These specs apply only to PCM, and what DSD rate they are converted to for digital-to-analog conversion. Cayin's 1-bit products do not alter the native DSD rate. Whatever DSD file you feed it, will be decoded as is – i.e. DSD64 = DSD64, DSD512 = DSD512.

I’d like to draw everyone’s attention away from the tubes being the same as the SP3000T, to ask about the signal path designed around AK’s tubes: ie does it have an analog volume control? Not a rhetorical question, I really don’t know.

Er, yes? And then, in “Tube” mode, the tubes output directly in XLR. And in “Trans” mode, the op-amps are used.

Oh dear 😂

Only the tubed RCA out uses transistors in the circuit. The rest are all transistor-free. The tubes directly drive the outputs in XLR tubed. Think of 'Trans' then as "tube-free".

Valid points all around. Just a quick note that that 'Trans' mode means 'Transistor', the iDAC-8's solid-state output.

Right now, it's the M5 Ultra's 6.6ohms balanced output impedance that makes me have the most reservations about it.

Not very sure how we can help you more in our notes, other than to say iHA-8 does the big Hifimans justice in every way. See if you can get a listen around.

The early impressions of @HiFiWar with his Susvara should clarify whether iHA-8 meets the requirements.

In Hyper mode, swing goes to +-15v.

I guess I ought to come out and admit that our demo's chassis is rigged and made of lead, to give the impression that there's no interference 😨 (Obviously, I'm kidding, right?)

We're talking about RF components right beside the tubes, in the chassis of the player. The tubes are shielded from external sources by the chassis. Of course, you could always use a longer cable if that makes you feel more comfortable. But Wi-Fi 7 modems and 5G signals have infinite reach...

SGD.

Not to worry. That's part of the new firmware actually. Those lock volumes on the R8II, R6 Pro II and R6III when nothing is plugged in. It's meant to ensure that your HiBy functions properly as a transport. Don't be alarmed though, it'll only output at max volume when outputting USB or SPDIF...

Be sure to take this up.