[nicolasb]

I do a lot of headphone listening. For this I have a dedicated headphone amplifier, so an important question is how to get the best possible source-level signal for it. This means I occasionally consider outboard stereo DACs, especially those that have an effective jitter-removal stage and are therefore relatively immune to the influence of a cheaper transport.

I was interested to read (in another thread) that it's possible to take the signal from the B60's tape outputs and feed it through an attenuator and back into the B60's amplification section - and that, if you do, the result can sound better than it does going through the B60's pre-amp section.

This made me wonder - can you get a source-level signal out of (say) the tape outputs of a B60DA, and thus use its D/A conversion capabilities while bypassing the pre-amp stage?

And could one do the same thing with a BP25DA?

We've already heard from James T that the BP25 has a lower noise floor than the B60 pre-amp section, thanks to the external power supply. But, assuming one can bypass the preamplifier section and use either device simply as a stand-alone stereo DAC, I'd be interested to know how the those signal qualities compare. Is the BP25DA a superior stand-alone DAC, and, if so, how big is the difference? (Smaller than the difference in the pre-amp stages?)

[nicolasb]

(bump)

James T, I'd welcome your comment on this!  

[WEEZ]

I would be interested to know if the Bryston DAC will be available as a stand-alone (separate component) in the future. Much like the stand-alone 1.5 phono stage. Would the cost be prohibitive?

WEEZ

[James Tanner]

Hi,

No plans at this point for a stand alone DAC.

james

[James Tanner]

Thanks for the inquiry.  There are some limited circumstances where the gain provided in the B-60's line-driver section is not necessary for the output level required. In those cases, taking the output from the Tape Monitor and passivlely controlling the level will suffice to drive the amplification section.  Less gain equals less electronic noise as well, so the signal could be a tiny bit quieter in this instance also.  Keep in kind, however, that the line driver in the B-60 is also the headphone amplifier, and the B-60's headphone driver has been rated as among the best available anywhere, if that is one of your listening preferences.

   It is certainly possible to pull the post-D/A signal from the Tape Monitor as well, if you wish.  That can be done on either the B-60DA or the BP-25DA.  There was a time when the S/N of the BP-25 was slightly superior to that of the B-60's preamp stage, but improvements to the B-60 have brought it to the same quality as the BP-25 with its new power-supply, based on our most recent tests.  The D/A module used in the BP-25DA and the B-60DA is the same unit.  Thus, the sound quality is of course exactly equal.

   I hope the above is helpful, but please let me know if you have any other questions. Thanks for your interest in Bryston audio components!

Sincerely,
Chris Russell
Bryston Ltd.

[nicolasb]

There was a time when the S/N of the BP-25 was slightly superior to that of the B-60's preamp stage, but improvements to the B-60 have brought it to the same quality as the BP-25 with its new power-supply, based on our most recent tests.

James/Chris, I just want to make sure I understand you correctly, as this may raise an important point.

Imagine two systems:

1) Source -> BP25 -> Bryston 4B-SST-> speakers

2) Source -> B60 input -> (via pre-amp output) -> Bryston 4B-SST -> speakers

So it's the same system, but one uses a BP25 as pre-amp, and the other uses the pre-amp section of a B60. Are you saying that the B60 system willl sound just as good as (or identical to) the BP25 system?

The reason I'm making rather heavy weather of this is cost.

If I buy a BP25 in the UK right now, it costs £1825 (roughly 4,500 canadian dollars), while a B60 costs £1775. In other words (if I am understanding you correctly) a pre-amp with additional power amp capabilities costs slightly less than an identical pre-amp section alone. That seems a bit odd.

[James Tanner]

Hi Nicolas;

Hi,

Thanks for your thoughtful question.  Indeed the B-60 is a
delightful value, but its preamp section is not the exact equivalent
of the BP-25.  A more accurate price comparison would be with the
B-60R, of course, as the BP-25 has a remote, but beyond that, the
BP-25 has quite a few more functions than the B-60 preamp
section; more inputs including two balanced-ins, balanced out, a
polarity-invert function, etc.  Yes, the sound quality is the same,
but the BP-25 is more a full function preamp than the relatively
simple switching functions on the B-60.  I hope this clears up any
confusion, but please let me know if you have more questions.  

Sincerely,
Chris Russell
Bryston Ltd.

[nicolasb]

please let me know if you have more questions

No, I think that clears things up very nicely. Thank you, Chris/James.