DAC recommendation

This too is misleading. @ra7 wouldn't have been comparing using his echoic memory, its far too short-term for that. Rather he'd be using another part of his brain, likely secondary or tertiary auditory cortex. See the sections on 'Melody' and 'Rhythm' in Wikipedia's article here.
Sorry, but you are only speculating. The suggested "slower tempo" most probably was not real so the findings from the studies mentioned in the Wikipedia article are not relevant.
 
The suggested "slower tempo" most probably was not real so the findings from the studies mentioned in the Wikipedia article are not relevant.

The perceived (not 'suggested', that's editorialization) 'slower tempo' was clearly significant enough to that he checked to see that the music was indeed what he thought it was.

@ra7 wasn't doing a 'listening comparison' so I don't see how the ITU reference is relevant.
 
I cited those sections as evidence contrary to your claim that 'long- and medium-term aural memory is unreliable'. Clearly if a listener can tell when there's a note out of tune that indicates they're not relying on echoic memory which was what you claimed wasn't reliable. So please explain, within your framework of understanding, how a listener's previous musical experience (because that's longer ago than 3-4 seconds) cannot be the basis for noticing something out of place?
 
Doesn't cut it for you, clearly, however that's just opinion. Your unsupported assertion that 'long- and medium-term aural memory is unreliable' remains unsupported and contrary to what's cited in the literature.

Focussing on 'the tempo' is rather a distraction - the key observation here is that @ra7 did not recognize a familiar recording. 'Slower tempo' is just his best attempt to explain why he failed to recognize it. He knows as well as we do that it doesn't mean 'tempo' in the normal sense which is why he acknowledges it as 'sounding ludicrous'.
 
The DAC I use is the Apple USB-C one, which comes in two flavours:

A2049 1.0V output
A2155 0.5V output (EU regs)

In a non-earthed source like a headless raspberry pi this is fine, and it's easy to insert a decent 5V source for the DAC simply by snipping the red lead.
If you connect a monitor however, the earth of the monitor, via the HDMI, creates a 'computer music' ground loop, yes, I can play tunes by moving the mouse... which can be bravely battled with a 100 Ohm resistor to the incoming USB ground, but perhaps better is to splash out on a ADUM3160 USB Isolator dongle. That will probably make the USB connection more robust too, as the differential data can stray away from the local levels across that 100 ohm resistor, breaking the data connection.

You will also need a small USB-A to USB-C adapter, bear in mind that some don't work when plugged into a 'breakout' socket (see pic) as the pins don't seem to reach that far.
I like the sound of this, although in later Linux the kernel insists it use 48kHz, but the DAC itself can do 44 or 48 (24bit), so you may need sox to resample.

Reviewed here:
https://www.audiosciencereview.com/...pple-vs-google-usb-c-headphone-adapters.5541/

Also bear in mind that if you do what I did and go completely mad and build it into old gear, unselected inputs can be shorted, so what I did here was add a little board of 150R from DAC to AUX1, and 150R from AUX1 to the pre-amp section, so everything stays happy. Yeah - that 7805 - had less space than I thought :D

Another note - This switches off when it's got no music to play, and can't be found without the 3.5mm jack plugged in, so you hear the small power down 'click' when inter-song-gaps exceeds a couple of seconds, and while you are messing about with it - plug something into the end, or be puzzled! :D . Switch cleaner might also be a good idea for keep the 3.5mm connections sweet.
 

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Doesn't cut it for you, clearly, however that's just opinion. Your unsupported assertion that 'long- and medium-term aural memory is unreliable' remains unsupported and contrary to what's cited in the literature.
Your Wikipedia neuro-science remains unsupported in this case as well.
Focussing on 'the tempo' is rather a distraction - the key observation here is that @ra7 did not recognize a familiar recording. 'Slower tempo' is just his best attempt to explain why he failed to recognize it. He knows as well as we do that it doesn't mean 'tempo' in the normal sense which is why he acknowledges it as 'sounding ludicrous'.
It is clear that there would be a difference as the room, speakers, amp, dac were all different. Also the "excitement" related to this listening session may have instigated perceived differences.

My point was that due to the circumstances the results of that listening session are not reliable. To properly evaluate e.g. the perceived "slower tempo" would require comparisons against the original equipment. This IMO requires blind AB testing with matched levels.
 
Throwing basketballs at a hoop is notoriously unreliable, yet some people are much better at it than others.

The point is you can remember if you made a hoop at the end of a game, even if you can't remember the exact muscle coordination and mental focus you used to make happen. To remember that you made the hoop is an entirely different kind of memory, as opposed to a memory of reliving the experience of doing it.