BDA 3.14 DAC, preamp and streamer

aleduc · « **on:** 21 Nov 2019, 04:35 pm »

Hello all,

Being a fan of Bryston and soon want to upgrade my BDA-2 to a BDA-3 and my 135b3 to a 4B3, I was quite suprised to see that Bryston will be releasing the BDA-3.14 which includes a streamer and can be used as a pre-amp. So my question, how does the preamp in the BDA 3.14 compare in terms of SQ to the BP17-3? Is there still a need, from a SQ perspective, to buy a separate preamp and streamer if the BDA-3.14 does it all?

Alain

dhparker · « **Reply #1 on:** 22 Nov 2019, 01:21 am »

Good question - I have the same question. I have a 2.5B3 amp and I'm debating if I'll just buy this as my streamer/preamp. I noticed it does not have a trigger out, so I guess I'd have to leave my amp on all the time.. but the preamp option seems interesting.

Dave

James Tanner · « **Reply #2 on:** 22 Nov 2019, 02:34 am »

Hi Folks,

The preamp section in the 3.14 is the output of the DAC chips so it is not a substitute for a state of the art preamp like the BP17 or the BP26.

Digital volume controls like in the 3.14 are compromised as you turn the volume down because you lose BIT's. It's a reasonable option if your budget does not allow for a quality preamp.

james

bud1451 · « **Reply #3 on:** 22 Nov 2019, 03:40 pm »

I strictly stream Tidal and that is it....started with the Oppo 105 direct to my 4b3, then moved onto the Cambridge 851N with great results.
I ordered the 3.14 thinking it will be the next step up in performance .....Streamer/DAC/preamp combo is the future

aleduc · « **Reply #4 on:** 22 Nov 2019, 06:34 pm »

Thanks for the answer James on the pre-amp. What about for the streamer component of the 3.14. Any benefits of having a separate streamer such as the BDP-3 if you buy the 3.14?

James Tanner · « **Reply #5 on:** 22 Nov 2019, 06:53 pm »

Quote from: aleduc on 22 Nov 2019, 06:34 pm

Thanks for the answer James on the pre-amp. What about for the streamer component of the 3.14. Any benefits of having a separate streamer such as the BDP-3 if you buy the 3.14?

The Pi3 is a good computer for what it is but the quality of the digital bit-stream is not at the performance level of the BDP-3.
The DAC section of the 3.14 is identical to the separate BDA3 DAC.

james

GeAllan70 · « **Reply #6 on:** 23 Nov 2019, 04:04 pm »

Quote from: James Tanner on 22 Nov 2019, 02:34 am

Digital volume controls like in the 3.14 are compromised as you turn the volume down because you lose BIT's. It's a reasonable option if your budget does not allow for a quality preamp.

james

so pardon my lack of knowledge...similar to using an OPPO 105d as pre-??

George

James Tanner · « **Reply #7 on:** 23 Nov 2019, 04:32 pm »

Quote from: GeAllan70 on 23 Nov 2019, 04:04 pm

so pardon my lack of knowledge...similar to using an OPPO 105d as pre-??

George

Hi George

I am not that familiar with the OPPO but any digital volume control has the same issue. I would assume a DVD player would use a digital volume control.

james

James Tanner · « **Reply #8 on:** 23 Nov 2019, 04:37 pm »

Hi Folks,

DIGITAL VOLUME CONTROLS

Normal full volume level in BDA3.14 is 0dB.

16-bit sources

Even though -20dB drops only 3 bits out of 16 leaving 13 bits resolution which would be similar to a typical effective average music CD resolution the situation is somewhat worse because they normally leave the 4 bit margin when doing a typical CD and not utilize the full 16-bits. So 16-bit CD is really ~12 bits on average.

It also means that if you drop 3 bits (-20dB) out of the average 12 bit contents then you get 9 bits which will probably be noticeably granular and sound slightly "quantized" but not tragic. For 16-bit or CD sources I would recommend to use only 0dB to -10dB adjustment range and adjust the remaining range using external measures, for example and external preamp or use external passive attenuator.

24-bit sources

It would also drop the same 3 bits leaving 21 bits out of 24-bits original resolution which would probably be completely un-noticeable on the quality.

In this case there is no problem in adjusting the volume even down by 60dB or so.

Digital Bitstream from Pi vs BDP3

It is the same, bitwise as in BDP1/2/3 that is it depends on the source such as a file or a streaming service resolution and format. Raspberry PI uses the same format and most of the features, with a slower processor speed, and the physical connection in PI is I2S processed by the SPDIF chip in the BDA3 versus SPDIF output from BDP1/2/3 going to the same SPDIF processor in BDA3.

The PI is speed wise probably close to BDP1.

Pundamilia · « **Reply #9 on:** 24 Nov 2019, 05:22 am »

Does the same logic apply to using the software volume control in Manic Moose to reduce the volume on a BDPx? If I use that to lower the volume, am I also dropping bits?

James Tanner · « **Reply #10 on:** 24 Nov 2019, 01:15 pm »

Quote from: Pundamilia on 24 Nov 2019, 05:22 am

Does the same logic apply to using the software volume control in Manic Moose to reduce the volume on a BDPx? If I use that to lower the volume, am I also dropping bits?

Hi

Yes i believe so but I will ask Chris to respond.

That's why the default factory setup is full level.

james

PS - Chris confirms it is dropping BIT's as you lower the volume.

Pundamilia · « **Reply #11 on:** 24 Nov 2019, 03:03 pm »

Thanks, guys.

I guess this means that when I am listening to my BHA-1 and I want to change the volume, I have to get up off my tush and do it with the physical volume control!

James Tanner · « **Reply #12 on:** 24 Nov 2019, 04:00 pm »

Quote from: Pundamilia on 24 Nov 2019, 03:03 pm

Thanks, guys.

I guess this means that when I am listening to my BHA-1 and I want to change the volume, I have to get up off my tush and do it with the physical volume control!

Hi

Or use a preamp with remote volume

james

Alphonse · « **Reply #13 on:** 25 Nov 2019, 05:34 pm »

I have been using an Oppo 105 as a preamp with digital volume control direct to my Powerpac 300s via XLR and it sounds great to me. If bits are lost I am not hearing any degradation. YMMV.

Pundamilia · « **Reply #14 on:** 25 Nov 2019, 06:13 pm »

@ JT: I am using a BP-26MC as my pre-amp with the BHA-1 connected to one of the two sets of unbalanced outputs. When I adjust the volume on the BP-26 with the remote, the volume control rotates, but the sound coming out of the BHA-1 doesn't change. Are the two unbalanced outputs both fixed or is one fixed and the other variable? I checked the manual and it doesn't mention any differentiation between the two unbalanced output pairs.

James Tanner · « **Reply #15 on:** 25 Nov 2019, 06:51 pm »

Quote from: Pundamilia on 25 Nov 2019, 06:13 pm

@ JT: I am using a BP-26MC as my pre-amp with the BHA-1 connected to one of the two sets of unbalanced outputs. When I adjust the volume on the BP-26 with the remote, the volume control rotates, but the sound coming out of the BHA-1 doesn't change. Are the two unbalanced outputs both fixed or is one fixed and the other variable? I checked the manual and it doesn't mention any differentiation between the two unbalanced output pairs.

Hi

They are both variable on the 26.

I assume the volume control on the BHA-1 is setting the volume?

james

bud1451 · « **Reply #16 on:** 25 Nov 2019, 07:26 pm »

Quote from: Alphonse on 25 Nov 2019, 05:34 pm

I have been using an Oppo 105 as a preamp with digital volume control direct to my Powerpac 300s via XLR and it sounds great to me. If bits are lost I am not hearing any degradation. YMMV.

Pundamilia · « **Reply #17 on:** 26 Nov 2019, 04:07 am »

Sorry, I just checked and I was taking the output from the tape output, not from the Output output.

I was using the volume control on the BHA-1 to control volume. Do you have any recommendations as to relative setting of the BP-26 volume control vs. setting of the BHA-1 volume control to get the desired volume level. Ideally, I would like to keep the BP-26 setting as close as possible to the setting for using the 4B3 and speakers. Otherwise, should I forget to reset the BP-26 volume, when I turn on the 4B3, the volume will be unbearable? Is there any difference in SQ if more of the amplification is being done by the pre-amp or the headphone amp?

Thanks.

Again, I apologize for not checking the system first and posting something that was incorrect.

James Tanner · « **Reply #18 on:** 26 Nov 2019, 02:23 pm »

Hi

Around the 1 O'clock position on the BP26 would be unit gain so you could try that. I use the tape Out on my setup.

james

Pundamilia · « **Reply #19 on:** 26 Nov 2019, 03:06 pm »

Actually, I was using the Tape Out (before I switched it to Output) and it was with that connection, the remote didn't change the volume. How come yours does?