Bryston SP1.7 Bypass or Digital In ????


I am looking to purchase the Bryston SP 1.7 pre-processor and was wondering a few thing about the 2 channel bypass-vs-using the digital in. As of now I am using the BP20 Pre. I guess my question would be how well does the processor work as a DAC when I send a digital signal into as apposed to an analog one. As of now I am using a Krell Studio as a DAC. It should be a upgrade to that but I plain to replace my current transport with either the new Krell showcase DVD to rid myself of having both a transport and a DVD player, or if that does not work maybe the 280CD. Is the DAC in the SP 1.7 going to be better then using the analog outs of those players.

How good is the DAC ???, will I be happy using it or should I look to a player or DAC and use the bypass ??? How much of a issue is it that the analog is RCA in only and no XLR ???

Thanks in advance,

Pete
ebelgee
I have been using the Bryston SP-1 for several years as my sole pre/pro. I use the SP-1 as the DAC for all of the digital sources in my system (both 2-channel and surround processing), as well as the analog preamp for my vinyl playback system (see system link for description of my system). I think the quality of the DAC is excellent -- it was a clear improvement over the DAC in my Rega Planet CD player.

The SP-1.7 is essentially the same unit as the SP-1, except for the inclusion of additional channels of surround processing, analog inputs for SACD or DVD-A, and the inclusion of Dolby Pro-Logic 2. Both the SP-1 and the 1.7 use the analog circuitry from the Bryston BP-25 preamp.

There are better stand-alone DAC units on the market (such as the Chord DAC-64), but you will have to spend a lot more money to do much better (and none come with Bryston's 20-year unconditional warranty). I cannot comment on the quality of the Krell unit you mention, siuce I have no direct experience with it. What I can say, however, is that the Bryston SP-1 and 1.7 pre/pros offer very high value / sound quality for the money.
I used to use a Rotel RCD-971 in bypass mode with my SP-1 for two channel music. I now use a very cheap Sony DVD player (approx $150) wth my SP-1.7 in digital mode with much better results. I have the RCD 971 hooked up to the SP-1.7 with analog and digital interconnects. I have tested it several times and found the sound to be more to my liking in digital mode vs bypass. In my non-expert opinion, I think the Rotel's DACS are either emphasizing the midrange, or lopping off the highs and lows, compared to the Bryston's DACs.I haven't heard an expensive CD player connected to an SP-1.7 in bypass mode, but my experience may give you some idea of the quality of the Bryston's DAC's. I don't want to detract from the SP-1.7's bypass mode. It's just that I'm happy with the DVD player. There's a Bryston discussion forum at audiocircle.com which might provide more information.
Use 'em both. I have digital out from my CDP and both analog sets of outputs hooked up. This way I have choices. Two different ICs and the inboard DAC if I choose.

I prefer analog bypass using the CDPs DACs. I guess its the tube output..? or maybe its the full analog signal path you get in bypass. Either way, all you have to do is select the input, bypass, or digital from the front of the unit or remote. The Bryston offers a ton of flexibility and sounds fantastic.

There isnt "A" bypassed input, ANY/ALL the analog inputs can be bypassed at the touch of a button. Which is great. You arent bypassed if you choose "digital," then obviously the inboard DAC is doing the decoding, hence no bypass. But the beauty is, you can have 'em all hooked up at once, and select which you want to hear.

RCA only inputs is an issue for some. Most of the time the source is close to the Pre/Pro anyway. Mine are, so its really not an issue for me, I do use XLR to the amp for the front channels.

This is a serious performing Pre/Pro and I bet your going to love it.
I use a Phillips DVD963SA as a digital source and prefer the 2 channel bypass over digital. The digital input has good detail and sounds very clean but sounds a little thin. The analog bypass gives much more "air" around the instruments. Everything seems more like real instruments in a real recording space. Instruments seem to have more "weight" with the bypass. I had just the opposite results with an AVP2 that I previously had. That sounded significantly better through the digital input.

I don't mean this as a knock on the digital input of the Bryston, I just think that the analog input is extraordinarily good. One of the great things about this preamp is you have the option for analog bypass on every input. Overall I agree that the SP1.7 is an excellent preamp, especially if you have quality analog inputs (ie vinyl).
I use the SP1.7 in 2 channel bypass mode. To me the beauty of this it allows use of your sub(s) in bypass mode. The Dac in the SP1.7 is very good compaired to others I have listened to (Arcam AV8, Mac MX132 Anthem AVM 20) to name a few. I use the AA Capitole CDP with excellent results in 2 channel bypass thru the SP1.7
Faziod, this was knew to me. I had been using the Bryston for a while and didnt even know it. Until you corrected me on this. Being the consummate skeptical, I emailed Bryston, I had a response in the typical couple of hours, on a Saturday!!! Unbelievable customer service response time, anywho. When selecting Sub output when bypassed, it is a full range signal, so you need a sub with a built Xover. Which obviously most subs do. Nonetheless I like the way Bryston was committed to the "Analog" part of the Bypass. This unit and company continue to impress me. Thanks again Faziod for the tip.

I am pretty sure the PCM D/A conversion is handled by the Motorola 56367 chip in this unit. It is SOTA for Multi-channel decoding but I think other dedicated DACs may be better at PCM. No problem though, just run Analog ICs and a digital input both. You can setup the input to "default" to the digital input(inboard DAC), Analog with DSP(outboard DAC), or bypassed(outboard DAC), then switch to whichever one you want, whenever you want at the press of a button.
Distortion Agreed 100% on Brystons customer service. I e-mailed them early on a Sunday morning and by 8:30 am I had a responce back from James Tanner. Now that is CS support.
He also sent me some hidden codes on the SP1.7s remote if your interested let me know.
Faziod, you bet I am. You can send them to my email via A'gons auto mailer. Thanks so much. James Tanner obviously stays very near a computer.
I have been using both an Sp1 and 1.7 for quite some time now with excellent results on both the passthrough and digital in. In my experience it really depends on the quality of the dac in the player. The Sp1 is used entirely in two channel mode with a Theta Miles and for the most part I prefer the Theta's DAC over the Bryston. I say "for the most part" because some recordings sound better using the Bryston's dac which seems to be a little more forgiving - which may mean a little more veiled than the Theta. At any rate you can hook both up and switch back and forth.
With the 1.7 I have a Denon 2900 hooked up and MUCH prefer the Bryston's DAC to the Denon's in two channel. I have noticed that the quality of the transport makes a much bigger difference than you might imagine. With a cheap DVD player playing as a transport through the Bryston it doesn't sound very good - particularly at the frequency extrems.
Again, just experiment and let YOUR ears be the judge.
Distortion, could you please elaborate on "Analog with DSP (outboard DAC)" part of your post. I understand "Bypassed (outboard DAC)" part.
I'm using SP-1.7 in digital mode currently, since I have TacT before Bryston and did't want to introduce extra D/A conversion (Bryston's DAC sounds better to my ears than TacT's DAC).
While we at it: Is SP-1.7 multichannel path a "true" 6- channel analog preamp?, I mean for SACD/DVD-Audio playback.
Maril, I'll do my best.

Do you mean my 11-29-03 post which says.....

"I am pretty sure the PCM D/A conversion is handled by the Motorola 56367 chip in this unit. It is SOTA for Multi-channel decoding but I think other dedicated DACs may be better at PCM. No problem though, just run Analog ICs and a digital input both. You can setup the input to "default" to the digital input(inboard DAC), Analog with DSP(outboard DAC), or bypassed(outboard DAC), then switch to whichever one you want, whenever you want at the press of a button."

When I say "PCM D/A conversion" I am talking about a digital signal. An Analog signal would have to be first converted to digital (A to D), before the DSP could process it.

It is my understanding, though I could very well be wrong, that the SP1.7 has only the 56367 Processor to concvert all incoming digital signals to analog, including PCM (two-channel 44.1khz/16bit which is the standard output from a CD player). In other words, I dont believe the SP1.7 has dedicated PCM DACs. Though an Email to James Tanner would clear this up.

I am not sure whether the 5.1 input is fully seperated from the Digital like the 2 channel bypass. At first I was assuming (dangerous indeed) that because there was Subwoofer control in 5.1 bypass that the signal must pass through the DSP engine. Thus, not "true analog." Faziod, and then James Tanner, enlightened me that indeed there was a "full analog" summed (full-range) signal output to the sub. So (assuming again), the signal path is present. Therefor it could be a "true analog" 6 channel preamp. Once again I am not sure and I bet James could clear this up right away.

I am sorry I dont believe this post was very helpful.
Thank you, Distortion. Actually, I've asked James this same question ("true analog" preamp), and at best, his answer wasn't explicitly clear, meaning, that I'm still wasn't sure, that there is a completely separate MCH preamp, analogous to BP-25-like analog 2-CH bypass. Well, I'm using it for MCH playback, even though was thinking lately about trying dedicated multichannel analog preamp, like McCormack MAP-1, McIntosh C-45, Bel Canto Pre-6 and separate HT processor, or just Dolby Digital/DTS processing of my player.
BTW, I'm very interested if anyone had a chance to compare Bryston SP-1.7 for SACD with the above mentioned analog preamps and if yes, was there an improvement, that could justify such a switch. Regards.
Faziod, I have my new to me SP 1.7 in the mail and was checking out the post here. What are the hidden codes for?? and would you be willing to share this?

Thanks,