Monday, October 18, 2010

Audio-Gd DAC19 DSP

Talk about quick shipping ! My order with Audio-Gd has been pending for quite some time now as I wanted some customised inputs done (gave up the USB input to convert to another coaxial input). It was shipped out on Saturday afternoon and arrived in Singapore at my doorstep on Monday evening.

The order process was hassle free and the unit was well packed and arrived in good shape.

The DAC19 is based on two Burr Brown PCM1704UK DAC chips paired with Audio-Gd's proprietary DSP filter. Audio-Gd's principal, Mr. He Qinghua has made an announcement that he is discontinuing his products based on the PCM1704UK due to difficulties in obtaining supply of the chip. That was enough reason for me to take the plunge.

You can refer to http://www.audio-gd.com/Pro/dac/DAC19/DAC19EN.htm for full technical details.

The DAC-19 in finished in a shoe-box sized case that is rather utilitarian. The case is decently finished and will not win any prizes for either fit or finish. Given its asking price and performance, this is acceptable to me. I can do without paying a lot more for a snazzier case that does nothing for performance. There is a little bit of free play on the front selector switch, but otherwise, the rest of the switches and jacks are functional and do the job.

It has been suggested elsewhere that the DAC-19 is not particularly sensitive to quality of transport, digital cables etc, or power cables, by reason of its powerful jitter reduction and power supply quality respectively. I believe that it is wrong to disregard those factors and use of the DAC-19 over the short time I have had it suggests that strong dividends may be reaped by paying careful attention.

Transport duties were handled by Slimdevices Squeezebox 3, linked with Oyaide's DB-510 digital cable. Out of the box, the DAC-19 sounds detailed and resolving in the midrange and high-frequencies, albeit sounding a bit bleached and light weight. Bass in particular is not deep or impactful and the overall balance is a bit dry. Things changes drastically after extended burn in, with vast differences heard past the 50 hour mark and 200 hour mark. New owners who suffer from buyer's remorse upon hearing the DAC-19 would be well served to persist in their burn-in duties and not give up !

Once well cooked, things become a bit interesting. Both the top and bottom end of the DAC-19 open up and you get tight tuneful bass, as well as extended and airy highs. What you do not get is any form of euphony or colour in its presentation.

Comparing the DAC-19 to my Lite DAC-50 was an academic lesson in extremes. First off, my Lite DAC-50 is quite extensively modded, with changes in the power supply as well as some circuit modifications in its tube output stage and coupling caps. Once modded, the Lite is rich, organic while sounding open and dynamic. It would be considered by most to be a musical sounding DAC. It also has a strong sonic signature and its richness of tone as well as its weighty and deep bass are obvious in all recordings.

The DAC-19 sounds neutral, rich or lean, depending on the recording. It seems truer to the recording than most, and as such will not help systems that are deficient in certain areas. As such, the DAC-19 would work best in systems that are already well-tuned for a neutral  source. Paired with the Acrolink 4020-7N power cord, the DAC-19 sounded a bit bright and thin. Changing the power cord to Acrolink's factory terminated 4030 power cord fixed this..

Similarly, a bit of tuning was needed in respect of the footers supporting the DAC-19. A trio of Finite Element's Ceraballs made the sound too forward. Replacing that with Golden Sound's DH cones struck the best balance between cleaning up the sound and adding some weight to the presentation of the DAC-19.

Describing the DAC-19's sound is more difficult than most equipment, because it does not seem to have any intrinsic sonic signature of its own.However, after extended listening, the one striking quality of the DAC-19 is its ability to resolve and present instruments and voices in the most complex of mixes in a coherent, well placed and separated manner. The Lite DAC has a tendency to spotlight the main vocals and principal accompanying instrument, with the other instruments relatively obscured. The DAC-19 resolves both well, with a surprising amount of low level detail that is not immediately apparent on other equipment.

For it's asking price, resolution of this nature is class leading. I am quite sure that a DAC of this quality with a Western manufacturer badge and snazzier case could easy cost 3 times as much as the Audio-Gd. If you are looking for a DAC that digs deep into your recordings and presents a true picture of what's there, you would be well advised to check out the DAC-19.






Pictures from Audio-Gd's official web-site

Postscript

My Audio-Gd recently started losing sound in one channel (December 2013) after 3 years of ownership. I loaned the unit to a friend and he was getting intermittent drop-outs that were almost impossible to recreate.

When I received the unit back, one channel was totally dead. I popped the hood and reseated the DSP board, and it works perfectly now. My guess is that despite being tightly screwed down, the pin connectors may develop contact issues over time. The movement during transport certainly didn't help. Worth a shot if you having problems with your unit.

13 comments:

Anonymous said...

What's better for original sampling playback? DSP or DF version? Have you any ideas about this (I was trying to find out without success)?
P.

Eric said...

Hi, I have not directly compared the DSP against the DF version so I cannot comment personally. However, some have said that the PMD-100 is musical while the DF1704 is analytical. The DSP is said to have a balance in between the PMD-100 and DF1704.

Handoko said...
This comment has been removed by the author.
Handoko said...

Hi Eric, would you share the tweak taht u did to your DAC 50? because ! have one and want to do some mods too.. thanks

Eric said...

Hi Handoko,

Do you find your DAC-50 warm, but lacking in resolution, and very recessed sounding ?

The most obvious modification is to bypass the cathode resistor with a capacitor. Sanyo Oscon works very well for this. I tried Panasonic FC, Blackgate, Cerafine and Silmic, but the Oscon still is preferable to my ears. 180 uF/20V works well.

The second modification is to convert the C-R-C power supply to C-L-C, but removing the resistor and substituting it with a good quality choke.

You could also do other things like upgrading the coupling caps etc, but I find the above two modifications are the most effective. If you leave me your e-mail address, I can send you the schematic.

Handoko said...

Hi Eric,
I did a few tubes changes, from Siemens gold pin, Siemens CCa, Amperex bugle boy and Mullard box plate. When i using Mullard box plate the sound is recessed but the others make the sound a little bit forward in my humble system.
yes, please send the schematic to my email address; sensphoto [at] yahoo [dot] co [dot] id.
I planned to upgrade the quality of IV Resistor and using tube rectifier but i will follow your suggestion at first.
Thank you very much

Handoko said...

Hi Eric, I put Oscon 220uF on cathode resistor the sound is amazing, more resolution.
i do some change in digital filter(c10-r2) to be 220nF and 270 Ohm, bypassed with 3n3, in my humble opinion the sound now more analog and separataion is better.
I put SideReal Caps for coupling cap to replace the stock cap, this week will try old PIO Cap
I'm still waiting for Riken resistor for IV R and 10H/100mA choke.
thank you

Eric said...

Hi Handoko,

I am glad you like the modifications.

I can't remember what resistors were used originally for the I/V, but I remember changing some of the values and using Dale RN55 resistors.

The Lite DAC-50 once modded still has a warm sound, so I preferred to use more "neutral" coupling caps, compared to more musical and liquid caps like PIO types.

Do let me know if you like the choke in the power supply. You can also consider bypassing (in parallel with the existing electrolytic cap) the last "C" in the power supply with a 1.5 uF MKP cap

Handoko said...

hi Eric, last night i try to bypass the last elco with PupCap (NOS film cap 2uF/600v) and i blown up the R in CRC network (150 Ohm 3 watt) and still dunno why :)

Eric said...

Hi Handoko,

Sorry to hear about your mishap.

The bypassing of your elco with such a small value should not have resulted in any damage to your power supply.

Handoko said...

Hi Eric, I put 5H/180mA Permako choke as a replacement from CRC to CLC DC Supply, the sound is amazing, clearer and more precise in staging.
the treble and bass more balance.
this week end will try 10H.
thanks for the advise.

George Ho said...

Hi Eric, I like your blog. I got an Audio-gd 19MK3 having the same problem as yours once had. One channel no sound and before that there were some drop-outs. I tried your method but not as lucky. Maybe I should check is there any bad soldering being developed over time on the pin sockets of the DSP board. Anyway your encounter surely gave me a good place to start off to troubleshoot my DAC19.Cheers and keep writing.

Eric Teh said...

Hi George,

Sorry to hear about the mishap. Yes, I would carefully check all the connections and soldering on the DSP board again.

Regards

Eric