2. amps-preamps
  3. 1045803816

tube pre-amp feedback...

I have recently switched from a solid state pre to a tube pre with my Odyssey Stratus amp. Now while I like the sound and combination, the EAR 834L pre I am currently using does seem to cause some feedback/light buzzing. I find this the most when the volume is all the way down, becoming quieter as I turn the volume up (yes, even when I don't have anything playing). I also find it sounds like something in the line is picking up a radio frequency or something.

This seems strange to me, as I know the person I purchased the EAR from used it with a Bryston. I'm a tube novice looking for advice. Any thoughts appreciated. Thanks!
one_speed
5 responses Add your response
one_speed OP
15 posts
 
Appreciate the thoughts. The pre is not on other equipment, though cables could be crossing. I'll check that as well as tube treatments.

As for the sound, I prefer it over the Adcom GTP-502 I had been using. While the Adcom sounded great for it's price, I think the EAR only sounds better. Better focus, bass, mids, etc.

I'll do some experimenting. Thanks!
socrates
247 posts
 
That's just what the Stratos does with a tube preamp, at least, it's what I heard with the Rogue and McIntosh tube preamps I tried with it, neither of which I could live with, the noise drove me nuts. FWIW, in my system, a good SS preamp always sounded better then the tube preamps w/the Stratos in most every way. I would suggest an A/B test with a similarly priced/quality ss pre to make sure you've choosen wisely....
elevick
2,636 posts
 
Try to isolate the pre better. Is it sitting on top of other gear? Tubes are sensative. Also, what kind of cables are you using? You may need to either get better shielded ones or simply run the cables in a way to make sure that interconnects never cross power nor speaker cables. If they do have to cross, make sure it is at a 90 degree angle to limit contact area-hey, use a little tape or gum bands.
newbee
4,767 posts
 
I never had this problem w/my EAR834L but i have had this problem when my interconnect came too close to a transformer or other power source(and in one case when they were near a big woofer). Check your cable routing. You can also check to see if there is hum due to grounding - float the ground on either your amp or preamp and see if anything changes.
marakanetz's avatar
marakanetz
5,473 posts
 
If you're sure about radio freequency than I assume the preamp tubes very often can pick up even a voice or will do the noise even if you blow on them.
The tube dampers and coolers sold from Michael Percy www.percyaudio.com can work-out for you in that case. Make sure that space in preamp allowes you to "dress" tubes.
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