[Chris J]

A balanced amplifier will still be referenced to ground.
How does the balanced DAC reject noise?
The DAC has a balanced output, goes thru a balanced cable and is accepted by a balanced input in the amplifier.
So the noise is rejected in the amplifiers input stage, assuming the noise is COMMON to both the Non-inverting and Inverting signals.


By the way, you need to REjECT noise to get rid of it.
some of these so called "balanced" topologies seem to do nothing to reject noise, they just continue to amplify it in a "balanced" configuration.

If an amplifier has a balanced input, then Common Mode noise is rejected and we are left with the noise the amplifier circuit itself generates.

Whether the amplifier is Single ended or Balanced amplification, there will still be noise generated within the amplifier circuit.

 

[Chris J]

Why there are full balanced layouts like GS-X or HDV600 on the market?

Because there is more than one way to build a balanced amplifier.
Matrix Quattro configuration is completely different than Audio GD NFB-6 which is completely different than the Bryston.

 

[James Tanner]

Hi Folks,
 
Here is a link to a newsletter I did years ago about Balanced lines - hope this helps.
 
http://bryston.com/PDF/newsletters/Bryston_Newsletter_V1_1.pdf
 
 
james

 

[R Giskard]

Fully balanced amplifiers have no noise rejection, differential amplifiers do. Fully balanced amplifiers pass the signal unaltered amplifying it along with the noise. Differential amplifiers reject the noise on it's input by their common mode rejection factor and then amplify the signal. The BHA-1 is a differential amplifier as far as I know.

 

[James Tanner]

Here was a follow up newsletter on the subject: "Is Your System Out Of Balance"
 
http://bryston.com/PDF/newsletters/Bryston_Newsletter_V3_1.pdf
 
james

 

[James Tanner]

MEMO: To All Bryston Customers
SUBJECT: Bryston BHA-1 Award!

February, 2014

Hi James,

This is award we received yesterday evening for the:

BEST Headphone amplifier chosen by 26.000 readers in Germany!


Best regards,

Edvard
AViTech, Dkfm. Edvard Potisk e. U.
Czerningasse 16
1020 Vienna, Austria

 

[Hubert481]

Hi James, it is also the best headamp in austria! ))

 

[Chris J]

Fully balanced amplifiers have no noise rejection, differential amplifiers do. Fully balanced amplifiers pass the signal unaltered amplifying it along with the noise. Differential amplifiers reject the noise on it's input by their common mode rejection factor and then amplify the signal. The BHA-1 is a differential amplifier as far as I know.

 

Yes, the Bryston is a differential input amplifier.
Reference:
schematic in the Owner's Manual

I agree with everything you said.

 

[Trance_Gott]

Thank you James!
Seems Full Balanced is worser than Differential Input because of noise overload.

 

[Chris J]

Thank you James!

Seems Full Balanced is worser than Differential Input because of noise overload.

 


Beware of "Balanced" amplfiers that put two single ended amplifiers in a box and call it "Balanced".
For example:
The Matrix Quattro Amp

 

[Trance_Gott]

Has someone tested Audio GD Master 9 vs. BHA-1?

 

[R Giskard]

Hello!

I have a question for BHA-1 and Sennheiser HD800 owners. I am interested in purchasing this balanced cable:

http://en-de.sennheiser.com/dynamic-headphones-high-end-around-ear-hd-800

It is the Sennheiser CH800S balanced cable that uses a 4-pin XLR connector. 

Am I safe to assume this cable is compatible with BHA-1 amplifier? I cannot find a picture of the pin arrangement on the cable anywhere so I do not know whether this will work properly with Sennheiser HD800.

Any comments would be appreciated!
Antun

 

[Rob80b]

  Hello!

I have a question for BHA-1 and Sennheiser HD800 owners. I am interested in purchasing this balanced cable:

http://en-de.sennheiser.com/dynamic-headphones-high-end-around-ear-hd-800

It is the Sennheiser CH800S balanced cable that uses a 4-pin XLR connector. 

Am I safe to assume this cable is compatible with BHA-1 amplifier?

You'll be fine as the Bryston BHA-1 accepts either a single 4 pin Male XLR connector, like the CH800S or a dual 3 pin Male XLR cable.

 

[jonahsfo]

Report:  Bryston BHA-1 running Sennheiser HD800 and Audeze LCD-X
 
My BHA-1 just arrived yesterday, and I've had headphones glued to my head since it arrived.  I've been enjoying the sound of a high-quality balanced amp on both my Senn's and LCD-Xs.
 
The sound on both cans is amazing -- ironically, it closed the gaps between both headphones. I originally got the LCD-X to offer a counter-point to the airy, open sound of the Sennheisers.  But on this Bryston amp, it filled in the gaps of the lower registers of the HD800s, and seem to have cleaned up the sound of the LCD-X a bit (sound a touch more accurate).  On the previous amp (Benchmark DAC2 HGC), both cans sounded great, but each had a distinct "character".  On the Bryston, they ironically sound much more similar -- although each one is a clear improvement, so I'm not at all complaining.
 
TL;DR: For anyone looking at this amp for either the HD800 or LCD-X, all I can say is "Wow, holycr4p!"
 
Note:
The one oddity of this amp is that it doesn't really have a "zero" volume.  Even with the gain switch at "low" and the volume turned all the way down you can still hear the music clearly (although softly) with the source at line-level.   I never really thought of the HD800s as sensitive, but both headphones come through pretty loud by the time you get past the 7 or 8 o'clock position on the volume control.  
- if you have really sensitive cans (the LCD-X are pretty damn sensitive), you may want to make sure you have a source where you can adjust the output.
 
Don't take this as a negative -- both headphones sound amazing, but I was surprised that the amp seems to have so much headroom that the listenable range is within a rather small turning range on the volume pot.
 
[edit: fixed spelling]

 

[Kiats]

Yes, it is quite an amp: powerful and yet refined. My beyer T1 has never sounded so lush and smooth as it does now on balanced cables. it even does a good job on the HE-6.