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I know this has been discussed in part before, but could someone sum up the differences between the 1792, 1790 and 1791 (apparently only available to Denon), and 1738 Dacs. Someone on a different forum posted that the 1791 is a better DAC than the 1790, even though it is used in a cheaper Denon player.Yes, I understand that implementation may be more important than the part quality of a Dac, not to mention power supply, analog section, etc. But how relevant are these changes in Dacs? Is the the new generation of players (ie Denon 5900) potentially better than the cream of the previous crop (such as the XA777es)? I am, of course, particularly interested in MC SACD performance.
Follow Ups:
As the resident Burr-Brown DAC guru....he he....here goes:The 1791 is a completely different animal than the 1790/1792. It costs $3.00@ 1000 pricing, and has a built-in opamp that does I-V (current to voltage) conversion. It is rated at 112db dynamic range. It is way less good than either the 1790 or 1792 and for that matter a 1738.
The new 1792 DAC chip ($13.00+@ 1000 pricing) is rated at 127db dynamic range, has very high current outs (so you can use your own I-V converters), has separate power supply feeds for both channels (for better channel separation, dynamics, clarity). This DAC chip is not in any player known to me(anyone?). It was released in March and no player has the chip in it. It can also be run in mono mode for 130db dynamic range.
The 1790 (custom made by Burr-Brown for Denon and used in the 2900 and 5900 players) looks on the surface much like a 1792...maybe it is, in fact. It has separate power supply feeds, higher current out just like the 1792. Last years top of the line Burr-Brown DAC chip (the PCM 1738) does not have as much current out and does not have separate power supply feeds for both channels current out. Since there is no way to get specs on the 1790 there is no way to confirm how close it is in perfomance to a 1792...however....I will say....I am impressed by its aural performance.
The Denon website originally posted the DAC chip in the 2200 as the 1792. I contacted Denon and it turned out to be a mistake (website now changed to reflect the truth)....probably how people started thinking it had a super DAC chip. The DAC chip in the 2200 is the 1791.
As you said, it is implementation that is most important. The Teac DV-50 uses the 1738s but I bet it sounds better than the stock Denon 5900. Of course, the Teac lists for $5500, it should be implemented better!!!
MF Tri-Vista 21 DAC
Stephen
Must be pretty recent - haven't read about it yet in Stereophile. They are slipping. ;-)
Regards,
Metralla
I.e., the new XA9000ES. Which chips were used in the past top of the line players? Weren't these rebadged? Thanks for the great info, btw.
I imagine the new XA9000ES will still be using the 1738 but maybe the 1792. I really don't know. We shall see when they come out.The XA777ES and the C555 used the 1738 (six of them in the XA777ES) whereas some cheaper models used the DSD1702. They are also using AKM DACs in their DVD players (999ES for instance). The earlier Sonys used Sonys own DAC system. They went to other companies DAC chips when they went to multi-channel.
Yes, Sony puts their own number own the parts, but they are stock items from Burr-Brown or AKM.
All things being equal (they never are) then a better? DAC chip would equal better sound. But I will take a fully souped up player with a 1702 chip (106db dynamic range, single ended out, built-in opamp for I-V conversion) over most commercial players under $2000 with a 1792 (127db dynamic range, differential cuurent out) any day. By the way, the Consonance SACD player uses the 1702 DAC chip and is suppose to sound quite good. I saw a post somewhere where someone is getting a Denon 5900 and is going to A/B with his Consonance. Should be interesting......Again, it is execution that is paramount. The Pioneer DV-45A ($350 street price) uses the Burr-Brown 1738 but no one would sonically mistake it for a Teac DV-50 ($4800? street price) which also uses the same chip!!!
The novice naturally trys to find a spec or DAC chip or something that can lead him to making a purchase. I wish it were that easy. The only way to know which machine is sonically the best is to listen yourself and read reviews by others who have done serious listening A/Bs (on the same system) with the products you are interested in.
:-)
http://www.avihifi.co.uk/LabSeries CD/LabCD.htmlQuote:
"There are several DACs competing for top spot, all sound slightly different and after careful consideration, we have chosen the Cirrus Crystal 24 bit Delta Sigma, 192kHz D/A Converter. In our opinion it is the most musically rewarding and gives the best results with the widest range of program material."FYI only.
....Even if Burr-Brown comes up with -150db Dynamic range and THD+N, it will still sound as BB. They have changed a lot, but Crystal does not stay still during that time....:-)Regards,
Alex
What puzzles me is that a lot of these commercial companies do not tell you much of anything about their equipment except they choose a particular DAC chip or are using 50mhz Bipolars (this company as an example). They don't show pictures of the insides, they don't talk seriously about their design philosophy, just a bunch of fluffy words. Where's the beef? Its no wonder we are all confused. So many products, so many fluffy words and so few ways to tell if this amp or CD player is any good. It is what makes high end so interesting and so darn confusing/frustrating at the same time. At least with video and computers it is pretty darn straight forward. In audio, for every company that chooses one DAC chip you have another that chooses another. Which company has better ears?Hey, we will all have fully digital signal paths soon(player directly into the amp)and we won't have to worry about DAC chips any more! he he.
Full digital systems (with digital amplification) create all kinds of new problems that need new solutions. High RF noise is one.There has to be some kind of conversion from redbook sampling frequencies in the 40Khz range and digital switching amplification frequencies in the 200 to 800Mhz range. It does not always work out the best. It is better for SACD though.
The Solar Hifi forum on audiocircle addresses this real well.
Why do most digital amps (BC, PSA, etc) only accept an analog signal?
all class D (or "switching") amplifiers are Analog. "D" stands not for digital!
They may feature a digital input that accepts PCM, but this is always converted to analog ( yes... a dac inside) before being converted to PWM. And PWM is Not a digital signal.The overruling feature for a signal to be digital is that it contains BITS at a certain Sample Rate, and those Bits form a Word with a specific length; and this word contains specific data, stored as such into this word according to some complex mathematical structure. PWM is just a square wave that is modulated in the time domain by the analog signal that comes out of the (internal) DAC, with the help of a comparator (kind of fast opamp in open loop configuration).
For DSD this is different, this is directly converted to PWM because their composition schemes are somewhat similar. Still: after this conversion the signal is essentially Analog.
This all, however, does not disqualify class D in the least: the big bang of Class D is imminent and beware: it sounds better than anybody is willing to admit - if applied properly, which nobody has done so far (commercially - at least).
A note about HF noise: No such thing affects data in the all-digital audio chain, until the signal reaches the final amp stage. Here the signal amplitudes are so large and the HF is so far out of audible territory that it don't reach your ears.
Kevin of Solar is deceptive...talking about digital amps that are immune to jitter but can be too accurate. Are you kidding?
No digital: No jitter? Wrong! Jitter is just "timing errors".
The 350 kHz to 600kHz square wave that is the carrier for the audio signal must not be allowed to vary beyond what is dictated by the audio signal, because variations in time will automatically translate into a lower frequency that is put on top of the audio signal; and from this point on (if it will pass the output filter) it has become an undistinguishable PART of the audio signal.Who is going to separate these two? There is as of yet no system capable of determining which part of an analog audio signal is distortion and which is the undistorted music part. Would be fancy, just taking the distortion out of your music, at the end of the chain! Would take a hell of a library to store all possible sounds, number them all, and have them available for comparison at lightspeed...
Class D has its own set of distortions, and it will take time to iron them out. But they are fewer, and they are easier to understand.
No more hassle with thermal compression, negative feedback that is always too late, output transistors that loose all their current gain when emitter currents reach over just a couple of ampères, or open loop bandwidths of just a couple of kHz introducing horrible phase distortions.As Ric sez: the revolution has begun.
I say: Beware of "poyama people" that want to block progress because they just can't handle it. Or don't understand it.
.
Regards,
Metralla
There are several companies that are doing this (usually with many patents). Sony, TI (they bought Tocatta Tech) and Apogee all have pure digital input modules. Sharp also.PCM can be upsampled to DSD or to higher sample rates before conversion to PWM (class D). It is much easier to design an analog input class D amp then it is to make one with pure digital input. That is why there are so many analog input amps. But with the TI, Apogee chips, (I don't know if Sony will license its technology to others), and others coming, the pure digital path is coming to roost. Tact was the first (using Toccata Tech, now ownded by TI) but look at the progress. Tact's first two channel amp was $10,000 and now you can buy the Panasonic with 6 channels for $300!!!!!
Sony is releasing some very interesting pure digital products. One you mentioned was the XA9000ES with the top of the line new digital receiver. This receiver does 200 watts a channel for 7 channels. It can accept the digital SACD or CD info from the XA9000ES and goes directly to the amp with no conversion to analog. Another even more interesting (to me, at this point) product is the new Sony AVD-S500ES DVD receiver. This 6 channel-80 watts a channel(8 ohms)receiver is pure digital and has a built in DVD/SACD player. So the DSD and PCM info go directly to the built in digital amps......Now we are talking...no cables even. This machine lists for $800 and will naturally be discounted. This, I want to mod!!!
The Panasonic recevier has 100 watts a channel of pure digital in but can only take up to 24/96...no DSD. It uses the TI main chip and supposedly sounds quite remarkable.
This is just the beginning. I predict that within 5 years all commercial lower cost gear will be digital (analog and/or digital in) and that more and more high end companies will have digital amps (both digital and analog in). The revolution has begun.
As far as RF, this has ever been a problem with digital, so a digital amp is just the same. Some people who have these amps (both digital and analog in) think they sound quite remarkable. Of course, they will get better, just as SACD players, etc. have all gotten better.
So far, only the Sony and Sharp can do DSD and PCM direct into the amp, but I am sure, more will follow.
No, these digital amps will never sound like tubes (notice the Solar Hifi guy putting a tube in front of the digital module for "increased" musicality). But hopefully, they will be transparent to the source. We shall see. Ever the optimist.
Yes, digital technology has certainly moved along fast. It also has a ways to go.
If you care about measurements, a lot of the digital gear does not test very well.
It is not entirely transparent either, as various implemmentations have differing sonic signatures, call it "coloration" or not.
There are also various complaints of noise and hiss out of the new Sony ES digital receivers
I am not saying that analog is any better, just that digital is not the end-all be-all (yet?).In the end, it comes down to system synergies, budgets, priorities, source material quality, long vs short term listening etc etc - and each persons situation is obviously different. Just like a Ford Tauras stationwagon is not the best car for all of us.
And that is why this hobby is so much fun (or not)!
Considering the different DACs on these two units, has anyone done a direct listening comparison between the 2200 and the 2900? I am still looking for a less expensive SACD player for my secondary music system; even if cost is a consideration, is it worth spending the extra $400 for the 2900 because it is a subtantially better player?
I would also look at the new Sony DVP-NC555ES with Euromods (from Oade) for less than $600 with full warranty, or even the Marantz 8260 for around $800.
According to the Japanese Stereo Sound Mag, JPY 350,000.Regards
PS Yeo
1. how does the 1738 compare to the 1732?2. have you heard any direct comparisons of the 1738 against the 1792 or 1794 (ie in otherwise identical ancilleries in a custom built "DAC box")?
TIA
1732? Is that the one with the HDCD filter? Whatever it is, it is not on the TI site(where I just looked anyway). If it is the one with the HDCD filter then it is just a 1716 with the built in HDCD filter....if I remember correctly.No, I have not heard of anyone playing with a 1792/1794 chip and/or comparing to 1738....They are in the same family....they just tweaked the perfomance of the 1738 more, with higher current, separate power supply feeds and a better digital filter...so I imagine, the 1792/1794 would sound better. I am sure some manufacturers have it and are prototyping it for next years (maybe late this year?) players. Stuff is usually designed months ahead of release. We do have the 1790 now and it may be as good or close.
Then how would the 1716 compare to the 1738?
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