Do all compressors hum ?

[AllAboutTone]

yes return it, you can buy a symetrix 501 compressor on ebay and get a great warm sound, at least a lot better then aphex. 501s are good on about anything .

[Tim Farrant]

He probably can't return it, it's second hand!

It will be the power transformer, more than likely a laminated steel transformer, that is mechanically vibrating with the AC power. It's possible you could get inside (unplug it first!) and if the transformer has bolts holding it together, you might be able to tighten these and the noise should reduce. Failing that, a tech could swap it out with a toroidal type, which will not vibrate.

Hope this is of some help.
Tim.

[Kiwiburger]

Acoustic hum/buzz from transformers is a pet peeve of mine.

Funny - I understood toroidal transformers were worse for this??

If it's really bad, it's usually a sign that your AC power quality is very bad. Specificially - instead of being a pure sinewave, it has harmonics - tending towards a square wave. There are many reasons for this - mostly outside of your control.

I'm investigating sinewave UPS to solve this problem. Certainly some gear is better than others - but even my best gear makes this hum.

The important thing is that the unit is totally free of electronic hum and hiss in the audio signal.

Otherwise, the solution is to put all your gear outside your room, or at least get some distance from your ears/mics. This is why I hate active monitors - cheap amps with buzzing trannies right in your face. Brilliant.

Sine waves ...

[Jim Williams]

I have 4 651's, all modified and draw more current than the stock one's do. All are very quiet. It's the transformer, of course. It's got some wraps or a laminate loose so it needs to be replaced. A torroid is difficult to mount in these due to minimal spacing in the bottom panel to fit the mounting screw. A replacement from Aphex is the way to go as I've not ever seen another with this problem and have reworked well over 100 of these.

Jim Williams
Audio Upgrades

[RobMacki]

Originally Posted by grexter

it does make a tiny humming sound that in a very quiet room is somewhat audible even from a a few feet away - at least to my ears. Is that normal?

This one hummed.

[grexter]

i appreciated your input, thankx

[Ravian]

Originally Posted by RobMacki

This one hummed.

mmmmmmmmmmhhhhh if it was mine it who'd be humming all day.
envy the world is'nt FAIR CHILD