Audio-GD Reference 7 - the new flagship DAC
Jan 15, 2010 at 7:04 PM Thread Starter Post #1 of 2,738

scootermafia

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Someone had to do it.

What is it - successor to the Reference 1 flagship DAC from Audio-gd. Flagship DAC with balanced and current-mode outputs, eight PCM1704UK chips, triple-mono power supply (separate board, transformer, and power circuitry for left/right decoding/output stages and digital input section).

Price - ~$1750USD or 10,000RMB

When's it out - February, to our knowledge thus far

Why is it called REF7 - The Ref1 was always the top DAC which was the successor to the DAC8 and added the new programmable DSP board, the DSP-1. The Ref2 was similar but with Phillips chips over Burr-browns and cost a bit less. The Ref3 was not a DAC at all, but a digital transport/digital switcher/upsampler unit. Then Kingwa skipped three numbers.

New features - Screen, input selector, and 5 inputs (coax x 2, BNC, optical, AES/EBU)

Bit rates - the PCM1704UK chips despite providing some of the best sound max out at 96/24. Those of you who actually have 192khz music will have to settle.

How is it different - here's what I see. The output stages are new modules with some different parts I spy, the digital input area has some extra chips I assume to handle the new inputs, the power filtration circuitry is totally revised with all of the previously chassis sinked transistors now on their own heatsinks, the transformers are all r-cores on some nice looking boards. Then of course the extra inputs, curved edge Phoenix look, screen and input selector and moved power button. The chinese translation says that the clock is upgraded.

Initial sound impressions - Kingwa says that it sounds slightly more clear.

Will I buy one? Probably. It's expensive, but I do need the DSP-1 board that my DAC8 lacks, that thing can't even do 96/24. Since the Ref1 is no more, it will make an even nicer upgrade, once I can find the money (and a loving home for my DAC8).

RE73.JPG

RE75.jpg

RE78.jpg
 
Jan 15, 2010 at 8:11 PM Post #2 of 2,738
odd no 24/96 at that price. i expect 24/192 at that price
 
Jan 15, 2010 at 9:00 PM Post #3 of 2,738
It can do 24/92, when scooter said "that thing can't even do 24/92" he was referring to the dac 8 which uses pmd-100 which can only do 16/48. And the reason this can't do 24/192 is because the pcm1704uk only goes up to 24/92.
 
Jan 15, 2010 at 9:25 PM Post #5 of 2,738
Quote:

Originally Posted by haloxt /img/forum/go_quote.gif
It can do 24/92, when scooter said "that thing can't even do 24/92" he was referring to the dac 8 which uses pmd-100 which can only do 16/48. And the reason this can't do 24/192 is because the pcm1704uk only goes up to 24/92.


You mean 24/96.

Also, to correct Peter -- it only has 4 selectable inputs, not 5. It has 5 connections.

Input 1 = AES/EBU
Input 2 = BNC or RCA
Input 3 = RCA
Input 4 = Toslink
 
Jan 15, 2010 at 9:28 PM Post #6 of 2,738
Quote:

Originally Posted by fault151 /img/forum/go_quote.gif
"Initial sound impressions - Kingwa says that it sounds slightly more clear. "

At that price it best sound a lot more clear! looks nice though.



I guess you haven't heard the Ref1 then. It is already super transparent and close to as clear as I have heard under $8-$10K. It does have an analog filter which makes the unit sound natural by taking the edge off the upper highs. The Ref1 has a slope of -0.5dB at 12kHz and -1.5dB at 20kHz, and I would imagine it is the same for the Ref7.
 
Jan 15, 2010 at 10:02 PM Post #7 of 2,738
Quote:

Originally Posted by IPodPJ /img/forum/go_quote.gif
I guess you haven't heard the Ref1 then. It is already super transparent and close to as clear as I have heard under $8-$10K. It does have an analog filter which makes the unit sound natural by taking the edge off the upper highs. The Ref1 has a slope of -0.5dB at 12kHz and -1.5dB at 20kHz, and I would imagine it is the same for the Ref7.


I cant identify any flaws in the reference 1 to improve.

Part of me hopes the refernce 7 is even better though (that would be amazing!)

The reference 1 is the only dac I have ever owned that doesn't have any flaws or coloration I can hear that annoy me. This includes Wadia, Naim, Cambridge

It is wonderful !
 
Jan 15, 2010 at 10:10 PM Post #8 of 2,738
Quote:

Originally Posted by IPodPJ /img/forum/go_quote.gif
It does have an analog filter which makes the unit sound natural by taking the edge off the upper highs. The Ref1 has a slope of -0.5dB at 12kHz and -1.5dB at 20kHz, and I would imagine it is the same for the Ref7.


confused_face(1).gif


It makes it better by making it less accurate, i.e by removing data that is meant to be there

Call me old fashioned but that hardly seems like a good approach to High Fidelity
wink.gif



[size=xx-small]not that I can hear anything at 20k anyway.....[/size]
 
Jan 15, 2010 at 10:17 PM Post #9 of 2,738
Quote:

Originally Posted by nick_charles /img/forum/go_quote.gif
confused_face(1).gif


It makes it better by making it less accurate, i.e by removing data that is meant to be there

Call me old fashioned but that hardly seems like a good approach to High Fidelity
wink.gif


[size=xx-small]not that I can hear anything at 20k anyway.....[/size]



With headphones I especially think it is a benefit because the drivers are so close to your ears and highs are often perceived as harsh. By taming it a little the sound is more natural. Many high-end DAC companies do this. You can go to Stereophile online and look at the graphs.

However, if you want the output to be perfectly flat from 20Hz-20kHz, Kingwa can remove the analog filter for you. I wouldn't do it though.
 
Jan 16, 2010 at 12:24 AM Post #10 of 2,738
Quote:

Originally Posted by IPodPJ /img/forum/go_quote.gif
It does have an analog filter which makes the unit sound natural by taking the edge off the upper highs.


Wrong. At 16-20 kHz there's almost nothing in the music that a 1-3dB roll off (out of 80dB) would affect noticeably. Most treble is in the 2-10 kHz range, with the upper treble going to about 16 kHz. You posted the correct answer previously in fact:

Quote:

Originally Posted by IPodPJ /img/forum/go_quote.gif
Wish granted, Les. Here is Kingwa's response:

PART 1:

Dear Philip,
I think this test is by RCA output.
We always design RCA output has a little warm than XLR and CAST, so RCA output is a little roll off than XLR, but you can ask some one to test most wellknow oversea brand CDP or DAC, years ago I ever test Marantz ,Accuphase, Marklevinsion ect CDP and DAC, they also roll off a little.
I accurate remember Marantz CD7 (because it was my love), it roll off -2DB at 20KHZ.

Why most CDP or DAC will roll off?
PCM data has a lot high frequency noise, so oversampling DAC apply the digital filter to attenuation these noise , but after digital filter, feed to D/A chip, the DA chips also bring the new noise, so the normal DAC must design a 1nd to 4nd analogy filter after the DA chips, the analogy filter usually roll off -3DB at 25KHz to 44KHz , and let the brand under 20KHz has a little roll off.

If the DAC is NOS, the roll off is much more than OS DAC, usuall at 20KHz has -6 to -10 DB roll off.

If the DAC/CDP don't design the analogy filter, the high frequency easy make not roll off at 20KHz, but the problems is the noise no attenuation, and feeb to the amp, the noise will effect the signal and let the amp born a lot distortion, though high frequency is not roll off but sound much bad.

I ever buy a lot oversea CDP and DAC for study at some years ago, they all have the analogy filter and let the hign frequency less or much roll off, this is normal, but I also see some bad grade CDP or DAC not roll off indeed boost up the high frequency, these not they have good technology, the reason is the output amp has oscillate.

Upon is base of normal analogy technology, but if apply CAST technology and CAST output, there is much excellent than normal analogy technology, so I think CAST is much neutral than normal output, and said XLR only has 85% of CAST in the combo.

And I want to say, human ears much different to test meter , zero distortion, very wide brand, the test meter will tell you this is a excellent gears. But if listen to these gears, you maybe not gree with the test instrument. Just like Tube gears, they has unacceptable distortion and noise, but why a lot fans love listen to tube gears?

A lot student if finished electronical university course, they maybe can design and make a amp has very excellent test parameter, but do you think they all can make the good gears for listen music?

There are a lot audio brand in world, because there are most fans will enjoy different music style, some will love warm or tube like , some will love dynamic, some will love neutral. But what is neutral? I think there are a lot manufacturer affirm there gears is neutral. this depen on the designer experience , not depend on the test meter.
If depen on the test meter, I think all gears in world only has one sound style. Just like the copy humans in << Star War>>.

Finally, I think you can ask some one to test some other well know brand CDP/DAC like Krell or Wadia or other well know brand, then you can understand what happen.

Kingwa


PART 2

Dear Philip,
BTW, we can make the DAC output no roll off,(cancel the analogy filter only), but I don't think this will has better sound level.
Kingwa



Quote:

Originally Posted by nick_charles /img/forum/go_quote.gif
confused_face(1).gif


It makes it better by making it less accurate, i.e by removing data that is meant to be there

Call me old fashioned but that hardly seems like a good approach to High Fidelity
wink.gif



[size=xx-small]not that I can hear anything at 20k anyway.....[/size]



Then all high-end digital is no good and you need to stick to your vinyl.
tongue.gif


Discussion of this was here.
 
Jan 16, 2010 at 12:47 AM Post #11 of 2,738
Ah, I forgot about that blurb. But remember there was a graph taken of the output and it showed -0.5dB at 12 and -1.5dB at 20. I don't remember where in the thread it was though or even if it was in this thread.

And if you don't consider 12 - 20 upper highs, what do you consider it? Super super upper highs? Like he said, -3dB at 25kHz which falls right in line with -1.5dB at 20 and -0.5dB at 12. I know a lot in that area is noise and not music (I had said sound, not music), but it still translates into sound that we can hear and it results in fatigue unless it is tapered.
 
Jan 16, 2010 at 2:04 AM Post #12 of 2,738
I'm guessing that's why most headphones have a huge drop in their FR response above 12k. Most people cannot hear much above 16k anyway, so all in all it's moot.
 
Jan 16, 2010 at 3:39 AM Post #14 of 2,738
Quote:

Originally Posted by gevorg /img/forum/go_quote.gif
This looks like a minor upgrade/revision to Ref1, I wouldn't upgrade to it from Ref1.

As for lack of 24/192, don't worry about it, 24/96 is plenty.

Hopefully this year Kingwa will finally master proper 24/96 over USB.



When I was buying my REF1 from KW he said it would play 192 as 92Khz.
 

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