Can you use that filter for real-time conversions during playback?
Super-computer? My cheapest/lowest power machine running upsampling to DSD256 with my ASDM7EC modulator is i5-7600T. That computer is quite a bit cheaper than lot of audio gear audiophiles typically buy.
Yes, you can.
How many concurrent zones, and what type of processor would you need for say two zones?
HQPlayer doesn’t have concept of “zones”. So I cannot comment on such.
And with which filter, modulator and what kind of output rate? How many channels?
Let’s say the filter with 260M taps, playing back two stereo 44.1/16 sources, up-sampled to 705.6/32?
You won’t get that number of taps at such low conversion ratio with any of my filters. Since it would cause 169 seconds delay which would be quite annoying.
But pretty much any filter runs on almost any CPU to such low output rates as 705.6k. No trouble running for example 1 million taps at that rate.
Thanks. I though so. I would rely on my DAC to do the up-sampling then.
So if you don’t get 260M taps at very low 705.6k rate you rather go with 64 taps in your DAC?
I rather run less taps with <0.000000005 dB ripple and >300 dB stop-band attenuation to 705.6k output rate, rather than relying on high ripple and low stop-band attenuation.
I just wanted to show that any processing is resource-constrained in some way. Yes, computers are less constrained than DACs, but when you reach 0.002dB ripple and -120dB stopband, you are orders of magnitude below what anyone can distinguish. It’s simply not worth spending money on a DAC like D90SE just to spend more to bypass what it does so well.
Well now we are talking!
Don’t tell some members here though…….
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Lol this is what happens when thread title doesn’t mention HQPlayer. We get stray (vinyl) cats lol.
Maybe @andybob can add HQPlayer to thread title? I know it’s already in HQP section but easy to miss that
Interesting discussion though
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That was a joke. It can happen no matter the title.
Which way? I’m not seeing any resource constraints.
It’s not extra expenditure in hardware if you are already using a computer to feed it.
I rather spend more on a DAC that doesn’t have anything to bypass. Something that doesn’t put something I don’t need (resource constrained DSP) on the signal path. I just want a D/A converter that only does D/A conversion and leaves the DSP part out.
P.S. Filters with highest number of taps are not the ones with highest reconstruction accuracy…
That would be true if HQ Player was free.
Oh, now I see where you’re going. 
The only way to avoid DSP in a DAC is to use a NOS DAC. But, since D/A conversion at low rates and high bit depths is not feasible, you could implement the delta-sigma modulator (i.e. up-sampling and bit reduction) in software and then have the DAC do just the D/A part. I know there are ADC chips that allow you to bypass the decimation part and get the direct converter output (at say 256fs/6 bits), but I don’t know if that’s also true for DACs. I think that would make an awesome pet project, but I believe the sound quality gains would still be unnoticeable.
That’s what some of us are doing, like Holo Audio users.
And myself with my RME ADI-2 FS DAC (AKM chip running in DSD Direct mode bypasses on chip filtering and SD modulator).
Without HQPlayer, the RME performs great. With HQPlayer, Jussi has shown it performs even better.
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If the differences are not audible, the argument is moot. Although as an engineer, I have to admit it’s more intellectually satisfying
I know there are chips that accept DSD directly, but I was thinking whether there are DACs that accept multi-bit. 1-bit has inherent flaws and should in general be avoided, but that’s a different discussion.
So enough with the boring hypothesising then? Join the dark side? 
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Nah, I have other hobbies to attend to.
Haha good chat then. Take care.