Accuphase DG58 Necessity or Novelty

[nvp]

Originally Posted by Mattia

But nvp said that for maximum transparency one has to set gain to zero and lower the level on the source

I am not sure to which of my previous answers you are referring. What you have written above is not true when one has a pre-amp. Therefore, if I have said what you have written above, then I was referring to your situation, i.e. no pre-amp.

I’ll try to clarify the situation. Most likely, I was talking about how you should check that your DG-58 unit is 100% transparent and does not degrade the sound fed to it from a digital player. To do such a test you would need to disable the room correction and equaliser functions and also to set the gain to zero. However, since you do not have a pre-amp you would need to lower the volume from the cd player as otherwise you might damage your speakers/ears. Once you have done all these, you can start the test by simply switching between the transport and digital coaxial input of your cd player. (Of course, I've assumed that your DG-58 and DP-510 units are connected via the digital coaxial connection.)

I have suggested to set the gain to zero so you can do the comparison on the fly, i.e without the need to readjust the volume each time you switch between the two inputs of the DP-510. Be aware, however, that when the gain is set to zero the DG-unit can be overloaded if you play music with large dynamic variation.

[Mattia]

Martin,

The .dg5 files serve to save/restore DG-58 settings to/from an external USB storage device.
I couldn't open them on my PC (file format unknown). It must be a proprietary Accuphase file format containing all DSP parameters for a given memory location.

Yes, same for me.

The only possible program that I found out that outputs/reads .dg5 files was this one DeltaGraph .

But they don't offer a reader-only nor a demo, so... but out of curiosity maybe I can contact them to see if there is a connection

[Mattia]

nvp

in fact I was referring to this bit:

I can corroborate your findings about the transparency of the DG units. (...) To achieve this, however, one has to set the gain of the digital input to zero, i.e. the digital signal that enters the DG units should not be dumped at all.

But no worries: all is now crystal clear

You were referring to *test* the transparency, not in normal use

[nvp]

Originally Posted by Mattia

Just to have a bit more food for thoughts,
I understand that both the DC-901 and the DP-720 have the EXT-DSP option, useful for putting my DG-58 in the loop.

Now, in the nvp idea (using DP-720 directly to power amp and regulate with it the volume - or level), what would likely give me better results between DP-720 and DC-901 in this scenario?

Because if the results would be equals or similar, I'd get a 720 and have a "free" player

Then again, if the DC-901 would be markedly superior regarding DA conversion (note: I am not particularly interested in new hi-res formats, nor interested in USB from computer), I'd opt for it. Also the more digital inputs of the 901 would be interesting for me (more than having a SACD drive).

What do you guys think?

The EXT-DSP connection is not necessary, viz. the DG units can be connected in a loop with any (Accuphase) player that has a pair of “in" and “out" digital connections. As far as I know the DC-37 DAC is the only recent Accuphase digital unit that does not have the required digital output connection.

Regarding the DP-720 vs. DC-901 issue, IMO there are pro and contra arguments for each choice:

DP-720 pros:
- a single box
- requires no additional cables
- requires no additional transport
- very good volume control
- has large and bright numerical led indicators (which can be seen clearly even when one sits 5 meters away)
- it is bit cheaper than the DC-901

DP-720 cons:
- only 4 digital inputs (though you also have those in the DG-58 unit)
- DAC section not as good as the one in DC-901 (though of very high quality)
- its volume control may not be as good as the one in the DC-901 (I only speculate here as I did not try the DC-901)
- limited format decoding capability given its price

DC-901 pros:
- state of the art DAC
- many digital inputs
- it might have a better volume control than DP-720

DC-901 cons:
- two boxes together with your DP-510
- more expensive than DP-720
- since your DP-510 does not have a HS-link connection you are forced to use the digital coaxial/optical connections which in my opinion are inferior
- small and not very bright led numerical led indicators
- limited format decoding capability given its price

[nvp]

Matia & Martin,

Regarding the .dg5 format, I am wondering whether these files are actually meant to be open by the users. Maybe they contain information that is meant to be read only by the DG-58 unit, e.g. equalisation curves and target curves for the room correction algorithm. Did any of you try to open these file with a text viewer?

[Mattia]

I tried the classic "drag to Notepad" trick on a borrowed Win PC, tried various programs under OSX to no avail.

It shows only garbage, so I very possible that they are meant to be read only by the DG-58.

But I am very curious

Plus, knowing that the DG-58 uses a Windows derived OS, maybe Accuphase only licensed the software I linked to package the information.

Does the DG-48 also output .dg5 files?




Regarding your Pro and Contra, It is a very well written, objective evaluation! Problem is that for me there is not a clear "winner" between the two

On the volume question, I think on paper the DC-901 should have a slight edge due to the double amount of the ESS Sabre 9018 chips averaged and consequent even lower noise floor.

But I also bet that I would anyway be absolutely incapable to ear any difference, even with speakers waaaay better than mines

On the digital/analog volume question, here is an interesting paper:
http://www.esstech.com/PDF/digital-v...me-control.pdf

I cite the conclusion:

Conclusion:
– Analog volume controls easily outperform digital, unless the digital control has access to the data path of the DAC
(ie is internal to the DAC)

– Exquisitely well designed analog volume controls can still beat even the very best internal digital volume controls if they have a lower noise floor than the DAC itself

• The -135dB of the ESS Sabre DAC would need an exceptionally low noise analog volume control to beat its internal digital one

Now one just has to know from wich Accuphase Preamp lineup (if not all) we start to have a lower volume noise than -135dB.

[nvp]

Matia, as promised I compared the sound of the DP-720 -> A-65 and the DP-720 -> C-3800 -> A-65 combos. I have used the following songs for comparison:

1) Richard Strauss - Symphonic Poem (Track 1 on the Accuphase “gold" SACD)
2) Johann Sebastian Bach - Toccata and Fugue (Track 1 on the Accuphase “blue" SACD)
3) Arvo Part - Silentium (Tabula Rasa album)
4) Musica Nuda - Eleonor Rigby & Imagine (Track 1 & 15 on the album Musica Nuda)
5) Josefine Cronholm - In your wild garden (Track 2 on the “The Dali CD vol. 2”)
6) Dream Theater - The Mirror (Track 7 on the Awake album)

(Unfortunately for you I have no G'n'R albums.)

I did short (10-20 second) and long (i.e. the entire song) listening test. The volume was matched by hand & ear as I was too lazy to use my dB meter. (So not the most accurate test.)

To cut a long story short the DP-720 -> C-3800 -> A-65 combo sounded better than the DP-720 -> A-65 combo. Given the level of the C-3800 pre, however, I do not think this is surprising. On the other hand, the DP-720 & A-65 combo also sounded very very good. Without the direct comparison with my full system, I would have had a hard time to find flaws about its sound. In fact, the sound of the DP-720 -> A-65 combo was so good that in the beginning of my test I have started wondering whether it would not be better to sell my C-3800 and A-65 units and buy a pair of A-200 instead.

Regadring the actual differences in sound, with the C-3800 pre added between the DP-720 and A-65 the music was more relaxed and a bit fuller. When moving from C-2810 to C-3800 I have noticed a significant improvement in the bass, i.e. significantly more bass which went lower but was also clearer and better defined/focused. In the case of the test I have performed yesterday, this was apparent only when listening to the tracks "1)" and "2)" in the list above. Both these pieces have a lot of low level bass and the addition of the C-3800 provided a more visceral presentation. (I should stress though that the DP-720 & A-65 combos had killer bass too.)

One analogy that IMO sums up quick well the differences between the two combos, is the differences between two world-class virtuoso drummers. That is, a younger drummer (the DP-720 & A-65 combo) who feels the need to draw attention to himself and to impress the audience, and an older drummer (the DP-720 & C-3800 & A-65) who technically is just as proficient as the young one but does not feel the need to draw attention to himself, i.e. his goal is to serve the music. The two drummers are both spectacular, which one would one prefer it's a matter of taste (and money!).

There is one important thing I need to stress. That is, you need to test the DP-720 (or DC-901) vs. the C-2420 on your own amp. My experience is that the results you will obtain depend strongly on the amp you use. As I have mentioned before, the C-2410 pre made a big positive difference when used between the DP-600 player and the A-45 amp, but it made a small difference (if any) when used between the DP-600 player and the A-65 amp. It is possible, that like the A-45 your P-700 is not “transparent" enough (for lack of a better explanation) to be used without a pre-amp. (Also, a friend told me that after connecting his DC-801 DAC, which also has a good digital volume control, directly to his P-650 power amp his system sounded like a clock-radio.) Consequently, I would conclude that while the noise floor of the pre-amp and the DAC implementation are very important, they do not tell the whole story. The power amp used also plays a crucial role.

Finally, note that there are also some discussions (not very many though) on this topic on audiogon. Bvdiman (who is also active here) has tested the DC-901 vs. the top of the line FM Acoustics pre using the Accuphase A-200 monos. His report can be found on a thread about the C-3800 pre. Further, there is somebody there (aka Maxen) who is using a DP-100/DC-101 player connected directly to a A-60 power amp. If I remember correctly he has found the C-2810 pre unnecessary in his system.You might also want to check those discussions.

[Mattia]

nvp,
thank you for your in-depth comparison! Much appreciated

Plus, and it is a bit plus in this kind of comparisons, you absolutely do not seem to have the sadly common "I've bought it so it must be better at all cost" approach, but a much more objective, scientific one. So I trust you judice.

Your findings are also very interesting.

A pair of questions.

Do you think that the (slight) differences you encountered would not be "matchable" or coverable with a slight tune on DG-48/DG-58?

What is exactly is your definition of "transparency" on a power amp? Being able to amplify without adding absolutely any coloration on the signal?


Regarding my (ultra limited) experience with P-700 and an Accuphase preamp, the coeve C-275 I used to have added his signature, but not what one might expect. Instead of the typically slight rolloff on high frequencies of old machines, I had a slightly more "present" presentation, a bit more tiresome that the direct connection player-->P-700.

(I need to tell that all those nuances in my case where *minuscule* in comparison of the ambient and EQ variables. I think ambient treatment was by far my most discernible investment).

[Banter]

This discussion is going way over some of us! At least I do not care if it uses Archimedes principle or Isaak Newton's – all I care is it does what it says and does it well.

But for many of us what is important is – It is not a USB DAC. Therefor for many of us with analog sources Analog connection is the only way to go. I do not see any harm in that.

[Mattia]

At least I do not care if it uses Archimedes principle or Isaak Newton's – all I care is it does what it says and does it well.

I always like to know as much as I can on how the machines that I use work: more often than not that has given me the possibility to use them to their maximum potential.
Plus it is interesting

Therefor for many of us with analog sources Analog connection is the only way to go. I do not see any harm in that.

Me neither, but nobody here said otherwise I think