Inno-maker HiFi DAC Pro HAT - first impressions

[TheOldPresbyope]

My interest in this DAC (HiFi DAC Pro) was kindled by a recent post from @the_bertrum which referenced a blog posting by Archimago. The majority of that blog post (but not the reason it was cited by the_bertrum) was devoted to a review by a technically minded user comparing the Inno-maker DAC to the Khadas Tone 1 USB DAC. I have the later and like it a lot. Still, I decided to buy the Inno-maker DAC as well because

• the performance was reported as comparable (and great!) both in measurements and in listening --- both are based on the ESS SABRE ES9038Q2M chip,
  
• the HAT configuration meant I could avoid the extra box and cabling I'd need for a USB DAC (target: a headphones-only build)
  
• The Inno-maker is selling for just USD60 on Amazon at the moment, a quarter to a third less than the Khadas Tone 1 currently sells for in various places
  

The Inno-maker user manual says in the moOde setup section  to "select ‘allo-katana-dac-audio’ for DT overlay." It goes on to say

Do not select ‘All Katana DAC’ for Named device. Otherwise the Moode system will be breakdown and only re-image. There may be a BUG for moode. [English is not their first language.]

Hmmm.

The DAC has arrived and I have mounted it on a Pi4B. I chose to power the DAC from the Pi but optionally could have powered it separately. I connected the unbalanced audio output to a headphone amp, and booted 64bit moOde 8.3.2. As prescribed by Inno-maker, I selected the allo-katana-dac-audio DT overlay, kept all other moOde audio settings at their default values, and rebooted.

With my hardware and my aging ears, the audio is indistinguishable from that with the Khadas Tone 1.

Notes:

• software volume control only
  
• the interface does not report DSD as a supported format so moOde in Native DSD mode transcodes DSD to PCM during playback
  
• the oddity - the software volume control functions on PCM-encoded tracks but not on the transcoded DSD tracks; full volume regardless of volume control setting (so downstream volume control still essential for DSD tracks)
  
• the Allo Katana DT overlay and driver expose a selection of four different oversampling filters but without the extra coding of the Named I2S device setup, they aren't available as chip options in the moOde WebUI. They can be changed, however, with alsamixer or amixer from the command line as demonstrated in the blog post measurements. (It's a moot issue for me; with my ears I can't distinguish between them.)
  
• the weirdness - if I choose instead to set Named I2S device to "Allo Katana DAC" it does indeed bork the install.
  

I'll be exploring this last point on the Support sub-forum.

As an aside, The reviewer in the Archimago blog post said he was unable to get DSD to work in his setup (with Ropieee). I on the other hand seemed to have some success with setting MPD to DoP instead of Native DSD mode but experienced some inconsistent behavior I haven't run to ground yet.

More later, including the usual reports from aplay, amixer, etc.

Regards,
Kent