I tried a couple different vintage amps between the B1 and Buchardt S300s in a 14x15 room.
JBL Urei 6230 (150WPC) had lots of low end torque. Mids and highs were nice but uninspiring.
Sansui Six (>34WPC) Had more defined yet less powerful bass than the Urei. There was some magic in the mids/highs but they were a bit too quiet next to the melodious bass.
Marantz 2238B (48WPC) Pretty balanced in this combo except for soft bass. clarity behind the hk and JBL
Harmon Kardon hk 505 (>60 WPC) My favorite. Unmatched in midrange clarity. Nice treble presence. These speakers never overdo the treble. This combo sounds the most in the room. I have a Baldwin grand in my house and the hk in this setup sounds the most like the real thing to me. It gets voices and guitars right too. It's doesn't have as much low bass kick as the Urei. The upper bass isn't as euphonic as the Sansui.
Soon I'll be fooling around with tubes and biamping behind the B1. If I don't transcend the next step may be to save up for an XA25. What do you think?
JBL Urei 6230 (150WPC) had lots of low end torque. Mids and highs were nice but uninspiring.
Sansui Six (>34WPC) Had more defined yet less powerful bass than the Urei. There was some magic in the mids/highs but they were a bit too quiet next to the melodious bass.
Marantz 2238B (48WPC) Pretty balanced in this combo except for soft bass. clarity behind the hk and JBL
Harmon Kardon hk 505 (>60 WPC) My favorite. Unmatched in midrange clarity. Nice treble presence. These speakers never overdo the treble. This combo sounds the most in the room. I have a Baldwin grand in my house and the hk in this setup sounds the most like the real thing to me. It gets voices and guitars right too. It's doesn't have as much low bass kick as the Urei. The upper bass isn't as euphonic as the Sansui.
Soon I'll be fooling around with tubes and biamping behind the B1. If I don't transcend the next step may be to save up for an XA25. What do you think?
I think if I was going to buy a Pass Labs product I would probably get the integrated.
Pass LabsINT-25 - Pass Labs
Or I would get an SIT-3
That is if I was buying, but building is more fun and you can go crazy with over engineering it.
Pass LabsINT-25 - Pass Labs
Or I would get an SIT-3
That is if I was buying, but building is more fun and you can go crazy with over engineering it.
I'm usually crazy even without over-engineering part, much easier ....... 
anyway - when using amps of FW power range ( max 25W) and let's say that, by usual Papa's wakoo approach, XA25 is rated as is (Berserker nature well disguised) ........ it's usually beneficial having bigger cones, more efficient and more sensitive
I'm not disputing preferences for small coned speakers........... just saying that I'm often finding them perfect for covering mid range ........ speaking of size, while still preferring loud ones
XA25 is good choice; if you miss some sugar (2nd harmonic) just bring some toob in preamplification
anyway - when using amps of FW power range ( max 25W) and let's say that, by usual Papa's wakoo approach, XA25 is rated as is (Berserker nature well disguised) ........ it's usually beneficial having bigger cones, more efficient and more sensitive
I'm not disputing preferences for small coned speakers........... just saying that I'm often finding them perfect for covering mid range ........ speaking of size, while still preferring loud ones
XA25 is good choice; if you miss some sugar (2nd harmonic) just bring some toob in preamplification
I am enticed by the underrated output of the XA25. And the new generation output transistors are probably a step forward from older designs. I'm not sure I even have the palete to hear the difference though.
Another contender is the X150. My Buchardts are 4Ohm 88dB. That should squeeze 40WPC out of a SIT-3, maybe 100WPC from an XA25 or 300WPC from the X150.
I just don't know. I'm always switching genres and volume levels. I'll review the setup with the MTX hopefully soon
Another contender is the X150. My Buchardts are 4Ohm 88dB. That should squeeze 40WPC out of a SIT-3, maybe 100WPC from an XA25 or 300WPC from the X150.
I just don't know. I'm always switching genres and volume levels. I'll review the setup with the MTX hopefully soon
I ended up getting a SIT 3. I tried out a mtx (vfet) car amp both in-house and in-car. Those vfet mtx's are good old American amps. Ballsy.
In car the mtx is awesome. In house it lacked some finesse.
So anyway the SIT 3 is a revelation. Picodumbs you made a great recommendation 👍
Im a little obsessed with the connection between the mind and body. That's my frame.
Finally I'm experiencing hifi. Listening to music is different now. I feel a connection to the songs in my head and torso. Its a blissful feeling. This First Watt/Buchardt combo feels good in to listen to
In car the mtx is awesome. In house it lacked some finesse.
So anyway the SIT 3 is a revelation. Picodumbs you made a great recommendation 👍
Im a little obsessed with the connection between the mind and body. That's my frame.
Finally I'm experiencing hifi. Listening to music is different now. I feel a connection to the songs in my head and torso. Its a blissful feeling. This First Watt/Buchardt combo feels good in to listen to
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I just looked at probably the same sales brochure and it said "Vertical-Mounted FETS" So you may be on to something. On the other hand that brochure was probably written by an ad-man and not an engineer. I'm surprised a company would lie like that while also underrating their amps at the same time. Those amps regularly test at double their rating.
Either way I can't turn my SIT off and it definitely has real VFETs
Either way I can't turn my SIT off and it definitely has real VFETs
You can find pics of the PRO752 at MTX Blue Thunder PRO 752 - AMP Performance
I have my doubts about the VFET content...
I have my doubts about the VFET content...
All power SIT are metal package TO3, TO79, RF, Pucks and some other varieties not seen from Amp Performance photos. No SIT there, no mystery.
Yes Gerd, there are a few small SIT, I happen to have a few Sony 2SK63 and 2SK79. The 2SK63 is metal TO39 and the 2SK79 is sort of grayish rounded corner TO92L. I am pretty sure there is no K79 there. 
Anyway, SIT parts are expensive and quite an odd choice for consumer grade car amplifier targeting subwoofer driver duty.
Anyway, SIT parts are expensive and quite an odd choice for consumer grade car amplifier targeting subwoofer driver duty.
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