[Rob80b]

  Rob80b,
................................  
i'd like to know the maximum input value for Bryston expressed in dBu or volt rms.Just to be sure to se the correct output from my reference dac.
 
I hope that someone at  Bryston technical department can give me a clear answer about that (i've already emailed them but got no answer)

Ok see where you are going.
 
Haven’t done actual measurements but the input section of the BHA-1 is fairly robust but I’ve found that the amp section can be distorted if pushed too hard.
To explain, I did some tests earlier on when acquiring my BHA-1, I also ran my 2BLP pro amp (which has a headphone out) off the balanced pre outs at the same time.
What I found was that when pushed too hard, way beyond safe listening levels, I was able to hear discernable distortion out of the BHA-1s headphone outputs but the same volume level and higher off the 2BLP was fine.
So I’d be safe in saying that the BHA-1 should be fine in handling what ever you throw at it, +18dBu (6.15 volt rms) to +26dBu (23.7 volt rms), any distortion which might then incur from the amp section would be at a volume level way too high for any safe listening and the death of the headphones
 
But again, if the input level is too high, I’d actually would prefer around 4dB, one would be extremely restricted to the amount of open gain on the volume control.
 
You may want to call Mike Pickett, usually much better than email and who’s a very friendly and knowledgeable person at Bryston 1-800-632-8217.

 

[Rob80b]

  ...........
 
The thing is that I have balanced cables on order and I read that that increases volume by another 6 db's, so the only option I can see is to not bypass the preamp in my M-DAC and turn down the volume on the M-DAC.  Do you think this will cause lesser sound quality if I turn it down around 10-15 db on the M-DAC?
 
Thanks.

That's my one pet peeve with the BHA-1, either too much gain or not enough depending on the source.
 
If the volume control of the M-DAC is not in the digital domain and tied in with the bit rate a few dB attenuation you should be fine.

 

[Dave74]

  That's my one pet peeve with the BHA-1, either too much gain or not enough depending on the source.
 
If the volume control of the M-DAC is not in the digital domain and tied in with the bit rate a few dB attenuation you should be fine.

Ok.  Thank You.  That is probably what I will have to end up doing once I go fully balanced. 
 
I also ordered a pair of Alpha dogs for home use so I am hoping that they will pair well with the Bryston/M-DAC combo.  I love the HE-500's with the BHA-1, so much better than my Lyr, the bass is much more controlled and refined and the mids and highs are far more detailed without being fatiguing.
 
Thanks.
Dave.

 

[Chris J]

My dac in my audio mastering studio has a balanced xlr line output that can be set from +6dBu (1.54 volt rms) to +24dBu(12.2 volt rms).


Which is the recommended balanced input level for the Bryston BHA-1? I'd like to buy it to use as my new reference headphone amplifier.


 


Mr Tanner? Anyone?


 


thanks!

 


Start with +6dBu.
Anything more has a good chance of overloading the input stage of the BHA-1.
The volume control in the Bryston BHA-1 is AFTER the input stage.
So once you overload the inoput stage, turning the volume down will not help you, i.e. if you tuen the volume way down, the SPL at your headphones may be quiet, but is it still be distorted.

 

[fradoca]

Chris J,
thanks you for your advice.
I hope also to get official information from Bryston about optimal input level.

 

[Chris J]

Chris J,


thanks you for your advice.


I hope also to get official information from Bryston about optimal input level.

 


Since you are in Italy I just HAD to help!
Tuscany is beautiful............................

 

[Rob80b]

Start with +6dBu.
Anything more has a good chance of overloading the input stage of the BHA-1.
The volume control in the Bryston BHA-1 is AFTER the input stage.
So once you overload the inoput stage, turning the volume down will not help you, i.e. if you tuen the volume way down, the SPL at your headphones may be quiet, but is it still be distorted.

 
Excellent advice, hopefully the input stage can handle double that but I guess we will not know unless someone tries.
Mike, James are you listening (reading)?
 
Maybe time to head over to http://www.audiocircle.com/index.php?topic=104028.0

 

[Hubert481]

Using mdac and bha1, i cannot hear any difference by using the mdac with 0dB or -20 dB in soundquality

 

[Dave74]

Using mdac and bha1, i cannot hear any difference by using the mdac with 0dB or -20 dB in soundquality

Thanks. I won't bypass the preamp anymore. I just wasn't sure since the BHA1 can be used as a preamp, and the M-DAC manual says that when using with a preamp you can disable the M-dacs preamp so you can use it as a stand alone dac. I guess the benefit will be that I be able to turn the volume higher on the BHA-1 and I will also be able to use the remote on the m-dac to control the volume.

 

[Chris J]

Thanks. I won't bypass the preamp anymore. I just wasn't sure since the BHA1 can be used as a preamp, and the M-DAC manual says that when using with a preamp you can disable the M-dacs preamp so you can use it as a stand alone dac. I guess the benefit will be that I be able to turn the volume higher on the BHA-1 and I will also be able to use the remote on the m-dac to control the volume.

Nice!
Very nice!

 

[James Tanner]

Hi
 
Please email Stuart Taylor at Bryston - I spoke with him today about your questions and he has some questions in return
 
He also said we could do a custom unit for you if needed.
 
staylor@bryston,com
 
james

 

[Hubert481]

Correct Dave, i prefer Volume from 10-12 and not 8-9 on BHA1 - For my opinion it sounds better on the BHA1.
And control remote via MDAC.
Maybe there might be a difference, but i cannot hear any "bad sounding" by using even -30dB on the mdac.
For me it is the perfect combination - great sound and comfortable remote control of volume

 

[Dave74]

Thanks Hubert, I think this will benefit me especially when I go balanced as the volume will already be 6db higher.

 

[Rob80b]

  Hi Folks,
 
The volume control we use in the BHA-1 is 'laser trimmed' to be accurate within 1/4dB throughout its rotation.  From 7 o'clock to 11 o'clock  there is a smaller gain (volume) change than between 11 and 3 o'clock to allow for more efficient phones being used at the lower settings.
 
Also remember the Bryston BHA-1 runs pure Class A so the volume control is actually a volume 'attenuator' - so full volume has no more or less distortion than minimum volume settings.
 
james

 
 

Correct Dave, i prefer Volume from 10-12 and not 8-9 on BHA1 - For my opinion it sounds better on the BHA1.
And control remote via MDAC.
Maybe there might be a difference, but i cannot hear any "bad sounding" by using even -30dB on the mdac.
For me it is the perfect combination - great sound and comfortable remote control of volume

I’m currently stuck with opposite problem, with music running balanced from my BCD-1 CDP all is well either with single ended or balanced phones , but unbalanced from my preamp and/or AVP even with balanced phones at high gain I'm usually maxed out on the dial with little maneuvering to find the sweet spot.

 

[Rob80b]

  Hi
 
Please email Stuart Taylor at Bryston - I spoke with him today about your questions and he has some questions in return
 
He also said we could do a custom unit for you if needed.
 
staylor@bryston,com
 
james

   
 
I’m currently stuck with opposite problem, with music running balanced from my BCD-1 CDP all is well either with single ended or balanced phones , but unbalanced from my preamp and/or AVP even with balanced phones at high gain I'm usually maxed out on the dial with little maneuvering to find the sweet spot.

Hi James
 
Obviously the BHA-1’s “raison d'être” is that of a fully balanced headphone amp and an excellent one at that but I’m sure there must be other users who are also experiencing the opposite problem with the gain on the unbalanced input.
This sort of mirrors the headphone gain on my previous BP25P and B60R and was surprised that the maximum gain was not increased on the BHA-1 when using unbalanced sources.
The way I see it is that if the overall gain of the BHA-1 is increased to accommodate the unbalanced input the balanced chain may be too high, the gain switch and volume control have been configured as such to accommodate a number of different headphones and works as intended.
Maybe I’m asking too much, but I’m wondering if in fact it may have been better to have incorporated a more conventional linear volume control and that the gain switch equalized the volume level when switching between the balanced and unbalanced input as the ‘majority” of users appear to be using full-sized lower efficient phones.
 
Robert