[hattrick15]

I only use my DAVE with Focal Utopia headphones driven by PC USB. Does the M-scaler in the Blu2 have such a transformative effect on the sound for headphones or is this improvement mostly felt for speakers? I ask because most of the comments on this thread seem to be about speaker set-ups.

 

[jlbrach]

Sure the M scaler is for better marketing - but I use the term because it makes a vast difference to the sound quality, and these changes were unexpected. In the past, every time you double the tap length, you double the accuracy of the interpolation; so timing errors are halved; and I expected the 512,000 taps that I initially designed to simply sound better than before; indeed, I actually expected the law of diminishing returns would apply, and that it would be no great deal.

But I was profoundly wrong; when I listened to 512,000 WTA taps it was a very different sound to the 164,000 taps in Dave. So I decided to push the boat out, and get that absolute max out of the 200T FPGA, which actually was a big design struggle - but I managed to exceed 1 M taps with 1,015,808 taps.

Now 1 M taps is very personal to me, as going back to my university days in the early 1980's I said that 16 bit digital would never work properly unless we had ideal sinc function interpolation filters with the coefficients of the sinc function accurate to better than 16 bits; and that if we didn't do this, the timing errors in reconstructing transients would be too audible. So the 1 M taps had a lot of personal interest for me. So when I actually heard the huge changes wrought by a million taps, plus the technical fact that we are now guaranteeing reconstruction to full 16 bit accuracy, meant that it would make sense to promote the idea by giving it a unique name.

What is strange is that there really is something odd about 1 M taps; you can convert Blu 2 to 500 k taps by selecting 384 kHz output - and the difference is huge. You can also go to video mode, when it is 2/3 M taps, and that too is a big step backwards. So the M scaler is not just marketing hype!

Going back to your original question - yes an M scaler is the same as software up-sampling - but differs in two important ways - one being the use of my WTA algorithm; the second is the huge amount of computational power needed to do true 1 million taps 16 FS filtering; to do this I use 528 DSP cores running in parallel - when a PC has only 8 cores and is not suited to do real time processing.

Rob

so which setting should i be using if i am using my laptop into the USB of the Blu 2 to transfer Tidal?Or if i am playing a CD?....

 

[jlbrach]

any guidance regarding the sample rate switch options would be helpful....when would you use each of the options?....

 

[Jawed]

Well, for example, you would set Blu 2 to 176,400Hz if you wanted to feed digital into the NAC272, using the digital 1 input which is BNC. NAC272 has a maximum digital input sample rate of 196,000Hz.

I get the part of the Dave + blu2 makes something specially but those who are looking for a cd transport for their dacs/streamers, does blu2 bring something speciall or not?
Is it a "Dave only" product or does m scaler will work with my naim nac272 till I get a Dave as Well?

It would also work with Hugo 2, using the full 1 million taps, which you only get if the DAC accepts 705,600 or 768,000Hz sample rates.

I think it should work with Mojo, as Mojo accepts 705,600 or 768,000Hz sample rates.

I don't know how many taps you'd get with Blu 2 when doing upsampling to 4x 44,100Hz to feed NAC272. It might be a quarter of the full 1,015,808 taps, i.e. 253,952 taps. That's quite a bit more taps than DAVE. But the target of 4x CD sample rate is worse than the first stage upsampler in Hugo, so it might not sound as good as Hugo, let alone Hugo 2. Hugo 2 and DAVE work so well because the first upsampling stage is 16x CD sample rate.

So here are some combinations you could listen to:

1. Hugo 2 -> analogue into NAC272
2. DAVE - > analogue into NAC272
3. Blu 2 -> digital into NAC272
4. Blu 2 -> digital into Hugo 2 -> analogue into NAC272
5. Blu 2 -> digital into DAVE -> analogue into NAC272

I'm sure over the next few months we'll hear from people who have tried Blu 2 with varying up-sampled rates into some non-Chord DACs. Hopefully they'll compare with either Hugo 2 or DAVE connected to Blu 2.

Now playing: Ani DiFranco - Every State Line

 

[x RELIC x]

Spoiler

Well, for example, you would set Blu 2 to 176,400Hz if you wanted to feed digital into the NAC272, using the digital 1 input which is BNC. NAC272 has a maximum digital input sample rate of 196,000Hz.


It would also work with Hugo 2, using the full 1 million taps, which you only get if the DAC accepts 705,600 or 768,000Hz sample rates.

I think it should work with Mojo, as Mojo accepts 705,600 or 768,000Hz sample rates.

I don't know how many taps you'd get with Blu 2 when doing upsampling to 4x 44,100Hz to feed NAC272. It might be a quarter of the full 1,015,808 taps, i.e. 253,952 taps. That's quite a bit more taps than DAVE. But the target of 4x CD sample rate is worse than the first stage upsampler in Hugo, so it might not sound as good as Hugo, let alone Hugo 2. Hugo 2 and DAVE work so well because the first upsampling stage is 16x CD sample rate.

So here are some combinations you could listen to:

1. Hugo 2 -> analogue into NAC272
2. DAVE - > analogue into NAC272
3. Blu 2 -> digital into NAC272
4. Blu 2 -> digital into Hugo 2 -> analogue into NAC272
5. Blu 2 -> digital into DAVE -> analogue into NAC272

I'm sure over the next few months we'll hear from people who have tried Blu 2 with varying up-sampled rates into some non-Chord DACs. Hopefully they'll compare with either Hugo 2 or DAVE connected to Blu 2.

Now playing: Ani DiFranco - Every State Line

Didn't Rob say that you need dual 768kHz coaxial inputs to get 1mil TAPs? Also, I believe it's been said that other devices will get 0.5mil TAPs when used with the Blu mk2.

 

[Jawed]

I presume the halved tap count for other DACs is because there is only a single BNC cable, which will only support a maximum sample rate of 384,000Hz. So the tap count is halved when the sample rate is halved. Which is why I think the tap count would be halved again for 176,400Hz sample rate.

Hugo 2 has a dual-input on it's electrical SPDIF socket, so it is effectively the same as using the dual BNC cables for DAVE.

Now I realise that Mojo would be limited to 384,000Hz input sample rate, because it doesn't have the special connection that Hugo 2 has.

Now playing: Kronos Quartet - John Cage - Totem Ancestor

 

[x RELIC x]

I presume the halved tap count for other DACs is because there is only a single BNC cable, which will only support a maximum sample rate of 384,000Hz. So the tap count is halved when the sample rate is halved. Which is why I think the tap count would be halved again for 176,400Hz sample rate.

Hugo 2 has a dual-input on it's electrical SPDIF socket, so it is effectively the same as using the dual BNC cables for DAVE.

Now I realise that Mojo would be limited to 384,000Hz input sample rate, because it doesn't have the special connection that Hugo 2 .has.

Now playing: Kronos Quartet - John Cage - Totem Ancestor

Yes, I understand your logic, but I also remember reading that with 'other' DACs the Blu mk2 would still provide 500000 TAPs of benefit. I could be wrong.

*Wanders off to find the info...

 

[Jawed]

In the example I gave, the NAC272 has a DAC that can't cope with anything more than 196,000Hz sample rate, and I guess that when Blu 2's sample rate switch is in the middle position it will utilise less taps. Other DACs which can accept 384,000Hz sample rate will benefit from more taps.

Presumably the sample rate switch should be left in the bottom position unless the DAC can't accept 8x upsampled digital. Obviously the switch is left in the bottom position when connected to DAVE with either 1 or 2 BNC cables, giving half a million or a million taps.

Now playing: Kronos Quartet - Hildegard von Bingen - O Virtus Sapientie

 

[Rob Watts]

Rob, I'm aware that the final verdict about how close to a perfect «reconstruction filter» the M-Scaler gets is postponed until Davina is in operation (given that existing «low-res» recordings suffer from imperfect ADC and/or decimation); but since most of my favorite music is still in 44.1 kHz (and will remain), how much, in your opinion, is now missing with the M-Scaler/DAVE playing 44.1 kHz recordings – compared to the best audio formats available, let's say good 384 (or 192) kHz recordings? Have you already been able to decimate existing hi-rez recordings to 44.1 kHz with a Davina prototype and do a comparison?

The other way round: How much do hi-res recordings benefit from the M-Scaler now compared to the redbook format?

Another question: It has been speculated that the PPA amps will work with an M-Scaler alone, without the DAVE. Is that realistic?

The M scaler is a great leveler - and I guess that's not surprising given the residual transient timing error (of which Davina will tell us all how significant that error actually is) is pretty much independent upon the original sampling rate of the source material. So what makes more of a difference is the actual recording quality itself. That said, M scaler has a bigger effect on good 1960's recordings than modern 96 kHz ones using Dave as the starting point.

No the decimation filter has not been completed yet.

All material sounds much better; but recordings that before were too edgy or harsh seem to benefit the most in that they sound much warmer; 96 k recordings tonal balance don't change so much.

Actually I thought I would test that last statement. So I listened to Chandos new Copland symphonies volume, and yes you can hear it sounding warmer - but what really hits you is how the sound-stage completely opens up. And this effect is really weird, as I have not had depth improvements before when tap length increases. But the improvement in warmth seems bigger, or that you need it more, for older 1960's redbook.

So I have just switched in the M scaler on the 1963 Decca Maazel Sibelius 1. Again, with the M scaler engaged, the sound-stage opens up markedly; and the change in warmth is much more apparent; also you get a better feel of tangibility, with instruments sounding separate; everything is just much more real. Now it won't make a bad recording sound great; but if there is great music on a bad recording I find I am able to emotionally access the music more much more easily.

Rob

 

[Rob Watts]

I get the part of the Dave + blu2 makes something specially but those who are looking for a cd transport for their dacs/streamers, does blu2 bring something speciall or not?
Is it a "Dave only" product or does m scaler will work with my naim nac272 till I get a Dave as Well?

I have not tested an M scaler on non pulse array DACs - and other DAC's will see a benefit - but you would be better off upgrading the DAC first. Pulse array DAC's have much better transient timing performance anyway, as it can innately resolve 9.6 nS. R2R DAC's and conventional delta sigma/DSD have poor timing resolution, they simply are not fast or accurate enough.

 

[emrelights1973]

Thank you all for kind answers, I want a cd player for my collection a better one than my cd2x naim
It would be ideal to get Dave + blu2 but there is the cost factor
It would be nice to get them with a year apart..
Maybe get a hugo2 or try my mojo as a temp dac
Let's wait how blu2 comes to use, if any without dave

 

[lovethatsound]

I only use my DAVE with Focal Utopia headphones driven by PC USB. Does the M-scaler in the Blu2 have such a transformative effect on the sound for headphones or is this improvement mostly felt for speakers? I ask because most of the comments on this thread seem to be about speaker set-ups.

Hi hattrick15 you should be able to hear the difference with your utopia headphones,don't have crossfeed on with your utopia,it's not needed.Also demo it if possible.

 

[Crgreen]

1960s recordings are not, of course, natively red book but analogue. The Maazel set of Sibelius symphonies has recently been released on a set in remastered red book and 96/24 on Blu-Ray. I've ripped both to disc and it will be interesting to make a comparison through the m-scaler. I'll probably order the Blu-II this week.

 

[adyc]

Triode,

Can you please give your further impression on Blu2 after you spend few more days with Blu2?

 

[Triode User]

Triode,

Can you please give your further impression on Blu2 after you spend few more days with Blu2?

It is difficult for me to be more precise about the Blu2 except to say that if you have listened to the Dave then the Blu2 sounds to me even like more of the Dave sound. In particular I find that lower register notes are more defined, not more analytical or dry, just more identifiable. The same carries on through the whole register. This gives life to the music.

The affect of the Blu2 is very very easy to hear. This is not a minor upgrade to the sound.

Was the sound with only Dave a bad sound? Of course not, it is ridiculously good by itself.

Is the upgrade with the Blu2 / M Scaler worth it? Only you can priortise your spending but for me the answer is YES.