Allo Boss v1.2 first impressions.

I just received a new Boss V1.2 (rev 1.4) from Allo (India). Caveat, the
supercap mounted on the bottom can interfere with the PI’s heat sink.
I had to insulate / separate the supercap and heatsink with a piece
of boxboard.

Initial listening will be with the PI supplied power. This will give an direct
comparison to my existing Piano 2.1 running dual Mono (no Kali).

We have been seriously listening to the Piano 2.1 (dual mono) feeding
Totem Mani-2 fed by 2 x 120W Bryston), no pre-amp for
4 months now. With sources on local USB Key for optimal soundstage,
this setup is so convenient (and “good enough”) that I don’t bother
to fire up my tubes and ESL mains.

Hoping to move up a notch, we decided to try out the Boss(v1.2) with
the master clock (jitter-free). Should give us much tighter LF and
more “space/air” in the sound stage.

The Boss v1.2 is VERY fatiquing to listen to. Channel separation is inferior
to the Piano 2.1. There is little sound stage between the speakers and
almost none outside the speakers. Front to back is also very limited.
To me, it is MID-fi, a decided step BACKwards from the Piano 2.1. The
HF (upper end of vocals are shrilled). It is just not musical and I don’t
consider the DAC audiophile.

In fustration, I disabled the on board PSU to the Boss and fed it with
5V@3A SMP. Ah… Better. Hazing mostly gone, stage beginning to
appear. Separation of complex passages are still not as good as the stock
Piano 2.1 (on board PSU). With this cheap external PSU, the Boss is more
resolving in details, but not in separation of the details (call it a thin
sound stage).

The HF is still not at smooth (musical) as the Piano 2.1. The basic Piano 2.1
is easier to listen to and richer sounding. (apples to apples, both run
upsampled at 32bit/384K).

LF is decidedly better than a stock Piano 2.1. The fair comparison is
to run a Kali-ed Piano 2.1 which I may eventually have to try.

To me, it looks like I will have to investing in an ultralinear supply or
run off LiPO batteries before I can make a conclusive decision. And
after serious burn-in (200hr) I will chime in again.

Out of the box, I do not believe that Boss v1.2 is the “magic bullet”
and will rely heavily on the quality of independently supplied power.

Don’t get me wrong, all this is still good fun for $100. Kudo to
Allo for bringing us these wonderful devices.

Wait min 48h . Check the sound again

Will do. This AM having it run over night with off board PSU, the stage has opened up a tiny bit.
Still exhibit digital haze which is not present in the burned in Piano 2.1. Fingers crossed. 8).

Ultra linear 5V PSU enroute via AliExpress.

hi any improvement post the burn in ?

Not much improvement. The ultra linear PSU is here. I will give it another listen soon.
I disassembled the Boss and went back to DigiOne feed my ancient DAC. Less
Detail, less LF, but at least it was music sans headache/fatigue.

I too use an “ancient DAC” with my Pi for the same reason. TDA1387, straight outta the 90s!
New implementation, though. https://volumio.org/forum/build-nos-dac-hat-for-matt-garman-1387-front-end-t9569.html
What it lacks in resolution, it makes up for in musicality.

How did the new PSU change the Boss sound? Hope you got some improvement.