Help troubleshooting Elekit TU-8500 preamp

[sadik]

Good to know your problem is solved. Happy listening.

 

[IndianEars]

Hi, after replacing the resistor it's finally working and I can hear beautiful sound! Thanks so much IndianEars for your help!

You diagnosed it, identified n replaced the faulty component all on your own!

CONGRATS!

 

[christopherjf]

Hello all,
I am new here so , this might be a question that has already been asked. I just finished an Elekit TU8500 and I have an issue. One of the channels has a hum (probably 60 cycle) If I touch one of the ground screws in the cabinet, the noise backs off a lot so, it appears that I have grounding problem so something like that. Has anybody got a suggestion on fixing this problem?
regards

 

[rajan-]

Hello all,
I am new here so , this might be a question that has already been asked. I just finished an Elekit TU8500 and I have an issue. One of the channels has a hum (probably 60 cycle) If I touch one of the ground screws in the cabinet, the noise backs off a lot so, it appears that I have grounding problem so something like that. Has anybody got a suggestion on fixing this problem?
regards

I am assuming your chassis is expected to be connected to the earth wire on the 3pin socket.

have you checked / getting continuity from the chassis and the earth plug pin ?

 

[christopherjf]

I am assuming your chassis is expected to be connected to the earth wire on the 3pin socket.

have you checked / getting continuity from the chassis and the earth plug pin ?

Thanks for the idea, I haven't checked that yet. The cord has only a 2 prong plug on it so maybe I'll try a 3 prong as well.

 

[rrunner]

At the end it was a faulty resistor that leads to VCC. All Bridge rectifiers were working fine. I will post an update after I'll receive the new resistor

Hi, was it r59 resistor that was damaged. Did you figure it out using continuity check. Thx

 

[christopherjf]

Thanks for the idea, I haven't checked that yet. The cord has only a 2 prong plug on it so maybe I'll try a 3 prong as well.

I found a resistor that was bad in the section of line 1 at the 12au7 tube. Just fell on it right out of the blue after hours of checking solder connections. Thanks for the help.
The TU8500 works well now. I read that you can change 4 caps to a higher value. What would be the gain in that be?
Thanks