Accuphase multibit vs delta sigma products

[Mattia]

With all the discussions about multibit vs delta sigma that new Schiit audio multibit DACs have brought to life, I wonder what is your take about the question, specifically regarding Accuphase products.

First, I must point out that I am not interested in SACD, DSD or PCM hires material, simply because 99.9% of the music I am interested to is only available in PCM 16/44, so one advantage of modern delta sigma products does not really matter to me.

I have, and therefore can compare, a DC-81L (discrete resistor ladder), a DP-75 ("mmb" 16x PCM 1702) and a DG-58 ("8 mds++" 2x ESS 9018).

To be as precise as possible, without adding speakers & room distortion to the result, I compared them with headphones: Stax 009 + 007 amp, and Accuphase 2420 + Audeze LCD-2.

The result surprised me a bit.
There was not, in my opinion, such big differences that 26 years in audio evolution should have brought to the table.
If one follows what it is said every time a new product comes to market (e.g. "It is better than before") then the DG-58 (even if is not a dedicated top-of-the-line DAC, but Accuphase says it is "electrically not too different from DP-720", that is also "electrically not too different from DC-901") would have absolutely trounced the DC-81L in every aspect.
But in my absolutely humble opinion regarding these three machines, that is not the case, or maybe the DG-58 really is "better", but big differences really are not that perceivable by my ears.

Anyway, to me the DC-81L sounded a bit more bright and seemingly more detailed than the others, while the DP-75 was the most smooth in the high portion of the frequency range. The DG-58 is a nice compromise between the two: relaxed but still resolving, and a little more "really void" space between instruments positioned on the scene.
Other than that I could not ear differences such as timbre, timing, decaying time or other characteristics I sometimes read. All three sound "good" and noise floor at normal listening level is practically zero.

So maybe you can help me learning something interesting. What should I pay attention too? Wich song or particular instrument do you suggest that could tell apart such different DAC typologies, born 26 years apart?

As I said, they all sound really good to me, and that is the important part, but I also like to learn


(addendum: my DG-58 is one year old, the DC-81L was recently restored by Accuphase (some capacitors changed and a somewhat mysteriously-translated from Japanese "distortion regulation") and the DP-75 has never been serviced. So maybe his "smooth & soft" sounding is related to that. Also, to avoid differences, the DAC portions of all three were tested with a DP-80L + CD and then with Oppo + Tidal as source).

(addendum 2: I know that is not only the simple DAC that gives a sonic signature, but PSU and analogue output stages are important. I just assume that in hi level Accuphase products, these aspects are a-ok. Maybe just a bit more refined in top level.)

[bart]

Thank you Mattia, for an honest report.

[Mattia]

Well Bart, trying to learn something while enjoying music

Just like to know other people impressions about digital to analog conversion of vintage Accuphase products compared to modern ones, when used with PCM 16/44 material.
Because maybe if Accuphase waited 8 years (and SACD "necessity") to bring to the market the successor of the DC-91 (1992-2000), they thought that for Redbook CD a 32x PCM63 arrangement like that was optimal to the format.

Then we have PSU (I don't think there were big technology improvement in that field. Am I wrong?) and analog output. Regarding this last aspect, is for example an analogue out of say a DC-901 better than the corresponding DC-91 one?

[Elberoth]

Mattia - you are not alone. I also like the discontinued 800/801 combo (multibit) much better than the current 900/901, which is ESS based (delta sigma). Sounds more organic, more real, with greater tone density.

[Mattia]

Hi Elberoth, thank you for your impressions! I sometimes have spoken with people that preferred the 801 because the 901 was, in their opinion, a bit too "detached".

I should point out, however, that the 801 is also delta sigma based (in the title of the topic I was referring to really vintage multibit R2R solutions, sorry for the confusion):
8x AD1955 chip from Analog Devices http://www.analog.com/media/en/techn...ets/AD1955.pdf

And that fact opens the all new topic: not all delta sigma are similar or equal in the sound (obviously).


Anyway, maybe I also should look at the matter in another way: a DG-58 with two ESS9018 and a digital/analog shared PSU is capable, with Redbook CD, to obtain results that are similar (slightly better, slightly worse: depends mostly on tastes I think) to the results that 26 years ago required a obscenely costly discrete ladder DAC arrangement and top notch separated PSU (DC-81L), or 22 years ago required 16x PCM 1702 chips, that are not cheap by themselves and also they require all their bells and whistles (DP-75).

In that respect, there was indeed an evolution. If built today, with current component, labor and material costs, I think that a machine like a DC-91 or worse a DC-81 would have a really, really high price tag, even by Accuphase standards.

[Elberoth]

You may be correct. But still - all those AD1955 based designs sounded better to my ears than the current ESS based ones.

[Mattia]

Sadly I never could directly compare the latest generation Accuphase machines to the previous one (E.G. DP-700 vs DP-720 and 900/901 vs 800/801), but as I said, your findings match various sources I read or spoken to.
I think there was also a review in a Polish audio magazine that had exactly your same opinion, but I don't remember witch one.

There are also those who prefer latest ESS based machines obviously, so maybe it is also personal preferences or different systems/speakers/room combinations at play.

[One and a Half]

For the S/PDIF input on the DP-720 analog out compared with Playback Designs MPD-3 analog out, I will give the sound quality advantage to the MPD-3. The USB source from the computer is treated with an Intona Isolator, and two Mutec MC-3+USB converters. The MC's have a parallel output of an AES3 and S/PDIF fed into each DAC, so it's easy to compare.

Inherently AES3 is the less noise transmission, whereas S/PDIF in the coax is unbalanced and can suffer from shield noise, it's just inevitable. AES3 has the transformers to isolate again, whereas S/PDIF does not to meet standards. I've tried transformers for S/PDIF plus less gain into the DP-720 don't bother.

However. Play an SACD or a CD for that matter in the DP-720 and it can walk over the MPD-3 when played with DSD or CD material of the same album. The main advantages are that individual instruments can be easily identified in a 3D space, the soundstage is wider and higher. The MPD-3 has a very good soundstage and can also reproduce micro-details, but the smaller universe in the DP-720 does have its advantages.

This is the first Accuphase SACD/CD player I've owned, so cannot compare directly with vintage Accuphase players.