[hikari]

Sorry I took so long to get back 
 
I'm writing a review for my blog I will shoot the url when i'm done with it (www.lifewithtech.net)
 
Any how I think the amp is a solid build and sounds really nice...
I've did a decent amount of burn in and today I noticed a hum when the amp starting at 50% the hum gets louder when you continue to go louder. 
I can only hear it when there is no music playing. I've pulled the RCA's. The amp is plugged into a UPC so shouldn't be a ground issue. 
 
I've talked to Jason at Schiit he stated the Asgard would be a better fit for the k240. 
He says the K240's are to efficient it will reveal the noise floor of the Lyr and most tube amps  (not exactly sure what he means by this, I asked if it had to do with the ohms he said not exactly)
 
Any how i'm returning my 240's and ordered Q701 in white which is what I am waiting on then will finish up my review of the amp.

 

[proton007]

A hum is a tone, not noise. 
Its probably because of a faulty tube, faulty caps or something wrong with the power supply.
Personally I feel you should not be changing the headphone because of the amp, its a bad idea. Headphones don't reveal noise floors, so I doubt its got anything to do with sensitivity.

 

[hikari]

Quote:

A hum is a tone, not noise. 
Its probably because of a faulty tube, faulty caps or something wrong with the power supply.
Personally I feel you should not be changing the headphone because of the amp, its a bad idea. Headphones don't reveal noise floors, so I doubt its got anything to do with sensitivity.

Yes thats what I thought when I hear it something to due with the tube. 
I have another set of tubes I have not tested them yet but plan to tomorrow. 
 
As for the noise floors I know nothing about this stuff this is what Jason the co-founder of Schiit told me 
"Lyr works fine with 32 ohm orthodynamics--it's a matter of efficiency. If a headphone is too efficient, it will reveal the noise floor of the Lyr (and most tube amps)"
 
As for the headphone I was playing with the idea of the 701's was just a nudge to get them..
 
Is there any other way of testing to make sure it's not the amp?
I also have a pair of monster mils davis trumpet's and the hum comes through at the same point 50% and get's louder when making the music louder as well. However Jason says"IEMs are out with Lyr--it's too noisy, as you've noticed."
 
Thanks...

 

[BrownBear]

Yeah and the K240 isn't exactly the most efficient headphone though, right? I mean I've always been under the impression that the K240 isn't all that efficient at 91dB/mW. And I'm a total noob, really, but the insinuation that the K240 'wouldn't work' well with that amp because of the sensitivity strikes me as rather odd.

 

[mikeaj]

If the amp has enough noise or any type of hum, you will hear it if the headphones are efficient enough.  The headphones are just outputting whatever it is the amp's giving them.  Modern K240 aren't efficient at all, compared to a lot of stuff that's out there, but some of those ~32 ohm orthodynamics are even less efficient, so the noise will be less loud on those.

 

[hikari]

Quote:

Yeah and the K240 isn't exactly the most efficient headphone though, right? I mean I've always been under the impression that the K240 isn't all that efficient at 91dB/mW. And I'm a total noob, really, but the insinuation that the K240 'wouldn't work' with that amp because of the sensitivity strikes me as rather odd.

actually the way he explained it to me was that the 240 is TOO efficient but I know nothing of this stuff still wrapping my head around it.

 

[PurpleAngel]

Quote:

Actually the way he explained it to me was that the 240 is TOO efficient but I know nothing of this stuff still wrapping my head around it.

I'm getting the impression that your not that happy with your purchase and Schiit is not explaining the problem in a way that you understand, so return it.
Order yourself the O2 (Objective 2) headphone amplifier, $155.

 

[BrownBear]

I still find it very odd that the K240 were deemed 'too efficient'. I just can't see that being the case. Again, I'm pretty much a noob, so I could be way off base, and I'd appreciate someone correcting me if I so need it. If the K240 is too efficient, that what would the deal be with Grados? Anyway, just my confused opinions/thoughts.

 

[proton007]

Quote:

Yeah and the K240 isn't exactly the most efficient headphone though, right? I mean I've always been under the impression that the K240 isn't all that efficient at 91dB/mW. And I'm a total noob, really, but the insinuation that the K240 'wouldn't work' with that amp because of the sensitivity strikes me as rather odd.

 
Well said.
Impedance and sensitivity are not related. 91dB/mW is pretty low sensitivity. The noise floor is what, -70 dB? I doubt any headphone can convert it into sound unless the volume is very high, especially something like the K240s. IEMs are highly sensitive, most go >100dB/mW so you're definitely going to hear the hum with them. If yes, the noise is too high, something's not right. And Schitt does not publish any THD or S/N figures, so hard to judge.
Its an amp problem clearly, but I'm not sure if its because its a high power amp, or because of some faulty component.

 

[WiR3D]

Quote:

 
Well said.
Impedance and sensitivity are not related. 91dB/mW is pretty low sensitivity. The noise floor is what, -70 dB? I doubt any headphone can convert it into sound unless the volume is very high, especially something like the K240s. IEMs are highly sensitive, most go >100dB/mW so you're definitely going to hear the hum with them. If yes, the noise is too high, something's not right. And Schitt does not publish any THD or S/N figures, so hard to judge.
Its an amp problem clearly, but I'm not sure if its because its a high power amp, or because of some faulty component.

 
It probably is an impedance issue, sensitivity is the wrong word.... 

 

[proton007]

Quote:

It probably is an impedance issue, sensitivity is the wrong word.... 

Feels more like an amp issue to me.

 

[WiR3D]

Quote:

Feels more like an amp issue to me.

Could be, the Lyr is the wrong amp for a 55ohm headphone, I dont know why someone didn't correct him earlier...

 

[BrownBear]

Quote:

Could be, the Lyr is the wrong amp for a 55ohm headphone, I dont know why someone didn't correct him earlier...

Is it though? How about the Audeze LCD-2 at 50 ohms? I know they're planar headphones, but what I'm saying is that I don't think it's related to impedance. I could be off with that though, someone correct me if I'm wrong.

 

[proton007]

Quote:

Is it though? How about the Audeze LCD-2 at 50 ohms? I know they're planar headphones, but what I'm saying is that I don't think it's related to impedance. I could be off with that though, someone correct me if I'm wrong.

 
I'm not sure what the specs of the Lyr are. Maybe the Vrms is too high.

 

[BrownBear]

Well, I was just guessing that WiR3D was saying the impedance was too low for the amp. What I meant was that I've read of people successfully using the Lyr with the K702 at 62 ohms and the LCD-2 at 50 ohms, so I didn't think that the 55 ohm K240 would be an issue, and that going by impedance alone might not yield the best solutions. I thought that the issue might be with something else like we discussed earlier in the thread, or with the amp, like you said.