[ahendler]

I want to add something that hasn't come up hear about R2R dacs
I have had several. The one that I have never let go is the Teredak Chamelion.
It does not have the resolution of the dacs we have been discussing but it is so
musically engaging. When I go back and listen to it I find myself just listening to cd after cd
If you want to be introduced to R2R ladder dacs this one has 16 1543 chips and as far as I know still available
with shipping for $580 directly from Teredak.com
Alan

 

[jusbe]

+1

DSD was intended to be a storage format for Sony catalogues. Further, DSD has to be converted to PCM during the mastering process in order to balance, equalize, fade, etc. Then it is converted back to DSD, therefore no DSD recording/mastering process remains as DSD from beginning to end.
There is nothing DSD does better than 24/96 PCM.
Two words: marketing spin.

And...the vast majority of music available as DSD are hi rez 'transfers' (not hi rez 'recordings') from old analog tapes who's recording equipment was only capable of capturing 60-70dB of dynamic range which requires about 10-12 bits...well below Redbook CD.

You then enter the loudness war and compression which removes any of the fidelity that's left.

Nailed it.
 
This is one of the reasons why very good Redbook CD can be more than sufficient. The fewer times a recording is interfered with/re-interpolated/converted, the better. Even 'high resolution' or extended resolution digital, recorded to CD, will likely sound fantastic and better than normal CD - and normal CD with R2R can sound very good too.

 

[daerron]

Hi guys,

Just picked up a Theta DSPro Gen III for a really good price!! The price is just too good to resist not giving it a try. Decided to go the R2R route because the current crop of sigma delta DACs just don't cut it, especially those with the ESS Sabre silicon (Ahem)

R2R became my cup of tea when I chanced upon a Naim CD5X with dual mono PCM1704 configuration and sold my Mytek 192 DSD to fund it. The Naim is just spot on in tone.

The Theta is one league higher. It has the fantastic tone expected of R2R, and with bass texture, punch and solidity on an unprecedented level. The PCM1704 implementations I've heard, though spot on in tone, sounds very slightly vague in bass. I'm starting to suspect that the PCM63P-K may be the best DAC chip in existence, superior to the PCM1704 in pure sound quality alone, if not for the fact that the 1704 can handle a 24 bit stream.

My rig

Internal shots of the Theta. Just look at the quality of engineering.



The two PCM63P-K's from Burr Brown Japan

 
I suspect you might have got conned with that, looks like a single ended Theta, it should be balanced. My Theta DS Pro Gen 3 looks a lot different inside than yours does. I have two analogue output boards with four PCM63s and balanced outputs.
 
Beautiful headphone setup though, looks very nice with the La Figaro 339!

 

[MazzStrikers]

I suspect you might have got conned with that, looks like a single ended Theta, it should be balanced. My Theta DS Pro Gen 3 looks a lot different inside than yours does. I have two analogue output boards with four PCM63s and balanced outputs.

Enjoy your Theta!! Nope when the owner advertised it he told me it was single ended only, and then I went to do a Google search. The DSPro Gen III comes in single ended and balanced versions, the single ended having two boards while the balanced has four. Different price points, identical sound so it depends on whether you need the balanced connectivity. I got it for a darn good price though! If I am not mistaken the DSPro Gen III has an option to add ST fiber input option (it's a proprietary optic fibre way superior to Toslink) too, so Theta has all bases covered.

The DSPro Gen V, which is the successor to the Gen III (somehow Theta didn't produce a Gen IV maybe due to the negative connotation in some markets), is only available in a balanced config with four PCM63-K boards. If I'm not mistaken, the analogue boards are identical to the Gen III, but the Motorola DSP with custom firmware has been upgraded. Would love to get the chance to hear the Gen V, but prices have skyrocketed so bad as people have already recognised how good it is even in light of the modern DACs. Cheers!

 

[daerron]

   
Quote:

Enjoy your Theta!! Nope when the owner advertised it he told me it was single ended only, and then I went to do a Google search. The DSPro Gen III comes in single ended and balanced versions, the single ended having two boards while the balanced has four. Different price points, identical sound so it depends on whether you need the balanced connectivity. I got it for a darn good price though! If I am not mistaken the DSPro Gen III has an option to add ST fiber input option (it's a proprietary optic fibre way superior to Toslink) too, so Theta has all bases covered.

The DSPro Gen V, which is the successor to the Gen III (somehow Theta didn't produce a Gen IV maybe due to the negative connotation in some markets), is only available in a balanced config with four PCM63-K boards. If I'm not mistaken, the analogue boards are identical to the Gen III, but the Motorola DSP with custom firmware has been upgraded. Would love to get the chance to hear the Gen V, but prices have skyrocketed so bad as people have already recognised how good it is even in light of the modern DACs. Cheers!

 
Interesting, I didn't know they made single ended versions of the DS Pro Gen 3 series. I definitely notice the processor boards are the same and you can see there aren't any cut outs for balanced outputs. Here is what mine looks like in comparison. The caps on mine look a bit strange as it has been recapped recently. Mine also has the fiber module, but not getting my hopes up of getting a matching transport yet, but the Theta disc transport is one of the best I've heard so far!
 

 

[doctorjazz]

No DSD. DSD and Delta-Sigma pretty much go hand in hand and R2R will not play a DSD signal unless converted to PCM first.

IMO, it's a compromise from a software and hardware side where audio fidelity, timbre, layers, and realism is concerned. Knowing now the history where DSD came from, and how it is decoded to an analogue signal, I'm convinced I'll never, EVER, seek out DSD for its phantom superiority. Knowledge is power.

There are gobs of info on the subject and the more I read - and listen - the more I'm convinced that R2R is the best way to go.

+1

DSD was intended to be a storage format for Sony catalogues. Further, DSD has to be converted to PCM during the mastering process in order to balance, equalize, fade, etc. Then it is converted back to DSD, therefore no DSD recording/mastering process remains as DSD from beginning to end.
There is nothing DSD does better than 24/96 PCM.
Two words: marketing spin.

And...the vast majority of music available as DSD are hi rez 'transfers' (not hi rez 'recordings') from old analog tapes who's recording equipment was only capable of capturing 60-70dB of dynamic range which requires about 10-12 bits...well below Redbook CD.

You then enter the loudness war and compression which removes any of the fidelity that's left.

By this logic, R2R digital should KILL vinyl playback. Sorry, but to my ears, my R2R gear I had (Adcom, Proceed, Museatex Bidat) never came close to my Linn LP12 turntable in my set up. Did allow me to listen to and enjoy the shiny silver discs, but I could play both for non audiophile friends and surprise them with how much better the LP12 sounded (remember, this was way before the vinyl resurgence, "perfect sound forever" days).

 

[x RELIC x]

By this logic, R2R digital should KILL vinyl playback. Sorry, but to my ears, my R2R gear I had (Adcom, Proceed, Museatex Bidat) never came close to my Linn LP12 turntable in my set up. Did allow me to listen to and enjoy the shiny silver discs, but I could play both for non audiophile friends and surprise them with how much better the LP12 sounded (remember, this was way before the vinyl resurgence, "perfect sound forever" days).

Not what I was saying at all. I love vinyl. I was comparing conversion techniques from digital to analogue. Different conversation friend. :wink_face:

 

[Cardiiiii]

Is the NAD M51 considered an R2R DAC?

 

[doctorjazz]

Point taken...I was responding more to vlach, who quoted you. On vacation and mostly posting with my phone, which makes editing a pia. The whole quote also gives the context. I listen mostly to some version of digital, much easier, moves with me. I recently set up my Linn into Project tubed phono preamp, MicroZOTL2, Norne Zoetic cable, HE-1000. MAN, did that sound AMAZING. Not great ergonomically, though. The way the room/system is set up, 1 good sneeze and I'd have sent the MicroZOTL flying! May need a Norne extension...

 

[MazzStrikers]

Interesting, I didn't know they made single ended versions of the DS Pro Gen 3 series. I definitely notice the processor boards are the same and you can see there aren't any cut outs for balanced outputs. Here is what mine looks like in comparison. The caps on mine look a bit strange as it has been recapped recently. Mine also has the fiber module, but not getting my hopes up of getting a matching transport yet, but the Theta disc transport is one of the best I've heard so far!

Yup the fiber is good stuff if you can source the matching transport Wow those caps! I'd love to have mine undergo a little refresh including getting the stock power cord replaced with some good Furutech cord and plug, but it just sounds so good now that I'm afraid I'll tilt the perfect balance! It's not too often in this hobby you find a piece of gear that you can confidently say that it is not necessary to add spikes/isolation devices, expensive power cords, fuses etc because it just sounds right.

As for transport, I'm trying to desperately find a Theta one as well though it is almost impossible here in Singapore. Not to mention, the eBay sets are all 110/120V mains so oh well... Then again, locally there is a pre-owned Levinson No.37 (even sicker transport than the Theta) that is still within my reach, though as with all transports of this age (Theta included), spare parts are close to non-existent. Decisions!!

 

[daerron]

By this logic, R2R digital should KILL vinyl playback. Sorry, but to my ears, my R2R gear I had (Adcom, Proceed, Museatex Bidat) never came close to my Linn LP12 turntable in my set up. Did allow me to listen to and enjoy the shiny silver discs, but I could play both for non audiophile friends and surprise them with how much better the LP12 sounded (remember, this was way before the vinyl resurgence, "perfect sound forever" days).

 
I have to say with the Theta it would be a tough choice for me whether to go back to vinyl (I had a good Thorens TD-2001), not sure how good those converters were that you are referring to? I agree a well set up turntable is going to be good, but vinyl has its own set of issues, including the media and that modern vinyl records are cut from CD masters, but they do manage to avoid the heavy compression.
 
Entry to mid level level turntables do sound better to me than their equivalent DACs. Keen to hear whether new generation multibit DACs like the Schiit Audio Gungnir MB manage to change people's perceptions and the balance in favour of vinyl. I certainly enjoy my Theta a lot in combination with Tidal Hi-Fi streaming.

 

[MazzStrikers]

Is the NAD M51 considered an R2R DAC?

Quoted from the Stereophile review of the M51 "The NAD resamples everything you throw in its direction and converts it to a pulse-width-modulation (PWM) signal, the native format for DSD, at a sampling rate of 844kHz, all controlled by a clock running at 108MHz."

Basically it is uses the sigma delta conversion technique, the only difference compared to the traditional SD DACs is that it upsamples and converts the incoming PCM bitstream to one similar to DSD before sending the bitstream for conversion. If I'm not mistaken, this will yield similar results to having a Mac software convert the PCM bitstream to DSD and feeding a DSD compatible DAC in real time. Also, NAD has tried to keep the DAC chip or FPGA responsible for the SD decoding under wraps, and is highly likely to be proprietary hence thumbs up to them for not trying to buy a DAC chip off the shelf and it shows. I've heard an M51 and for the price they command nowdays I'd take it over plenty of the Sabre implementations. For this reason Chord DACs have gained plenty of popularity as they are SD implementations, just that Chord has developed proprietary code programmed into the FPGA to do the decoding duties, hence sounding quite different.

By definition, R2R decoding has to be done by using discrete resistors to generate the many different output voltages required to produce the analogue signal hence, the more resistors are involved, the smaller the increment of voltages can be generated, the higher the resolution of the DAC. Think of it as a giant potential divider we learn in Physics class. Hence we hardly see R2R DACs capable of the full 24 bits of true resolution because it would mean an insane number of resistors. The venerable PCM1704, contrary to popular belief, only has 20 bits of resolution. It is just able to accept a 24 bit stream. I'm not too sure but I think the expensive MSB DACs, TotalDacs etc are the only few DACs that can do higher than a proper 24 bit resolution, correct me if I'm wrong.

 

[doctorjazz]

By this logic, R2R digital should KILL vinyl playback. Sorry, but to my ears, my R2R gear I had (Adcom, Proceed, Museatex Bidat) never came close to my Linn LP12 turntable in my set up. Did allow me to listen to and enjoy the shiny silver discs, but I could play both for non audiophile friends and surprise them with how much better the LP12 sounded (remember, this was way before the vinyl resurgence, "perfect sound forever" days).

I have to say with the Theta it would be a tough choice for me whether to go back to vinyl (I had a good Thorens TD-2001), not sure how good those converters were that you are referring to? I agree a well set up turntable is going to be good, but vinyl has its own set of issues, including the media and that modern vinyl records are cut from CD masters, but they do manage to avoid the heavy compression.

Entry to mid level level turntables do sound better to me than their equivalent DACs. Keen to hear whether new generation multibit DACs like the Schiit Audio Gungnir MB manage to change people's perceptions and the balance in favour of vinyl. I certainly enjoy my Theta a lot in combination with Tidal Hi-Fi streaming.

It's a bit of an unfair comparison...the Linn LP12 is considered TOTL, though there are certainly more expensive tables or there. The Adcom was budget hi-fi, but still seems to be highly regarded in these parts. Proceed was a Mark Levinson spin off, less expensive than the true ML gear. And the Bidat was mid 80s high end, and still has people who search it out (I mentioned I looked into the Bidat people refurbishing my unit, at least one former Museatex person who has assumed the mantle, but not sure I want to sink $700 into it when I have other gear...I believe it was $1500-2000 range when new, which wasn't inexpensive, but it included a separate transport, which has died. I don't believe it was R2R, though I'm not sure. Think it was one of the earliest 1-bit dacs with proprietary software). The Linn would still be higher end, I believe. The difference was dramatic, though.

 

[Wildcatsare1]

It's a bit of an unfair comparison...the Linn LP12 is considered TOTL, though there are certainly more expensive tables or there. The Adcom was budget hi-fi, but still seems to be highly regarded in these parts. Proceed was a Mark Levinson spin off, less expensive than the true ML gear. And the Bidat was mid 80s high end, and still has people who search it out (I mentioned I looked into the Bidat people refurbishing my unit, at least one former Museatex person who has assumed the mantle, but not sure I want to sink $700 into it when I have other gear...I believe it was $1500-2000 range when new, which wasn't inexpensive, but it included a separate transport, which has died. I don't believe it was R2R, though I'm not sure. Think it was one of the earliest 1-bit dacs with proprietary software). The Linn would still be higher end, I believe. The difference was dramatic, though.

It is going to very difficult for a digital rig to beat a top flight turntable like the Linn. In convenience yes, SQ, probably not. Love my R2R, and it is actually close, but vinyl just has that warm, rich tone.

 

[doctorjazz]

Bought a used Theta Data (2, I believe), put it in my basement storage, wouldn't read many discs, was frustrating. Don't know if mine was just a lemon, it had problems with more modern discs, but didn't work out.