Substitution for no longer available AD 1955 AD1955 Evaluation Board

[tiefbassuebertr]

I have used several times the AD-1955 demo board like that from the photo by post #9 about
AD1955 Evaluation board schematics
and the photo URL
http://www.diyaudio.com/forums/attac...amp=1191364151

Unfortunately the AD-1955 demo board is since several years no longer available

This board is much more better than the DAC Yulong DAH1 (DAH-1)
to find about this weblinks:
YULONG DAH1 MARK DAC /Pre amp/headphone amps : hi-end headphone amplifier
Yulong DAC DAH1 Mark headphone amp - Head-Fi: Covering Headphones, Earphones and Portable Audio
and the attached photos

The main disadvantage of Yulong's DAH1 (DAH-1) are the very hot voltage regulators (with the small heatsinks). I have this problem solved by screwing this voltage regulators on the inside of the alu housing (no longer there are this hot spots on the PCB). This work was very unpleasant and time consuming.

I want to have similar evaluation board than that one with AD1955.
Which type could be an adequately substitution (same sonic quality)?

[Marlowe]

How about the WM8741 evaluation board?

Wolfson Microelectronics plc: WM8741EV1M, WM8741 Evaluation Board User Documentation

[Nazar_lv]

I want to have similar evaluation board than that one with AD1955.
Which type could be an adequately substitution (same sonic quality)?

for what you need this board?

[abraxalito]

What about this DAC? - it has a replaceable module for both the AD1955 and PCM1794. Price looks to be very reasonable here in China (around $220). At least two of the regulators look to have heatsinks

HA-INFO NG94 MkII

[tiefbassuebertr]

Originally Posted by Nazar_lv

for what you need this board?

for music reproduction in high quality

[Nazar_lv]

for music reproduction in high quality

from EVB? sorry but not funny...

[tiefbassuebertr]

Originally Posted by Nazar_lv

from EVB? sorry but not funny...

Yes, from EVB.
A much more better solution it would be the redesign of an ultimate DAC (what I am doing in the moment), which is still considerably better than this EVB but also much more expensive.
A series of features here will be found, which we find nowhere else - e. g. switchable NOS/4xOS/16xOS, different DACs and switchable different reclocking variations.

The EVB for AD1955 uses for low-pass filter and output stage of the AD797 - for this price really not too bad. The DAH1 from Yulong uses instead AD797 the OPA2134. But I don't know, whether this is the only reason for not so good sound by DAH1.

Therefore I want to find this EVB from Analog devices and that is the reason to start this thread. If there are used devices, I am also interested.

[abraxalito]

Originally Posted by tiefbassuebertr

The EVB for AD1955 uses for low-pass filter and output stage of the AD797 - for this price really not too bad. The DAH1 from Yulong uses instead AD797 the OPA2134. But I don't know, whether this is the only reason for not so good sound by DAH1.

Therefore I want to find this EVB from Analog devices and that is the reason to start this thread. If there are used devices, I am also interested.

In my limited experience with the AD1955, the output filter components have a big influence on the sound quality. The best-looking published filter to my mind is indeed the one that AD shows with the AD797s on the EVB - with the notable exception of the 100pF cap between the complementary DAC output pins. Do you have a schematic for the Yulong output filter? - I might be able to make some suggestions to improve the sound. The AD EVB has one notable omission - analog supply regulators - as designed, it does require a low noise, low impedance external supply.

[Nazar_lv]

The EVB for AD1955 uses for low-pass filter and output stage of the AD797

one of the worst opamp for standard i\u and high output current dacs

[abraxalito]

Originally Posted by Nazar_lv

one of the worst opamp for standard i\u and high output current dacs

Worst in terms of sound quality? Or worst tech specs for this purpose?