IRS and Aragon

[rxter]

New to the forums - hello.

Recently purchased IRS Sigmas and Aragon 8008 amp to go with. Amp was recently serviced as follows.

" 2 new transistor
Repaired relay board
Readjusted bias and complete checkover"

This came with a $370 labor charge so 2 hours??

It sounded find when purchased but has developed a buzz after a short (2-3 minute) warmup. The buzz transfers through to the speakers. I've tried a couple of different configs to see if the input is contributing, but it buzzes with no input connected at all. And I've hooked up a few different speakers to it and the buzz is loud and clear. Any ideas?

Buzz seems to be coming from the indicated area.

Thanks

 

[uvafan420]

New to the forums - hello.

Recently purchased IRS Sigmas and Aragon 8008 amp to go with. Amp was recently serviced as follows.

" 2 new transistor
Repaired relay board
Readjusted bias and complete checkover"

This came with a $370 labor charge so 2 hours??

It sounded find when purchased but has developed a buzz after a short (2-3 minute) warmup. The buzz transfers through to the speakers. I've tried a couple of different configs to see if the input is contributing, but it buzzes with no input connected at all. And I've hooked up a few different speakers to it and the buzz is loud and clear. Any ideas?

Buzz seems to be coming from the indicated area.

Thanks

Welcome. This might help you out http://audiokarma.org/forums/index.php?threads/aragon-4004-mkii-humms.645939/

 

[rxter]

Thanks 420. This buzz/hum reaches the speakers unfortunately. I called the tech that did the service in July and he suggested trying a non-grounded plug - did not help. He also suggested trying a different circuit in my house so he was focused on the incoming power supply. Unfortunately I do not have a power conditioner to test.

 

[uvafan420]

Thanks 420. This buzz/hum reaches the speakers unfortunately. I called the tech that did the service in July and he suggested trying a non-grounded plug - did not help. He also suggested trying a different circuit in my house so he was focused on the incoming power supply. Unfortunately I do not have a power conditioner to test.

Is this hum also coming from the amp itself, and then out to the speakers as well? I would have the bias rechecked, as that is usually the culprit for hum in the transformer etc... A lot of amps require you look at voltages after 1 min from cold start up, 5 min, etc... Something a tech should do that knows those specific amps (a history of working on them). That is what I would do anyways. Or, ask around on the DIY audio sites out there. Lots of them work on Aragon as well.

 

[rxter]

Is this hum also coming from the amp itself, and then out to the speakers as well? I would have the bias rechecked, as that is usually the culprit for hum in the transformer etc... A lot of amps require you look at voltages after 1 min from cold start up, 5 min, etc... Something a tech should do that knows those specific amps (a history of working on them). That is what I would do anyways. Or, ask around on the DIY audio sites out there. Lots of them work on Aragon as well.

Yes the hum is from the amp and at the speakers. I'm planning to take it to a local vintage repair shop so they can take a look at it. Other than the hum it works great. Thanks for the responses. I'll post what we learn.

 

[rxter]

Local repair shop said that the transformer is shot. That's a bit hard for me to believe so I'll check the DIY circuit. Any other ideas are welcome.

 

[pauljh]

Local repair shop said that the transformer is shot. That's a bit hard for me to believe so I'll check the DIY circuit. Any other ideas are welcome.

DIY circuit?

And are you are saying that the amp itself hums/buzzes as well as the audio output having a hum?