anyone have any suggestions on where else I could get the same ac127's, or perhaps suggestions for other close germanium alternatives? Thanks for the help guys! :]

The challenge is that good quality NPN germanium transistors like the AC127 have gotten pretty hard to find and are consequently quite expensive--$20 to $30 for a tested pair is about the going rate. If you go this route, be sure to deal with a reputable party; not a good idea buying these on eBay, unless the seller has a ton of positive feedback. Stick with tested pairs--these transistors often have high current leakage and low gain, since many stocks have been "cherry-picked" for the best examples. I'd suggest trying Small Bear Electronics, a source well known to be trustworthy.

Alternatively, you can modify an ESV Fuzz build to be positive ground so that PNP germs can be used. These are more readily available and about half the price. The downside of a positive ground pedal is that you have to power them either with a 9V battery or dedicate a "wall wart" to them. If "daisy-chained" with a negative ground pedal (the vast majority of effects pedals are this type) on the same power supply, a power short to ground is created, and neither pedal will work. The build modifications are pretty simple to make the ESV Fuzz positive ground--you have to modify the wiring to be like the positive ground ESV 2-Knob Bender, and the 22uf electrolytic cap and LED need to be mounted with the opposite polarity.

One more option of note if you decide to go with a positive ground configuration: our pal Brian over at Madbean Pedals sells a nifty little PCB called the "Road Rage" that will convert normal +9V voltage supply to (among other things!) -9V, which can then be used to power a positive ground ESV Fuzz without all the wiring changes. This makes a positive ground pedal power-compatible with negative ground pedals, so no dedicated PS is required. I just finished an ESV Fuzz kit night before last built exactly this way, and it works like a charm. Used a pair of tested & matched PNP germs that I bought from another forum member here, and the pedal sounds fantastic. I have a wiring diagram for the ESV Fuzz/Road Rage combo if you (or anyone else) needs it.

Thanks for all the information, I really appreciate it! Buying NPN type germs as a direct replacement from small bear seems like the most viable option, but I think the ESV fuzz/Road rage combo seems pretty interesting, and I may end up trying it! If it's not too much trouble could you post up the schematics for this modification? Thanks again in advance, if it wasn't for your help I might've ended up buying leaky germaniums through ebay, haha.

No trouble at all:

Awesome! Thanks again.

Bean's RR is a cool little diddy isn't it. Small and easy to slap on a side wall.

[Shameless promotion hijack.]
And if you don't have access to a roadrage you can build this on vero

The military green cable from ring in the layout above connects to the hole lowest right corner

Sweet! Thanks Fuz!

We are all here to share and learn my friend

I haven't been on this board for ages, but I built one of the early versions of the fuzz face clone. I've had it for years and I've auditioned quite a few transistors in it. I did a little tweaking last night and I came up with a really sweet transistor combo.

Q1 - 2N2222A (silicon purchase off of ebay supplier in CHINA)
Q2 - AC127 (germanium purchased off ebay seller laststore4tec in portugal)

I'm only posting this because this combo really stood out, full of rich harmonic content. A lot of transistors will work in there but I am finding SI in Q1 and GE in Q2 makes the Q2 a little less critical.

I've also tried these in Q1
AC127, AC176, BC109C
and these in Q2
AC176, BC109C

The AC127's that I bought on ebay ($19.50 for 20) had a smaller tabbed metal can, unlike the bigger cans on the original transistors that came with the kit. AC176's work ok but they are kind of harsh and flabby by comparison.

I am currently building a FF replica from a pigeonFX kit with all original caps and resistors and some matched/tested NKT275's I'll report on that later. I'm trying to build a 'reference' pedal based on the original circuit and components without spending $1200+