I received my TR-07hp mk2 some weeks ago and i'm verry happy with it. The amp is nicly
build with a DIY touch what i like. As you may know the amp use 2 vfet transistors from Sony
(2SK79), the are discontinued since years and hard to find. Vfet have a triode characteristic,
so a tube like sound is the result.
The bass is detailed, deep and strong - hard to finde a portable amp so competent. The mids
are soft and nicely balanced, some extra details are missing, the focus here is on a enjoyable
side, not a analytic one. The highs are not very extended but fits the character of the amp very
well. Some will say that the amp is missing here some parts of the music. Overall is a natural
sounding amp with the focus of enjoyment and easiness, not neutrality. Soundstage is either
super wide nor narrow, that fits fine. The presentation is not very 3d, leans on the flat side.
What is realy nice that this all comes with a quite speedy and direct prensentation - not muddy
oder sticky like other tube amps. If you know the neslon pass house sound, think of it minus
some details in the highs and limited 3th dimension.
The power output is weak, don't try to use low efficieny and/or high ohm headphones. Works
great with sensitive headphones like Fostex TH-900, here the not so prominent highs fits the
character of the TH-900 perfect. With the Piano Forte X the bass gets some extra power and
the presentation is super smooth. At the moment i used it most of the time with some AK T8ie,
a great pairing too.
The amp needs some time to sound best, about 15-20 minutes. It gets warm after 1 hour.
Runtime is short with about 4 hours, charging time long with about 8 hours. So its not the
best amp for portable use due the limited runtime and warm up time.
It's a amp for people who like to dive into the music and not into analytics. This amp brings
you to the music no away from it.
Update 04/2016
Love is strong for this amp after some weeks, it realy shines with easy to drive headphones or
iem. With the AK T8iE the Bass around 150 hz gets to dominant for me, i eq these iem with a
bump of -3 db around 150 hz. Direct driven from the AK240 i would put the bass down only the
half. A weakness of this amp are complex multi layered arragements, like in a opera where the
whole orchestra is playing, the instruments blend together and loosing contour, that was special
to realise because the amps nature is quite speedy and i wasn't expecting this. I never had this
effect with any amp who is at the same time not on the slow or muddy side. It's for me not a big
no go because you need to throw a lot of musical information at the same time at the amp that
this happens but when it does it's obvious. No problem at all when you listen to jazz, country,
latin or arragments with a dozen instruments. Maybe it's like a supercar performing perfect but
when the limit is reached he failes heavy. But anyway, i often grab this combo at home even if
i could choose great desktop gear/full size headphones, a pleasure to dig deep into the music.
I measured the charging power, it's 0.65 a and drop to near zero after 4 hours, so the battery
should be near full after 4 hours.
Receiving the Ocharaku Flat4-Sakura Plus tomorrow after they get out of the customs i'm very
exicted to discover this new combo
, have a good feeling that's also a great pairing.
22 mf 630V !!! Nearly 50% as big as the whole amp. it was fun. The low end was AWERSOME!!!. Thinking of making an external connection for an big caps for home use. With the possibility of quick switching off...