Ideas for Biamp with mc611 and mc275?

Instead of buying one of the new combo Mcintosh solid-state tube amplifiers (mc451 or 901), how practical would it be to get 2 mc275s (each set to mono) to biamp speakers along with the mc611 solid state mono?


Huh? Like 2 amps per side with the 611’s driving the bass and the 275’s driving the mid and treble?

May work but there could be a gain problem where one of the amps is playing louder than the other.  Call Audio Classics first and see if it can be done.  They are the experts, they will know for sure. 

Excellent point, you have no control over each amplifiers spread of signal to different drivers.

Audio Classics has tons of used gear.

@jumia Wrote:

you have no control over each amplifiers spread of signal to different drivers.

You will have control of the crossover signal to each driver, if you actively bi amp the B&w 802 d3, see below:

Active is the only way to go. And don’t forget to bypass the internal speaker crossovers!


How does one go about bypassing the crossover's? Is this a DIY exercise which I guess requires you to go inside the speakers and remove the filters and have the drivers directly wired to binding posts.   

Yes, you will need to access the drivers and binding posts and disconnect the internal crossovers from the binding posts. Or simply add another set of binding posts. 

Men 220

Not sure I understand the value of a men 220.  Unfortunately it doesn't come with Home theater capability, and it doesn't provide a graph of your room situation.  It's a box that requires you to test the room and then it comes back with a room correction for all those pressure amplitudes that may be out of sync. Basically it cost $6000 to treat your room, and then you leave it connected to your system. It does provide crossover capabilities but that's a small piece of it I guess.

It does seem woefully over priced. 

It can be done but you need to preamps/volume controls.

the first preamp needs two outputs. One would go to the less powerful amp and then one would go to the second preamp/volume control then out to the more powerful amp. This way you could adjust the balance with the second preamp then use the first one as a master. 

For what it is worth my local shop was playing around and use a MC275 and MC7200 to byamp a pair or 805D3s. I did not listen in extreme detail but it sounded nice on the surface. 

The Men 220 has crossover controls that you will need to send the signals from the 2 different amps so that they do not try and play the same signals to the speakers. 













I’ve done this for years and it sounds excellent. are use the Macintosh C50 pre.  Speakers are Tekton Moab with the bi-amp crossover. Everything sounded balanced and perfect, except that I had cleaner base, more base, actually and warmer mids and Highs.  I have to believe that the mackintosh MC 451 amp is maybe a little bit better because it was designed exclusively for the task at hand.  I believe it’s called horizontal bi-amping.


What crossover device do you use for bi-amp?

I saw your system, is mc275 used for the higher ends?


My speakers were designed as a bi-amp speaker. There were four connections on the back of the speaker cabinet instead of 2. If that’s what your speakers have been, you’re fine the speaker company has designed it to be crossed over inside the speaker. When the signal gets sent from the amplifiers, they both send a full signal. The crossover is what filters out what the speaker wants. If you don’t have a speaker that is designed with that kind of crossover then you’re gonna need to rip out the existing crossover and use an electronic crossover. 

I looked up your speakers, and you are good to go. Just take two separate outputs from your preamp and put them into the two separate amplifiers. The magic happens inside the speaker. For instants on the back of your preamp, you may have a RCA set of outputs and a XLR set of outputs. Run the XL wires to the MC 275 and the RCA’s to the MC 601. You’ll be good to go because the preamplifier will feed the voltage to each amplifier at the same rate. If you don’t have two different outputs, then just use a Y splitter and runs one of each to the amplifiers. That’s it you don’t need anything else. Hope this helps. I’ve been doing it for years and it sounds great.