The volume is controlled digitally inside the ES9018, so there is no variation to the output DC bias.
Hi all!
I am a member of Chiaki's & Bunpei's SDTrans group here in Tokyo, and recently I had a chance to borrow Bunpei's recently built dual-monaural BUF II (two 9018s, two IVY III etc.) wired directly to the prototype hand-wired SDTrans. The clocks on Bunpei's BUF II has been replaced with another group member's specially developed and hand-built "over 80 MHz" Bipolar Clocks. (This clock is proprietary and will debut in an upcoming DAC/Preamp here in Japan, and they will also be available for DIY upgrades.) However, our findings also show that the BUF II will also work with other well-designed and executed clocks of a frequency between 80MHz and 100MHz. Experiments will determine which frequencies work the best.
With these particular clocks installed on the BUF II (and also specially ordered NDK clocks for the SDTrans itself), the system is capable of playing all files including 2L supplied 352.8kHz 24bit 2L files from Norway. Also, even if we have been able to technically play these files for some time, the latest combination of BUF II and SDTrans provides a compelling, truly natural and dynamic, musical performance from these files. A the same time we experience really stellar playback also from regular files ripped from CD (using highest level settings from ExactAudioCopy).
Congratulations to Russ & Brian for developing the excellent BUF II (I am also an owner of both the previous and current version, but had not built the pure dual monaural version yet), and also to Chiaki & Bunpei for their stellar performing SDTrans.
Our test shows that you need an especially careful approach to clock performance that goes further than buying anything "off the shelf" for successful playback of the 352.8kHz 24bit DXD files. However, the additional reward is that you also get even better playback performance from "regular files" if you clear the hurdle of becoming able to play 352.8kHz 24bit DXD files in a stable manner.
Cheers
I am a member of Chiaki's & Bunpei's SDTrans group here in Tokyo, and recently I had a chance to borrow Bunpei's recently built dual-monaural BUF II (two 9018s, two IVY III etc.) wired directly to the prototype hand-wired SDTrans. The clocks on Bunpei's BUF II has been replaced with another group member's specially developed and hand-built "over 80 MHz" Bipolar Clocks. (This clock is proprietary and will debut in an upcoming DAC/Preamp here in Japan, and they will also be available for DIY upgrades.) However, our findings also show that the BUF II will also work with other well-designed and executed clocks of a frequency between 80MHz and 100MHz. Experiments will determine which frequencies work the best.
With these particular clocks installed on the BUF II (and also specially ordered NDK clocks for the SDTrans itself), the system is capable of playing all files including 2L supplied 352.8kHz 24bit 2L files from Norway. Also, even if we have been able to technically play these files for some time, the latest combination of BUF II and SDTrans provides a compelling, truly natural and dynamic, musical performance from these files. A the same time we experience really stellar playback also from regular files ripped from CD (using highest level settings from ExactAudioCopy).
Congratulations to Russ & Brian for developing the excellent BUF II (I am also an owner of both the previous and current version, but had not built the pure dual monaural version yet), and also to Chiaki & Bunpei for their stellar performing SDTrans.
Our test shows that you need an especially careful approach to clock performance that goes further than buying anything "off the shelf" for successful playback of the 352.8kHz 24bit DXD files. However, the additional reward is that you also get even better playback performance from "regular files" if you clear the hurdle of becoming able to play 352.8kHz 24bit DXD files in a stable manner.
Cheers
I Think the SDTrans is an interesting project, but it has not proven suitable for me so far. I still have hope for it though.
Actually, I have no trouble playing 352khz sampled music with Buf32S or BufII with the stock 80mhz (already superb) clock. It does sound excellent.
I have used 3 different 352khz PCM sources now. And two worked quite well.
Only the SDTrans worked poorly for me. I think they are working to resolve these issue though. There is an issue with the bit clock timing. A 100mhz clock does make the DAC a little more forgiving of the poor PCM signal though. But the measured THD+N at 352khz coming from the SDTrans was not good at all. about -85db.
At 192khz the SDTrans works quite well. But above that it needs some additional work.
Cheers!
Russ
Actually, I have no trouble playing 352khz sampled music with Buf32S or BufII with the stock 80mhz (already superb) clock. It does sound excellent.
I have used 3 different 352khz PCM sources now. And two worked quite well.
Only the SDTrans worked poorly for me. I think they are working to resolve these issue though. There is an issue with the bit clock timing. A 100mhz clock does make the DAC a little more forgiving of the poor PCM signal though. But the measured THD+N at 352khz coming from the SDTrans was not good at all. about -85db.
At 192khz the SDTrans works quite well. But above that it needs some additional work.
Cheers!
Russ
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Hi Russ,
Could tell me how can play 352kHz with the Buffalo DAC? due to the fact as per Sabre data sheets:
"The SABRE32 Reference supports up to 200kHz input sampling rates"
Thanks to share.
Which datasheet are you looking at?
Look a little deeper and you should see a section that describes clock requirements.
In any case I am not sure the point of your question...
It does indeed play 352khz. You simply need a clean PCM source and a clock > 68Mhz or so.
If you are using a 40mhz clock then 200khz would be about the maximum sample rate. The DS you are looking at may assume a 40mhz clock.
Also if its a ES9008 datasheet all bets are off, as I have never tested that chip with anything higher than 192khz.
Cheers!
Russ
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Its not that hard to find, but there is certainly not much variety out there. Its 352.8/24bit.
I get most my stuff directly from the studio.
I have built two PCM streamers for myself. One that uses the beagleboard, and another a PIC32 demo board. Both worked great, but the beagleboard version was better.
I have far more 192khz sampled files than I do 352khz.
Before anyone asks, no I do not plan to release such a project, at least not in the near future. Its just too complex for the uninitiated.
Cheers!
Russ
Thank to your reply to my earlier post regarding SDTrans, Russ. I know that Chiaki & Bunpei very much appreciate and respect your input regarding their project. They are also very much aware of that a further improved next version needs to be made, and indeed the evaluation input from the testing of the current version is needed to provide data for the future improved version.
Regarding clock testing, our own results show that no 80MHz (or lower frequency) clock in BUF I, BUF II, or ESS 9018 evaluation DAC has been able to play 352.8kHz/24bit files in a satisfying manner. There has been noise problems, drop outs, and a generally harsh and mechanical sound. Going to a 100MHz clock reduced the problems, but we still had unsatisfying sound. Only after we started to experiment with a custom made bipolar clock with various frequencies between 80MHz and 100MHz did we reach a level of complete stability and very satisfying sound, even at a high-end audio level. I can say that personally this is the best sound I have heard from digital (and I have access to various very seriously high end hardware). As some will know; my heart is with analog playback, so I expect no less from digital!
I understand well that it is not yet "prime time" for the SDTrans, and that this project is very much evolving. Also the user interface leaves a lot to be desired ;-)
However, I am proud and happy to be a direct participant in this project (I have purchased two SDTrans units from Chiaki & Bunpei), and I am also proud and happy to be a direct participant in the TwistedPearAudio BUF I and BUF II where I have bought multiples of each version.
The more I listen the more I smile! This might be the player that finally makes me stop buying records! Ok, well, maybe at least not as much as before.
Hi toufu,
witch tube type do you listening to? Did you have time to try different ones?
Which datasheet are you looking at?
Look a little deeper and you should see a section that describes clock requirements.
In any case I am not sure the point of your question...
It does indeed play 352khz. You simply need a clean PCM source and a clock > 68Mhz or so.
If you are using a 40mhz clock then 200khz would be about the maximum sample rate. The DS you are looking at may assume a 40mhz clock.
Also if its a ES9008 datasheet all bets are off, as I have never tested that chip with anything higher than 192khz.
Cheers!
Russ
I'm looking Esstech data sheet ES9018, link:
http://www.esstech.com/PDF/Sabre32 DAC PF 081217.pdf
Possible you have other data sheet from manufacturer that isn't available in the web & only for customers, could you share?
Other important thing: wich interface can support 352 khz?
USB 2.0 = 480 Mbps
FireWire 400 = 400 Mbits similar to Usb 2.0
FireWire 800 = 786.5 Mbits more superior than USB 2.0 used by Apple
As I know USB 2.0 maximum can reach 192khz, only known interface available M2Tech. Do you know other interface can support 352khz, Firewire 400 is faster than USB 2.0 but I don't know if can support?
Thanks in advance
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Ah ok. At least I can stop checking the page as frequently for now
Do you think preorders will start before a couple weeks, or is that what you meant, that preorders won't be for a couple more weeks? I'm not really in a rush, I just worry that the next round will sell out before I notice they are back in stock and I'll miss out.
Hi elecon,
Your result is to be expected if you have used only the SDTrans. Try a different source. I have tried three 352.8khz 24bit sources. I have used 80mhz and 100mhz clocks.
I did some analysis of the condition of the DAC when receiving signal from all three of my sources.
What I found was that reading the 32bit DPLL registers while playing silence from all three sources gave the best indication of which one was working well. I created a logger that tracked the adjustments the DAC made to the DPLL. With the two sources that worked flawlessly the DPLL register barely moved. While with the SDTRANS the DPLL would not only swing wildly but occasiionally unlock. Reading the DPLL registers is quite easy, and quite effective. If it is moving a lot (a little is ok) then the DAC is having to work too hard to keep a lock.
Now if you use a faster clock, the DPLL has a bit more headroom to do its magic, but this is really masking the deeper problem which is a less than optimal PCM signal. The issue seems to be with the bit clock to word clock timing, or possibly the bit clock itsself.
Now here is the bottom line. I have used the SDTrans and I very much appreciate the opportunity. I love the idea. I really like the attitude of the two people behind it, Bumpei and Chiaki have been very gracious to me. I am doing my best to help them make their module better.
Here is the great news, at 192khz it works quite well, but I agree the UI could use some work.
So I think I have explained things the best I can.
My experience is that the ES9018 handles 352.8khz 24bit flawlessly with a 80mhz master clock so long as the source has cleanly encoded PCM.
Cheers!
Russ
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