New ESS Sabre32 (ES9018) based DAC from Audio-gd....the NFB-1 - Page 13

Buy it and do us all a great service and give us a comparison :D
 

Quote:

Originally Posted by TigzStudio 

Oye decisions decisions....wait until I hear people's impressions or buy one now to compare to my Ref5.....hmmmm.  

$1350 is an amazing price point for a DAC of this magnitude.  And obviously so is $1750 for the RE7 which uses 8 expensive DAC chips.

I posted it in the DI thread, but it'd be interesting to see if the DI improves the S/PDIF direct input or not. 

Quote:

Originally Posted by borrego 

I think even the best amps are having SNR <100db. So a DAC with 110db SNR will be good enough.

 

The ES9018 chip has internal digital volume control. The best way of using this chip is actually to in a DAC/Preamp configuration to make use of the digital volume control. If Kingwa makes a ES9018 preamp with direct ACSS connection to one of his ACSS power amp, the high SNR of the Sabre DAC will be better utilized.

 

Think a ACSS enabled Peachtree Audio Nova... I think it is what Kingwa should make

You clearly know a lot about this stellar chip!

I do have one question though... I do not see a button on the Ref 7 for changing any of these said filters, nor do I see one on the NFB-7... can you even change the filter on the Ref-7 or is this all hypothetical "there is a better implementation surely in the future" talk, or is the ref-7 actually capable of doing said changes.

Also, I think I read the Ref-7 has an analogue filter... why would I want this? Isn't my headphone supposed to be that filter? Less than flat from a source seems less than ideal to me.

That being said, is there a real difference having an ultrasonic filter? The whole premise we are dealing with the ultrasonic should render it useless, no? I mean redbook only goes up to 20khz so why would I need the filter? So, basically does said filter fall into the "cable" category of audio upgrades, or is in the amp/headphone upgrade section. IE> one not being universally accepted and recognized, and the other being universally accepted and recognized.

Other than that, all things equal, is there any reason the Ref-7 would be better if the R2R vs Sigma Delta seems to be mostly a matter of preference and implementation?

Thanks for your help!

Hi Sokolov,

The filter is needed for DAC oversampling operation. Here is the datasheet of the filter chip DF1704 (http://focus.ti.com/lit/ds/symlink/df1704.pdf) , which is the "official" filter chip for the PCM1704. The DSP1 module was used instead of the DF1704 in the Ref7 and on the DSP1 board there are DIP switch for the filter roll-off selection. (http://www.audio-gd.com/Pro/dac/DSP1/DSP1ENspecs.htm)

This oversampling filter is at the "digital stage" to remove ultrasonic noise to improve SNR.

That's the digital filter you're talking about, Borrego.  But there is also an analog filter, as Sokolov mentioned.  You will find this same curve in very expensive DACs.  It eliminates some of the information at the highest frequencies where only noise resides, no musical information.  The curve lies at -0.5dB at 16kHz and -1.5dB at 20kHz.  Kingwa can disable it for you, but he does not recommend it.  I'd listen to the man.  There's nothing I can think of that I'd want to change on my RE7.  I did have it rewired with the OCC copper, which is an option he sells, as well as sending him OCC silver to use on the AES/EBU input and Illuminati Coax on the RCA and BNC inputs.

Quote:

Originally Posted by IPodPJ 

$1350 is an amazing price point for a DAC of this magnitude.  And obviously so is $1750 for the RE7 which uses 8 expensive DAC chips.

How much do they cost?

Quote:

Originally Posted by .Sup 

How much do they cost?

That depends on how many you buy at one time.  Between $23 and $40 each.

Quote:

Originally Posted by tim3320070 

I wonder what the sound signature is compared to the 1704 without DSP (this does not seem to have the DSP chip)? This must be due to the 1704 chip being out of production.

 

The ESS sabre is a great dac, and with 4 dac's configured in differential mode its a great dac.  Kingwa said that it has in-built jitter correction and a few other new features time domain error correction etc, that jitter is no longer a issue when using this dac.

After listening to the OppoSE (ESS9016 based), i feel that its quite analytical sounding and may/may not be to your liking.  For me, if he creates a 'musical' version of it, like using a then i may give it a go. 

Yes, he also did say that sourcing 1704 chip is getting more expensive and may no longer be cost viable (like the good ol TDA1541A and crown versions). 

Quote:

Originally Posted by borrego 

Hi Sokolov,

 

The filter is needed for DAC oversampling operation. Here is the datasheet of the filter chip DF1704 (http://focus.ti.com/lit/ds/symlink/df1704.pdf) , which is the "official" filter chip for the PCM1704. The DSP1 module was used instead of the DF1704 in the Ref7 and on the DSP1 board there are DIP switch for the filter roll-off selection. (http://www.audio-gd.com/Pro/dac/DSP1/DSP1ENspecs.htm)

 

This oversampling filter is at the "digital stage" to remove ultrasonic noise to improve SNR.

Thanks for that info, much appreciated.

Just one thing though, if the ultrasonic filter is to help noise in the aim to improve SNR, how then does the NFB-7 have a better SNR than the Ref-7?

Is the technology simply better/ easier to implement?

Quote:

Originally Posted by sokolov91 

Thanks for that info, much appreciated.

 

 

Just one thing though, if the ultrasonic filter is to help noise in the aim to improve SNR, how then does the NFB-7 have a better SNR than the Ref-7?

 

Is the technology simply better/ easier to implement?

The SNR stated by Kingwas were measure from the XLR/ACSS/RCA output, so the quality of the analog stage also play an important part. I think the NFB7 and RE7 will have similar SNR at the XLR/ACSS/RCA output. NFB1 may beat RE5 at SNR as RE5 only uses 4 PCM1704.

I do think the Sabre32 chip is easier to implement than the PCM1704. So the RE7/RE5 are well worth their prices

Quote:

Originally Posted by borrego 

The SNR stated by Kingwas were measure from the XLR/ACSS/RCA output, so the quality of the analog stage also play an important part. I think the NFB7 and RE7 will have similar SNR at the XLR/ACSS/RCA output. NFB1 may beat RE5 at SNR as RE5 only uses 4 PCM1704.

 

I do think the Sabre32 chip is easier to implement than the PCM1704. So the RE7/RE5 are well worth their prices

NFB-7

RCA Output
S/N Ratio:>119db
Output Level:2.56V 

Frequency Breadth:20-20KHz



XLR Output
S/N Ratio:>122db
Output Level:5.12V 
Frequency Breadth:20-20KHz

ACSS Output
S/N Ratio:>127db
Output:2.0MA 

Frequency Breadth:20-20KHz

Ref-7

RCA Output
S/N Ratio:>118db
Output Level:2.5V 

Frequency Breadth:20-20KHz



XLR Output
S/N Ratio:>121db
Output Level:5V 
Frequency Breadth:20-20KHz

ACSS Output
S/N Ratio:>126db
Output:4MA 

Frequency Breadth:20-20KHz

sources http://www.audio-gd.com/Pro/dac/RE7/RE7ENsepecs.htm

http://www.audio-gd.com/Pro/dac/NFB7/NFB7ENsepecs.htm

He also never corrected the current output specs of the Ref7.  It is not 4mA.  It is 2mA.

SNR numbers are irrelevant in modern gear. Above 50 = same for all.

The ACSS is something Kingwa really proud of. Will like to know the SNR comparison between the RE7 and RE8 which does not use ACSS.

I read somewhere about the Audiolab company was implementing the ES9018 chip in their latest DAC. The Audiolab designer stated the most SNR they can get out from the ES9018 after I/V conversion was 117db, using what they called the "balanced active voltage ground?", or something like that... while the NFB7 can do 122db from its ACSS XLR.