2. tech-talk
  3. 182988-180709

Never heard an amp do this before, ideas?

I have a primaluna 100 unplugged from any inputs. It has this awful high pitched sound coming from the speakers when it's turned on. It happens on both channels, and through headphones.

I have turned off all electricity in the apartment, turned all breakers off except the one it's on, moved the amp around the apartment, tried a humx, and different power cables. I even replaced the unit with another primaluna and they both do it.

I'm running out of ideas, anyone ever seen this before?

 

hobbes101
tkhill's avatar
tkhill
80 posts
 

Do not EVER turn on a tube amp without a load. Misery is guaranteed.

 

tkhill's avatar
tkhill
80 posts
 

& is it possible this is data from somewhere? Once I worked at a radio station & the chief engineer, no doubt competent in the early 20th century, laid a data line next to a mic-level line. You can guess who won that one.

 

ieales's avatar
ieales
1,201 posts
 

Do not EVER turn on a tube amp without a load. Misery is guaranteed.

Depends on the amp.

A stable amp can be on but not driven without a load. 

An unstable amp may be a problem with or without a load.

ieales's avatar
ieales
1,201 posts
 

the sound comes through the headphones.

Is the sound present on all inputs?

Does the level change with the volume control?

truman
167 posts
 

I too was stumped when there was noise in my tube preamp and in my tube phono. Turns out to be the Wi-Fi modem and (especially) repeater boxes were too close to my equipment. I could hear the noise abate as I moved them 12 -15 ft away. It falls off rapidly in an electromagnetic inverse squared fashion ....but if even turning off your internet equipment doesn't have an effect, it could be your neighbor's.

More to discover