Does tubed gear make your speakers hum/buzz?


I've just started using my first piece of tubed gear. It's a Dared SL-2000A pre-amp. I've had it running in the system for about a week now. I really like the improvements this has made to my system.
My only is problem is that I just noticed that my speakers make this humming/buzzing noise when the pre-amp is on but no music is on. It's only noticable when you put you ear right next to the speaker but I still don't want it there. I'm not using any power condition on my system and I'm in a highrise apt building in NYC. Could this be the cause or does it have something to do with the tubes? I'm currently using it with the tubes that it came with.

By the way, I already tried the 3 to 2 prong,,,,,,didn't work.

help.

meech
meech33
HELLO.. my tube amp and tube pre also hum in the speakers.i have no problem with it...when music is playing i hear nothing...i would not worry unless you can hear it from accross the room...
Meech, Put your money away! It is common to hear some tube rush sound or a tranny buzz in some designs. One thing to consider is floating the ground on the preamp and then try floating the ground on the amp itself. You may have a common ground loop. Go to your hardware store or Home Deposit and buy a ground floater plug and try it on the preamp and then the amp. Another source for buzzes is from your VCR. The source is actually from the coax from the cable company. They make filters for that as well.

The worst case is that the Dared has a poor grounding schema and you are stuck with the buzz, hiss or tube rush.

Good luck
Mr. 33,
I have had similar problems upon occasion. You might try different tubes to see if they make a difference. The vintage tubes that people make such a fuss about can really make a difference both in reduced noise and in better musical tone. Change the driver tubes (the ones closest to the source) first since they can often have the most influence.

Sometimes it is a tradeoff between good sounding tubes and a slight buzz. My system has what you describe, a slight buzz if you put your ear right against the mids or the tweeter, but I cannot hear it one meter away.

Good luck,
Tubes hiss. I don't know any solution for that.

Regarding Hum...It is possible to make a tube preamp that has no hum (well almost).

My first preamp was a Heathkit (which I understand was basically a Fisher design). It was quite difficult to build because it had lots of twisted wires, some of them running inside spring-like metalic shielding. It humed.

My next preamp was a dyna-kit. It had DC filiament power for the tubes. The whole design was much simpler that the Heathkit, and performance was superb. There was not a single piece of twisted or shielded wire in the unit. It did not hum.

One thing that we used to do to minimize hum in tube circuits was to open up the chassis, turn up the volume so that hum was audible, and take a grounded wire and try contacting it to various points in the circuit that ought to be ground. Be careful not to short out any hot points!!! Sometimes this trial and error method of optimizing grounding gave a significant improvement. "Dressing" (relocating) the internal wires can also help (or hurt).