doobooloo
Headphoneus Supremus
- Joined
- Nov 3, 2002
- Posts
- 2,544
- Likes
- 11
Well well, finally. Got the kit while I was in China over summer, just finished it. The original group buy thread is here, if you're interested.
The chassis style is an extension of the dblab ppa project, it's just longer and only one output jack is present. Four heatsinks line each side of the amp board, with MOSFETs and regulators connected with teflon coated silver wire.
Basically, almost everything on the board has been swapped out. Resistors, capacitors, etc. etc... The filtered IEC power jack has been replaced by a regular jack, and the RCA jacks replaced with a higher quality pair. A second input (aux) and pre out were eliminated as I have no use for them.
Also, the stock Hitachi J77/K214 MOSFET pairs have been replaced with higher speced (and more expensive) Toshiba J313/K2013 pairs. The pinout was different, but since I was wiring them off board anyway, this wasn't such a big problem. Also, the 8050 transistors have been "replaced" with 8050s (the kit came with some other set of transistors).
Anyway, on to listening impressions...
First thing I noticed was that the background was now black. No noise, even with low impedance phones. With the stock model, noise was a rather significant issue with my PortaPros, but to my surprise this one was just silent even with the PortaPros. Of course, the background is just pitch black with higher impedance phones. I think this could be a result of several things, including isolated ground, thermal isolation of MOSFETs and regulators, better resistors and larger power supply rail capacity. But, whatever the reason, it was great to have a nice black background.
And the sound. Well, I really liked how the stock amp sounded, I can't describe it very well but it was very tasty. Mmm. It was not exactly the most detailed and lively, but full of bold energy. So, I already liked it before all the mods, a nice companion to the very detailed and analytical PPA (I had AD8610s installed in my previous PPA then). This one, after the mods, goes a huge step forward and becomes an amazing amp. The details are all there, very nice and sparkling just the way I like them, yet it retains the strange but good "energy" that the amp seemed to have over the PPA. The quieter background definately adds to the improved energy and dynamics. The one thing that really jumped at me was the three dimensionality of the sound that came out of this amp - with all types of phones, music just came alive, meaning that it was now all around me. Very sweet.
Anyway, those are my first impressions of my newest creation... It's only been an hour or so since I finished it and was able to listen to it, so I'm going to go back for a night of critical listening and enjoyment - may I then end this post with a few nighttime pics until I come back later for more impressions:
dblab ppa sitting on top of its new big brother, dblab hp-100a:
another angle:
with some light:
another angle:
with ppa off its back:
tube... mmm... tube...:
another angle:
overall, with lid open:
Any comments would be greatly appreciated! Thanks!
The chassis style is an extension of the dblab ppa project, it's just longer and only one output jack is present. Four heatsinks line each side of the amp board, with MOSFETs and regulators connected with teflon coated silver wire.
Basically, almost everything on the board has been swapped out. Resistors, capacitors, etc. etc... The filtered IEC power jack has been replaced by a regular jack, and the RCA jacks replaced with a higher quality pair. A second input (aux) and pre out were eliminated as I have no use for them.
Also, the stock Hitachi J77/K214 MOSFET pairs have been replaced with higher speced (and more expensive) Toshiba J313/K2013 pairs. The pinout was different, but since I was wiring them off board anyway, this wasn't such a big problem. Also, the 8050 transistors have been "replaced" with 8050s (the kit came with some other set of transistors).
Anyway, on to listening impressions...
First thing I noticed was that the background was now black. No noise, even with low impedance phones. With the stock model, noise was a rather significant issue with my PortaPros, but to my surprise this one was just silent even with the PortaPros. Of course, the background is just pitch black with higher impedance phones. I think this could be a result of several things, including isolated ground, thermal isolation of MOSFETs and regulators, better resistors and larger power supply rail capacity. But, whatever the reason, it was great to have a nice black background.
And the sound. Well, I really liked how the stock amp sounded, I can't describe it very well but it was very tasty. Mmm. It was not exactly the most detailed and lively, but full of bold energy. So, I already liked it before all the mods, a nice companion to the very detailed and analytical PPA (I had AD8610s installed in my previous PPA then). This one, after the mods, goes a huge step forward and becomes an amazing amp. The details are all there, very nice and sparkling just the way I like them, yet it retains the strange but good "energy" that the amp seemed to have over the PPA. The quieter background definately adds to the improved energy and dynamics. The one thing that really jumped at me was the three dimensionality of the sound that came out of this amp - with all types of phones, music just came alive, meaning that it was now all around me. Very sweet.
Anyway, those are my first impressions of my newest creation... It's only been an hour or so since I finished it and was able to listen to it, so I'm going to go back for a night of critical listening and enjoyment - may I then end this post with a few nighttime pics until I come back later for more impressions:
dblab ppa sitting on top of its new big brother, dblab hp-100a:
another angle:
with some light:
another angle:
with ppa off its back:
tube... mmm... tube...:
another angle:
overall, with lid open:
Any comments would be greatly appreciated! Thanks!
