McIntosh MC75 MkIII Amplifier Review

[djwhog]

Wow Dan, another great write up, but then that also leads me to just how good these amps are to deserve your excellent review to date. Seems they offer a lot of current and good headroom, which at some levels and conditions means so much more than just wattage. I seem to think that these tube amps are more powerful than the ratings given from the factory.

Man you have be wishing I had a completely separate 2nd system and a pair of these beauties. I know if I could ever afford it I would get tube McIntosh amps to replace the 452 or replace even my 601s maybe 4 of these or the big boys
.....................
yes I would if I only could Simon and Garfunkel

They should ship these or offer the power cord+tube upgrade as a factory package IMOP. I wonder after they are broken in more completely just how many % points better is still to be had?

If I was retired it would be awesome to take a pair like yours to a McIntosh dealer and do the A to B comparison of your amps with the upgrades Vs the stockers. I sure wish I had the money, time, and patience and a great dealer and rigs to accomplish this.

Well I guess Dan, that is where you and Ivan come in a LOT, thank you so much, so much better than that St...o Re....w mag

thank you Dan, great job as always

[jdandy]

Originally Posted by doguniverse

Dan, a well written review. You have them with the PMC speakers, could they also power you sonus faber speakers?

David.......Yes. In Fact the Sonus faber Amati Anniversario speakers have a sensitivity of 92dB/1w/1m. That's 3dB higher sensitivity that the PMC EB1i speakers. What that equates to is the Amati Anniversario's with produce the same volume level as the PMC's with half the power.

[jdandy]

Originally Posted by djwhog

Wow Dan, another great write up, but then that also leads me to just how good these amps are to deserve your excellent review to date. Seems they offer a lot of current and good headroom, which at some levels and conditions means so much more than just wattage. I seem to think that these tube amps are more powerful than the ratings given from the factory.

Man you have be wishing I had a completely separate 2nd system and a pair of these beauties. I know if I could ever afford it I would get tube McIntosh amps to replace the 452 or replace even my 601s maybe 4 of these or the big boys
.....................
yes I would if I only could Simon and Garfunkel

They should ship these or offer the power cord+tube upgrade as a factory package IMOP. I wonder after they are broken in more completely just how many % points better is still to be had?

If I was retired it would be awesome to take a pair like yours to a McIntosh dealer and do the A to B comparison of your amps with the upgrades Vs the stockers. I sure wish I had the money, time, and patience and a great dealer and rigs to accomplish this.

Well I guess Dan, that is where you and Ivan come in a LOT, thank you so much, so much better than that St...o Re....w mag

thank you Dan, great job as always

Dave.......Great post. Made me smile, and thank you for the compliment on my review. The amplifier's are in fact already broken in. I am the second owner. The original owner traded them for a pair of MC2301's. This pair of MC75 were well taken care if, mint in fact, and have approximately 550 hours on them now, which includes the nearly 100 hours I have put on them. The Gold Lion power tubes I installed were brand new, but they typically reach their permanent voice at about 60 hours, so the amplifiers are in their prime operating condition right now.

It would be great fun to do a head to head comparison of a pair of MC75's with a MC275 MkVI. I am sure the results would be interesting.

[Audiophilehi]

Hey Dan....I would love to see how the MC75’s compare to your MC2301’s in a head to head in your studio.

Inquiring minds would like to know.

[jdandy]

Originally Posted by Audiophilehi

Hey Dan....I would love to see how the MC75’s compare to your MC2301’s in a head to head in your studio.

Inquiring minds would like to know.

Paul.......I knew that idea would eventually present itself. Perhaps in the future when I am feeling energetic enough to haul the MC75 amps to the studio and back upstairs when complete. A shoot out such as this is easier said than done.

It is interesting to note the output of a 300 watt mono tube amp is only 6dB higher than a 75 watt mono tube amplifier. Is is typically recognized that to double the volume level of speech or music a 10dB rise is necessary. Knowing that reveals a MC2301 (300 watts mono) will not play music twice as loud as a MC75 (75 watts mono), using the same speakers of course. To play music twice as loud as the MC75 you would need an amplifier capable of delivering a sustained output of approximately 900 watts.

[Audiophilehi]

Originally Posted by jdandy

Paul.......I knew that idea would eventually present itself. Perhaps in the future when I am feeling energetic enough to haul the MC75 amps to the studio and back upstairs when complete. A shoot out such as this is easier said than done.

It is interesting to note the output of a 300 watt mono tube amp is only 6dB higher than a 75 watt mono tube amplifier. Is is typically recognized that to double the volume level of speech or music a 10dB rise is necessary. Knowing that reveals a MC2301 (300 watts mono) will not play music twice as loud as a MC75 (75 watts mono), using the same speakers of course. To play music twice as loud as the MC75 you would need an amplifier capable of delivering a sustained output of approximately 900 watts.

Thanks Dan...understood. Enjoy the heck out of them. I wasn’t looking to put you to work. .

I’m sure the MC2301 will win the war in the headroom department but at moderate levels it would be interesting to know the results.

[MCenthusiast]

Originally Posted by Audiophilehi

Thanks Dan...understood. Enjoy the heck out of them. I wasn’t looking to put you to work. .

I’m sure the MC2301 will win the war in the headroom department but at moderate levels it would be interesting to know the results.

I'd be interested in this comparison as well but it will have one fatal flaw if ever carried out. Efficiency is really the key to success in matching amplifiers to speakers.

I have a pair of 25W amps that have loads of headroom, dynamics and the potential to clear any residential room because they are paired with vintage speakers that are 97db and 16 ohms. The 2301's would be complete overkill in this system. Most newer speaker designs are much less efficient and the MC75's are quite versatile making this comparison interesting to anyone who might consider these amps with their current speakers. It sounds like Dan has found a great pairing and could compare these amps with speakers in an efficiency range that is quite common.

Manufacturers have conditioned us to buy more larger and powerful amplifiers to pair with inefficient speakers but history has taught us that the more efficient the speaker, the less powerful the amp needs to be for optimal pairing. That said, I hope Dan tries it and posts his findings.

[bunski]

Originally Posted by jdandy

It would be great fun to do a head to head comparison of a pair of MC75's with a MC275 MkVI. I am sure the results would be interesting.

Looking forward the outcome comparing MC75 vs MC275 VI. This would be very interesting.

[jdandy]

I just placed an order for two HiFi Tuning Supreme fuse (T2.5 Small) for the pair of MC75 amplifiers. I already have a HiFi Tuning Supreme fuse in the C2300 preamplifier that drives the two amps, so this will be interesting to hear what performance advantages appear with the HiFi Tuning Supreme fuses installed in the power amps.

I have been a long time user of the HiFi Tuning Supreme fuses in both the living room gear and the studio system gear. The studio system has HiFi Tuning Supreme fuses installed in the C1000 preamp and both MC2301 power amplifiers since February 2012. I have been completely satisfied with both performance and longevity. Now looking forward to having the HiFi Tuning Supreme fuses in the MC75 tube power amps in the living room system.

[jdandy]

In addition to ordering the HiFi Tuning Supreme fuses this morning, I also added some window dressing to my two MC75 amps. Since they are positioned in the rack where the speaker, input and Power Control cables are all visible I decided to purchase the McIntosh branded cables for Power Control. The cheap Parts Connection stereo mini jack cables I currently have in place aren't exciting my senses. I am perfectly aware the considerably more expensive McIntosh mini connector cables, a one meter and a two meter, have nothing to do with the sound quality of the amplifiers since their sole purpose is to trigger the amplifiers' turn on and turn off functions, but I want to raise the aesthetics bar of the connectors plugged into the Power Control jacks. The cheap molded black plastic connectors on the Power Control cables now in use irritate me each time I glance at the amps. The gold plated McIntosh branded connectors on the new upgraded Power Control cables will be much more pleasing to view.