McIntosh MI350 / MC3500 - so . . . how powerful are they really?

damacman

damacman

Resident Psycho
A discussion in another thread had me looking for some information - specifically, just how much power can the MI350 / MC3500 power amplifier make? So, I reached out to a friend of mine that owns a pair, owns an amplifier manufacturing company, and owns the test equipment required to ascertain the answer. That friend is Stephen Mantz of Zed Audio.

Here is the link so that you may read up on his personal amplifiers - http://www.oestex.com/tubes/Mac/ZED-MI350.html

Today, I emailed him and asked - "Stephen, out of curiosity, what kind of power is an MC3500 capable of at the 8 Ohm tap from 20Hz-20kHz?" His answer - "My MI350s do 460w at 8 ohm with 120v mains."

For those that don't know, an MI350 is an MC3500 with optional balanced inputs. Other than that, the amplifiers are identical.

Way cool. Just way cool.

Stephen claims these amplifiers are the ". . . finest tube amplifier ever designed and built." That's something coming from a guy that has earned quite a living designing audio amplifiers. So . . . twiiii, you may be on to something here . . .
 
Very interesting, thanks for the link! I believe Dan owns one of these also, I think he got it from somebody associated with the Grateful Dead possibly?? Either that or it is a stereo version 500? I am sure he will pop in
 
damacman said:
A discussion in another thread had me looking for some information - specifically, just how much power can the MI350 / MC3500 power amplifier make? So, I reached out to a friend of mine that owns a pair, owns an amplifier manufacturing company, and owns the test equipment required to ascertain the answer. That friend is Stephen Mantz of Zed Audio.

Here is the link so that you may read up on his personal amplifiers - http://www.oestex.com/tubes/Mac/ZED-MI350.html

Today, I emailed him and asked - "Stephen, out of curiosity, what kind of power is an MC3500 capable of at the 8 Ohm tap from 20Hz-20kHz?" His answer - "My MI350s do 460w at 8 ohm with 120v mains."

For those that don't know, an MI350 is an MC3500 with optional balanced inputs. Other than that, the amplifiers are identical.

Way cool. Just way cool.

Stephen claims these amplifiers are the ". . . finest tube amplifier ever designed and built." That's something coming from a guy that has earned quite a living designing audio amplifiers. So . . . twiiii, you may be on to something here . . .
Click to expand...
Very, very cool, but the question begs: Can they be strapped???? :)
 
Audio Classics had a beautifully restored pair of MC3500 sitting on the shelf a while back when I was up there. They were an awesome sight.
 
ron-c said:
One of the magazines reviewed these back in the day, Stereo Review I believe and they measured 550 watts at the onset of clipping.

Ron-C
Click to expand...
I recall hearing that. Really quite amazing. What kind of power are the MI200s capable of?
 
MI200s are capable of more than 200 watts. Kind of depends on the AC line current and how healthy the six regulator tubes are. These are of course all day 24/7 watts.
Under load MI200s will spin the electric meter pretty fast.

Ron-C
 
62caddy said:
Audio Classics had a beautifully restored pair of MC3500 sitting on the shelf a while back when I was up there. They were an awesome sight.
Click to expand...
Saw them. Untouchable to me, short of a winning lottery ticket. (Which I never buy anyway)
 
A guy local to me and certified audio nutcase apparently had 3 3500's in his Mac collection. 2 years ago he was telling me how AC bought them and came down with their own truck to give them a safe ride back to NY. Sadly I never got to see or hear them.
 
Frank Gow and I have had many discussions about the 3500 vs, the 2301 before he died. We both thought and preferred the 3500. You all do realize 2301s are not a pure tube amp, its a hybrid with SS devices in the signal path where the 3500 is pure tubes. Frank felt KT 88's have their own sound. He loved the 225 for that reason. I knew there was a difference in sound between the 3500 and 2301, but don't know if the main contributor is the tube difference, or other differences. I do know a 3500 has a lot more power capability. I used 3500's with stacked and distributed AR 3 and 3a, used them driving Altec 210s, 817's and Multicells with multiple 288 drivers, installed them driving Bozak Concert Grands. I heard our pair drive ml-4c versus 2300's. For me it was always the best tube sound I ever heard. Can you imagine a pair of Grands putting out the same peak levels as a klipschorn. With the meters of the 3500's indicating 35 watts Grands took you to the front row of any concert. For Ray Charles and Neil Diamond concerts I have seen our 3 3500 's draw so much power the meter illuminating lamps would dim, yet there was never indication of a sonic issue. Thanks for reposting the piece on upgraded 3500's.

When Davie at our Mac clinics checked our 3500's he had to by pass his variac and used our wall power which was around 124 volts and the amps put out 500 watts with out any sign of clipping. It was unbelievable at the time.
 
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I knew you had a pair! I came across a pair in like '94 but someone beat me to the punch. I tried like hell to buy 'em though.
 
damacman said:
I knew you had a pair! I came across a pair in like '94 but someone beat me to the punch. I tried like hell to buy 'em though.
Click to expand...

The asking prices are off the chart today. A pair on the famous overpriced junk site asking 59K, and for sale over a year. Perfect condition looking but not 59K worth. A working restored pair should fetch a solid 30K to a serious no nonsense buyer. They are rare and antiques with only a handful of working pairs. Definitely an over the top design with German engineering quality. This pair is fully service/restored by the boys at AC in 2007.

A tube tester is required!
 
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