AVS Forum banner

1 - 9 of 9 Posts

·
Registered
Joined
·
117 Posts
Discussion Starter #1
Hey guys I hooked up my new Polk RTi6s and CSi3 last night to my onkyo 505. They sound great but on some listening modes there is a slight hum. It gets worse as the volume goes up. What could this be and how can I fix it?


Thanks


T
 

·
Registered
Joined
·
117 Posts
Discussion Starter #5
I thought it might be a ground loop. I have a power conditioner coming next week which should give me better options when it gets here over my simple walmart power strip. I will wait until it gets here to see if it fixes the problem. if not I will go though the steps to find out what it is.


Any other suggestions


Thanks


T
 

·
Premium Member
Joined
·
7,507 Posts
I have a pair of Mythos ST powered towers (they are not grounded - two prong), and when they were hooked up to my Onkyo 905, they were silent.


I then hooked up an older but more powerful Parasound, 1206 amp, and while I'm much more pleased with the sound overall, the STs now exhibit a buzz (the buzz level is low and constant, and does NOT increase with volume level)


I disconnected the RCAs from the 905 to the Parasound, and even put a ground cheater on the Parasound to test (and tried a second high quality power cable), but the buzz is consistent. It seems to be eminating from the Parasound itself (not that the 1206 is buzzing - it's not - but the buzz from the STs is coming from the 1206)


Does this sound like something the PSAudio Humbuster would address, or is it more a characteristic of the Parasound that will always be there?
 

·
Registered
Joined
·
3,782 Posts
If it doesn't increase with volume then the buzz is most likely internal to the amp...probably low level transformer hum being passed to the speakers. I have experienced this with every toroidal amp design I've had including Parasound. I really don't mind it as long as it is inaudible to me at the listening position...and in fact it is inaudible up to about a foot away.


In my experience bad/failing capacitors can also contribute to hum.


PSAudio is redesigning the Humbuster early this year.
 

·
Premium Member
Joined
·
7,507 Posts

Quote:
Originally Posted by ClarkeBar /forum/post/12998450


If it doesn't increase with volume then the buzz is most likely internal to the amp...probably low level transformer hum being passed to the speakers. I have experienced this with every toroidal amp design I've had including Parasound. I really don't mind it as long as it is inaudible to me at the listening position...and in fact it is inaudible up to about a foot away.


In my experience bad/failing capacitors can also contribute to hum.


PSAudio is redesigning the Humbuster early this year.

Thanks - if it's a capacitor issue, the Humbuster would not matter, correct?
 

·
Registered
Joined
·
3,782 Posts
I would not think so. Leaking/bulging caps in an amp usually are only correctable with replacement. But Cap induced hum will grow louder over time (cap-age) and will most likely vary in intensity during power on/off cycles...meaning it will fade somewhat after warm-up/bleed-off. A cap hum is usually louder than most 60Hz hum in my experience, depending on cap condition. From your description I don't think this is your problem...most likely transformer hum/buzz described on the PSAudio link provided earlier.
 
1 - 9 of 9 Posts
Top