Hitachi 3D2 box, humming/buzzing

[Sel The Don]

Hello all, picked this cool looking box up over the weekend, had a few things that needed sorting (tuner wire come off it's guide, general cleanup etc, but I have this buzzing/humming sound that is always in the background.

Would a cap change sort this? I've checked grounds and they are all ok (less than 1 ohm resistance).

Cheers!

 

[hopey]

try running off dc or batteries. It could be your ac supply.

 

[Radio raheem]

I agree with hopey, i have a toshiba like this so im also gunna try this solution

 

[Sel The Don]

Ok cool, I'll give it a check!

 

[Wes125]

i had a hum problem with a samsung box. it was the smoothing cap on the mains supply

 

[hopey]

I have just discovered a Telefunken of mine does that hum thing. It's rated at 220v but running it on 240v works perfectly fine just keep your coconut away from the speakers or turn it up louder to cover the hum.

 

[hopey]

I have just discovered a Telefunken of mine does that hum thing. It's rated at 220v but running it on 240v works perfectly fine just keep your coconut away from the speakers or turn it up louder to cover the hum.

Tested on batteries the hum is still there but less. So I presume that running at a higher mains voltage increases the hum however it's not from the Transformer caps its from the OP Amp for cassette as the radio doesn't hum.

 

[hopey]

Tested on batteries the hum is still there but less. So I presume that running at a higher mains voltage increases the hum however it's not from the Transformer caps its from the OP Amp for cassette as the radio doesn't hum.

I fixed mine it was the audio cable from the Tape head to the PCB. Stripped back the termination and separated the cores it's a ground loop due to failing insulation in the Left and right channel Cores.