How do I fix loud buzzing from Penta Mk1, only happens when no music playing!

Hi all,

Recently received some great help from this forum for which I am really grateful.

 

I have a pair of Mk1 Pentas, model 6602. Now I've managed to change the plug to a GB 3 pin and get the right cable to connect an audio source, there is an issue.

When no music is being played the speakers hum/buzz. It's quite a lot louder on one than the other.

As soon as I play music the speakers stop humming and play the most beautiful sounding music. When I stop the music there is a delay of a few seconds then the humming starts again.

Does anyone have any experience of this?

I would love to get these speakers to a usable standard, they mean quite a lot to me.

 

Thanks for the help.

 

Chris

I know this behavior from my Beocenter: I thin the electronic increases the sensibility to the max when there's no signal silo you hear the 50Hz frequency of the power supply.

But I don't know how to fix it...

 

 

 

I've seen this issue on other amps. Is the source a mobile phone? Or a computer?

It seems that as a power saving feature the audio circuitry is turned off on the mobile device when not outputting any audio. This has the same effect as unplugging the jack and you get hum.

Hi guys,

 

Thanks for the replies, I would have responded sooner but I didn't get an email saying there had been activity on the thread.

 

Lee, the input was a phone. When I pause or stop the music it is fine for a few seconds then starts to buzz. I see what you are getting at, but the strange thing is that there is no buzzing if I just unplug the RCA cable.

 

Any help.will be greatly appreciated

 

Chris

I have the same problem when I plug my Samsung phone into the cars line-in and pause music... After a couple of seconds of silence I hear a little pop and then get a humming sound. It's the phone that's the issue. I think what happens is the audio circuitry is powered off when no audio is being used and this causes the aux cable to pick up noise.

Was the phone charging at the time?

For reference I don't have the same issue with my iPhone.

What 3.5mm to RCA cable are you using? It would be worth making sure it's a shielded type of high quality.

 

 

Hi Lee,

 

Thanks for the reply. I'll try plugging it in to my TV and see if that changes anything. I'll try my pc also, unfortunately I don't have an iPhone.

 

The cable I have is fairly cheap. I'll consider upgrading if switching input doesn't work.

 

Reply much appreciated!

 

Chris

 

Lee you were right, I plugged the cable in to my pc and the noise disappeared

Thanks for the advice.

 

Just got to refoaming them now!