Really like to hear more about it for sure!!
39 responses Add your response
I will give you a sneak preview and let you know it keeps getting better for awhile. It beats the Hex in pretty much every way, and I think the Hex sounds quite good. By running the Antipodes DX source through the Pavane, I am not sure what else I would want, or how something could sound much better. BTW, I am using the Gemini unpowered USB cable. I would like to try the CAD cable. |
People have compared TOTALdac usb to everything everyone seems to pick the Totaldac. I wonder how their aes/ebu is? I have aerial 20t's i am hoping if i get the Pavane the bass will be really good as well. There is one guy that has the Pavane and a Totaldac d-1Dual and claims he likes the Pavane better to listen too a little richer in sound. |
The Schiit Yggdrasil is also R2R using 4 $75 exotic 20 bit super precision Analog Devices DACs to give "pure 21 bits of info". My friend has one he lightly modded and he says its outrageous. You can see the mods on my website: http://www.tweakaudio.com/EVS-2/Schiit_mod.html He is in Pocoima, CA and would love to A/B with the Pavane or other fine DAC. |
Yeah, my experience with 1bit DSD DAC was... beyond horrible. 6bit R2R Delta Sigma DACs are actually pretty good, Burr-Brown call it "advanced segment", Onkyo receivers/processors got it and it sounds great and is super cheap! Sabre Delta Sigma DAC sucks, similar to 1bit DACs, sigh. And finally, fully R2R DACs are heavenly. Let's see where the DIY Soekris R2R DAC goes, could be awesome sound quality at dirt cheap prices. |
The AD5791 datasheet describes it as providing a voltage output, but one that is unbuffered, and that has a high nominal output impedance of 3.4K. So when used in a DAC component it would almost certainly require a separate buffer stage, and as Ric indicated it is very conceivable that its voltage output is driven directly from the resistor network. Regards, -- Al |
Sorry Al Separate Buffer? or separate I/V then buffer?? Correct me if I'm wrong. As from what I saw there were no current (mA) output figures given for it's output, which all manufactures give for current output dacs. Also Look at page 26 Positive input to the opamp, and no grounding of the negative. Now look at the page 9 of the PCM1704 I/V stage neg input with grounding of the positive for low impedance input. Same for what I've seen for most current output dacs on data sheets. http://www.google.com.au/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&sqi=2&ved=0CCQQFjABahUKEwiixfXOwqzHAhWlqqYKHRcmAYI&url=http%3A%2F%2Fwww.ti.com%2Flit%2Fds%2Fsymlink%2Fpcm1704.pdf&ei=p_DPVeLVNKXVmgWXzISQCA&usg=AFQjCNEK5ScUy3tujTC6njrwwvKnluukTg&bvm=bv.99804247,d.dGY Cheers George |
George, As I described earlier it is possible to make an R2R DAC that has voltage out and not current out. This is what TotalDAC has and so does MSB. They do not need IV conversion. Maybe the 5791 does the same. The amount of voltage out on the 5791 is determined by the power supply voltages you use on the DAC. The Yggdrasil actually puts out 4.6VRMS out of each DAC chip (4.6V per phase). This was just measured on an Yggy today. There is no measureable DC offset on the output of the DACs. The voltage coming out of the output stage buffers is 2VRMS per phase so the buffers actually lower the voltage coming out of the DAC. I will call Analog Devices on Monday and ask them if there is a built in IV converter.....I don't think so. Anyway, the stock Yggy sounds great and the modded one sound way better and now I will be putting my zero feedback fet buffer on the output instead of the Schiit stage and see what we get....fun times ahead. |
I don't understand your post, George. I think we're both agreed that the AD5791 provides a voltage output, as the datasheet plainly says in numerous places. But it has a very high output impedance, and as Ric indicated it seems very conceivable that the voltage is directly generated by the resistor network. Rather than via an internal active stage that would perform an I/V conversion. Although without further information we can't say that with complete certainty. Also, I don't see the relevance of your reference to the PCM1704. The stage (U1) you referred to on page 9 of the PCM1704 datasheet is, as you said, an I/V converter. While the stage (U6) you referred to on page 26 of the AD5791 datasheet is a unity gain buffer configuration, which would provide an output voltage closely matching its input voltage. Regards, -- Al |
Sorry Al, I misunderstood your post. As to no experimentation with any I/V stages, as I originally posted with this dac. As great leaps have been made with I/V stages (away from the norm) and this dac doesn't allow this. As it would have standard text book I/V embedded within the dac itself which looks to be A1 on the data sheet, but with high output impedance. That's all Cheers George |
As great leaps have been made with I/V stages (away from the norm) and this dac doesn't allow this.George, note that A1 is configured as a unity gain buffer, not as an I/V converter, and that it is not even in the path to Vout. Its purpose, as shown on pages 24 and 25 (pdf pages 25 and 26) of the datasheet, is to support a number of different configurations of the external buffer or other amplifier that would be driven by Vout. Regards, -- Al |
Yes, that appears to be the case as far as I can tell from the datasheet, George. With the slight qualification that while the D/A conversion is accomplished by a resistor ladder, strictly speaking it's not an R2R ladder (see page 19, pdf page 20, of the datasheet). We'll see if Ric can obtain confirmation of that when he calls Analog Devices. But as he indicated, that interpretation is given added credibility by the fact that TotalDAC and MSB Technology, which use R2R ladder approaches (albeit with discrete resistors, and at vastly higher price points, and with at least several additional bits worth of performance), also do not require or incorporate I/V conversion. Regards, -- Al |
I think I see now, this may have been done before on other dac chips, I think with those who understand it, say it's a hybrid? Part low res R2R ladder Multibit, part Delta Sigma? Would this dac then do you think be tarred with the same brush? If this is the case "those that say it's a hybrid" say it's still not as good as real R2R Ladder Multibit? But it's easier/cheaper to manufacture than true R2R Multibit. Cheers George |
Hi George, Yes, per the description I referred to in the datasheet, it is what is referred to as a hybrid D/A converter. But without any part of it being delta sigma, however. As defined in this Wikipedia writeup, it uses a segmented architecture, combining "thermometer coding" for the most significant 6 bits, and R2R architecture for the other 14 bits. So as I indicated, the structure as a whole can be considered to be a multibit ladder, but not an R2R ladder. Regarding your question, I have no particular quantitative feel for how that all may trade off performance-wise against other approaches providing similar resolution and speed. Maximum speed, btw, looks like it is not much faster than redbook, as the digital data is described as being clocked into a 24 bit register serially at 35 MHz max (indicated as 50 MHz max in one place, perhaps incorrectly). Regards, -- Al |
A few of the "gurus" say it has a problem with dynamic accuracy? http://www.diyaudio.com/forums/digital-line-level/275444-most-accurate-r2r-nos-dac.html#post4350335 http://www.diyaudio.com/forums/digital-line-level/275444-most-accurate-r2r-nos-dac-2.html#post4369948 Cheers George |
A correction to my previous post. When I said: Maximum speed, btw, looks like it is not much faster than redbook, as the digital data is described as being clocked into a 24 bit register serially at 35 MHz max (indicated as 50 MHz max in one place, perhaps incorrectly).Delete the reference to "not much faster than redbook." A 24 bit serial interface running at 35 MHz is easily capable of accepting data at hi rez sample rates. Apologies for the error. Regards, -- Al |
I looked at my AD account and AD has an AD5791 Evaluation Board complete up and ready to go, available for around $150usd all you need is power and a chassis and be an account holder and you have your own dac. http://www.google.com.au/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0CCkQFjAAahUKEwjQ6M_VwrPHAhXlrKYKHR8XAX4&url=http%3A%2F%2Fwww.analog.com%2Fmedia%2Fen%2Ftechnical-documentation%2Fuser-guides%2FUG-185.pdf&ei=PJzTVdDaBeXZmgWfroTwBw&usg=AFQjCNENr4SFOC4ZcTxbgqOUNF9bb7CIXw Cheers George |
I built an AD1955 dac based on AD Evaluation Board, and they are made very nice. here is a pic of the one I made up years ago. So the AD5791 should be just as well made. http://www.diyaudio.com/forums/digital-source/227677-using-ad844-i-v-34.html#post3672888 Cheers George |
only one person has this dac in the world?Yep, just me. The rest are listening to music and not hanging around on this forum. Unfortunately, I have not listened to dozens of high end DACs. The last disc player I owned was a very high end player from Muse, but I have owned the Ayre C5xeMP player. For DACs, I have had the Lampi L4G4 here, and also the Aqua LaScala II. My previous DAC (that I will be selling soon) was the Hex. All I can say is that IMO, this Pavane is better than all of those, at least in my system and for my preferences. If you read the reviews, they get it pretty close. However you cannot discount what source you use to feed it. Going to the Antipodes DX was a significant last step toward full-bodied, musical enjoyment in my system. I still own my tricked out Mac mini, that has an outboard linear power supply, inboard filters, an inboard SSD, outboard AV drive connected by firewire and also powered by the linear supply, Atomic platform, and more, playing Pure Music in memory mode. As good as that was, the Antipodes DX is more natural sounding, analog-like some would say, and more enjoyable, at least with my system. I believe Srajan's take on the Pavane may have been different (even more specifically positive) had he been using something better than his computer as a source. The EAR review by René van Es is very strong and, while the level of impact the Pavane has on your system may vary from what Rene' states, or from how it impacts my system, I found the comments about sonics to be on track. The review by Jaap Venstra is also quite strong, if you choose to translate it on Google Translate. I am sure there are differences between the Pavane and other top, or near top, DACs. The Pavane takes the best of the R2R presentation of the Hex, and makes it better. Not surprising with a S/N of -140dB. Bass is very good, in my system. Clarity is outstanding as is soundstage. It goes deeper than the Hex, and wider. High frequencies are natural-sounding, not rolled off and not overdone but very clear with good impact (when called for) and realistic decay. Super black background, etc., etc. I run a fully balanced system so have not evaluated the single-ended outputs. Also, I am able to run the unpowered leg of a dual USB cable into the Pavane (as I did with the Hex) since it has internal power for the USB input. Compared to the LaScala, the Pavane was certainly not as warm but that doesn't mean it isn't as musical or as full-bodied. I found the LaScala comparatively a little forced sounding, maybe due to the highish output voltage. The LaScala had great body and was certainly fun to listen to but the Pavane can transport you to the event better, again, in my system/room/opinion. I agree, it is unfortunate they do not currently do demos. I believe there may be a return policy, and you should look into that. After having it in my system, I did not even think about returning it. YMMV |
only one person has this dac in the world?Yep, just me, at least on this forum. The rest are probably listening to music and enjoying their DACs. Unfortunately, I have not listened to dozens of high end DACs and have not compared the Pavane directly, at the same time, with other DACs, except for the Hex. My comparisons also include the last disc player I owned, which was the top player from Muse, which bettered the Ayre C5xeMP player, which I also owned. More recently, I have had the Lampi L4G4 DAC here, and also the Aqua LaScala II. My previous DAC (that I will be selling soon) was the Hex. All I can say is that IMO, this Pavane is better than all of those, at least in my system and for my preferences. If you read the reviews, IMO they get it pretty close. However you cannot discount what source you use to feed it. Going to the Antipodes DX was a significant last step toward full-bodied, musical enjoyment in my system. I still own my tricked out Mac mini, that has an outboard linear power supply, inboard filters and SSD, outboard AV drive connected by firewire and also powered by the linear supply, Atomic platform, ifi power for galvanic isolation, signal only USB cable, and more, playing Pure Music in memory mode. As good as that source was, the Antipodes DX is more natural sounding, analog-like some would say, and more enjoyable, at least with my system. Although Srajan's 6moons review of the Pavane was positive, I think he would have liked it even more with an upgraded source. The EAR review by René van Es is very strong and, while the level of impact the Pavane has on someone's system may vary from the impact Rene' heard, I found his comments about how it sounds to be on track. The review by Jaap Venstra is also quite strong, but needs to be translated. I am sure there are differences between the Pavane and other very good DACs. The Pavane displays the natural, organic presentation that R2R DACs are known for, and improves on the very good sonic qualities of the Hex. Not surprising with a S/N of -140dB. Bass from the Pavane is very good, in my system. Clarity is outstanding as is soundstage. It goes deeper than the Hex, and wider. High frequencies are natural-sounding, not rolled off and not overdone but very clear with good impact (when called for) and realistic decay. Super black background, etc., etc. I run a fully balanced system so have not evaluated the single-ended outputs. Also, I am able to run the unpowered leg of a dual USB cable into the Pavane (as I did with the Hex) since it has internal power for the USB input. Compared to the LaScala, the Pavane is certainly not as warm but that doesn't mean it isn't as musical or as tonally dense. I found the LaScala comparatively a little forced sounding, maybe due to the highish output voltage. The LaScala was warm, musical, and full-bodied, and it was certainly fun to listen to but, for me, the Pavane was better able to make me forget I was listening to a stereo and helped me to simply enjoy the music. It is unfortunate the USA Metrum distributor/dealer doesn't promote demos. I believe there may be a return policy, and you should look into that. After having the Pavane in my system, I did not even think about returning it. YMMV |
