[James Tanner]

I've ripped my cds to an external hd in apple lossless using itunes.  If I take that external hd and attach it to the bdp-1, what would navigation of my collection look like?  Would I have cover art?  Could I browse by genre (or other info that itunes stores)?

If I get a Mac Mini with a large enough internal hd, could I connect that as my source for the bdp-1?

Thanks for any guidance.

Hi drewant,


The navigation would be determined by the Music Player you used with the external harddrive.  There are a number of Linux music players available.  I am not that familiar with iTunes album art because I use dbpower amp to rip my cds and the album art is always attached.

NO - sorry you can not connect the mini-mac to the BDP-1 - they are both 'hosts'.  You must use a USB harddrive or thumbdrive.

james

[James Tanner]

Hi Folks,

I am been trying to put together a discription of how the digital data gets transfered in the many USB DAC's out there and Ethernet streaming.

A big thanks to JIM for putting this together for me.


"USB DACs use what is called ‘isochronous transfers” to receive data from the host, typically your computer.   With all isochronous methods, a constant stream of data needs to arrive in fixed intervals to the DAC without starvation.  USB audio devices will receive an audio stream that contains a millisecond of data one thousand times a second.  Any failure to deliver the data accurately will result in dropouts, corrupt data or substandard audio synchronization. 

Almost every digital interface found on a computer follows the OSI Model which defines specialized tasks required to transfer data into seven layers.  These layers can employ various techniques to detect, correct or resend the data for a reliable transfer.   Sadly, isochronous transfers cannot take advantage of the features that detect uncorrectable errors and requests a retry.  It’s up to the design of the USB DAC to either allow or drop the flawed packet.

To further complicate this, USB DACs can use one of three modes for clock recovery with isochronous transfers: synchronous, asynchronous or adaptive: 

•Synchronous solutions will align the clock from either a beacon sent every millisecond or draw on source-synchronous techniques from the data packets sent on those fixed intervals.   Hubs and This is a great example of how clock jitter can be additive even if the DAC uses resynchronization techniques.

•Asynchronous solutions will perform clock and data recovery using an external clock oscillator as data is expected to arrive within a given duration.  The challenge here is to minimize jitter per frequency 44.1, 48, 88.2, 96, 176.4 and 192 kHz. 

•Adaptive solutions will convert the data to match that of an external clock oscillator to a fixed clock frequency used by the internal DAC.  The obstacle with this method is converting music from 44.1, 48, 88.2, 96, 176.4 kHz to 192 kHz (as an example) without losing any information about the waveform.  The advantage to be had is playing a 192 kHz source on a USB DAC tuned for a ‘natural frequency’ of 192 kHz. This setup has the potential to outperform the other two with less cost if the user can play files that match the natural frequency of the USB DAC.


Three common questions one would have if using a USB DAC are:

•Since there is no data recovery, how reliable is the connection between the computer and the USB DAC such that data can arrive safely without electrical noise or bandwidth issues?   (same question for every streaming solution)

•How accurate is the clock-recovery mechanism employed in the USB DAC such that it can produce the lowest possible jitter for a high-quality playback?   (same question for every digital product targeting high-resolution audio)

•Is placing a computer next to the stereo causing additional electrical noise to bleed into the other components?   Should the computer be on an isolated circuit from the stereo?  Will there be any audible noises coming from the computer that will lessen the experience? (same question for every digital product)

From a user’s point of view it’s rather simple to add a USB DAC between a computer and their stereo to get very good sound.  The user can select any digital music player application and operating system of their choice for playback and even download high resolution music. The user also has full control on managing the data, applications running and resources attached to it.   And as long as you don’t mind having a dedicated computer next to your stereo and one can overlook any audible noise it produces, this is a great high-resolution solution with a tremendous amount of flexibility but with the known drawbacks with USB isochronous transfers. 

Note: Firewire DACs also employ isochronous techniques very similar to USB DACs.

Streaming audio over Ethernet will have all the same issues as a USB DACs but with the added complexity of the network.  There are several different solutions for stream audio and they all are built on top of or is a variant of what is called User Datagram Protocol (UDP).  Without going into the details of these solutions, they simply allow transmission without concern of safe arrival."

[werd]

Werd, it's not a DAC.... if anything you can related the BDP to a CD transport.  The NAS feature is already there and requires no change for Bryston other than to market it as a feature if you connect up drives to it.  If anything they could make a HDD enclosure with a reasonable power supply.

I know its not a dac. Since it has to be hooked up to a dac i was just trying to make it seem more like a high performance audio player than a something that resembles a computer.

Like you said Skunark it is a transport. My view is: what ever usb device i use it has to be the starting gate in my system. That is what defines the meaning for me being a transport-starting gate. Is this piece the starting gate?  The first thing i learned with the bdp and hooking up hard drives is - it may not be. The more you start interfacing it with your computer the more the computer starts becoming the transport (bad bad bad --- very bad). I had such a bad experience with a 12 volt power Omega HD that it drove this point home in spades. To noisey to ignore.

The BDP is a very sensitive audio component. You need that to get the 96khz and 192khz through. I have heard usb devices that claim to be hi rez and really don't sound any different than its  regular redbook counterpart in hirez. I own a creative 2496 adapter right now that sounds worse in 96khz than it does on redbook from my cd transport. Only because its not built to generate a decent hirez signal. You start throwing HD's in the bdp1 and more network capability you guys have to ask, how much more do you want to pay to ensure that all the added interface circuitry can guarantee a good transport?

The way the bdp is now, the computer is just there to send control data via ethernet. Thank god for that. I am sure there are employable techniques in interfacing your computer but you really need to know what you are doing. Not me !!!!! and i am sure a great many of Bryston's customers are not great at setting up silent networks either.

Here is a good example of what i respect about the BDP. Before i bought my 14B i owned the BCD/BDA combo. What i notice was how close the bcd sounded on its own when compared to using it as a transport into the bda. Almost identical. Some slight differences but so close you could easily call it the same. When i sold my bcd to make funds for my 14B i started using my old modded Sony S7700 transport again. Differences in transports is significant, I lost a lot of the Bryston front end sound. Its sounds good but very different than the bcd/bda combo. With the BDP i got the bcd sound back. Now everytime you start employing more capability into the bdp the more it starts slipping into a more generic sounding component.

How much do you want to pay to keep the Bryston front-end sound with no noise and more computer type interfacing.  Its going to be costly. No thanks $2200 is enough.

[Napalm]

I own a creative 2496 adapter right now that sounds worse in 96khz than it does on redbook from my cd transport. Only because its not built to generate a decent hirez signal.

This one Werd?



 

It would be so easy for me to dismiss it as a POS and  at you for ever buying such.

Instead I will explain you what went wrong.

1) When you set it at 96Khz, there will be upsampling, and this will be performed by *Windows* according to an unspecified algorithm that doesn't sound stellar at all.

2) That box is "adaptive USB" i.e. it converts in real-time and largely depends on the audio stream to be accurately timed and error free. Which won't happen with most general-use computers.

P.S. The BDA is the same. That's why it sounded different with the different "transports" you used. And that's why you'd want the BDP in order to extract maximum performance.

P.P.S. All this would be fixed once for all by including a DAC inside the BDP; or having a BDA-2 with async USB.

P.P.P.S. It won't happen as it seems that James wants to sell 2 boxes @ $2000 each, which probably produce better profit than 1 box @ $3000.

P.P.P.P.S. Connect the SB box to a BDP and you'll be surprised.

Nap.

[terrycym]

Hi Terry

What cd ripper are you using?

If you use dBpoweramp once you put the cd in your drive and it will scan it, then it will check the internet for meta, the album art should appear then, however you have options to check the internet for better pics, or if no album art appears you can google the album and try to find the album art, save the pic to a file, then add it or scan the cover art then add it.

You then can check the meta to see if it matches the CD info. I try to check both of these items and try to get the best match before I rip the cd.


Have fun and good luck

Larry

Hi Larry,

I'm not ripping CDs, I've purchased hi-res music online.
My question concerned where the artwork should be

Terry

[werd]

This one Werd?



 

It would be so easy for me to dismiss it as a POS and  at you for ever buying such.

Instead I will explain you what went wrong.

1) When you set it at 96Khz, there will be upsampling, and this will be performed by *Windows* according to an unspecified algorithm that doesn't sound stellar at all.

2) That box is "adaptive USB" i.e. it converts in real-time and largely depends on the audio stream to be accurately timed and error free. Which won't happen with most general-use computers.

P.S. The BDA is the same. That's why it sounded different with the different "transports" you used. And that's why you'd want the BDP in order to extract maximum performance.

P.P.S. All this would be fixed once for all by including a DAC inside the BDP; or having a BDA-2 with async USB.

P.P.P.S. It won't happen as it seems that James wants to sell 2 boxes @ $2000 each, which probably produce better profit than 1 box @ $3000.

P.P.P.P.S. Connect the SB box to a BDP and you'll be surprised.

Nap.

No mine is way older than that and you have to install drivers for it. Go back to 2003. I don't even think the usb input is 2.0   

[nikon]

Hi James

Would you have an approximate date when the BDA-1 will be available with the new cosmetics without placing a special order

[James Tanner]

Hi James

Would you have an approximate date when the BDA-1 will be available with the new cosmetics without placing a special order

This month but I would still make sure the dealer says NEW BUTTONS on BDA-1.

james

[skunark]

No mine is way older than that and you have to install drivers for it. Go back to 2003. I don't even think the usb input is 2.0   

Oh god not the creative drivers...

Nap I wouldn't really call the BDA "adaptive", it's not converting 44.1 kHz to 192 kHz, but to 176.4 kHz nor is it converting 48 kHz to 176.4 kHz but to 192 kHz.  Converting from 44.1 kHz to 176.4 is rather simple compared if the conversion was to 192 kHz.  Also, you can disable the upsampling in the BDA.  The fact that the BDA re-clocks does make it more 'adaptive' like, but adaptive solutions only have one natural frequency like that creative PITA.

I will have to congratulate Werd though for owning up to mistakes on his hardware purchases.  So creative, omega, anything else you need to take to your confessional?

Nap, why do you keep on about USB DACs?  It's the last solution I want to use.

[Napalm]

1. Nap I wouldn't really call the BDA "adaptive",

2. Nap, why do you keep on about USB DACs?  It's the last solution I want to use.

1. Forget upsampling, it's "adaptive" as it syncs to the incoming data rate via PLL loop. It doesn't really reclock to an internal, fixed, high precision clock. So it "adapts" the clock to whatever comes in.

2. An "async" USB DAC would be the next best thing to the BDAP-1 (BDP with internal DAC). I'm not interested in anything going through S/PDIF.

Nap.

[werd]

1. Forget upsampling, it's "adaptive" as it syncs to the incoming data rate via PLL loop. It doesn't really reclock to an internal, fixed, high precision clock. So it "adapts" the clock to whatever comes in.

2. An "async" USB DAC would be the next best thing to the BDAP-1 (BDP with internal DAC). I'm not interested in anything going through S/PDIF.

Nap.

Me like ...uhg..... sampling up .... off. Sounds good madonna play. me like also.... bda sample up...uhg..... on. play 96khz hi reez.... 192khz sound light beep on....



 

[Napalm]

Me like ...uhg..... sampling up .... off. Sounds good madonna play. me like also.... bda sample up...uhg..... on. play 96khz hi reez.... 192khz sound light beep on....

Werd, you sound like last night you had too much pussy after too much booze....



nap. 

[skunark]

1. Forget upsampling, it's "adaptive" as it syncs to the incoming data rate via PLL loop. It doesn't really reclock to an internal, fixed, high precision clock. So it "adapts" the clock to whatever comes in.

2. An "async" USB DAC would be the next best thing to the BDAP-1 (BDP with internal DAC). I'm not interested in anything going through S/PDIF.

Nap.

USB DAC isn't the next best thing to a BDA, it's a small to huge step backwards based on your computer environment.   The next best thing would be to use a CD transport.    

To improve on the BDA and BDP connection would be to push for i2s instead of SPDIF.   This is an option to the DAC in the BDA and is probably on the soundcard chip that the BDP uses.  I'm guessing you already know this with your push to combine the BDA and BDP.        When SPDIF has a clock alignment issue it's rather minimal and could be calculated by the quality of the clock oscillators in BDP and BDA.  USB DAC, there are other factors at play besides the clock-recovery and it's a difference of losing one cycle of data versus one milisecond of data. 

Perhaps I misread the BDA literature, but it does reclock.   Asynchronous USB DACs could also reclock as it's typically just a feature of the DAC, but hopefully they do use i2s between the USB audio device chip and the DAC.
Jim

[James Tanner]

^^^^^^^^^^^^^^^^^

YES we do use i2s between the USB audio device chip and the DAC

james

[Napalm]

^^^^^^^^^^^^^^^^^

YES we do use i2s between the USB audio device chip and the DAC

james

But not between the BDP and the BDA....

[Napalm]

USB DAC isn't the next best thing to a BDA, it's a small to huge step backwards based on your computer environment.   The next best thing would be to use a CD transport.    

C'mon. Wasn't this an exercise in avoiding those plastic discs? otherwise you can just get the BCD-1 and forgetaboutthewholedacthing.

Nap.

[pimandro]

james, using Bryston maxi, there's a way to turn on Shuffle Songs? thanks

[James Tanner]

james, using Bryston maxi, there's a way to turn on Shuffle Songs? thanks

Hi primandro,

No I am sorry if you want that feature you would have to use one of the other Linux music players - Minion, MPod, Gnome.

james

[pimandro]

Thanks for the quick response.
I have tried all the systems to control the bdp1 with both PC and ipod with IPAD, what I like best 'is Brystonmaxi with IPAD, with minor improvements that I wrote some post above would be perfect.
Last thing, is theoretically a better self-powered external HD or external HD 2.5 "which is powered directly via USB?
Thanks

[skunark]

^^^^^^^^^^^^^^^^^

YES we do use i2s between the USB audio device chip and the DAC

james

James,

I did side-step the topic a bit but if i2s was used between BDP and BDA, this would eliminate any drawback that SPDIF might have even if you used a AES cable. (and might shut NAP up a little)

A little more off topic, does the BDP include the linux usb audio drivers?   One could use the BDP as device to compare USB DACs and SPDIF DACs.