Audio-GD audio global delivery

audio-gd gears fans centre for discussion.

pin - dsp setting

http://www.head-fi.org/forum/thread/483899/review-of-the-audio-gd-dac-19-dsp-c2-amp-the-acss-connection/405#post_6701065

A little bit about the Audio-gd company and its gears. The designer behind Audio-gd is Mr He Kingwa, a honest and humble person who prefers to maintain low profile. Audio-gd is a small company out of Guangzhou China. He was the First Prize winner of the American National Semiconductor Audio Design Contest. Among the diy community, he is wellknown for selling the discrete opamp (Earth, Moon and Sun), power supplies and current output interface. Quality is his trademark and looking at his system layout will reveal more. His headphone amps are one of the top leading products among the head-philers.

His gears are sold all over the world and a large follower of audio-gd products
are from mainland China and Hong Kong. Recently with the aim to go glabal, Audio-gd has reached far towards many corners of the world as shown in its delivery consignment page.

Audio-gd gears are best enjoyed with its signature current mode. Such design simplify the expensive interconnect cable requirement but places a strict requirement on circuit design and component selection. Current mode transmission is not new in the hifi gears
as shown in the Japan Satri and Krell Evolution.

The reference DAC has a built in DSP as iin most of recent high end DAC.At The digital front end stage, The DAC uses DSP processor (Altera) which has user selectable settings such as 8x,4x,NOS/Phase Lock Loop, dithering/stopband frequency. Such technology are usually found in highend gears such as Esoteric, Boulder, Simaudio, Wadia, etc. The result of using the DSP processor for filtering is smoother and clearer sound (less jitter dependent) even when low quality transport is connected. In default config, it is 8x oversampling with Phase Lock Loop On and dithering On.
http://www.audio-gd.com/Pro/dac/DSP1/DSP1CHspecs.htm

The decoding uses the R-2R ladder dac through 8 nos of 24bits BB PCM1704U-K (4
chips per channel in fully balance output). PCM1704UK is a 24bit/96KHz capbale
DAC. Matching of DAC chips, good selection of audiophile components, careful
power supply treatment and attention to analogue output circuit is the key to
the good sound of Audio-gd DAC.

The Audio-gd top flight DAC comes with 2 different flavour. The ref 1 or ref
7(from the same group) belongs to the neutral group while the Ref 8 belongs to
musical group.

At the output stage, they are many debate as to neutral flavour vs musical but
in short

"neutral" as in neutral and faithful like, doesn't have any particular
character.Usually apply the ACSS (current based, thus avoiding expensive xlr/rca
cables) technology to get neutral sound. The current based connection is not
newsuch as Japan SATRI and Krell CAST technology.
http://www.audio-gd.com/Pro/dac/RE7/RE7EN.htm

The "musical" flavors mean the gears always have a little coloration, slightly
on the warm and soft side, it can bedeck the shortcomings of your source and
musical files.
http://www.audio-gd.com/Pro/dac/RE8/RE8EN.htm


On the downside, the DAC is rather expensive due to expensive components being
deployed and the software development costs of DSP processing. However compared
to the highend gears such as Esoteric DAC (D1) or the Mark levinson, its costs
is not so formidable.

Hi Chua,
Which Audio GD equipemtn you have?
I have a DAC 19 Mk3 with PCM-100 fitler chip. Mine is with Jumper setting. Up to now I still dont know how to do setting on it. Basically it does make change to sound..

Also still wondering how to convert RCA plug to ACSS.. if it is possible. Thanks.

The ACSS is inherent in the design and convert to RCA (using a resistor). In its native form, ACSS is the better transmission medium. Newer model of DAC 19dsp comes with ACSS / XLR but it is single ended.

i heard that there's a new Audio-Good CD player in town ...

Introduction
There are many brands in the market who produce good DAC such as the Cambridge Audio, but i think for the price i pay there are no other manufacturer can provide me such a good specification DAC like the DAC-19 DSP. Moreover, the component used to build the DAC is totally professional grade, the most important is DAC-19 DSP used the nearly discontinue highest grade PCM1704UK DAC chips which we can found in most high end Naim cd player.



There are 2 version for the DAC-19, with DSP or without. Lucky i get the DAC-19 DSP late, Mr. Kinghwa has upgrade the integrated USB transport to TE7022 which the same chip use in Terra Link X2 to support up to 24bit 96Khz digital signal. This is extremely important to me cause i use computer to play high resolution audio files and videos, so i can save the fund for another good USB transport.

The main feature of DSP that integrated, is build by a powerful signal processor to reprocess the signal to reduce jitter. But my experience found, the DAC-19 DSP is still very sensitive to the source!! even the USB cable make a very very big changes!!!, so now i am start to look for a good USB cable @@"

Performance
I has already running in my unit around 4 days 24/7, but I still hardly tell the sound or characteristic, because it sound very clean without any color or characteristic, it is very depends what you feed, the cable or the source, this has prove that the Mr.Kinghwa Neutral flavor DACs.

Since i am not using the Audio-GD's amplifier, the ACSS (Audio-GD Current Signal System) is not used, all the test will using the RCA output and integrated USB transport.



Once the DAC out from the box, it sound very open and the sound stage is grow into very big yet the instrument position(定位) is still very good.
After few days of running in, the most impressed me part is the instrument position, which very solid(紮實) make me feel the instrument is there and the instrument or mouth size scale is much accurate. In addition, the background is so dark compare to my old Tian Yun Zero DAC with Audio-GD Earth OPA.

DAC-19 is also a very good detail digger, most of the songs, the bass normally cover by mid and high which make the bass definition is hardly listen, with the DAC-19 now the bass definition is much clearer but it has no emphasis any frequency, all the detail come smoothly and the attack of the music is much much better feeling like my Nait 5i has a power cord change

DSP
The integrated DSP is the most fun part of the DAC, there are 8 + 5 DIPs switch on the DSP board to control the signal processing option.

chua55 wrote:
Dip 1: if dip 1 is off (default) PLL is active. Dip 1 on = PLL inactive.
Dips 2 and 3 control the amount of stopband attenuation (-50dB, -90dB and -130dB).
Dips 4 and 5 control the oversampling amount (1x, 2x. 4x and 8x).
Dip 6 enables/disables 16bit to 24 bit dithering algorithm.
Dip 7 is famous NOS switch: if it is on (default) oversampling is engaged. Turn it off - you have NOS DAC

The original setting is
PLL active, -130dB, 8X, Enable dithering, Enable oversampling

Few more days after i write this simple review, finally the system is stable down but i found the super high frequency seems much lesser than when i am using the Tian Yun Zero DAC and there is some flavor added in the music to make the vocal more emotional but i feel it is not "live" enough and make the singer more mature, so i consult our board's Audio GD experienced user chua55, he has suggested me to disable the PLL and lower down the filter cut off to the minimum.

Current setting
PLL Disable, -50dB, 8X, Enable dithering, Enable oversampling

After change the setting as above the DAC sound lively and transparent to produce much RAW sounding especially the instrument, vocal has lesser color or flavor but the "RAWness" of DAC has bring even more detail and to let me feel the singer's real emotion. But this has bring some side effects also, because i found this setting has make the sound more analytical to make the bad recording or mp3s sound bad but very transparent when playing high quality records.

For the dithering and oversampling option is remain it enable, because after disable i found the sound even much more analytical and emotionless, sound very flat like studio equipment, moreover when disable the oversampling has bring vocal much forward like listening to headphone.

Conclusion
Good component and designer is the base of a good equipment, i am very satisfy with the performance of the DAC-19, it lead my system to another level of high definition audio but yet is sound very lively, Thanks Mr.kinghwa.

Tips
When playing music with Foobar player, make sure you had change the buffer to the minimum, it make a day and night improve and WASAPI is still the best for me.

Audio GD Reference 1 listening impressions
Having had the Ref1 for some time, the unit has run in to its condition. The introduction of this unit needs no further introduction as described attached. Prior to this, I was using the CD63 modded and Audio-gd DAC 100 which are retired to the Ref 1.
http://www.head-fi.org/forum/thread/416120/audio-gd-reference-1-dac-56-k-warning#post_5546295
To me, my taste of music leans towards clear and direct representation of music being recorded. I would like to my gear to be like a gear, a cup of water. I typically shy away from warm sounds as this will tend to sound color on certain music elements. At the same time, the tonality/timbre of vocal/violin/guitar/sax/cello/Chinese violin/ etc must sound accurate.
The Ref 1 comes with DSP which is a 208-pin PQFP Altera package, Manufactured on 300-mm wafers using, 90-nm low-k dielectric process. Devices offer advanced features for high-performance digital signal processing (DSP) applications with up to 250-MHz.
http://www.audio-gd.com/Pro/dac/DSP1/DSP1ENspecs.htm
On DSP-1 you have two dip switch panels: one with 8 dip switches and other with 5 (see picture). We play just with the one that has 8 dip switches.
Default setting is all pins off, except pin 7 to on
Dip 1: if dip 1 is off (default) PLL is active. Dip 1 on = PLL inactive.
Dips 2 and 3 control the amount of stopband attenuation (-50dB, -90dB and -130dB).
Dips 4 and 5 control the oversampling amount (1x, 2x. 4x and 8x).
Dip 6 enables/disables 16bit to 24 bit dithering algorithm.
Dip 7 is famous NOS switch: if it is on (default) oversampling is engaged. Turn it off - you have NOS DAC
http://currawong.net/head-fi/DSP_settings.html
Pictures of my system
To be posted when ready.

Test tracks
guitar – 1. John Powell – I am Sam, 2. Roger Wang – Platinum Collection
Vocal,piano, cello – Xiao Gang – Please follow me, Bluevolution – The sound of silent
Violin – Master and Commander
Flute – John Neptune Kaizan - Korea Idea
Modern/drums – AR Rahman – Robot, He Xun tian

Listening gears
Audio-gd CD7FV -> Ref 1 -> Audio-gd C3 FV -> DIY pass Lab Aleph J -> Dynaudio Focus 140 [with Richard power company 400]

Initial Sound impressions
As I was using listening to John powell track 1 guitar, I notice guitar sound fuller and lively compared to my earlier cdp and dac. For flute, I usually play the track by John Kaizan Neptune - Korea Idea track. This track also place a demand on bass and dynamic reproduction. Without the juices and the correct DAC, the bass will sound lethargic or weak. One can hear the gasping sound while inhaling the air. Going on to vocal, the tonality is well balance and good vocal representation. On the soundtrack Master and commander, the pace of the music seems well balance with drums sounding so effortlessly. I can hear better low level details than I used to and better texture from the acoustic/bass being played. Overall listening to this dac is very satisfying as I get good accuracy and detail with this piece of instrument.

A picture says a thousand words

Gears used for the listening impressions

transport : Audiogd CD7FV

DAC : Audiogd Ref 1

Preamp : Audiogd C3 Final Version
http://www.audio-gd.com/Pro/pre/C3End/C3endEN.htm

Power amp : Audiogd C1 SE
http://www.audio-gd.com/Pro/amp/C1SE/C1SEEN.htm

Speakers : Dynaudio Focus 140

Richard Gray power company + AudioGD power conditioner
Cables connection - ACSS current transmission

Hi,
I've just send my final payment for my Audio-Gd ref 7 Dac to "kakibook" today. Hopefully to be delivered by this Sunday. Will be using it with Esoteric DV50S as transport. fed into Bel Canto Evo Gen 2 and ProAc Response 2.5. My other source is through M2Tech Evo hiface with Audio-GD usb interface power supply (ordered with ref 7). Looking forward ...

welcome to audio-gd. the stock unit has some settings that can be adjusted to your taste and gears. just refer to the earlier post for the dip settings.

When I put the PLL ON (meaning PLL deactivated), I hear more details as my source clock is more accurate.

Putting on pin 2 and 3 (filter stopband) will also have some effects on the sound.

Your Evo hiface has good master clock.

Pin 4 for dithering is not recommended although it will alter the sound character too.

Got my Dac ref 7 last Sunday. Had a listening sessions with chua55. Our listening is based PC with foobar fed to M2Tech Evo Hi-face as a source. Digital cable used - Black Cat, Oyaide 510 & XV2 (IMO they are about the same SQ). Once i replaced my stello dac with ref 7, it's the whole new game, more details coming through, bigger soundstage and bass goes down very low and punchy. Very pleased with the purchase. Recommended...

BTW i've purchased audio-gd usb interface power supply rated 10v to power my hiface Evo. It works.

mohfudz wrote: Digital cable used - Black Cat, Oyaide 510 & XV2 (IMO they are about the same SQ).

Congratulation on your excellent purchase.

I have a 1.3m Oyaide lying around waiting for a suitable BNC connector to terminate. Can you confirm that BC, 510, and the XV2 have similar SQ?

Right now I am using a generic RG59U/B cable given by my security contractor terminated with BNC(output) and RCA(input). Seriously, I don't ear any differences compare to the Chord Indigo Plus digital.

Does all digital cables sound similar?

I've connected both XV2 (BNC) & Oyaide (RCA) to Evo Hiface to Audio GD Dac Ref 7, switching back and forth between BNC & RCA, to my ear I can't tell difference, only thing i call tell Oyaide slightly has bigger bass. they are both good.

With stello da220 mkII dac, Oyaide goes a bit deeper in bass but slightly loose, XV2 has more sparkle on top end and a bit forward.

Prior to this I have signal cable silver ref & transparent digital cable, they are less details & smaller soundstage.

Hi mohfudz

Thanks for the feedback. Maybe I should get my 510 terminated to replace my present cable.

Before I even get used to the new version of DSP, audio-gd has released the DSP1 V5.0. Overall improvement comes in the soundstage and imaging as well as the smoother.

mohfudz wrote:I've connected both XV2 (BNC) & Oyaide (RCA) to Evo Hiface to Audio GD Dac Ref 7, switching back and forth between BNC & RCA, to my ear I can't tell difference, only thing i call tell Oyaide slightly has bigger bass. they are both good.

With stello da220 mkII dac, Oyaide goes a bit deeper in bass but slightly loose, XV2 has more sparkle on top end and a bit forward.

I tend to have the same hearing on the oyaide DB-510 and the blackcat as per your description. they are both equally good.

If you have RCA and BNC end, always connect the BNC to the DAC.

chua55 wrote:

If you have RCA and BNC end, always connect the BNC to the DAC.

Too bad my new DAC doesn't have BNC input. On my old DAC I changed the input to BNC and there were immediate noticeable improvement in the SQ.

chua55 wrote:Before I even get used to the new version of DSP, audio-gd has released the DSP1 V5.0. Overall improvement comes in the soundstage and imaging as well as the smoother.

What?? does this mean my newly purchased Ref 7 is outdated...

It is more like a free upgrade available. It normally costs some money to redesign for improvement. In this case, the dsp software change is free. and you have the sound improvement. I just hope one day instead of 32bit DSP audio-gd can give 64bit DSP.

chua55 wrote:It is more like a free upgrade available. It normally costs some money to redesign for improvement. In this case, the dsp software change is free. and you have the sound improvement. I just hope one day instead of 32bit DSP audio-gd can give 64bit DSP.

Wonder if 64bits is better? Maybe lga775(no, I am not referring to the land grid array socket) can shed some light on this.

chua55 wrote:It is more like a free upgrade available. It normally costs some money to redesign for improvement. In this case, the dsp software change is free. and you have the sound improvement. I just hope one day instead of 32bit DSP audio-gd can give 64bit DSP.

That's a relief, I thought it's a hardware change, in that case, how do i get the software upgrade done? Appreciate your help & guidance.

tycham wrote:

chua55 wrote:It is more like a free upgrade available. It normally costs some money to redesign for improvement. In this case, the dsp software change is free. and you have the sound improvement. I just hope one day instead of 32bit DSP audio-gd can give 64bit DSP.

Wonder if 64bits is better? Maybe lga775(no, I am not referring to the land grid array socket) can shed some light on this.

may I know what is this LGA775 non socket u are referring to.

not sure if 64bits is better, but newer technology seems to get better. but some may prefer the older technology.

chua

lga775 is the intel cpu socket on the mobo. Incidentally, there is a forum member by this nickname here.

Cham,

Audio-gd is never good at digital front end for which it requires a special dsp developer and it carry a hefty license tag for each upgrade, but this is never pass to user.

wow...audio-GD is the great design...i am very interested to hear the sound...one day i must get it.....

microkernel wrote:wow...audio-GD is the great design...i am very interested to hear the sound...one day i must get it.....

If you have a bit of dough, go for ref 7 dac, you'll never regret it, unless currently you have super duper dac. For 6k, is well worth every ringgit. Hopefully this is my last DAC. Probably I may need to spend more than 10k to get any further improvement. My ref 7 still in the process of burning in (70hrs another 130hrs to go) but the SQ is amazing. Smooth, neutral, tight bass, minute details which I never heard before. (Previously I had Stello Da220mkII). Love it..

It looks like the PCM1704U-K is out of stocks. one the dac chip will end up like TDA1541 S. Do you guys think DSP filter is important to the overall DAC sound?

PCM1704U-K is rare parallel multi-bit non sigma delta DAC still on production, some test has found the parallel multi-bit produce more "ear friendly" distortion but finally the TI stop the PCM1704U-K production because 32bit DAC is going to float the market.
A lot of high end digital source has build in DSP filter too, from the pass experience i found it is useful to adjust the input digital signal become optimum to feed the DAC to let the DAC run on it's best condition, but overly signal conditioning i found it may lost some attack or change the presentation different from the original recorded content, this is why there are still a lot of NOS DAC fans around.

I just slot in the DSP 1 V5. Before this I was using DSP1 V3. The dip switch still remain.



Initial impressions of the DSP 1 v5 is clearly distinct. The instrument accuracy is more dfine. the details are there and it sounds smooth. The bass goes lower and the mids give more of the presence. The air surrounding the singer is more obvious and the music is more refine. While enjoying the music, I really felt reluctant to turn it off.


Good job and it is well done.

All these DAC discussions are very nice .... but if ever there's a chance, should also go and have a listen to real analogue sources.

Then when going back to DACs, there will be a certain "harshness" and "plastic'ness" which is really hard to describe but glaringly obvious.

And then the DAC chip which gives the closest thing to the real analogue sound, that would be the DAC chip/system to go for.

Just ask the regular moderators here.... they are all vinyl-heads despite having dabbled with very exotic CD Transport/DACs over the years.

>>>And then the DAC chip which gives the closest thing to the real analogue sound, that would be the DAC chip/system to go for.

Which is ? Any suggestion ?

Carz, u may try TDA 1541 with tube output.

I have heard of the properly setup TT using VPI and I really like the sound alot. It is really good and the sound not those found in the digital play playback.

Since I know nuts about TT, I might as well stay away of it or else i would open another can of worms and a deep blow to the pocket.

In addition, the availability of software with every throttling of bytes is another factor to maximize on the digital age.

carz wrote:>>>And then the DAC chip which gives the closest thing to the real analogue sound, that would be the DAC chip/system to go for.

Which is ? Any suggestion ?

This one if you are on a tight bajet! TDA1541A S1 chipset.

for the first time, audio-gd DAC Ref 5 is featured on a 6moons review.

According to their website today, Audio-GD are discontinuing some models, one of them the DAC 19 that had such a good reception on Headfi and elsewhere. PCM1704U-K Chips running low.