Two DACs - specs are identical, price is not. Why?

[caustic386]

i'm having a hard time understanding something - I'm shopping around for a new DAC, and the NAD M51 comes highly rated. About a year ago, NAD released the C510 with identical specs. However, it's $500 cheaper than the M51 with the difference being the M51 boasts a better power supply. I asked the sales rep what that means in the real world, and he literally said "I couldn't tell you." So if the 2 units have literally identical data sheets, what does one get with an improved PSU? Specs below, from the service manual for each unit:

M51:

Rated distortion (THD+N with AES 17 flter) <0.0005% (ref. 1 kHz 0 dBFS)
<0.002% (ref. 1 kHz -60 dBFS)
IM distortion <0.0001%
Signal-to-noise ratio < -123 dB (ref. 0 dBFS 2V out)
Channel separation > -115 dB (ref. 0 dBFS Volume -1dB)
Sample rate 32 kHz to 192 kHz (USB and digital S/PDIF)
Frequency response ±0.5 dB (ref. 20 Hz – 96 kHz @ 192 KHz sample rate)
Output level 2V (ref. input 0dBFS)

C510:

<0.0005% (0dBFS) <0.002% (-60dBFS) IMD Distortion 0.0001% Signal/Noise Ratio <-123dB (ref. 0dBFS 2V out) Channel Separation >-115dB (ref. 0dBFS Volume -1dB) Sample Rate 32kHz to 192kHz (USB and digital S/PDIF) Frequency Response ±0.5dB (ref. 20Hz - 96kHz @ 192kHz sample rate) Output Level 2V (ref. input 0dBFS)

 

[slipperybidness]

i'm having a hard time understanding something - I'm shopping around for a new DAC, and the NAD M51 comes highly rated. About a year ago, NAD released the C510 with identical specs. However, it's $500 cheaper than the M51 with the difference being the M51 boasts a better power supply. I asked the sales rep what that means in the real world, and he literally said "I couldn't tell you." So if the 2 units have literally identical data sheets, what does one get with an improved PSU? Specs below, from the service manual for each unit:

M51:

Rated distortion (THD+N with AES 17 flter) <0.0005% (ref. 1 kHz 0 dBFS)
<0.002% (ref. 1 kHz -60 dBFS)
IM distortion <0.0001%
Signal-to-noise ratio < -123 dB (ref. 0 dBFS 2V out)
Channel separation > -115 dB (ref. 0 dBFS Volume -1dB)
Sample rate 32 kHz to 192 kHz (USB and digital S/PDIF)
Frequency response ±0.5 dB (ref. 20 Hz – 96 kHz @ 192 KHz sample rate)
Output level 2V (ref. input 0dBFS)

C510:

<0.0005% (0dBFS) <0.002% (-60dBFS) IMD Distortion 0.0001% Signal/Noise Ratio <-123dB (ref. 0dBFS 2V out) Channel Separation >-115dB (ref. 0dBFS Volume -1dB) Sample Rate 32kHz to 192kHz (USB and digital S/PDIF) Frequency Response ±0.5dB (ref. 20Hz - 96kHz @ 192kHz sample rate) Output Level 2V (ref. input 0dBFS)

Bragging Rights

 

[BoredSysAdmin]

If you have practically anything to serves as DAC today, I won't bother changing it.

 

[caustic386]

Currently I'm using a BDP-105; I know it's a big hit on this site but I compared it to a Benchmark DAC2 and in my system the differences were quite noticeable. Certainly not like buying a new pair of speakers, but thus far I rather enjoy the change. The DAC2 is often compared to the M51 (slightly cheaper), which is how I got here...

I somewhat suspect that the volume control on the 105 isn't the greatest - lower volumes are where the BEnchmark really shines comparatively.

 

[BoredSysAdmin]

Currently I'm using a BDP-105; I know it's a big hit on this site but I compared it to a Benchmark DAC2 and in my system the differences were quite noticeable. Certainly not like buying a new pair of speakers, but thus far I rather enjoy the change. The DAC2 is often compared to the M51 (slightly cheaper), which is how I got here...

I somewhat suspect that the volume control on the 105 isn't the greatest - lower volumes are where the BEnchmark really shines comparatively.

Then you compared them - did you actually a) made an effort to match levels properly and b) did blind comparison?
Without a and b - you conclusion of clear superiority of Benchmark dac2 is baseless.

 

[caustic386]

Then you compared them - did you actually a) made an effort to match levels properly and b) did blind comparison?
Without a and b - you conclusion of clear superiority of Benchmark dac2 is baseless.

I'm never really sure how to respond to posts like this...? OK, thanks?

 

[lovinthehd]

Just like many of us aren't sure how to take "comparisons" the way you did it. Ok, thanks?

 

[PENG]

I'm never really sure how to respond to posts like this...? OK, thanks?

You should get the M51 because if it has better and more expensive PSU in it then it is a better unit whether you can hear the difference or not. If you go for the cheaper one you may end up second guessing for a long time. By the way, I also have a 105 and I am quite sure my HA-1 DAC sounds slightly better. The problem is, I am even more sure I can only tell them apart in sighted comparisons.

 

[mtrycrafts]

I'm never really sure how to respond to posts like this...? OK, thanks?

Yes, it is tough to respond when someone is challenging a claim.
But, credible evidence wins every day.

 

[herbu]

i'm having a hard time understanding something

Me too. Questions about which DAC is better are not uncommon... thus my confusion. A DAC executes a digital conversion. Parameters are standard. One cannot have a "brighter" treble or a "chocolatey bass". There are no physical differences like cones and ribbons in DACs. You put in a digital signal and get the same analog output in every DAC.

So how can one DAC sound "better" than another?

 

[ski2xblack]

I'll go out on that limb and defend Caustic's claims of audible differences at low volumes. Keep in mind that the Oppo's volume control is handled in the digital realm, reducing data (program content) as the volume is decreased. The Benchmark's is analog, and just reduces voltage.

I don't see the logic in any kilobuck DACs, that just seems ridiculous to me. I'm just trying to indicate that there may be a valid, reductive explanation for Caustic's claims that you guys are not taking into consideration.

 

[BoredSysAdmin]

Keep in mind that the Oppo's volume control is handled in the digital realm, reducing data (program content) as the volume is decreased.

It is digital, but it's 32 bit structure, designed to minimize such issues almost entirely.
http://www.oppodigital.co.uk/UserFiles/Docs/PDF/BDP-105EU Direct Power Amplifier Connection V2.pdf

 

[ski2xblack]

Hmm. Well, that undermines my argument, but if that thread is reliable source of information, they're both 'really' digital. And this is kind of academic anyway, given we're skipping over the whole validation-of-the-OP's-claims aspect. He really does need to take steps to keep himself honest in this endeavor, otherwise he's just wandering the consumerist maze blindly.

 

[M Code]

The DAC brands have different ways of measuring specs... Has to do with their noise floor and measuring filters used.. But note DAC prices have dropped big-time over the last 5 years, due to high unit volume of entry-level products that use them.. Also note multi-channel DACs in a single chip are popular as well...

Note that many of the popular brand AVRs actually use a combo chip, includes DIR (digital interface receiver), A/D and DACs..

Just my $0.02...