I bought the Boyuu A9 el34 tube amp from China. It will not play as loud as my cell phone. I replaced all tubes and that did not fix the problem. I think he may have sent me a 220 volt instead of 110 volt. Argued with him for 2 months and finally gave up. Any help or a point in the right direction would be greatly appreciated. Cannot send it back.
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Get a meter that can measure AC volts. The octal sockets up front have a 6.3V heater winding powering pins 7 and 8 of the tube. Set the meter to AC volts, put one probe on pin 7 and one probe on pin 8. If you see 3V AC there instead of 6, you have a 220V transformer.
There is a separate loooong thread about this amp with lots of discussion and tips:
Boyuu EL34 A9 Tube Amp
Boyuu EL34 A9 Tube Amp
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It tests at 2.7 volts ! It must be the 220 volt version !
Thank you ! It tests at 2.7 volts on pins 7 and 8. The guy sent me a 220 volt unit, yet he assured me over and over it was 110 ! Now I will follow the second piece of advice and see if the thread can help me figure out how to convert it to 110 volts.
Thank you ! It tests at 2.7 volts on pins 7 and 8. The guy sent me a 220 volt unit, yet he assured me over and over it was 110 ! Now I will follow the second piece of advice and see if the thread can help me figure out how to convert it to 110 volts.
Or you mistook the primary wire pair for the secondary ...
This is a kit, so you did the wiring ...
Did you ask the seller which colors belong to primary and which to secondary ?
Alternatively you can desolder both primary and secondary wires and then measure the dc resistance of both.
The 110v primary winding should have much lower resistance than the 280v secondary winding.
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