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    Building, troubleshooting and testing of these amplifiers should only be
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Single ended MM tube phono amp


2016-05-04 4:37 pm
I jut bought this from eBay and beside the fake caps I don't get if this is a real tube preamp of just a fake one. Apart from the passive components it has onboard: 2 x ZTX384 transistors, 2 x LM317T, 2 x 6J1 tubes.

Can you shed some light if it worth keeping and change the caps and tubes (already bought some Sylvania 6AK5 to replace the chinese tubes) or just return it?

Thanks in advance!


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Have you looked at the schematic?
LM317 is heater regulator, my guess.
ZTX384 is obsolete.
6J1 similar to EF95. Single pentode, IF amplifier. Possibly low noise.
If it was cheap, does it work? If it does what you want it to, keep it if not send it back.

Sorry to revive an old thread, but is there a schematic available for this "Douk Audio" phono?
Someone gave me theirs to play with, and it's humming loud. I quickly checked pin to pin on LM317 (one per channel), and I'm getting different readings voltage-wise and impedance-wise.

Thank you.