germanium power transistors and treble boosters

[Fossilshark]

Hi, I'm new to this forum and I recently found a bunch of Germanium PNP power transistors in the parts closet at school.

SP56
12M3 
2N554
2N555
2N178
2N3055
TI3028

and a few more oddballs.

Motorola ones have gold plated pins/casings and look rather snazzy if I do say so myself. I'm thinking military grade, but late 60's early 70's manufacturers cared more about component quality regardless so I'm not sure. Most also have a designation (9-32 for example) i'm thinking Hfe ratio of some kind?

Seeing as I'm currently building a clone LA60BL (Tony Iommi's amplifier) I wan't to build a really nice treble booster like the Dallas Rangemaster to go with it. I've built a few Rangemasters using AC127 but I was wondering if I could use one of these transistors? I'm well aware of the "but for why" factor so lets chalk this up to academic research. If the Rangemaster is not an ideal circuit (as I'm sure its not) can someone point me in the direction of how I can design a treble booster using just the datasheet, as I had a blast designing a J-FET preamp from scratch.

my main concern: a guitar signal probably wouldn't be enough to activate the transistor? and if I added a preamp, the transistor would output too much signal for the input of a guitar amp? then I would be talking about another stage to match signal levels. If I've learned anything about electronics it's that there is some other voodoo in the electrons I'm not thinking of that will hinder me in this quest.

I don't really care how complicated it gets, my main goal is to put a use to these transistors.

Thanks!

[rankot]

2N3055 is Si NPN (not Germanium), others probably are Ge based.

However, you must check them for structure (PNP or NPN) and hfe to see if you can use them for fuzz, and which one. Most fuzz pedals have PNP/NPN versions, and appropriate expected hfe ranges for best sound.

They all can be used in different positions, and their size is not important, they will work if hfe and polarity are OK.

[Fossilshark]

Wow thanks, that helps a ton.

[duck_arse]

Fossilshark - we are not permitted to answer questions like yours at least until you have posted a photo of your rare, snazzy gems. please.

[Fossilshark]

So I had it working perfectly (read: a crispy sabbath sound) until i was on stage for talent show auditions and gain suddenly dropped and sounds kind of farty?

It is still boosting the signal, just not quite as boosty i suppose.

Initial tests when it worked showed a gain of 8.5 (9v power supply, 1khz signal) but now its at roughly 7.5 and I have a suspicion the bandwidth decreased, but i never made a frequency response chart for it like it should have.

Wiring is a little messy but everything works. Also i was running it off a 12v supply when said incident happened (moar gain), but being a power transistor i am assuming thats OK.

My immediate thought is the bypass cap as if im correct that affects gain+bandwidth the most, but it was a brandy new cap.

Thoughts? Pics coming

[Fossilshark]

Pics:

[Fossilshark]

[thermionix]

Thermal?

[Joncaster]

Edited: OT

[Rob Strand]

So I had it working perfectly (read: a crispy sabbath sound) until i was on stage for talent show auditions and gain suddenly dropped and sounds kind of farty?

The problem is likely to be caused by leakage.

Given the input impedance is likely to be quite low you have the option to drop the values of the two divider resistors to try to fend-off some of the leakage.   If your transistors are very low gain you might find the pickups are quite loaded already.

Before you start get a base-line system working.     Tune the 68k value to get the sound you like.

Now halve the resistor you have in the 68k position and re-tune the 470k to get the best sound.   
If possible do A/B comparisons with the original.
Keep halving until you can hear the tone get muddy.
After that ratchet the value up again in smaller steps, or just use the last good values.

If the resistors get less than 10k then stop there.   You might need to up the 5n input cap bit.

[mac]

The problem is likely to be caused by leakage.

Thermal?

Have you tested for hfe and leakage?
Have you measure collector voltage to check if it stays near 7v?

I see your pics and I see a Deacy Amp-like on steroids

mac