yeah its negative sorry

I was checking voltages and noticed the voltage selector is wrong. It reads 100v, 120v and 220v, However the layout says 120, 220 and 240 so I flicked it down to 100v which should be 120v. Now my heater voltage is 6.3, my reverse bias voltage is 42.5 volts but my voltage across the 1ohm resistor is still 0.

Kevin

That negative dc bias voltage reads -48v with the trim pot all the one way and up to 68v with the trim pot the other way. This doesn't change weather it is on standby or not on standby.

Kevin

I checked my wall outlet and its exactly 120V

Kevin

I remeasured the voltage from the 2 brown heater wires with a different analog meter I have and its reading around 7.5 volts. I think my digital meter is reading AC incorrectly cause its reading 170v out of the wall outlet, this meter reads correctly. Is that closer to what I should have?

Also that -85v on pin 5 is now -50v with this other meter.

Kevin

Is there a way of testing the tubes? For the PT test I desolder the 2, 3.15v brown wires then touch one lead to each end and measure ac volts correct? Im at school so I cant test it for another 2 hours.

Kevin

ok, i checked pins 2 to 7 incorrectly the first time. With my meter across pins 2 to 7 on AC i measured 11.2 v. As for measuring from pin 5 to ground I have my meter on 200v dc and it says like 872 or something around there. Must have a decimal in there otherwise it wouldnt read that high so 87.2 makes sense. So you think it might be a bad power tube? Is there a way to check them, This is the first time i've ever even seen a tube

Kevin

I read 0 on pins 2 and 7, and -850v on pin 5 all with respect to ground. What should my voltages be. There was some confusion on the layout for me as for the heater let me explain what I did.

I daisy chained all the pin 2's with red and pin 7's with black. Then i tied in the 2 brown cables from the transformer (3.15v each according to layout) which also runs to the indicator.

Kevin

Hey guys I just built a 2203 jcm and ran into an issue. I turened it on and the indicator light is on.  I went to bias it but i am reading 0v at the end of the 1ohm resistor with respect to ground. The tubes are glowing dimly. Im not really sure how bright their supposed to be with full power on ive never used a tube amp before. I checked my wiring a few times and dont see any issues. I tried hookin up a guitar and playing it at a very low volume but i get no sound, no hum, no static nothing. Where should i check? I have a volt meter. This is my first time building an amp.

Kevin

Thanks man I got it, Perfectly explained.

Kevin

Hey guys, i got the 2203 kit and have it all build except the 2 shielded wires. From the layout I can see that one of them solders to the preamp tube socket and the other end to the center pin of the preamp pot. At the preamp pot part another wire joins it. The shielded wire is braided on the other side and solid on the inside. Do i just solder the joining wire to the braid? Also when I solder to the pot and to the preamp tube socket do I solder both the braid and the center? Im not to sure how shielded wires work. Hopefully someone could help me quick Id love to give this thing a go!

Kevin