manisandher
Addicted to Fun and Learning
I recently acquired a 13-year-old dCS Scarlatti CD transport, DAC, clock and upsampler.
What seemed immediately apparent to me was how different it sounded to the two modern DACs I have here: an Okto dac8PRO and an RME ADI-2 Pro BE. I think I hear very subtle differences between these modern DACs – the RME sounds really ‘dynamic’, and the Okto very ‘clean’… but I’m not confident that I’d be able to pass an ABX test with one against the other. However, against the dCS, the differences are obvious – the dCS sounds way more laid back, with a fuller bottom end. It sounds nowhere near as incisive as the modern DACs, almost to the point of sounding boring in comparison. I’m 100% certain I’d pass an ABX with the dCS against either of these modern DACs.
In any event, I wanted to explore what might be contributing to the differences I’m hearing. So, I set up the following 2 chains:
I played three different 24/44.1 tracks and captured the analogue outputs at 24/44.1 in order to perform null tests with @pkane 's superb DeltaWave software. The only settings engaged in DeltaWave were:
1. 1kHz sine @0dBFS
From measurements posted on ASR, the Okto has a SINAD of around 118dB, and the RME around 115dB, which place them both in ASR’s ‘excellent’ category.
Using the RME as ADC, I get the following results:
Both of these have higher 3rd harmonics than the ASR measurements, which is probably down to the ADC, but are otherwise in-line with expectations, I think.
And here’s the FFT for the dCS:
Clearly, the modern DACs measure better. So, could this account for the differences that I hear between them and the dCS? I suspect most people here would say “no”, as the differences seem too low in level to be audible.
Could DeltaWave provide any insights? Well, here are the results:
There are two surprises, to my mind:
2. Gearspace ‘Original2’
This is the track used on the Gearspace loopback thread: https://gearspace.com/board/gear-sh...ing-ad-da-loops-means-audio-diffmaker-76.html. This is real music, and not a test signal.
Here are the DeltaWave results:
Two more surprises here:
Especially with the old-timer ADC, the modern DACs are clearly achieving better RMS nulls than the dCS, so they're better, right? Well, it’s worth looking at the dBA and PK Metric scores in more detail.
dBA is a dB measurement that has been adjusted to take into account the varying sensitivity of the human ear to different frequencies of sound. Low and very high frequencies are given less weight than on the standard dB scale:
(from http://wordpress.mrreid.org/2014/02/27/dba-and-grey-noise/)
With the Prism, the dCS now measures the best in dBA.
The PK Metric is a (very clever) metric that @pkane has created that represents a much more perceptually-weighted result than the RMS Difference – it should be more audibly and perceptually accurate. You can read more about it here: https://deltaw.org/pk_metric.html.
With the Prism, but especially with the RME as ADC, the dCS now pulls aways substantially on the PK Metric score. Audibly and perceptually, it seems that the dCS is more accurate than the modern DACs!
I took many multiple captures with all the DACs, and these results are totally repeatable and consistent. But perhaps the dCS only does well with this particular classical music track? So, I repeated the procedure with another track…
3. Diana Krall – Temptation
Here are the DeltaWave results:
No... it's definitely the DAC and not the track!
******************************
I'd like to do more testing, but these initial results have surprised me.
Any thoughts/insights welcome.
Cheers,
Mani.
What seemed immediately apparent to me was how different it sounded to the two modern DACs I have here: an Okto dac8PRO and an RME ADI-2 Pro BE. I think I hear very subtle differences between these modern DACs – the RME sounds really ‘dynamic’, and the Okto very ‘clean’… but I’m not confident that I’d be able to pass an ABX test with one against the other. However, against the dCS, the differences are obvious – the dCS sounds way more laid back, with a fuller bottom end. It sounds nowhere near as incisive as the modern DACs, almost to the point of sounding boring in comparison. I’m 100% certain I’d pass an ABX with the dCS against either of these modern DACs.
In any event, I wanted to explore what might be contributing to the differences I’m hearing. So, I set up the following 2 chains:
- Roon (64-bit level-matching) -> RJ45 -> Auralic Aries G1.1 @0dB -> USB -> DUT @0dB -> XLR analogue output (2V) -> RME ADI-2 Pro BE @+13dBu -> USB -> RME Digicheck (on PC)
- Roon (64-bit level-matching) -> RJ45 -> Auralic Aries G1.1 @0dB -> USB -> DUT @0dB -> XLR analogue output (2V) -> Prism AD124 @+12dBu -> BNC -> Tascam DA3000 (SD card)
I played three different 24/44.1 tracks and captured the analogue outputs at 24/44.1 in order to perform null tests with @pkane 's superb DeltaWave software. The only settings engaged in DeltaWave were:
- match gain: ON
- subsample offset: ON
1. 1kHz sine @0dBFS
From measurements posted on ASR, the Okto has a SINAD of around 118dB, and the RME around 115dB, which place them both in ASR’s ‘excellent’ category.
Using the RME as ADC, I get the following results:
Both of these have higher 3rd harmonics than the ASR measurements, which is probably down to the ADC, but are otherwise in-line with expectations, I think.
And here’s the FFT for the dCS:
Clearly, the modern DACs measure better. So, could this account for the differences that I hear between them and the dCS? I suspect most people here would say “no”, as the differences seem too low in level to be audible.
Could DeltaWave provide any insights? Well, here are the results:
There are two surprises, to my mind:
- The dCS measures very closely to the modern DACs. Perhaps the ADCs are the limiting factors here?
- The 25-year-old Prism is bloody brilliant for its age, achieving the best null at -100.46dBA!
2. Gearspace ‘Original2’
This is the track used on the Gearspace loopback thread: https://gearspace.com/board/gear-sh...ing-ad-da-loops-means-audio-diffmaker-76.html. This is real music, and not a test signal.
Here are the DeltaWave results:
Two more surprises here:
- The RMS differences put the DAC/ADC combos here level with best-of-the-best in the Gearspace test!
- Again, the Prism does really well, achieving better RMS nulls than the RME!
Especially with the old-timer ADC, the modern DACs are clearly achieving better RMS nulls than the dCS, so they're better, right? Well, it’s worth looking at the dBA and PK Metric scores in more detail.
dBA is a dB measurement that has been adjusted to take into account the varying sensitivity of the human ear to different frequencies of sound. Low and very high frequencies are given less weight than on the standard dB scale:
(from http://wordpress.mrreid.org/2014/02/27/dba-and-grey-noise/)
With the Prism, the dCS now measures the best in dBA.
The PK Metric is a (very clever) metric that @pkane has created that represents a much more perceptually-weighted result than the RMS Difference – it should be more audibly and perceptually accurate. You can read more about it here: https://deltaw.org/pk_metric.html.
With the Prism, but especially with the RME as ADC, the dCS now pulls aways substantially on the PK Metric score. Audibly and perceptually, it seems that the dCS is more accurate than the modern DACs!
I took many multiple captures with all the DACs, and these results are totally repeatable and consistent. But perhaps the dCS only does well with this particular classical music track? So, I repeated the procedure with another track…
3. Diana Krall – Temptation
Here are the DeltaWave results:
No... it's definitely the DAC and not the track!
******************************
I'd like to do more testing, but these initial results have surprised me.
Any thoughts/insights welcome.
Cheers,
Mani.