Your power supply is 48v?
[SripBoard Design] Starving Student Millett Hybrid Vacum Tube Amp - Page 13
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0.42V between grid and cathode on the non working channel 1.7V on the working channel
5.12Volts on both mosfets
EDIT: It seems like one channel doesnt work at all, even after unplugging the non working channel , I hear no difference.
REDIT: I am not the only one with a similar issue apparently. LINK Checked resistance between cathode and ground, Same on both tubes
Edited by TestSubject - 12/27/11 at 7:47am
Draw 2 copies of the schematic by hand. Mark down what every resistance should be in your favorite color pen. Be sure to use ohm symbols.
If you can draw it from memory it is OK to use a computer printed copy, but I find drawing it by hand a few times helps me really "get into the circuit" so I'l pass that along.
With the amp off go through the amplifier and measure EVERY resistance you can. Measure from the furthest ends possible - IE if the resistor is on the board and connected to the tube with a long bit of wire measure from the ends of the wire. It doesn't matter that you used a 1Kohm resistor where a 1Kohm resistor belongs if you didn't solder one of the 3 joints its hooked up to.... Measuring one way only verifies resistor value, the other gives a pretty good assurance that you soldered it correctly too. Mark this down in PENCIL, making sure to use the ohm symbol.
It is OK for certain things to be slightly off from the values on the schematic, as long as both channels measure similarly. Depending how you measure, you may find stuff in the voltage divider to be off by a lot, but I doubt that's where your problems are.
After a bit of poking around with the resistance-meter you should have found something that makes absolutely no sense by now. Figure out why and fix it. Does the amp work?
If measuring resistances doesn't find anything (unlikely) turn the amp on. Measure voltages from EVERYWHERE to ground. Plate, cathode, gate, drain, source, etc. Mark this down on the schematics in pencil, making sure to note volts. Measuring voltages is often faster than measuring resistances, BUT it requires poking about in a live amp so Id save it for a last ditch effort.