Looking to improve CD playback

Ok, currently I am using a Arcam DV137 DVD player as a transport into a Bryston BDA-1 DAC via SPDIF coax.

I am considering the purchase of the Mirror Audio Tubador III DAC and the NuPrime CDT-8 dedicated CD transport. I have been keeping up with the threads regarding the Tubador DAC.

The Tubador can be purchased with I2S output via HDMI I believe this is an additional $400 cost to a $1500 DAC. The CDT-8 has I2S output via HDMI. I believe the general consensus is that I2S is the best interlink between digital components however have no personal experience using I2S. I know there are different connection types other than HDMI for I2S however lack knowledge about the benefits of any of the different types. I am looking for feedback on this DAC/Transport combination regarding benefits of the I2S connection provided.  

Obviously, I have options regarding timing of purchases. I could buy a the transport 1st and use SPDIF into my BDA-1 to explore the benefits of the CD only transport over my DVD player. I could purchase the Tubador without I2S at a later date. The Tubador could be updated with I2S at a later date if desired.  There are other transports available.

Any thoughts on this rather open ended question?  

I2S output via HDMI is the I2S format using an HDMI cable as opposed to a dedicated I2S cable. Same quality signal, some of the pins in the HDMI cable aren’t used. This is different than the HDMI format.
I2S is superior IME, the reason may be that power is separated from data. I had a PS Audio setup and preferred I2S.

Thanks for the quick response lowrider. Yes, I figured that given HDMI was designed to transfer audio and video that all cables within were not needed. This would require that the same pins in transport and DAC be used for the digital data. I wonder how standard is this? I agree that there are likely benefits from separating power from audio data, as with USB, however there must be benefits to the removal of SPDIF/I2S conversion at the DAC. Not sure how that works from the transport. As I understand it, I2S is the way a digital signal is handled within the DAC process, 

I am one who tries to gain knowledge regarding the 'objective' aspects of putting together an audio system understanding full well that one must ultimately make and adhere to 'subjective' decisions toward that goal. Given that, I am motivated by the thinking that use of a NOS R2R DAC with CD playback might prove best and wanting a tube output stage in the DAC. Just wondering how much 'icing on the cake' is provided by I2S.     
I recently acquired an outboard DAC to use with my Arcam DV 139. I bought a Benchmark DAC 1 Pre for $500, and it just sounds killer.

It's all the DAC I'll ever need. Like you, I was wanting I2S, but wanting to spend less than it would take to get one. I'm very happy with the DAC 1.

Best of luck, regards,
i2s over HDMI is not an industry standard.  There are several vendors that use HDMI cable to transfer i2s, but that doesn't mean that any transport can be connected to any DAC using HDMI/i2s. 

For example, both Wyred4Sound and PS Audio have solutions that transfer i2s over an HDMI cable.  However, the pin configurations are completely different, which means that you cannot just connect a PS Audio transport to a Wyred4Sound DAC using i2 over HDMI.

Some companies also transfer i2s over an RJ45 cable (same as ethernet).  Their pin configurations may be different as well.

If you're really interested, I would check with the vendors on those products and ask them about their i2s/HDMI pin configurations to see if they are compatible.

You can always upgrade to different digital COAX cables and that will have a significant improvement as well.
mesch OP
I am motivated by the thinking that use of a NOS R2R DAC with CD playback might prove best

You are correct in thinking this, try to listen to an R2R Holo Spring Level2 or 3 dac, you can switch on the fly between it’s NOS and OS modes. (And it does DSD if your into that stuff.)

And R2R Ladder Multibit is the best way to convert 16/44 24/96 or DXD all PCM and CD.

Cheers George
Isolate the CD player. Level the CD while spinning. Stabilize the CD itself. Get rid of scattered laser light. You’ll be light years ahead of everybody on your block.
Dan, I am sure your Arcam/DAC combination sounds great. As does my Arcam/DAC. I am just looking to maximize what I am getting from my CD collection. Also thinking now is the time to replace the BDA-1 while it will still provide me ~$700 on the used market, as I believe it remains a very good DAC. It just might be that I reconsider the I2S connection. 

Auxinput, I was concerned about there not being a standard for the HDMI I2S connection. I will consult with vendors regarding pin use. Given that the I2S input and other upgrades can be installed at a later date by Mirror Audio I am considering the purchase of the basic unit 1st and make decisions on upgrades after getting accustomed to the new DAC. It may be possible that Mirror Audio can configure the pin output to compliment a transport of choice. I will get to an understanding of this prior to making a purchase. Thanks!

George, Thanks for your support for my 'subjective' approach. Also the Holo Spring DACs are of interest to me as I have read reviews. Thinking the Tubador may better fit my budget. I am pretty sold on the R2R Multibit approach. Also looking to add tubes to the output stage which will drive my tube preamp.

Geoffkait, I will do my best to isolate the transport with consideration of routing internally generated vibrations and shielding from external ones.
I have a BDA-1, and it is a fine DAC (I now have mine in my second system).  I also have a Bryston BCD-1 CD player.  Some years ago before I got into streaming, at the same time that I auditioned the BCD-1, I also auditioned the BDA-1.  Both at the dealer and and with a borrowed BDA-1, I experimented with a number of  lesser CD players and DVD players, including my own Denon 2910 DVD/SACD universal player hooked up to the BDA-1. It was no contest, even thought the BDA-1 was the technically superior DAC to the similar DAC built into the BCD-1, in terms of SQ, the BCD-1 just simply outperformed any of the combos I compared it to.  I came into the shop thinking about buying a good DAC, but wound up buying the BCD-1 instead.  When it came to spinning plain vanilla Redbook CD's the BCD-1 with it's rock solid Redbook CD only transport was the clear winner.  So the transport really matters.  A couple years later after Bluesound integrated streaming from Tidal I picked up both an original Bluesound Node and a BDA-1 to go with it.  It was and still is a very good combo, but couldn't quite match the BCD-1.  It was only after I started using a Melco N1A as my NAS (effectively as my CD transport) that I was able to approach the BCD-1 level of performance.   
Jazzman, yes the transport matters. I probably should go that route 1st. Always a debate. I am going to take my time with this.

Given the quality of the BDA-1, I could purchase a transport 1st.
Then swap out the DAC later.

Given I have the DV137 I could purchase the DAC 1st and purchase transport later.

Seems your experience would suggest the transport should be 1st.

I'm just saying not to underestimate the role of the transport.
I also like the idea of controlling your variables and changing only one variable at a time. I know from experience just how good the BDA-1 is.  My suspicion is that when it comes to spinning discs, that your transport is currently the weaker link in your chain.  All things being equal,  DVD transports tend to introduce more jitter than dedicated Redbook CD transports. That is why so many high-end players are limited to doing Redbook CD only.  In my personal experience, the uptick in SQ feeding the BDA-1 from the BCD-1 was no where near as great as the SQ differential the BCD-1by itself had over the Denon 2910 / BDA-1 combo.
Jazzman, I very much appreciate your encouragement to not underestimate the role of transport. It is most likely that my DVD player used as transport is the weakest link for Cd playback, not the BDA-1. Thus, I am thinking towards the purchase of a CD only transport prior to purchasing a new DAC.

The question then becomes 'which one'? 
I have a Cambridge CXC transport which works smoothly and quietly.I haven't compared it to another though so that may not be helpful at all:)It only has one coax input.The only thing that's not good about it is the remote.It's meant to operate several other Cambridge products so the buttons for the transport are all down at the bottom in a small section.
I'm still loving the Tubadour after almost six months with it.It's very sensitive/responsive to tube and cable changes.It definitely sounds it's best with a good shielded pc.The other day I pulled out some old cables from my accessory box and swapped in a Gabriel Gold Revelation ic cable for the digital cable.It shouldn't have worked well at all but holy cow!Everything just came to life is the only way I can describe it.Crystal clear and "real".
Possibly one of the other types of connections would more easily transmit this quality of sound?I have no experience with them though.
Heck, I didn’t think the sound direct from those Arcam players was too shabby.
Jtcf, thanks for your thoughts on the CXC and the Tubadour. Wether I purchase a transport 1st or not I am truly interested in the Tubadour DAC. As of now it seems to be what I am looking for. I do have to admit that I would be purchasing it 'space unheard'.  

Unsound, I do consider my Arcam player to be very good. Just can't help thinking that a dedicated CD transport wouldn't be the best approach. I am amazed at what I get from the Arcam via DVD playback from my 2 channel system. 

nothing at all shabby about the sound direct from those Arcam players, or even from my old Denon 2910 ... but it's all relative ... and as with everything in this wonderful and sometimes crazy hobby ... everything matters as you move up the SQ food/supply chain.
It's hard to decide what to do first when we have to shop on the internet.I feel your pain:)Best of luck to you!
Look into the Sparkler Audio S503 "Spiral" CD player. It can be purchased as a transport or a complete 1 box solution. I have owned mine since early this year and like the naturalness of the sound. I have owned a number of 1 box and transport/dac combos. The last combo, highly modified 47 Labs Flatfish and ANK 2.1b Sig Dac was north of $8k. The $1700.00 S503 is close and IMHO an outstanding solution for redbook playback. Here is a review from John Richardson of Part-time Audiophile done back in August of this year...

Bought mine here...http://charneyaudio.com/sparkler.html
Hope you find a satisfying set up,

Nobody has figured out how to stop scattered laser light from entering the photodetector. Actually, it’s worse than that. Nobody is aware the scattered light is even a problem. Nor has anyone figured out how to completely stabilize the CD 💿 whilst spinning. Not counting your friend and humble narrator, of course. 🤗 Yes, I know what you’re thinking, doesn’t the Reed Solomon Error Correction fix all of that stuff?

Anyone in the DC metro area who wants to hear just what is possible with CD playback check out BWS Consulting.
Rodge, Thanks for the heads-up on the Sparkler. They have two options for player/transport, the 503 and the 507. I will keep Sparkler on my radar. Interested in the transport version. I remain inyerested in the Tubadour for it tube output stage.
Hope to hear additional thoughts from those experienced with/ interested in, my quest. Leaving for a backcountry excursion with my son. Will get back to all after the 16th. Thanks!
The best transport is no transport.  I suggest a different route, but it may take some work.  Rip your CDs.  Ultimately, better SQ and unbelievable convenience.
Get a nice DVD burner. Cheap and there's nothing better for ripping CDs. ;)