$22,000 and a hum that kills

[Lockoid]

Monitor Audio GR 60's $4000
Monitor Audio GR Cntr $1000
Monitor Audio GR 10's $1500
Parasound C2 $4000
Parasound A52 $2000

Absolutely kicks at high volumes... I am jaw dropped at the near 0 distortion. It IS quite remarkable what metal drivers can do. HOWEVER... there is a hum that is driving me nuts at zero volume. If I turn it all the way up a hissing occurs at +12 db... I don't think that is uncommon.... let me know otherwise...

but there is a mid-range hum that volume does NOT affect. Source does NOT affect. If I mute the Parasound.. it goes away.

now tell me... is it all about power conditioning? is it that rack on monster volt meters? please say no.... I have a $200 monster bar... that helped with hiss... but the hum? was there regardless. Please advise.

[topspeed]

Check your ground on the recepticle that the amp is plugged in to. Also, if you amp uses a grounded 3 prong male, try getting a 2 prong cheater and see if that helps.

Good luck.

[nick4433]

Also make sure your TV or cable/satellite receiver is not on the same connection or panel as your parasound is.

[sy_lu]

It is typical grounding problem. Parasound's amp is very senstive to ground problem. Contrary to nick4433's suggestion, the entire audio chain need to be on the same ground plan with as low resistance or impedance as possible to avoid the amp to pick up ground loop voltage differences. Another way as topspeed suggested, is to use a two prong conveter to by pass the ground on the amp. This solution is less desirable as power amp is high current device and there is safty concern without proper grounding. From a practical point however, it may be the easier solution as it is very difficult to totally get rid of ground loop problem even with all devices on the same ground as not every one has the same power cord characteristic. The Parasound has very lousy ground loop rejection desgin, I have an older Parasound amp and I end up use the ground converter cheater to get rid of it for the most part. It seems they have not improve their desgin much over the years.

[Lockoid]

It would seem the TV cable is the culprit. I took it out and kept it out and I am able to be in the room without that stirring feeling in my stomach. I literally FELT that hum, more than heard it.

[mtrycraft]

It would seem the TV cable is the culprit. I took it out and kept it out and I am able to be in the room without that stirring feeling in my stomach. I literally FELT that hum, more than heard it.


Yep, You will read so many posts similar to yours where the culprit turns out to be the cable TV hook up.
Easy fix. Radio Shack used to sell a ground isolator for the cable TV cable. If they don't have it anymore, try www.partsexpress.com. You might even want to call them if you don't find it at the web page.

[yebradoo]

Yep, You will read so many posts similar to yours where the culprit turns out to be the cable TV hook up.
Easy fix. Radio Shack used to sell a ground isolator for the cable TV cable. If they don't have it anymore, try www.partsexpress.com. You might even want to call them if you don't find it at the web page.

THANK YOU! My active Meridian speakers started humming mysteriously after I re-hooked up the TV's audio output to my Nakamichi receiver (it had worked fine before) - after reading your post I realized I had removed the Magic ground isolation gizmo from the cable TV hookup -- I put it back on and voila, the hum is gone. Now I know what that heavy little thing does.