[maverickronin]

It may be interference from something nearby.  Try turning off everything else in the vicinity and see if it goes away.

 

[kwkarth]

Quote:

It may be interference from something nearby.  Try turning off everything else in the vicinity and see if it goes away.

Or slowly rotating the amp while listening to the noise.  If it's induced noise you may find a null point as you rotate the amp.

 

[todd77]

Quote:

It may be interference from something nearby.  Try turning off everything else in the vicinity and see if it goes away.

Yep, everything that's connected to a wall socket has been turned off in my room but the faint buzzing is still there. The only thing that's probably still on is my roommate's cellphone and iTouch, which I can't seem to locate... Also, when I tried plugging my LYR to the same multi-outlet surge that is connected to the same wall socket as my laptop's, I get tons of interference - every move of my mouse will result in an equivalent buzzing noise - yikes!

 

[grokit]

You could try a cheater plug on the Lyr temporarily and see if the buzzing goes away. If it does, remove the cheater plug from the Lyr and try it on everything else one at a time until you isolate the culprit. This should work if it's a ground loop issue anyways.

 

[maverickronin]

Are you in a dorm or a crowded apartment building or something?  Its possible you've just got inordinate amounts of line noise.  If that's the problem you'll need some kind of power conditioner to get rid of it.
 
Also, is the mouse wireless?  Does noise from the mouse show up when the Lyr is plugged into a different socket?

 

[maverickronin]

Quote:

You could try a cheater plug on the Lyr temporarily and see if the buzzing goes away. If it does, remove the cheater plug from the Lyr and try it on everything else one at a time until you isolate the culprit. This should work if it's a ground loop issue anyways.

I don't think a cheater plug would do anything.  He said it does it even when nothing else but the power cord is plugged into the Lyr.  Based on that, its probably either line noise or RFI.

 

[todd77]

Yep, the cheater plug trick worked for the mouse interference (it's a USB mouse, BTW), which is why I moved the LYR to a different power tap and thus, eliminating that problem. However, the faint buzz remains.
 
I live in a house, actually, with a few others but I'm probably the only one awake at the moment and probably the heaviest electrical / electronic equipment user in the entire household lol... I'll try connecting the LYR to other electrical outlets in the morning to see if it's any different.
 
 

 

[grokit]

I was going to ask, wouldn't the ground loop come from the power plug? But never mind, you answered it already.

 

[Skylab]

Such a buzz can also be introduced by a dimmer switch for a light, and it can be almost anywhere in the house and still do that.
 

 

[Kremer930]

Yep, the best match I've found so far is indeed the Amperex Jan/CEP 7308

I am currently running the Genelex ECC88 tubes and compared to the stock tubes they add more air and more midrange detail and forwardness. The bass may also be attenuated slightly but on the HE6 there is still plenty left.

I really like them. I haven't tried them as yet with my K702 cans.

 

[foaming at the ears]

Todd,
 
I get the same buzz as you, but only with my more sensitive headphones.  The Grado SR225 and Shure 840 get a faint buzz, even when the volume is all the way down.  The HE-5 gets no buzz.
 
Since I only listen to the HE-5 these days, I don't really mind.

 

[mikerobe]

Interesting, I only got (the faintest) buzz/hum when I switched to my Amperex tubes.
 
I rolled back and forth from them this morning, essentially to confirm.  Those tubes just sound so great, I want to keep them.  My hum is quiet enough I don't notice it while listening to music, and I seem to not be getting any fatigue from it.  In fact I seem to be getting near minimal fatigue from my system right now, as I just keep listening and listening.

 

[Skylab]

Some vintage tubes will hum.  It's just the way it is.

 

[Jason Stoddard]

Hey all,
 
Like Skylab said, vintage tubes will hum. New tubes may hum too, though we sort for lowest hum and also do a bunch of tricks to make the heaters behave. 
 
If you're experiencing extremely low-level hum on high-sensitivity headphones (say, Grados)--and I'm talking *low*--as in, you're living on top of a mountain, nothing is on in your house, and you can hear a tiny bit of hum with your Grados--that's normal. 
 
If you're experiencing more than that, it may be grounding. Lyr is extremely sensitive to grounding. It really wants a decent wall outlet with a solid ground. You may get best results by connecting Lyr to a solid AC ground and lifting the AC ground from other components in the chain. Also, Lyr has enough bandwidth to amplify hash and grunge in the air, so if it's sitting on top of, or near to, a radiative component (computer, DAC, ham radio transmitter--ha) it may pick up some RF that it's radiating. It also should go without saying that Lyr's metal chassis should be isolated from any other metal chassis or rack.
 
That said, if you've gone through all that, and you simply have too much hum on headphones like LCD-2s, HE-4/5/6, or Beyer 600 ohm phones, there's something wrong. Contact us, and we'll be happy to help get the amp sorted out.
 
 

 

[todd77]

Thanks for all the replies. I was just worried that I may have gotten a faulty unit but it seems that it is normal, whew. I can finally go back to simply enjoying it.