To bi-amp or not, that is the question
 

Hi AA!

Was chatting with Ivan about my setup and we started down a path on bi-amping my Cantons. The specific scenario we were going through was to connect the monoblock MC2301's to the highs and mids (I love tube sound) and then to add a MC452 or MC462 to the lows.

Trying to get a sense of what to expect if I went this direction and if the potential gains would be noticeable.

This would be a passive bi-amp scenario as I still would like the speaker crossovers to do their thing. The Cantons have physically separated crossovers and would have no issues with the extra "umph" doing this would bring.

the connections would run from the C1100 to MC2301 left and right. Then from each MC2301 via Balanced XLR to a single MC452 (or 462).

Any thoughts or suggestions appreciated.

Bi-amping is great. But how will you match the gain of two different amps? I would stick to identical amps. If you want tubes, then go with two stereo amps like the new MC2152. Even less money than what you had planned initially.

What happens when the gain doesn't match?

The only gain setting is on the C1100.

The manual for my 2301's seems to indicate that it's no problem to bi-amp with a different McIntosh Amp.

https://i.imgur.com/EnvsfZY.jpg?1

Only if the two have identical gain. Since the only gain control is on the preamp, it cannot compensate for a difference in the two amps.

Thank you. I can find the gain on the MC462 but not the 2301... any ideas where to find that?

The Berners site is a good place to look for Mc specs.

From the MC 2301 Owner's Manual:
Ei=3.4 Vrms (balanced input) for 300 Watts into 8 Ohms.
Eo=SQRT(P*R)
Eo=48.99 Vrms

Gain in dB=20*Log10(Eo/Ei)
Gain in dB=20*Log10(48.99/3.4)
Gain in dB=23.17 dB

From the MC 462 Owner's Manual
4.2 Vrms (balanced input) for 450 Watts into 8 ohms
Eo=60 Vrms
Gain=23 dB

Close enough!

Now what's confusing is the gain spec in the 462 manual shows the following:
Voltage Gain
29dB, 8 Ohms
26dB, 4 Ohms
23dB, 2 Ohms

But they don't state if the gain is measured from the balanced or unbalanced input. If you do the math you'll find it is measured from the unbalanced input. I calculated gain from the balanced input, so my calculations are correct. McIntosh should specify which input they use to measure gain.

Either way, if you are consistent in the use of balanced/unbalanced inputs and output transformer taps the gain of these amplifiers is the same.
Happy Bi-amping!

Tom

No. It is not in the product spec nor in the user's manual. Shameful behavior.

You will have some additional gain control by using the different output taps on your Amps if needed.