New MC312 replacing the MC302

[effischer]

New member here and can't post this question directly. So, a bit off-topic but I am considering moving from my MC302 to a pair of MC301 (MC311?). I'm very happy with the 302; it drives my vintage Rogers Studio 1s very nicely and has a very neutral presentation. Imaging is good, but I'm thinking that going to balanced topology and monoblocks will improve both imaging and definition. I use a C50 as a preamp and am a vinyl head. Run a SOTA Sapphire with a Graham Phantom and DV XX2 Mk. II.

FWIW, I have a vintage Belles Model 1 and a MC7100. The Belles is one of the best sounding amps I've ever heard, but it just doesn't have enough power for the Rogers speakers. The 302 has the power, but I can't help thinking that I can get more out of dual mono amps.

Any feedback will be appreciated!

[Masterlu]

effischer... Welcome to AA!

[Formerly YB-2]

Agree with the OP's thinking. Monoblocks are the way to go (as I try to decide if I want to do the same thing....... do I really want another piece of gear? ).

[effischer]

Thanks for the welcome, Masterlu, and for the monoblock comment, Formerly YB-2.

In my case, it isn't the extra lump in the rack. I have plenty of room. I just want to fully evaluate an "upgrade" that is essentially the last amp upgrade on my primary system. 300 or so watts is a happy place for my current speakers & space. The potential speaker upgrades I'm considering on this path (ATC, PMC, possibly Magico or M-L Summit X) all have a 300W sweet spot as well. I don't want to chase the last 0.1% but do want serious reliability. My Belles and my Rogers have survived 30+ years just as they came out of production, so that's the benchmark I'm using. I've seen MC601s pop up second-hand for reasonable money, but they are just too damn big.

Running a pair of MC275s has also crossed my mind, but I prefer solid state amps and tube preamps when going that route. I'd had a C2300 paired with the MC302 and the combination was magical. That said, I don't have a lot of free time and the warm-up period on the C2300 was just too long. Compromising with the C50 was the only realistic alternative and has been totally satisfactory for several years.

An audition would be the ideal way to go, but I've not yet found a Mc dealer that has MC301s set up in my area (North Central OH). Paragon is the closest WOM location and that is a hike not well suited to a casual audition. Hence the search for community input.

TIA for anything further!

[70sMac]

PLEASE forgive the uninformed question, but we own [very] old equipment ... What's the basic difference between the MC300 we own and the MC3XX amps mentioned in this thread? Thank you in advance for the education.

[brownbear]

Can anyone comment on the push-pull complementary circuit design in the MC312 compared to quad balanced in the MC452? I'm considering these two amplifiers and am ok with 300w power output as opposed to 450w, but am wondering if I would be missing out without quad balanced.

[W9TR]

Hi brownbear,
I'll take a shot at it. Each channel of the MC 452 has two independent 225 watt power amps. These amps and all their input circuits mirror each other. They are fed a balanced input signal with one amp inverted with respect to the other. The outputs of these two amplifiers are then summed in the output transformer to get to the 450 watt output power. The advantage of all this is any distortion and noise that is common to these individual amps is cancelled out while the balanced signal appears at the output.

The MC 312 is a normal complementary symmetry design, where a single power amplifier drives the autoformer.

The disadvantage of the Quad Balanced design is the parts count is doubled and the outputs are not referenced to ground so can not be used with some speakers setups that are bi-amped.

Lots of McIntosh amps are quad balanced; MC 2KW, MC 1201, MC 501, MC 601, MC 611, MC 301, MC 602, MC 402, MC 352, MC 452, MC 462, MC 352, and MC 2301.
Apparently they like that design! The 602, 402, and 352 were released before marketing invented the Quad Balanced nomenclature.

As far as the sonic differences, I have no idea. I do think the non-quad balanced designs are offered to hit specific price points in their lineup.

Tom

[effischer]

Originally Posted by 70sMac

PLEASE forgive the uninformed question, but we own [very] old equipment ... What's the basic difference between the MC300 we own and the MC3XX amps mentioned in this thread? Thank you in advance for the education.

Found some information over at AudioKarma that might help you on this: The MC300 is reported to put out 85 amps at about -75dB S/N while the MC302 is said to have 60 amps at -95dB. If you have speakers that present a relatively stable impedance across their frequency range, that -20dB of lower noise will make a substantial difference.

Hope this helps & happy listening!

[brownbear]

Originally Posted by W9TR

Hi brownbear,
I'll take a shot at it. Each channel of the MC 452 has two independent 225 watt power amps. These amps and all their input circuits mirror each other. They are fed a balanced input signal with one amp inverted with respect to the other. The outputs of these two amplifiers are then summed in the output transformer to get to the 450 watt output power. The advantage of all this is any distortion and noise that is common to these individual amps is cancelled out while the balanced signal appears at the output.

The MC 312 is a normal complementary symmetry design, where a single power amplifier drives the autoformer.

The disadvantage of the Quad Balanced design is the parts count is doubled and the outputs are not referenced to ground so can not be used with some speakers setups that are bi-amped.

Lots of McIntosh amps are quad balanced; MC 2KW, MC 1201, MC 501, MC 601, MC 611, MC 301, MC 602, MC 402, MC 352, MC 452, MC 462, MC 352, and MC 2301.
Apparently they like that design! The 602, 402, and 352 were released before marketing invented the Quad Balanced nomenclature.

As far as the sonic differences, I have no idea. I do think the non-quad balanced designs are offered to hit specific price points in their lineup.

Tom

Thanks Tom, very informative!

[W9TR]

Happy to help. I wanted to get the quad balanced amp list out there because a lot of people, (including me) didn’t know the 352, 402, and 602 are quad balanced.