[MorbidToaster]

Have you tried moving it away from your other gear and seeing if it disappears? I got a new phono stage recently and there was a pretty loud hum from it. When I separated the 2 pieces it disappeared.
 
If some of your gear doesn't have a well shielded power supply it could be the issue.  

 

[Lappy27]

Quote:

I never listen above 11 o'clock and never hear any hum.

X 2

 

[jeffinator]

Quote:

 
Hi James, yes I can hear a low level hum even if the source cables are unplug. The odd thing is if you crank the volume pass 12 the hum disappear. Is it a normal noise floor? 
 
Thanks,
Jon

 
I am having the exact same problem, but the buzzing I'm hearing disappears around 11 o'clock. Although I can just barely hear it with my LCD-2s, it's really noticeable with my JH13s, whether using a balanced cable or single-ended...

 

[James Tanner]

Spoke with Engineering - Specs on BHA
 
 
TYPICAL BHA1 HEADPHONE AMPLIFIER PERFORMANCE
 
SETUP - SINGLE ENDED INPUT @ 1V  - DISTORTION MEASURED  20HZ TO 20 KHZ
 
LOAD 600 OHMS
GAIN HI - 10.9V OUT @ 001%   POWER 200 mW
GAIN LO - 5.45 V OUT @ 001%  POWER 50 mW
GAIN LO - 2.50 V OUT @ 001%  POWER 10 mW
GAIN LO - 788m V OUT @ 001%* POWER 1 mW
 
LOAD 300 OHMS
GAIN HI - 10.8 V OUT @ 001%   POWER 390 mW
GAIN LO - 5.40 V OUT @ 001%  POWER 50 mW
GAIN LO - 1.79 V OUT @ 001%  POWER 10 mW
GAIN LO - 583 mV OUT @ 001%* POWER 1 mW
 
LOAD 80 OHMS
GAIN HI - 10.4 V OUT @ 002%   POWER 1.35 W
GAIN LO - 5.20 V OUT @ 001%  POWER 383 mW
GAIN LO - 887 mV OUT @ 001%  POWER 10 mW
GAIN LO - 345 mV OUT @ 003%* POWER 1 mW
 
LOAD 32 OHMS
GAIN HI - 9.65 V OUT @ 0.150%   POWER 2.9 W - onset of clipping
GAIN LO - 4.84 V OUT @ 002%     POWER 732 mW
GAIN LO - 578 mV OUT @ 001%*  POWER 10 mW
GAIN LO - 185 m V OUT @ 005%* POWER 1 mW
GAIN LO - 4.00 V OUT @ 001%     POWER 500 mW - rated output
 
*= 80 KHZ FILTER
  mW = milliwatt
W = watt
mV = millivolt
V = volt

 

[Hooster]

Many thanks.

 

[BlackstoneJD]

Another example of how neutral this amp is. I have a line level pre-amp I really really like, an old Threshold T2. It is a heavy duty piece of gear. I was wondering what would happen if I put it in between my DAC and the Bryston. Well wouldn't ya know the Bryston passed along the sonic signature of the Threshold perfectly. It really imparts a very forgiving, warm almost tube like sound now.
 
My question is technical in nature. Assuming I want use use this very high-end preamp as my preamp/volume control, should I just fully open the Bryston's volume control and let the preamp do its thing or is there some kind of balancing act that need to take place between the output on the pre-amp and the volume control on the amp. My preamp reads amplification in digital output so I can set it to say, -10db which I believe is about line level and then the volume knob on the amp ends up pretty much where it had it when I used it straight from the DAC. at about 2:00. Or should I just open up the Bryston all the way and let the preamp control completely?
 
Does that make sense?

 

[Hooster]

Yes, if you are using something else to control the volume you should open it up to the max. I believe that this way you will essentially be bypassing the volume control pot on the Bryston.

 

[James Tanner]

Quote:

Another example of how neutral this amp is. I have a line level pre-amp I really really like, an old Threshold T2. It is a heavy duty piece of gear. I was wondering what would happen if I put it in between my DAC and the Bryston. Well wouldn't ya know the Bryston passed along the sonic signature of the Threshold perfectly. It really imparts a very forgiving, warm almost tube like sound now.
 
My question is technical in nature. Assuming I want use use this very high-end preamp as my preamp/volume control, should I just fully open the Bryston's volume control and let the preamp do its thing or is there some kind of balancing act that need to take place between the output on the pre-amp and the volume control on the amp. My preamp reads amplification in digital output so I can set it to say, -10db which I believe is about line level and then the volume knob on the amp ends up pretty much where it had it when I used it straight from the DAC. at about 2:00. Or should I just open up the Bryston all the way and let the preamp control completely?
 
Does that make sense?

 
Hi - put the BHA volume control at 12 -1 o'clock (unity gain) and use the remote preamp control for adjustment of level.
 
james

 

[Hooster]

If was you, I would do what James says. I would however not not be able to stand the temptation to experiment.

 

[BlackstoneJD]

12:00 - 1:00 sounds right on.

 

[musicman59]

Quote:

Another example of how neutral this amp is. I have a line level pre-amp I really really like, an old Threshold T2. It is a heavy duty piece of gear. I was wondering what would happen if I put it in between my DAC and the Bryston. Well wouldn't ya know the Bryston passed along the sonic signature of the Threshold perfectly. It really imparts a very forgiving, warm almost tube like sound now.
 
My question is technical in nature. Assuming I want use use this very high-end preamp as my preamp/volume control, should I just fully open the Bryston's volume control and let the preamp do its thing or is there some kind of balancing act that need to take place between the output on the pre-amp and the volume control on the amp. My preamp reads amplification in digital output so I can set it to say, -10db which I believe is about line level and then the volume knob on the amp ends up pretty much where it had it when I used it straight from the DAC. at about 2:00. Or should I just open up the Bryston all the way and let the preamp control completely?
 
Does that make sense?

The T2 is a great Pre-amp. I have two of them (one in each of my systems). I am actually using it together with a T50 to power my HE-6 and the sound is great!

 

[Hooster]

Yes, the T2 is pretty sweet.
 
"The T2's volume control is worthy of special note. In order to maintain the highest common-mode rejection ratio, a balanced control's tracking accuracy has to be ridiculously tight. Currently available rotary-gang potentiometers just didn't have the accuracy needed to do the job, so the Threshold T2 employs a 12-bit, modified-R2R resistive ladder network (similar to what you'd find in a DAC) switched by high-reliability relays. With this device, tracking-control accuracy is better than 0.01dB. The digital attenuator has 4096 discrete steps available—a few too many for audio purposes, so two custom-programmed Programmable Logic Devices are used to select 60 decibel steps, shown on the front-panel fluorescent display."
 
http://www.stereophile.com/solidpreamps/threshold_t2_preamplifier/index.html

 

[dleblanc343]

Hey guys, I've just discovered today from the Bryston rep that they have a new dac coming in very soon; the BDA-2. With a usb implementation of 24/192 asynchronous which the BDA-1 did not have, this makes things very interesting albeit the high price.
 
I am sure the BDA-2/BHA-1 would be a killer combo in terms of transparency.
 
http://www.computeraudiophile.com/f6-dac-digital-analog-conversion/new-bryston-bda-2-dac-13955/
 
 

 

 

[preproman]

Quote:

Hey guys, I've just discovered today from the Bryston rep that they have a new dac coming in very soon; the BDA-2. With a usb implementation of 24/192 asynchronous which the BDA-1 did not have, this makes things very interesting albeit the high price.
 
I am sure the BDA-2/BHA-1 would be a killer combo in terms of transparency.
 
http://www.computeraudiophile.com/f6-dac-digital-analog-conversion/new-bryston-bda-2-dac-13955/
 
 

 

 
 
Very interesting,   Hope it's an improvement over the BDA-1.  I read an article where the Ref 7.1 beat out the BDA-1 pretty good.

 

[Happy Camper]

If the DAC is as transparent as the amp, woah. I'd love to hear the LCD-3 on the combo.