High frequency hiss coming from Integra Research RDC-7.1 prepro

[BloggingITGuy]

Hi All,

I have a 1.5 year old Integra Research RDC-7.1 preprocessor.

When the prepro is on and getting no input signals it is outputting high frequency hiss to all my speakers. The hiss is only audible when you put your head right next to the tweeter of any speaker.

I verified that it wasn't the amp by replacing the amp with a newer one.

Also verified that it wasn't any other components in my system by unplugging everything else but the amp and the prepro.

Question is if this is normal behavior for a modern prepro or if I should call Onkyo and have them send out a replacement unit.

To the best of my knowledge my previous prepro, the Kenwood KM-C1 THX prepro did not have this issue and was 1/5th the price.

The hiss does not get louder or softer as I change the volume until about -5db of reference level.

Thanks for any and all inputs (other than buy a new prepro as that isn't happening anytime soon).

 

[markw]

As Tom Jones says, it's not unusual.

All powered equipment generates a little noise and this is sometimes emphasied by speakers with an upward tilt in the high end.

If it's constant at all levels, it's coming from the power amp. If it varies as you increase the volume, it's most likely from hthe preamp or one of the sources. It sounds like youi've got a little of both.

Odds are that if you put those speakers on another amp, odds are they would still hiss somewhat.

Since you have to put your ears up to the tweeter to hear it, I wouldn't worry about it. If you go looking hard enough for trouble in this hobby, you'll rarely be disappointed.