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I wouldn't mind having a go at building a Joe Bonamassa Fuzz Face, complete with the same Russian transistors as used in it....


Been hearing lots of good things about the Joe Bonamassa Fuzz Face....


I'm going to be ordering some stuff from Pedal Parts Plus soon, and some of it will be some AC127, AC187, and OC44 transistors...


Okay, should I try the AC127, or the AC187 transistors in my Germanium Fuzz Face build, or maybe OC44s?, I know it's highly subjective...


Actually, has anyone tried using OC44 transistors in a Fuzz Face, do they work and sound alright?....

slim_blues_boy wrote:
I'm thinking to buy a transistors tester, since I lost my transistor's measurement data and I must recheck all my transistors again. but they're quite expensive, the cheapest one would be DuoYi DY294. anyone has try it?

I haven't tried that one...I wound up getting the Peak, but I also use R.G.'s, which of course, is the least expensive.

It's cost about .25 cents:

http://www.geofex.com/Article_Folders/ffselect.htm

Have you tried grounding the fourth pin or have you just cut them off? Just wondering if that makes a difference to the noise.

Any time I've used a 4-legger, I've just chopped em off...and have had no ill effects yet...I've chopped a ton of em.

DrNomis wrote: Okay, should I try the AC127, or the AC187 transistors in my Germanium Fuzz Face build, or maybe OC44s?, I know it's highly subjective...

Actually, has anyone tried using OC44 transistors in a Fuzz Face, do they work and sound alright?....

you can get anything to work in a FF if you have the right gains & leakages and tweak the 8.2K

as you wrote, it's totally subjective and there are so many other factors like your amp, guitar, pickups, etc...

There are thousands of ge transistors and it's only your ears that can pick the best pair. I only can say, don't be a sucker and think that the original AC128's or NKT275's would be the best for your ears...

LucifersTrip wrote:

DrNomis wrote: Okay, should I try the AC127, or the AC187 transistors in my Germanium Fuzz Face build, or maybe OC44s?, I know it's highly subjective...

Actually, has anyone tried using OC44 transistors in a Fuzz Face, do they work and sound alright?....

you can get anything to work in a FF if you have the right gains & leakages and tweak the 8.2K

as you wrote, it's totally subjective and there are so many other factors like your amp, guitar, pickups, etc...

There are thousands of ge transistors and it's only your ears that can pick the best pair. I only can say, don't be a sucker and think that the original AC128's or NKT275's would be the best for your ears...

No worries and cheers, I guess I'll really have to give them a try and see for myself, finding transistors with the right gains/leakages shouldn't be a problem since I've got a semiconductor component analyzer....

I'm going to be building a Rangemaster Treble Booster pedal soon and I found a tagstrip with 8 lugs on it, will post pics of the finished build....

When it comes to germanium fuzzes I have found that the newer trannys are never the same

lamptone wrote:When it comes to germanium fuzzes I have found that the newer trannys are never the same

I just found a website that I can order some AC128 Transistors from online:

They offer a free next day delivery for registered customers, I'm going to order some tomorrow (Tuesday this week)....


http://australia.rs-online.com

DrNomis wrote:I just found a website that I can order some AC128 Transistors from online:

They offer a free next day delivery for registered customers, I'm going to order some tomorrow (Tuesday this week)....


http://australia.rs-online.com

I just went to this site to order some AC128 transistors and had a somewhat disturbing experience. Using the Real Time Stock Check button for quantity 1, 5, 10, 20, 25 or whatever, they are always In Stock for next day delivery, but when I order 10 it gives me a quantity-discount price and notifies me that they are temporarily out of stock, and are on back order.

I wonder if RS Australia actually have these, or if they have to come out from RS UK or somewhere else?

blackbunny wrote:

DrNomis wrote:I just found a website that I can order some AC128 Transistors from online:

They offer a free next day delivery for registered customers, I'm going to order some tomorrow (Tuesday this week)....


http://australia.rs-online.com

I just went to this site to order some AC128 transistors and had a somewhat disturbing experience. Using the Real Time Stock Check button for quantity 1, 5, 10, 20, 25 or whatever, they are always In Stock for next day delivery, but when I order 10 it gives me a quantity-discount price and notifies me that they are temporarily out of stock, and are on back order.

I wonder if RS Australia actually have these, or if they have to come out from RS UK or somewhere else?

Hmmmmm, maybe....strange that you're experiencing that, you could try contacting them by phone to see what's going on....

i bave heard many times that there is no evidence that AC128s were ever used in fuzz faces.

LucifersTrip wrote:

RnFR wrote:if anyone's got any non leaky low gainers they want to throw away, I'll take em! people always dis low gain Ge's, but you can get some great overdrive sounds out of them when used correctly. much better than any diode clippers, AFAIC.

here's a killer for low gain transistors. I modded the Fuzz Face to make it similar to the rare germanium Shin-Ei FY-2.
I used Q1/Q2 hfe 35/50

It's a loud, dirty fuzz nothing like the Fuzz Face




my final version:

how is this like an FY-2? looks like a fuzz face to me.

getting back to russian transistors... hopefully someone will find this usefull...

I bought a lot of gt311 and mp20.
the gt311 were listed with gains of 80-300, as I recall the mp20s were 80-150?

after using the geofx method to test for hfe with leakage taken into consideration... of 17 gt311s I got 4 in the 40-49 range, 4 in the 50-59 range, 4 in the 60-69 range, 1 in the 70-79 range, 2 in the 80-89 range, 1 in the 90-99 range, and 1 at 114. on the upside all had usable leakabe witch suggests to me their original testing for range was a bit 'loose'.

similar results with the mp20's although several had unusable leakage, and fewer were above 100.

long story short... the majority of mine showed up in a range that would be on the outskirts of use for a rangemaster, a couple would be good for stage 1/2 for a fuzzface/tonebender, and maybe 1 or two for stage 3 in a fuzzface.

haven't put them in a circuit yet, but I've read that they can sound fair.
cheers,

use the low gain and leaky ones for tonebenders (they have a lot of gain anyway). if the gain is not enough, use a 100k at the input instead of the 10k (like on the OC81D models)

yeah, the 311Es I got were very low gain as well. I'll push the 309s again. the gains are great, and they don't sound stiff at all. some models are definitely better than others.

I measured the capacitances from B-E and B-C of a couple of mine today. Dunno if it applies for all since I only tested around 2 dozen but the OC81s and NKTs I have all have higher capacitances than the 2n404s. Didn't get around to the Russians but I suspect they'll be around the same as the 2n404 or lower. Maybe that explains the differences people claim they hear between different types with the same gain and leakage. Will do more testing this weekend after I knock a paper out.

here's a killer for low gain transistors. I modded the Fuzz Face to make it similar to the rare germanium Shin-Ei FY-2.
I used Q1/Q2 hfe 35/50

It's a loud, dirty fuzz nothing like the Fuzz Face



my final version:

RnFR wrote:how is this like an FY-2? looks like a fuzz face to me.

you're thinking of the common silicon Fy-2 with the mid scoop:


here's the rare germanium one:


The whole idea of the "Fuzz Face w/ FY-2 mod" was to keep as many original values of the FF, but give it the topology of the ge FY-2, which sounds NOTHING LIKE A FUZZ FACE....it's great for low great trans.

The biggest change is the removal of the 470 and moving the output cap directly off the collector...and you have to use lower gain transistors & massively reduce the size of the vol pot. Also note the big difference in the voltages. Try it...It's brutal!

DrNomis wrote:I just found a website that I can order some AC128 Transistors from online:

They offer a free next day delivery for registered customers, I'm going to order some tomorrow (Tuesday this week)....

If you haven't already, do a quick read thru this when you have the time:
http://www.jacquesstompboxes.com/ac128.htm

you know what? I did try that one! I've got my version of it somewhere around here. it is pretty mean sounding.

regarding jacques- ill say it again, I don't think there is any evidence of original fuzz faces using ac128s.

LucifersTrip wrote:

DrNomis wrote:I just found a website that I can order some AC128 Transistors from online:

They offer a free next day delivery for registered customers, I'm going to order some tomorrow (Tuesday this week)....

If you haven't already, do a quick read thru this when you have the time:
http://www.jacquesstompboxes.com/ac128.htm

Cheers, yeah I've read that webpage a few times, just bookmarked it....

I just received a batch of GT404G (NPN) and GT402G (PNP) germanium trannys from Russia.

I've tested half the 404s with my DCA55 with the following results (Hfe + Leakage current):

105 / 5.22 mA
115 / 0.64 mA
110 / 0.51 mA
127 / 0.90 mA
106 / 0.79 mA
103 / 0.55 mA
160 / 1.07 mA
127 / 0.73 mA
115 / 1.13 mA
84 / 0.81 mA

I measured a couple of the 402s and got this:

116 / 0.19 mA
139 / 0.17mA

RG says "100uA is common, 200 happens pretty often. More than 300uA means the device is suspicious, and more than 500uA I would say is bad." [1]

So, based on that, all the NPNs I've tested are "bad" and the PNPs are good.

Is that a reasonable interpretation of these measurements?

R.

[1] http://www.geofex.com/Article_Folders/ffselect.htm