[Oldandslow]

Quote:

For S&G I made a recording of the "noise" I hear when I pause Foobar and turn the volume pot all the way up on the Asgard 2.  I used HD800's and SR325i's for the test.  Hi gain.  You can hear the ticking sound I talked about in an earlier post.
 
Files can be found here: http://www.borderlandabate.org/noise
 
The recording device was my iRiver H120, so not the highest quality but you can clearly hear the noise.  It is not much louder than the background noise in my case.  So it is not that big a deal in my estimation, but it may be different for others.
 
For reference I did the same thing with my Magni and there is very little noise at full volume on it, so did not bother to record it.
 
P.S.  I am really liking the Asgard 2 with the HD800's!!!

If you get a chance, try the "hum test" with the inputs to the Asgard 2 unplugged. I did, and there's no noise/hum at all. Dead quiet. The hum I heard was coming from the interconnects/d.a.c./computer, not the amp. Sorry about that, Schiit!

 

[Glam Bash]

I got one of the A2's with a hum I can hear across the room. It's strangely high in pitch unlike 60hz hum. However, when I pressed with my hand on top of the chassis it quieted down to where I could only hear it with my ear next to the amp. I put a heavy book on the transformer side away from the top vent for the weekend. I think the noise was amplified by the chasis.
     On a lighter note

, by Sunday night the midrange was coming around and letting the music through.

 

[NotAnAngel]

Quote:

For S&G I made a recording of the "noise" I hear when I pause Foobar and turn the volume pot all the way up on the Asgard 2.  I used HD800's and SR325i's for the test.  Hi gain.  You can hear the ticking sound I talked about in an earlier post.
 
Files can be found here: http://www.borderlandabate.org/noise
 
The recording device was my iRiver H120, so not the highest quality but you can clearly hear the noise.  It is not much louder than the background noise in my case.  So it is not that big a deal in my estimation, but it may be different for others.
 
For reference I did the same thing with my Magni and there is very little noise at full volume on it, so did not bother to record it.
 
P.S.  I am really liking the Asgard 2 with the HD800's!!!

 
Quote:

If you get a chance, try the "hum test" with the inputs to the Asgard 2 unplugged. I did, and there's no noise/hum at all. Dead quiet. The hum I heard was coming from the interconnects/d.a.c./computer, not the amp. Sorry about that, Schiit!

 
Well, I think bearFNF did find something. I tried this on mine; I also did what Oldandslow suggested, but in addition I connected my Musical Fidelity V-CAN II instead of A2 and did the noise/hum test again.
 
Using Beyerdynamic T50p (32 Ohms), here is what I could hear.
 
1. Just to establish a reference point, Musical Fidelity V-CAN II, volume at 100%: very slight noise, could barely hear it. No hum, zero. Nothing at 0% volume.
 
2. A2, low gain, 0% volume: very low noise and low hum; while I could hear it, I could only tell it was there if I unplugged headphones and then plugged them back in. This stayed the same until volume reached 2 o'clock, then hum started to increase.
 
3. A2, low gain, 100% volume: clearly audible hum; about the same noise (masked by hum completely).
 
4. A2, high gain, 0% volume. Clearly audible noise (same as MF V-CAN II with volume at 100%); low hum as in No.2. I was surprised by the noise here, honestly. Hum stayed the same until volume reached 11:30 o'clock, then started to increase.
 
5. A2, high gain, 100% volume. Very strong hum, almost as loud as would be music at moderate volume. If any headphones would require listening at this position, it would be completely impossible. Please note though that T50p listening position was with volume at 9 o'clock in high gain, which is not required at all (low gain is where T50p belongs).
 
6. A2 with no interconnects: almost no hum (high gain, volume at 100%). While one could conclude that the hum was coming from outside, it is not so (see No.1). Even without that, as I was using AudioQuest Cinnamon RCA interconnect coming out of Musical Fidelity V-DAC II, I doubt this equipment would produce any audible hum/noise (I do use MF V-PSU II though).
 
I will pay more attention to the above with my other headphones and will update if anything differs.

 

[blasjw]

Quote:

4. A2, high gain, 0% volume. Clearly audible noise (same as MF V-CAN II with volume at 100%); low hum as in No.2. I was surprised by the noise here, honestly. Hum stayed the same until volume reached 11:30 o'clock, then started to increase.
 
5. A2, high gain, 100% volume. Very strong hum, almost as loud as would be music at moderate volume. If any headphones would require listening at this position, it would be completely impossible. Please note though that T50p listening position was with volume at 9 o'clock in high gain, which is not required at all (low gain is where T50p belongs).
 

 
Clearly there is some issue related to the gain.  Refer to my post #138 on this thread where I include this picture from the bottom of the PCB.  The cut trace you see at the top of the "scratch" leads directly to the gain switch:
 
 

 

[hodgjy]

Since you have the V-CAN II and the A2, could you describe the sonic differences between the two?  I'd greatly appreciate reading your opinions.
 
Quote:

1. Just to establish a reference point, Musical Fidelity V-CAN II, volume at 100%: very slight noise, could barely hear it. No hum, zero. Nothing at 0% volume.
 
 

 

[NotAnAngel]

Quote:

 
 
Well, I think bearFNF did find something. I tried this on mine; I also did what Oldandslow suggested, but in addition I connected my Musical Fidelity V-CAN II instead of A2 and did the noise/hum test again.
 
Using Beyerdynamic T50p (32 Ohms), here is what I could hear.
 
1. Just to establish a reference point, Musical Fidelity V-CAN II, volume at 100%: very slight noise, could barely hear it. No hum, zero. Nothing at 0% volume.
 
2. A2, low gain, 0% volume: very low noise and low hum; while I could hear it, I could only tell it was there if I unplugged headphones and then plugged them back in. This stayed the same until volume reached 2 o'clock, then hum started to increase.
 
3. A2, low gain, 100% volume: clearly audible hum; about the same noise (masked by hum completely).
 
4. A2, high gain, 0% volume. Clearly audible noise (same as MF V-CAN II with volume at 100%); low hum as in No.2. I was surprised by the noise here, honestly. Hum stayed the same until volume reached 11:30 o'clock, then started to increase.
 
5. A2, high gain, 100% volume. Very strong hum, almost as loud as would be music at moderate volume. If any headphones would require listening at this position, it would be completely impossible. Please note though that T50p listening position was with volume at 9 o'clock in high gain, which is not required at all (low gain is where T50p belongs).
 
6. A2 with no interconnects: almost no hum (high gain, volume at 100%). While one could conclude that the hum was coming from outside, it is not so (see No.1). Even without that, as I was using AudioQuest Cinnamon RCA interconnect coming out of Musical Fidelity V-DAC II, I doubt this equipment would produce any audible hum/noise (I do use MF V-PSU II though).
 
I will pay more attention to the above with my other headphones and will update if anything differs.

 
I just tried low/high gain hum test with DT990/600, and it was *very* different.
 
In short, zero noise (nothing that I could hear anyway), and only very slight hint of hum at high gain, volume at 100%. It looked almost perfect with 600 Ohms headphones.
 
To summarize, "Impedance does matter":
 
a) there is no noise/hum issue with high impedance (600 Ohms) headphones;
 
b) there is quite a bit of noise and strong hum with low impedance (32 Ohms) headphones (although both are quite outside of volume/gain settings one would use with low impedance headphones).
 
I could still switch to high gain mode though with volume set at 9 o'clock for T50p/32 and that setting was not very good due to quite audible noise and very low but still audible hum.

 

[NotAnAngel]

Quote:

Since you have the V-CAN II and the A2, could you describe the sonic differences between the two?  I'd greatly appreciate reading your opinions.
 

Sure, will try to do a quick listening test tonight and will post tonight or tomorrow.

 

[aoiziptw]

Just want to update on my listening with the A2 with about 30 hours of unit burn in.
 
- it still hums with my UM3x IEM at low gain, the hum is there and you can notice the noisy floor. once i switch to my full size can, i can not hear any.
 
- the unit does hum(electrically), but i have to listening very carefully and put my ear around 3 ~ 4in next to the vent to hear it. Currently the amp is sitting about 2 arms length away and i can not hear the hum with or without the headphone on. i guess i have a unit that hum not as loud like other member on the board? or my ear is just plan woodie
 
- sound stage is improving, but the mid is still lay back with high a bit roll off on my HD650, with my W1000 it sounds only mid is lay off for sure, since this CAN is very vocal and it is easy to tell the vocal got pushed back a little.
 
- bass is nice and tighter with good control, it is not as booming as first few hours.
 
I have notice once i switched to high gain for both of HD650 and W1000, the sound sounds fuller.
 
~Ming

 

[NotAnAngel]

Quote:

Since you have the V-CAN II and the A2, could you describe the sonic differences between the two?  I'd greatly appreciate reading your opinions.
 

Here is a few points on some differences between A2 and V-CAN II with DT990/600.
 
1. Using headphones analogy, on a high level, V-CAN II sounds more like DT990 while A2 sounds more like AKG Q701 (overall sonic signature only).
 
2. V-CAN II is warmer, sounds fuller and more lush.
 
3. A2 is more accurate and has better resolution, especially in high frequencies.
 
4. V-CAN II is slightly mellow; it is very smooth with a natural sound. A2 is a bit harsh (mids mostly) and often sounds somewhat steely and edgy. 
 

5. A2 has much better highs extension with great resolution while V-CAN II sounds a bit dark there and somewhat lacks details.
 
6. V-CAN II has excellent soundstage; it is very spacious, which very often creates 3D like effect where I can totally feel the ambience as if I was there. In comparison, A2 has good imaging but spaciousness is much less pronounced (sometimes to the point I have to specifically look for it to tell it's there).
 
7. A2 has much more controlled and tight bass; most of the time I can tell exactly where it is coming from. V-CAN II has softer and much fuller bass; on some tracks it sounds like bass fills the whole environment.

 

[hodgjy]

Thanks a bunch.  Much appreciated!  

 
And, welcome to the community.  I see you just joined last month.  Glad to have you here.
 
Quote:

Here is a few points on some differences between A2 and V-CAN II with DT990/600.
 
1. Using headphones analogy, on a high level, V-CAN II sounds more like DT990 while A2 sounds more like AKG Q701 (overall sonic signature only).
 
2. V-CAN II is warmer, sounds fuller and more lush.
 
3. A2 is more accurate and has better resolution, especially in high frequencies.
 
4. V-CAN II is slightly mellow; it is very smooth with a natural sound. A2 is a bit harsh (mids mostly) and often sounds somewhat steely and edgy. 
 

5. A2 has much better highs extension with great resolution while V-CAN II sounds a bit dark there and somewhat lacks details.
 
6. V-CAN II has excellent soundstage; it is very spacious, which very often creates 3D like effect where I can totally feel the ambience as if I was there. In comparison, A2 has good imaging but spaciousness is much less pronounced (sometimes to the point I have to specifically look for it to tell it's there).
 
7. A2 has much more controlled and tight bass; most of the time I can tell exactly where it is coming from. V-CAN II has softer and much fuller bass; on some tracks it sounds like bass feels the whole environment.

 

[bearFNF]

Quote:

If you get a chance, try the "hum test" with the inputs to the Asgard 2 unplugged. I did, and there's no noise/hum at all. Dead quiet. The hum I heard was coming from the interconnects/d.a.c./computer, not the amp. Sorry about that, Schiit!

AH HA!!!

EUREKA!!!

  Ok, I will try to calm down.

  I have found the source of the noise...
So, before I get to that

, I tried the unplugging the inputs thing and there is zero noise indeed.  The Asgard 2 plugged into power with only headphones does not produce noise. That I can hear, anyway.
 
I got to thinking

about a post I read somewhere about laptops and charging circuits...

  So, I unplugged the laptop and did the test on the laptop battery only.  With inputs plugged in and ready to play music but with Foobar paused.  No ticking noise and only a very slight hiss of the volume.  Tried it with my [size=10pt]APC J15BLK[/size] ([size=10pt]J-Type Power Conditioner with Battery Backup[/size]) and the nosie was filter down, could barely hear the ticking sound and the hiss.  So this has to do with the AC coming from charging the laptop.  Or could it be the AC coming though the laptop to the Modi

? See the extra credit work below for the answer.

 
So for my final trick

, to confirm where the noise is coming from, I carted the whole lot into my computer room and hooked it up to my desktop.  No power brick or charging circuit here.  Just a very clean and line conditioned PSU on an APC AVR UPS, HEH

.  The result?  No ticking or hum.  Just the hiss of volume.  The computer cooling fans were louder than the hiss from the Asgard 2.

 

[NotAnAngel]

Quote:

Thanks a bunch.  Much appreciated!  

 
And, welcome to the community.  I see you just joined last month.  Glad to have you here.
 

Thanks, glad to be here 

 

[tuna47]

I have had mine for three days no hum and I am very happy with the sound on my he500 also plenty of power

 

[Rem0o]

How is this amp with the HD650? Anyone tested it?

 

[Gary in MD]

Quote:

AH HA!!!

EUREKA!!!

  Ok, I will try to calm down.

  I have found the source of the noise...
So, before I get to that

, I tried the unplugging the inputs thing and there is zero noise indeed.  The Asgard 2 plugged into power with only headphones does not produce noise. That I can hear, anyway.
 
I got to thinking

about a post I read somewhere about laptops and charging circuits...

  So, I unplugged the laptop and did the test on the laptop battery only.  With inputs plugged in and ready to play music but with Foobar paused.  No ticking noise and only a very slight hiss of the volume.  Tried it with my [size=10pt]APC J15BLK[/size] ([size=10pt]J-Type Power Conditioner with Battery Backup[/size]) and the nosie was filter down, could barely hear the ticking sound and the hiss.  So this has to do with the AC coming from charging the laptop.  Or could it be the AC coming though the laptop to the Modi

? See the extra credit work below for the answer.

 
So for my final trick

, to confirm where the noise is coming from, I carted the whole lot into my computer room and hooked it up to my desktop.  No power brick or charging circuit here.  Just a very clean and line conditioned PSU on an APC AVR UPS, HEH

.  The result?  No ticking or hum.  Just the hiss of volume.  The computer cooling fans were louder than the hiss from the Asgard 2.

You guys are great, and Schiit should pay you for your help in troubleshooting this issue.  Or at least provide credit towards additional schiit.  Or at least send you a t-shirt.  Or something, since you have helped them identify and fix a couple of problems in their product, allowed them to avoid large numbers of returns/reworks in the future, and probably helped future sales. 
 
In any case, I still think I'll wait a few months for you and Shiit to find and fix other bugs, and then make a decision between a more mature A2 and an even more mature MJ to drive my LCD-3s (by the way, any input into that decision would be appreciated... no, I won't send you money, schiit or a t-shirt... at least not a shirt that you would want to wear...)