Tube monoblock options?


Anyone have a good suggestion for tube monoblocks? I've been holding out for a used pair of MC75-III's, but hard to come by. The system is comprised of Oppo-205, Mcintosh C52 and McIntosh MC275-6.  I don't want to get another 275, since my dealer told me that "just because you can bridge the 275, doesn't mean you should".  Anyone have a comparable option to the mc75? Entire system is balanced, so would like to stay away from SE.
lilchris9
As a point of information, despite the use of the term "bridged" by the dealer and despite misuse of that term in some literature you may have seen, the 275-6 and other amplifiers in the 275 series cannot be bridged. When they are operated in mono mode the two channels are paralleled, which is very different than bridging.

A bridgeable amplifier can potentially supply as much as 4x as much power in mono mode as in stereo mode, depending on the specific design, but that increase in power capability is usually accompanied by several sonic downsides. Most notably not being able to handle low impedances very well, or at all, since a bridged amp will "see" the speaker’s impedance divided by two.

In the case of the 275-6, though, paralleling the channels results in a 2x increase in rated maximum power compared to stereo mode, while potentially **improving** the ability of the amp to handle low impedances. That is because in mono mode the 4 ohm, 8 ohm, and 16 ohm taps in effect become 2 ohm, 4 ohm, and 8 ohm taps respectively.

All of that said, however, I have no knowledge as to how the sonics of that particular amp compare in the two modes.

Good luck. Regards,
--Al

lilchris9

A bridgeable amplifier can potentially supply as much as 4x as much power in mono mode as in stereo mode, depending on the specific design, but that increase in power capability is usually accompanied by several sonic downsides
As bridging any good stereo amp takes a hit sound quality wise, for the sake of more watts.

Pity your 3 way Focal Kanta No.2’s aren’t bi-amp’able, (you could do it if you have the skills) then you can put the MC275 or 75 on the midrange and tweeter where it will sing doing 300hz and up, and then just use a Class-D or linear grunter, on the 2 x per channel bass drivers from 300hz down.
https://www.stereophile.com/images/1018FoKan2fig1.jpg

Cheers George
What is your budget?  What speakers are you driving? 
Driving focal kanta 2's. Budget is $10k. My apologies regarding bridging. My audio rep stated that you can parallel the 275, but shouldn't. 
How big is your room? That and how lively it is will say a lot about how much power you need.


would agree with atmasphere, how much power do you need and what are you driving?
if you need big power with Balanced inputs Series 2 or 3 of the VTL MB-450 should do the trick.

lilchris9 OP

Like I said above a 275 or 75 will do very nice for the Kanta’s mids and tops, but they won’t drive this kind of bass loading very well between 60hz to 150hz
As with the combined impedance and -phase angle it will look very nasty, down to 2ohms to those tube amps.
And if those tube amps were bridged, it would look far worse (deadly) to them.

https://www.stereophile.com/images/1018FoKan2fig1.jpg

If your not capable get some one who is, shouldn’t cost much, to spit the xover and add another set of terminals to each speaker for the double bass units, pretty easy job, and bi-amp with a Class-D on the bass.

Cheers George
And, though he has responded to this thread, Ralph is too classy to boost his products.
So, if I can speak for him, I would recommend Atma-Sphere amplifiers in a heartbeat.
Bob
Really!!!

If your referring to OTL's into those loads 🤦‍♂️ The bass will sound like a stick of salami wack’ed against a lounge your suit, and it’ll be all mid/highs dominated.
https://www.stereophile.com/images/1018FoKan2fig1.jpg
But if your referring to his up coming yet to be released Class-D, it has a far better chance of driving them.

Cheers George
Actually purchased the C52 because I have the most difficult room to tame when it comes to the low frequencies.  Added as much acoustic foam, inside canvas art, to the room as the wife would allow.  The C52 allows me to tame the 25 and 50 hz. The kanta's have deep bass extension, so needed it. I had the PSA BHK preamp, which sounded great at low volumes, but at higher volumes, the bass was too much. Just wish Mcintosh would bring back the mc75 because the 2301's are insanely expensive.