So is it a PC that provides the USB connection for the SRC:DX and do you have both Roon and HQP running on this PC?
Thanks
.sjb
Yes, it is an Intel Core i7 based fanless and linear powered PC running a stripped down Windows 11. I run roon on a separate NUC based ROCK on an Akasa fanless case which is on the network closet, I guess I could run them both on the Windows box if I wanted, don’t see any issues there, it’s just that the ROCK was here before and I didn’t want to mess with it. The HQ Player setup looks like this:
Once I get back to my main residence the whole thing will be properly racked, it is sounding very decent as it is though.
7 Likes
Wow that’s some set-up.
I realise a question like this can sound a bit passive aggressive but I don’t in any way mean it that way, but did you try an m-Scaler ?
.sjb
Is that a Stack Audio Volt PS ?
I’ve never auditioned the M-Scaler in my system, and frankly I don’t doubt for a second it must sound very good. The cost is more than what I was willing to spend, never seriously considered it for that reason and went straight to the alternative.
There are several digital filters in HQPlayer that are quite similar to WTA-1 according to the developer, particularly one called sinc-L which is two million taps when run at 16x (768kHz), but I honestly like the Xtreme and the Gaussian poly-sinc filters better.
The whole thing is very system dependent, not really a race for more taps IME, but having that many options to try and compare is quite nice if you like to tinker.
1 Like
If someone doesn’t like to tinker how easy is it to set up and get best sound?
Yes, it is the 19V-5A Volt for Nucleus, I normally run the Qutest with the 5V-2A Volt but it is being serviced, I messed it up and they were kind enough to take care of it free of charge.
1 Like
As an IT person I’m probably not in the best position to answer that question, I can only say pretty easy to setup. With the basic configuration in place you would simply choose filters from a drop down menu. Like with any software there are more advanced configuration options which only a few will ever need to worry about.
Absolutely HQPlayer is great and Jussi seems one of the good guys, I have a HQP license and did use it for a year or two into a Holo Spring DAC to wet my feet in the NOD DAC pool and DSD.
Probably unique to my personality but I found the permutations a tad overwhelming. Every time something did not sound wonderful I was busy changing filters and modulation - for me theirin lay madness, so I sold on the Holo DAC and Singxer SU2 and ultraRendu and PS and settled on PCM through a Hugo TT2 and added the M-Scaler.
I still have my HQP licence and now have a Pi4 with various Roon extensions on it beside my system and this can also be a HQP NAA so I had been thinking of comparing Jussi’s filters with the M-Scaler but was not aware of the SRC:DX. Did you try USB and find the dual BNC connection better?
.sjb
1 Like
Yes, somewhat better dynamic contrast and transients. The huge benefit was getting rid of the Chord white noise burst issue when up sampling to 768kHz over the USB interface.
1 Like
I don’t believe that I have ever used either of my NDX2, Atom, Mu-so2 or Mu-so QB2 as anything but a Roon endpoint, mostly with the Qobuz integration.
I own an mscaler … it is interesting… with certain recordings it can be quite pleasing to use, many other recordings I would say less so… but it is worth remembering with digital filtering there are two main approaches, Infinite Impulse Response (IIR), and Finite Impulse Response (FIR). So called taps or size of kernel filter where it is convolved (matrix multiplied) with the original digital signal in a moving window like fashion only applies to FIR, IIR uses a recursive algorithm to achieve a similar outcome, albeit theoretically superior outcome, for its filter kernel, it has no kernel taps at all… Each method has pros and cons, remember digital to analogue conversion is not a perfect process in the real world…
Naim for example use IIR filtering in its products (no taps) and Chord Electronics uses FIR (as many taps as it can)… there is no right or wrong … in the real world each filter style will sound or feel different and to a large extent is implementation dependent.
So my point is audio digital filtering is not all about taps… as there are different equivalent ways of achieving reconstruction filtering.
1 Like
@Sloop_John_B Hi John…Holo Audio seem to have some very interesting products. I take it you were using the ultraRendu as a Roon EP and then feeding USB to the Singxer. Were you feeding I2S to the Holo from the Singxer and then into Naim Pre-Amp?
Putting aside all the permutations how did you find the sound of the Holo in NOS or DSD mode and where did you buy it from?
Thx for any feedback
Since I got my mscaler it’s never been off and I have never considered that some music may sound better with it off. Is there any particular music that sounds better without?
Yes in my opinion rather processed productions don’t gain much - ie much contemporary heavily produced music. Some live recordings - and especially tape transfers sound really good with the scaler however…
I leave my scaler in circuit like you. Not sure I have felt the mscaler makes anything sound worse - just does slightly change the tonal balance of a track sometimes rather than changing much, if any, insight
1 Like
FIR filters are widely preferred for high end audio applications as their benefits far outweigh those of IIR, the exceptions are mainly related to the lack of computational resources. That doesn’t mean that good sound cannot be achieved with IIR filters, as naim clearly does, but I wouldn’t be surprised to see naim switch to FIR in future iterations of their products.
I believe that Roon Convolution filters are FIR and the Parametric are IIR but I may well be wrong here 
I do prefer Convo to Parametric for a more natural presentation.
That’s exactly how I was using it.
I bought the Holo DAC s/h that Magna HiFi in the Netherlands had originally sold and they procured an original box for me and I got a Singxer SU2 from them. Really sound guys and very quick response times.
I predominantly used the Holo for DSD 512 via HQP. After a Stereophile review I tried it as a pure NOS PCM DAC but couldn’t reconsile what the reviewer heard with what I was hearing.
I ended up with both Chord Hugo TT and Holo/ HQP on my rack and would have listened to both over extended periods and both certainly had their charms.
Once I got the m-scaler Hugo TT2 I found that I was listening to it for longer periods and spending less time with the Holo when I did plug it back in. When it came to 12 odd months without the desire to swap back in the Holo I sold it on. A factor in this I think was that my Auralic Aries G2 gave a better (cleaner?) signal to the chord (I use it wirelessly as I found this best - my room, my ears etc.) than the ulltraRendu gave the Holo (wired).
I wouldn’t say never again though, the Holo May DAC looks impressive and the Mano ULTRA mkIIA Music Streamer has ethernet in and iS2 out and looks a decent product.
Having said that I was looking for the DAC to cure a problem not of its making and found that HAF DSP filters ”cured” most of the problems I associated with my system.
.sjb
3 Likes
Any reason you not using an NAA isn’t it advised to use one to keep the noisy processing away from the audio kit much like Roon do.
Thanks John, very useful feedback.