Sechtdamon

Continuation of R2R DAC Discussion From Stax Thread

136 posts in this topic

We talked a lot about R2R dacs on Stax thread because of some bullshit design choices, And given the attention of the R2R, especially discrete dacs, I wanted to post all the findings in this thread.

Discrete modules I found to play with:

 Transient Modules (the dac modules of 2nd and 3rd gen Metrum dacs) and Diy parts based on it (most of the parts they are selling as oem but diy parts are also avaliable):

http://www.transient-audio.nl/    all parts can be found under this website

http://www.transient-audio.nl/Ordering.html    this is how to order guide

 

  Soekris Modules (there are two modules avaliable on each segment [oem and diy line], the differences between them are resistors which used on them):

Diy type(195-295 Dollars) :

http://soekris.com/products/audio-products/dam1021.html

Oem type(260-370 Dollars) :

http://soekris.eu/shop/oem_line_dam1121_en/

 

  Hibiki Discrete R2R module (I do not have any Info on it)

290 Dollars on taobao :

https://world.taobao.com/item/525195615222.htm?fromSite=main&spm=a312a.7700824.w4004-12659368213.2.4SmcUz

Between 202 - 754 Dollars (incl shipping) on this website, there are 3 versions of it and i do not know the difference between them or if expensive ones are finished producs rather than modules) This one says aero edition but i did not see any differences between the modules:

http://www.buyitmao.com/products/532950776394

 

Relatively Cheap Finished Products compared to well known abominations, based on discrete R2R modules:

 

Soekris Dac 1101(based on old 1101 module I suppose, relatively cheaper than others, 650 Dollars):

http://soekris.dk/dac1101.html

 

I guess everyone know Metrum Acoustics' dacs (based on transient modules) Between 1250 and 7000 Euros

http://www.metrum-acoustics.com/

 

Holo Audio Spring Dac Family (There are 3 versions with some differences between them) Between 1400 and 2400 Dollars:

https://kitsunehifi.com/product-category/audio-gear/dac/
 

Vinshine Audio DacR2R Ref (based on soekris module, I cannot read which one as piece of the chasis covers it) 2100 Dollars:

http://www.vinshineaudio.com/product-page/a5952b51-0edc-b170-4f94-648d4a9dec86

 

Denafrips Audio (I do not know anything about them but I guess they use their own R2R modules, and pretty neat boards they have. DAC-1Pro uses discrete module as they claim, I do not know about other producs) 3120 Dollars:

http://www.buyitmao.com/products/520399273447

Denafrips Dac1 main board.jpg

Denafrips Dac1 psu board.jpg

 

EDIT:  Link (roughly) to pages in Stax discussion where DAC discussion starts.

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I haven't looked into this at all, so could someone describe how these discrete designs compare to the old ladder chips (PCM63, 1704, et al.)? People like Audio-gd somehow got their hands on new old stock and are still making stuff with them, and most of HC probably still have an old DAC or two that use these R2R chips.

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We'll meet with Mr. Tyler, Sir. I got a dac based on AD 1862; MHDT Lab Atlantis. I guess, when the time comes we'll compare them properly.

Edited by Sechtdamon
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I know the AD1862 was always one, if not the favorite of Jocko (Pat).

My CD players are still PCM-63 and TDA1541A. Still a lot to be said for these. I know the AMR CD-77 still uses the TDA1541A.

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i've heard the 1704 is still manufactured for special customers but i could be mistaken. it's been in danger of being discontinued for more than a decade right?

i'm more worried about how to properly implement a spdif input without a tdr, there seem to be quite a few choices to try for the actual dac part



for my diy dac i wanted to try an 1862 with the sen iv stage, i came across one of the ayre qb9 usb input boards but i'm not 100% sure how to exploit it yet

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I know some manufacturers, uses 1704. Actually it is one of the most used chip on currently manufactured R2R devices, (Mhdt pagoda, all R2R dacs of Audiogd for example) along with tda 1543 as I know. I only listened 1704 on a hifiman dap (801 maybe) for a short while, so I doubt if I can judge how it sounds.

They have grades, nearly all R2R chips. "K" ones are extremely hard to find and to be honest I do not believe there can be that much differences between j and k ones.

I'll check further about tdp. But isn't it a cable impedance thing rather than input chip? But I only have Basic info about it. I'm using bnc on Atlantis, as I know bnc is more failsafe than rca on spdif. This can be helpful about your questions:

http://www.audiocircle.com/index.php?topic=25776.0

And why do you want to use specifically that I/V implementation?

I shared inside (one all in one board) of Atlantis on stax thread, you can check it too.

And If many people wonder about Ad1862 chip, I can send my dac to Usa, and maybe it can get a measurement. :)

I'll add non discrete R2R chips/who uses them too.

Edited by Sechtdamon

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All this talk of R2R DACs pushed me to future proof my setup. Just bought a DAC with PCM1704s and PMD100, so now I can relive HC circa 2010. I still also have my Parasound DAC1100 I bought from a member here, which uses PCM63s. 

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I think they still make the PCM56 which is still good up to 16 bits

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22 hours ago, nopants said:

I think they still make the PCM56 which is still good up to 16 bits

Nice, which DACs use PCM56? I wanted a PCM1704 DAC in case of 24 bit high res but to be honest, I don't think anyone cares about HRA outside of some audiophiles. Also, you seem to have collected a ton of R2R DACs over the years. Any thoughts/preferences?

10 hours ago, Sechtdamon said:

Analogmetric has some assembled boards.  here is one with some options on dac, digital reciever and oversampling chips (balanced I guess):

http://www.analogmetric.com/goods.php?id=593

Looks like bog standard opamp implementation that most of these DACs use, straight from the datasheet. Nice, I guess, if you don't want to deal with recapping older units and SMD and whatnot.

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1 hour ago, mypasswordis said:

I wanted a PCM1704 DAC in case of 24 bit high res but to be honest, I don't think anyone cares about HRA outside of some audiophiles

I don't know anything about being true 24 bit effects any way but, my AD1862 based dac plays 24 bit files just fine. I know being accept 24 bit and actually being 24 bit different things, but tbh I don't hear any differances between well recorded 16/44.1 and 24/96-192.

About DACs which uses PCM56, from MHDT Lab, Havana, Havana 2 (uses dac chips internal opamps, according to their website) and stockholm 2 (uses discreet I/V stage and no feedback, again according to their website)

http://dhost.info/mhdtlab/

And I doubt if they're still making Havana 2. They made balanced Pagoda too, based on PCM1704. All their DACs uses tube buffer stage based on 2c51.

 

 

And while lurking, i bumped to a website, Has some interesting products, and Diy friendly things:

http://www.sonicillusions.co.uk/projects.htm

pmd100dac.png

This is their discrete Dac module.

http://www.sonicillusions.co.uk/images/pmd_pcb.pdf

http://www.sonicillusions.co.uk/discrete_dac.htm

 

And anyone has info about BB PCM65? I searched about it a lot and all I found out two Pioneer cd players used them. And I guess it is the rarest of all.

And I found out I'm banned from Diyhifi cuz of spamming, I'm not even registered there.

Edited by Sechtdamon

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Hmm, the PCM56P-K is still available. RS has some in stock, Mouser and Digikey show them as obsolete but seem to have some SMD packages. Interesting.

So, you got on Jocko's shit list, ehh? :lol:

From what they were saying on diyhifi, the PCM65 is a PCM63 with maybe extra power and ground pins? Other pins seem identical to PCM63.

I don't believe there is a data sheet for the

PCM65. It was an internal part number for Pioneer (Proprietary) and was made only for them and not sold to anyone else. So you might be chasing your tail on this one. The only people that might be able to give you more information on this is Pioneer themselves.

The only available information, that I know of, is the pinout configuration that is in the Pioneer service manual and that is it, but if you study the schematics carefully you will notice that it is a dead ringer for the PCM63.....MSB adjust, Iout, supply rails etc, etc .

Edited by Pars
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While lurking around I found an interesting firm: LessLoss.

Here is their discrete ladder DAC based on their own module (haven't check for internal pictures yet) (5342 Dollars):

http://www.lessloss.com/echos-end-p-218.html

I though the wood used on chasis is mahogany but they uses something different:

http://www.lessloss.com/technology.html?zenid=513kq424j6utubrudk1b7iopq2

 

Off topic; their most interesting thing: A SD card player (91181 Dollars - I'm pretty sure they'll make 181 Dollars discount if you want to buy :D :

http://www.lessloss.com/laminar-streamer-sd-player-p-207.html

 

I'll add all the findings into main post/or not, not decided yet. Sharing all the info on 1 post can trigger laziness. :)

Edited by Sechtdamon

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Ahh Lessloss...kings of snake oil.  Best be avoided like the plague....

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37 minutes ago, spritzer said:

Ahh Lessloss...kings of snake oil.  Best be avoided like the plague....

Thanks for the heads up Birgir. It's needed in this topic more than anything else, I try to avoid known snakeoil sellers but I cannot know all of them. :)

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On 12/7/2016 at 2:10 PM, mypasswordis said:

Nice, which DACs use PCM56? I wanted a PCM1704 DAC in case of 24 bit high res but to be honest, I don't think anyone cares about HRA outside of some audiophiles. Also, you seem to have collected a ton of R2R DACs over the years. Any thoughts/preferences?

I think the MHDT Havana uses the PCM56, nothing particularly impressive. I was more throwing it out there if you wanted to try it out in a DIY affair. 

There are quite a few factors but I've never come across an R2R that I didn't like, mostly because they all have a similar quality where the treble isn't harsh. Lets me listen for hours on end, which is usually how I benchmark my equipment these days. I've mostly convinced (deluded?) myself into thinking that this is the correct way to reproduce treble. The soundstage presentation has always been different enough for me to prefer them over D/S solutions as well, mostly wider to keep things concise. Just a bit of context.

I think among all of these I've enjoyed the AR-T Segue (AD1862) and the Yggdrasil (AD5791) the most among the ones I've owned at this point (Adcom GDA600, Spectral off the top of my head). Of course those are the only ones I ended up keeping. I was attracted the Yggdrasil because of the marketing hype surrounding the closed-form filter. 

I'm mostly interested in rolling my own balanced kludge at this point, to see if the AD1862 lives up to the hype if you invest some effort into modernizing all the different stages. Unfortunately I lack the willpower (brain) to do something like implement my own filter, etc. Not to mention all the repeated whining I do over SPDIF. I'm curious to see what Kevin has in the works for his DAC.

On that note I need to find out how to see how to modify the PMD100 for use where an NPC filter currently sits...

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I've come to the same conclusion in regards to anything audio and life, really. The good stuff doesn't necessarily wow you immediately, but allows you to spend long periods of time without getting infuriated. Ideally, they are not mutually exclusive but that's pretty rare. 

Yeah, the rabbit hole is infinitely deep. Luckily HC members @cetoole and @Filburt know all about I/V converters and DACs in general, so maybe they have some advice to offer. The Holo Spring also gives another idea, with the nonlinearity compensation. These laser trimmed DACs, especially K grade, still have better precision than any discrete resistors today including foils, but if you want to squeeze every possible bit of performance then running an algorithm to at least handle chip-specific static nonlinearity errors would be nice. Apparently Holo are the first to do this in a discrete design, in which they use a digitally controlled second ladder, but they're doing it as an alternative to laser trimming. Maybe some attention towards deglitching would be nice, too. I'll leave it to you to look into designing FIR filters. Btw not sure which NPC you have, but the PMD100 datasheet says it is pin compatible with some. Just bouncing some ideas off you and see what you come up with, which might motivate myself to one day do something similar. Or we can just wait for KG's DAC, like you said. :)

I'll definitely check out the Yggy and Holo Spring at the NYC meet, but probably won't ever find a Segue to hear. Did you end up repairing your Spectral? 

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23 hours ago, mypasswordis said:

I'll definitely check out the Yggy and Holo Spring at the NYC meet, but probably won't ever find a Segue to hear. Did you end up repairing your Spectral? 

Spectral was charging me like 175/hour with a minimum of 3 or 6h to have it repaired, plus parts costs (the feet melted off). I ended up selling it for parts. It was a real shame, I liked the sound but the experience of owning one was such a pain. 

Funny you mention cetoole, I think I have like 5 of his I/V boards lying around somewhere. 

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I also like the R-2R sound. I am not sure the impact of the chip though? My Golden Gate is chip less and uses a DSD engine I believe. Sounds better than the earlier versions with a chip IMO. Also after having owned maybe 11 R-2R DACs of various types I believe a tube regulated power supply and tube output makes it sound more natural to my ears. I would recommend trying a good tubed DAC. My path was to find fatigue free digital audio, especially clean treble, I almost left digital many years ago but came back.

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6 hours ago, kevin gilmore said:

http://bbs.audio-gd.com/dispbbs.asp?boardid=2&Id=30313

audio-gd version, 8 for balanced sign/magnitude

 

Very cool! Hopefully he goes into more detail about the CPLD implementation and some of the header pins are for JTAG. I've been curious to play around with Verilog/VHDL. Can implement filters, too.

18 minutes ago, nopants said:

Spectral was charging me like 175/hour with a minimum of 3 or 6h to have it repaired, plus parts costs (the feet melted off). I ended up selling it for parts. It was a real shame, I liked the sound but the experience of owning one was such a pain. 

Funny you mention cetoole, I think I have like 5 of his I/V boards lying around somewhere. 

:( Damn, that sucks about the Spectral. You have enough I/V boards for balanced, so it's time to dew eet!

1 hour ago, lostinaudio said:

I also like the R-2R sound. I am not sure the impact of the chip though? My Golden Gate is chip less and uses a DSD engine I believe. Sounds better than the earlier versions with a chip IMO. Also after having owned maybe 11 R-2R DACs of various types I believe a tube regulated power supply and tube output makes it sound more natural to my ears. I would recommend trying a good tubed DAC. My path was to find fatigue free digital audio, especially clean treble, I almost left digital many years ago but came back.

:(:( Did you not read the last few pages of the Stax thread (see title of thread)? 

I recently read the Nagra HD DAC converts PCM to DSD... looked at the pics of the internals from the 6moons and was very confused. I tried reading some of the review and got even more confused. Seems like the Amanero is pretty ubiquitous these days, though.

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I would recommend the Soekris dac as an upgrade to the Golden Gate. It is much better on its own than that pile of fail. 

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6 hours ago, spritzer said:

I would recommend the Soekris dac as an upgrade to the Golden Gate. It is much better on its own than that pile of fail. 

You heard the Golden Gate? Thought not...

I think you may find the Big 7 and GG has or is using the Soekris board for PCM. The GG sounds much better on DSD (PCM up sampled). On PCM it is 'normal' or average for a good R-2R.

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i'm sure if i put my head far enough up my own ass i'd be able to hear what the golden gate sounds like without purchasing one

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2 hours ago, lostinaudio said:

You heard the Golden Gate? Thought not...

I think you may find the Big 7 and GG has or is using the Soekris board for PCM. The GG sounds much better on DSD (PCM up sampled). On PCM it is 'normal' or average for a good R-2R.

If I have to fucking find DSD for all my favorite albums just to hear better sound from the same DAC what the fuck is the point spending 20k on a shit? And most of the people (bullshitters or realistic people) agrees on DSD sounds better than PCM already, so what the fuck GG does specially? Every fucking DSD decoding capable DACs sound better with DSD. I love 44.1/16 from my modest dac, it sounds pretty good with these files. So enlight me please.

You said you've heard 11 different R2R dacs, obviously you got experience, Just answer me if you don't mind:

Is it the logic: spending shitload of money on something that does mediocre job; well below it's price, working your ass off to make it sound better than average or just follow snakeoil strains, and just be happy with the bullshit?

Edited by Sechtdamon
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