Sphinx project 4 service/repair manual

[theotdf]

Hello dear tube public,.. Can someone help me with a Service/Repair manual of a Sphinx project 4 (four) MK3 pre amplifier?


I would be very grateful

 

[kevinkr]

Moved to Tubes & Valves

 

[jfetter]

I would like to see it too.

 

[Lampie519]

Do you have a picture of this amp (the boards)?
I maybe have some boards laying around, so i could check or reverse engineer the schematic.

 

[jfetter]

There is a version 1 and 2 but for study purposes does not matter.
Thanks for looking.

 

[Lampie519]

These boards are not the same. Probably mine are older (much older). Anyway these are simple triode stage with a solid state buffer. The sound is a bit dull, that’s why i have the boards as the amp has been rebuild with a full tube version. I will check anyway what i can find for you.

 

[jfetter]

Yes I built a few hybrids sounding same dull.
The fix is very simple. Adding one resistor and move one trace.
Then sounds like SET.