Does MR need GE's?
I will happily send some.
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Hope Diyers get updates in the future
Attachments
just measured 0.141% distortion at -10dB level
not bad
I can see second harmonic ~-60dB, and third ~ -80 to -90dB, depending on the current I set with trimmers
....and hf rollof is still there
but it sounds awesome
done!
this is when cranked up at 20volts with LM317 regulator
distortion dropped to 0.076%, intermodulation at 0.101%
I will build another version, with bigger heatsinks
Congratulations
Hope Diyers get updates in the future![]()
What video are those screen captures from? Not sure I’ve seen that one
It’s part of the Steve Gutenberg series where Mr. Pass shows off his stash.
The right stuff: Nelson Pass' droolworthy parts stash - YouTube
The right stuff: Nelson Pass' droolworthy parts stash - YouTube
Stable. 100mA through one pair of transistor, total 200mA. Depending on the stubborn opamp, there may be 220 ... 230mA.
I wish you a successful completion of the amplifier assembly. What box will it be in?
done!
this is when cranked up at 20volts with LM317 regulator
distortion dropped to 0.076%, intermodulation at 0.101%
I will build another version, with bigger heatsinks
Hi Adason. Could You please post the final shematic, preferably with some DC points measured and 2 resistances of bias pot measured? I cant find what part of Ge power transistor You used? Thanks
Hi Adason. Could You please post the final shematic, preferably with some DC points measured and 2 resistances of bias pot measured? I cant find what part of Ge power transistor You used? Thanks![]()
From the pictures these are GT703A and GT705A (cyrillic markings).
Adjust the housing from the old amplifier.
Fantastic DIY work
Interesting pdf. ebook with Germanium parts
https://ia801705.us.archive.org/1/items/siemens_202011/siemens.pdf
source : Siemens - Delivery Program 1973/7 : Siemens : Free Download, Borrow, and Streaming : Internet Archive
https://ia801705.us.archive.org/1/items/siemens_202011/siemens.pdf
source : Siemens - Delivery Program 1973/7 : Siemens : Free Download, Borrow, and Streaming : Internet Archive
Attachments
Hi Adason. Could You please post the final shematic, preferably with some DC points measured and 2 resistances of bias pot measured? I cant find what part of Ge power transistor You used? Thanks![]()
Hi Zoran, sorry for late reply. I have not been following this thread anymore.
To be honest, i was not so happy with the result and i got distracted with other projects, especially those based on power jfet lu1014d. Since there was gb on adapters, and i got some jfets from Mr. NP, and bought many from aliexpress.
I built f1j and f3 with lu1014d. Great stuff.
Since i got plenty, i guilt headphone amp too.
I know its not germanium, so i am not going to post it. Just saying that the sound was way ahead, so i am finishing lu1014d into box, plus i will work on perfect power supply for it. I scavenged my germanium headphone amp for parts.
If you have lu1014d, build headphone amp i posted in 'whats on your bench tonight' thread. You will like it.
Its one of the best headphone amps i have (and i have about dozen icluding few shiit, acp+, whammy...).
About Germanium transistors
Transistor Structure: Bell Labs (1965) - YouTube
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