I completed J5Mk1, so I tested voltages before to connect the amp to a real speaker.
These are my voltages in J5 MK1 (expected values into brackets):
Without tubes, all tensions are OK everywhere, but V2 cathode is just 0.1V (0V).
Tubes installed, all tensions everywhere are OK, but V2.
I measured these values at V2:
- V2a anode: 247V (170V). Anode resistor R12 is 100K (100K).
- V2a cathode: 4,4V (1V). Cathode resistor R13 is 820R (820R).
- V2b cathode: 249V (173V). Cathode resistor R14 is 100K (100K)
Swapped tubes and nothing changed.
Tested circuitry schematics and everything seems OK. It seems like there is more current intensity at V2, hence higher voltages, but now I don´t know what to check. V1 and V3, heating wires and power suply voltages are all OK. What to check next?
Best regards.
Alvaro
[Blockierte Grafik: http://img265.imageshack.us/img265/2889/v2hc1.jpg]