I got about 100-150 GE PNP TO3 transistors.Mostly AD149 and ASZ series. But also about a dozen 2N555
Now Ive only ever done a P3A amp to replace a guitair amp for someone.
Is there any point in making an amplifier out of these? Just for fun. I can imagine i need to figure something out to avoid thermal runaway.
I got some MAT02's that could serve as the differential front end.
I can do board design just fine, im just wondering if there is anything worthwile to build with these.
Now Ive only ever done a P3A amp to replace a guitair amp for someone.
Is there any point in making an amplifier out of these? Just for fun. I can imagine i need to figure something out to avoid thermal runaway.
I got some MAT02's that could serve as the differential front end.
I can do board design just fine, im just wondering if there is anything worthwile to build with these.
an original leak stereo 30 would be good
You could also make a hybrid Silicon drivers and germanium output good for 15 watts into 8 ohm I will surprise you how good it can be
You are lucky to have these devices about you
just use high value emitter resistors about 1 ohm to assist with thermal stability
Trev
You could also make a hybrid Silicon drivers and germanium output good for 15 watts into 8 ohm I will surprise you how good it can be
You are lucky to have these devices about you
just use high value emitter resistors about 1 ohm to assist with thermal stability
Trev
Most of the pre-70's amps, including commercial ones were Ge, and were well regarded and perfectly stable
No need for such a luxury, a capacitively coupled single ended IP is quite sufficient, and was almost universally used at the time
The specs of these amps were ridiculous by today's standards, but build one (a good one preferably) and listen to it: you'll be pleasantly surprised.
I gave examples of vintage designs on numerous occasions, here is one: A collection of vintage, single supply, low to medium power amplifiers for Daniel
I have also posted a Ge Circlophone variant, and although it does work, I don't especially recommend it (but it is guaranteed free from thermal issues):
The Circlophone©, Germanium edition.
Take a look at YouTube.
Contains schemes on Ge (modern approach) and examples of implementation (layouts).
Bayu 63 - YouTube
Contains schemes on Ge (modern approach) and examples of implementation (layouts).
Bayu 63 - YouTube
Cool.. I just need to wrap my head around using two PNP”s for outputs.
I also have about 50 KC811 for... reasons they where cheap on eBay. They are supposed to be quite nicely matched as well.
That youtube video sounds quite nice.
Imma look at some schematics, i may fire up eagle.
I also have about 50 KC811 for... reasons they where cheap on eBay. They are supposed to be quite nicely matched as well.
That youtube video sounds quite nice.
Imma look at some schematics, i may fire up eagle.
Low-power BJT use Si. It would be nice and the Ge driver. Pay attention to Shaw's diode (diode-switched transistor).
811 Dual BJT (Tesla) 500mW 45V 45V 6.5V 20mA 155°C - - 100MIN
811 Dual BJT (Tesla) 500mW 45V 45V 6.5V 20mA 155°C - - 100MIN
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They were good for repairing old car radios and vintage stereo amps that used Germanium output transistors in the TO-3 package 😉