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post #166 of 269
Thread Starter 

I wired the mosfets following the schematic not using my design as they were just there for demonstation. Checking again now just to make sure.


Edited by TestSubject - 12/26/11 at 8:13am
post #167 of 269

If you are facing the part, the pins would be gate drain source, from left to right.

post #168 of 269
Thread Starter 

Like so right? then it should be fine. However, i spotted a mistake on my board, a jumper that wires the Drain to power is not placed properly,  however the other channel should be ok... Yet nothing.

 

EDIT: Fixed the Drain and fixed one tube wired wrong... man I know I should have went to bed instead of trying to rush the build. Hope nothing is blown. Still no sound

 

EDIT: PSU running at 65Volts... What is going on...

irf.gif


Edited by TestSubject - 12/26/11 at 9:16am
post #169 of 269

Check some voltages. Start at the power inlet.  Make sure the polarity is not reversed.

My first guess would be cold solder joints.

post #170 of 269
Thread Starter 

Could you indicate on the design some useful place to probe for voltages? I test for conductivity after each solder joint I make.

post #171 of 269

how about pin 4 or 5 on the tubes. One should be about 12v and the other should be zero.

post #172 of 269
Quote:
Originally Posted by TestSubject View Post

Any tips on how to add some LEDs under the tube circuit wise?

 

Also:

 

photo (3).JPG

 

Case need to be varnished and the external components needs to be soldered in, I should be done sometime today.



You are not finished in this pic? It looks like nothing connected to pin 1(plate) and a wire going to pin 9(should not be a wire on pin 9)

 

Up close pics would help.

 

post #173 of 269

the tube sockets are wired backwards. 

post #174 of 269
Thread Starter 

All right, here are some pictures of the sockets.

 

EDIT: I read about 17Volts between pin 4 and 5

 

TUBES.JPG

 

tubes2.JPG


Edited by TestSubject - 12/27/11 at 1:18am
post #175 of 269

Nikongod is right. The sockets should be wired looking at the bottom of the tube. They are backwards.

post #176 of 269
Thread Starter 

All right! Thanks, is this a standard way of laying down pinouts?

 

Soldering iron heating up.

 

Hope this works.

post #177 of 269

Yep, wire according to the diagram you posted earlier, while looking at the bottom of the socket.

post #178 of 269
Thread Starter 

OK Well i am pleased to say that I can hear sound! We are getting somewhere. One channel is louder then the other and i can hear a buzzing sound in the background. I have tried to switch the 2 tubes but the same channel is louder. Could the Buzzing be cause by the PSU? What could make one channel not as loud? Looking back to my first Cmoy amp the same thing happen when a capacitor had been damaged. hope it is not the case here, none of them are swollen but still.

post #179 of 269

Check some voltages and compare the 2 channels.

 

Power down and check the resistance from input RCA jacks to the grids, and to ground. Again, compare channels.

post #180 of 269
Thread Starter 

One Channel measure 19Volts between pin 4 and 5 while the other 27 Volts... Checking board now, probably a resistor right?

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