That's crazy good sounding!
I just got my HRM 50 built and doing the initial power up routine. I can only hope mine will sound as good.
Very nice indeed!
It will eventually, but not 'right out the package' remember it takes 80-100 hours before it has matured.
OK, As far as breaking in amp so far I started out with a speaker that was broken in already (10 hrs on amp ).
Since I got my WGS ET-65 ( 1x12 in homeade combo cab now )and upon startup (Yesterday)it was alot harsher sounding than the other speakers. I have a looper on my B%ss GT10 and just set a little rhythm track and then let play for most of day while I was out ( approx 8hrs )and then fiddled with it even longer.
Today I have been playin with it for a few hrs as well and it already sounds a hella of a lot better.
And I have found that the OD trim is the most sensitive of all knobs on this amp, Just barely(<9:00 ) past clean sounding is almost what gets the best sound IMO so far. After that it just starts to sizzle too much ( maybe a differnt Pot would be more suitable for OD trim).
Or hopefully that is some of the burn in hopefully