i understand that they will offer some kind of filtes so you can choose different tunnings? if so how will you do that, does it have an app or?

What Tempotec told that there will be six different firmwares released: they will need to be changed by flashing similar to updating.

thats a bit of a hassle, an app wouldve been way better.

Its a good option vs the FosiAudio DS1, because i have it but the Sonata provides more power and i think the match can be better with the S12 PRO

I do not have S12 pro and DS1. The power should be sufficient to drive IEMs on both. DS1 will likely be more drainy on battery, as most ESS9038 devices I encountered.

Ok thanks, no problem, yes the ds1 consumes too much power for me

I was going to get jcally AP20, but got swayed by your opinion. Now still torn between this and AP20 for my KZ PR2. Do advise

I compared with PR1, which is treble-rich.
So here are my impressions to help you with your choice:
AP20 mid-centricity feels to work well with PR1 to me,, complementing/balancing its treble.
BHD pro brings more in treble, but works for me. If you equalize - it should work well.
Space can become a bit too much. Space was likely designed for single DDs.

BHD pro is a nice dongle.
AP20 makes a lot of sense, if the battery is needed.
Both are fine choices, so select based on your needs and preferences.
I could not include an image here, but will now add a size comparison in the end of the review.

It's that how less refined AP20 is compared to BHD pro, will help me decide. Will I notice occasionally or more frequently?

"Less refined" or less "processed" is a question that is hard to answer. I would not put AP20 as any crucially deficient in sound (BGD pro feels more airy/refined, but specifically with PR2 it may be a less of advantage (?)), so the battery, size and more midcentric/thicker (AP20) vs. slight V and airy are the criteria for the decision.
I do think both can work well - so hopefully a nice enjoyable choice for you

From Andy of dongle madness, I understand that AP 10 belongs to the uncolored CS43131 group. Last questions about AP20. Does it have 85% power of E1DA? Will it widen the soundstage on PR2?

From my impressions and interpretation of Andy's AP10 review - it is more "musical" to him; thicker/mid-centered to me. The neutral/uncoloured would be Sonata HD pro. Then it would be more synergy with IEMs than neutrality that can matter. AP20 was really good with PR1. I tested also Sonata III, I thought its warmer skew will work with PR1 - not really after my brain got perhaps biased by Cirrus (or not enough power).
85% power of battery-powered E1DA SG3, would be a good simpleà000a conservative estimate of E44, BHD pro, Space and AP20.
AP20 has a very good power management and its independent battery. BHD pro is smart looking and promised firmware could give several sound rendering.

If AP20 is $50, BHD pro would be at par at $60-65 - if to try to express it quantitatively, to the best of my subjective opinion

Reviewed the AP10 a while back. Still have it. Eager to see how the AP20 fairs. They both use the exact same Cs chip and Savitech component. And the way you described the mid-centricness i'm guessing is its basically an AP10 with a battery attached to it.

Rattling buttons, rockers are dials should not be a "just nit-picking" thing. That's an issue in build quality. Tho it won't affect sound.. it does affect the feel in use. If we don't address that as a legit concern and issue then manufacturers will think that it's ok. Other than that, good review.

For AP10/AP20 question, I do not have AP10 directly (but do have a rebadged one by Lamscat) - my understanding and impressions that AP20 is exactly AP10 with a battery, and it works well for that.

When you post the full review of the AP20 please do include an in-depth comparison with the AP10/rebranded Lamscat. The new one has its power figure listed as 330mw@32 ohms Which i think is an upgrade over the previous. So there could be sound upgrades/changes.

I am not a reviewer, I just did my Tempotec's opinion for fun and my general affection for Tempotec (no any affiliation and any monetary gains/discounts, etc.)

So it is quite unlikely that I will review AP20.
Few words on the powe: I only use IEMs, so I won't be able to provide much feedback for using high power. Actually, more power without internal volume control, as for AP20, can be more problematic. Interestingly, Lamscat and AP20 are recognized by iBasso software, so it helps, but I really do not like to depend on some extra software for the volume control.
For me, a good powerful dongle should have an independent volume control, not the case with AP20.