Simple SE troubleshoot

[ChrisR1983]

Hi

I've finally finished my amp but need some pointers on getting it to work. I'm new to the amplification side of diy and only really have speaker experience.

Anyway... I switch on the amp and tada, both output tubes light up and the little 9pin tube does but the rectifier doesn't. No smoke, no heat, no sound.

Where should I start?

Thanks

Chris

 

[spopepro]

Chris, Start with checking to make absolutely sure that your octal sockets are soldered in the correct orientation (key is on the silkscreen side). Ask me how I know... Then with no tubes in check the heater voltages (pins 2 - 8 on the rectifier, 4-5 on the 12at7, 2 - 7 on the outputs). Remember to have your meter on AC for these. Also, what rectifier are you using?

 

[ChrisR1983]

Thanks. Just to confirm I have the amp switched, attach the black of my dmm to the ground and the red to each pin?

 

[spopepro]

For checking heaters? No. One lead on each pin. Voltages are less than 10V so holding leads is ok. But make sure that you are getting the correct pins, since two other pins on the same socket will have 350+vac across them, and you *don't* want to be holding leads in each hand across these.

 

[ChrisR1983]

Ok, I've just checked the rectifier voltage on pins 2-8 and it doesn't read any voltage at all. Thanks for your help so far, what should I check next? I'm using a jj gz34

 

[spopepro]

If you don't get anything, check the connections going backwards (and again make sure socket is soldered in correctly). Pins to board, board to connector T1-YEL, connector to correct traffo wires.

 

[Ty_Bower]

Where should I start?

I posted some photos of the checkout on my Simple SE. You can find my post in reply #5 of this thread:
http://www.diyaudio.com/forums/tubelab/158719-simple-se-checkout-dummies.html

Be sure you have a good understanding of the risks involved with high voltage power supplies.

 

[Ty_Bower]

Ok, I've just checked the rectifier voltage on pins 2-8 and it doesn't read any voltage at all.

What power transformer did you use? Are you sure you know which leads are the 5V winding for the rectifier's heater? Did you securely land them on T1-YEL? A photo of your wiring might show us something you missed.

Mine looks a little like this:

http://i69.photobucket.com/albums/i43/Ty_Bower/Simple SE/P1100370.jpg

 

[ChrisR1983]

Sorry about the late reply... I've got a 374bx. I have the yellow wires connected to t1-yel; is that correct?

 

[spopepro]

Maybe... Or maybe not. The datasheet says no. However, manufacturers have been known to change the insulation color without notice. Hook the meter up (with leads) and make sure you know which winding is which.