MC2.1KW 75th Anniversary

[Bushikan]

The MC2.1KW 75–like the MC2KWs, MC901s, MC451s, MC1.2KWs, MC1201s, MC1000s, MC1201 SEs, MC3500s, and MC3500 MKIIs—are for a select group of well-heeled Mac aficionados who either have very inefficient speakers or love the looks of them or both.

I fit none of those categories, although I certainly appreciate these amps for their design (no matter how ostentatious) and for what they can do. (I also don’t need, nor can I afford, a super-car.)

That said, I’d gladly hook up a couple of the MC451s, MC3500 MKIIs, or MC2301 MKIIs—as overkill—to my Klipschorns, if someone left them on my from porch (installed in my listening room would be preferable).

OTOH, I don’t really have a leg to stand on, since I’ve had a few visitors to my listening room whose eyes have bugged out upon seeing my ostentatious MC275 MKVI, with its green tubes. I guess each of us has his limits—and justifications and blind spots.

 

[grillebilly]

Mac seems to like to put a lot of bling on their products, and the higher up the chain gets you more to look at.
Who wouldn’t love some of those monsters?
They would look right at home next to the pinball machine.

 

[Bushikan]

They would look right at home next to the pinball machine.

Mixed in with a few blue and green Lava Lamps.

 

[motorstereo]

That said, I’d gladly hook up a couple of the MC451s, MC3500 MKIIs, or MC2301 MKIIs—as overkill—to my Klipschorns, if someone left them on my from porch (installed in my listening room would be preferable).

I always wanted to try either my mc2500's or my mc1201's on my khorns just because. But it meant moving either the k's or the stupidly heavy amps so it never happened. The closest I got was my mc2255 and I'll be darned if that wasn't my favorite pairing ever with the khorns. They might be very efficient but they like high current amps as well.

 

[Bushikan]

I always wanted to try either my mc2500's or my mc1201's on my khorns just because. But it meant moving either the k's or the stupidly heavy amps so it never happened. The closest I got was my mc2255 and I'll be darned if that wasn't my favorite pairing ever with the khorns. They might be very efficient but they like high current amps as well.

I’ve always been kurious—with a K—about that kind of matchup with my KHorns. Biggest amp I had, personally, was the MC152. That amp really pressurized the room and had deep, chest-thumping thwack on bass (AC/DC loved it); and I seriously considered keeping the 152; but, in the end, I missed the more liquid tube bass (less tight and deep but much more nuanced, especially in the mid-bass region) of my MC275 MKVI.

Be careful—even if it’s worth a hernia.

 

[damacman]

I always wanted to try either my mc2500's or my mc1201's on my khorns just because. But it meant moving either the k's or the stupidly heavy amps so it never happened. The closest I got was my mc2255 and I'll be darned if that wasn't my favorite pairing ever with the khorns. They might be very efficient but they like high current amps as well.

My buddy Mikey G ran a 7300 on his k-horns for a while ... he liked the Yamaha B-2 best on them overall but I'm sure he flashed the PG lamps a time or two on the 7300 ...

 

[Snappahead]

You'd need a dedicated 20 or 30a circuit for that amp, otherwise the headline specs would be just for bragging rights.

At a full draw of 2000 watts it would draw about 16 amps. You would never draw that much power so to be safe a 20 amp circuit would be fine.

 

[62caddy]

I cannot understand the rationale behind a large amplifier with a 105 dB K-horn. The most sensitive speakers I ever had were a pair of Heathkit AS-21 Legato (Altec Malibu in kit form) @ 99 dB that would drive me out of the room with 1 watt input. If a pair of Ks landed in my lap, I'd set up with my MAC1500 and never look back. Wasn't it PWK himself who said, "All the world needs is a good 5W amplifier"?

As to the 75th MC2.1KW, the first shipments haven't begun. I spent some more time listening to a pair of K Jubilees up at Audio Classics last week. Not bad but I think I prefer the sound of modern loudspeaker designs. They still haven't sold a pair yet. A lot of competition at $36k/pair.

 

[damacman]

I cannot understand the rationale behind a large amplifier with a 105 dB K-horn. The most sensitive speakers I ever had were a pair of Heathkit AS-21 Legato (Altec Malibu in kit form) @ 99 dB that would drive me out of the room with 1 watt input. If a pair of Ks landed in my lap, I'd look have them set up with my MAC1500 and never look back. Wasn't it PWK himself who said, "All the world needs is a good 5W amplifier"?

Eric, the same guys that like that nonsene are those that have cars with motors sticking out of the damn hoods . . .

 

[Bushikan]

AC’s Steve R., who built a 30’ x 40’(?) dedicated room for his own KHorns, years ago, said the absolute best amp he ever heard on them was a pair of Cary CAD 300 monoblock tube amplifiers (12 WPC).

 

[62caddy]

AC’s Steve R., who built a 30’ x 40’(?) dedicated room for his own KHorns, years ago, said the absolute best amp he ever heard on them was a pair of Cary CAD 300 monoblock tube amplifiers (12 WPC).

I once read that PWK's favorite amp with his Ks was either the MC30 or MC60. Years ago I purchased a pair of MC30s that were owned by a hi fi distributor in the Pacific northwest who was a personal friend of PWK in his personal system. The speakers were one of a handful of pairs that Paul had specially made in Brazilian rosewood as gifts to a few close friends and were never available to the general public. The man used the MC30s with the McIntosh C8/C8S preamplifier(s).

What I found the most astonishing of all was when I learned the man was still a hi fi distributor into the 1990s thus had countless opportunities to upgrade his electronics but never did. The rosewood K-horns were also offered to me but the price was way out of my league. I hope they found a good home.

**I just recalled - Thornton was the surname of the distributor.

 

[SaturationPt]

I’ve seen those rosewood K-horns, one of our members has two pair, and they’re stunning.

 

[Velocityboat]

At a full draw of 2000 watts it would draw about 16 amps. You would never draw that much power so to be safe a 20 amp circuit would be fine.

The MC2500 manual says to get full capable power use a 25 amp connection. But that is likely neede for an industrial shaker table.

 

[Snappahead]

The MC2500 manual says to get full capable power use a 25 amp connection. But that is likely neede for an industrial shaker table.

I am a home builder and I've had extensive conversations about electrical needs for stereos with my electrician who's excellent. Large circuits as explained to me simply isn't necessary. Most amplifiers just don't draw that much power. In most cases a 15 amp shared circuit is more than sufficient. When I built a room on my house we ran a single 15 amp circuit. The single circuit was more to eliminate any potential noise. When we wire homes, we will split receptacles and lighting circuits. In my basement that's how it's wired and I have 2 tube amps, 2 SS amps, a AVR, and all the sources and I've never tripped a breaker. When we tested it with a meter, with everything fired up and running there was a voltage drop of half a volt.

 

[ACRucrazy]

I have had a single, MC1.25 plugged into a MPC1500 running as far as I dared pushing it with very specific content.

The MPC1500 was showing over 12 amps current draw and voltage dropped well below 120 from the 122-123 it normally shows.

The 1200 watt and 2000 watt amps are fully capable of serious power. The advantage of the 20 amp circuits is not that of the added current but the required 12, and often installed 10AWG cable used for the circuit.

The thicker cable will help prevent voltage drop, that the thinner 14AWG cable on a 15A circuit can show when pushed.

IMO if you’re spending $30,000 to $100,000 on a pair of amplifiers, the cost associated with adding one or more dedicated 20A circuits will be the cheapest part of the whole audio solution.


That said… I’ve had pair of 1.25KWs along with a whole stack of more McIntosh gear plugged into an MPC1500 where all 12 outlets are used. Under normal use 99% of the time, the meter is at less than 3 amps. Sometimes it starts dancing above 3 when I turn it up.

Only one time where I got curious and wanted to punish a system with specific tracks on a single 1.25KW for testing and fun did I see what it could do.

It became apparently to me, the MPC1500 (yes I know it has an 11.3A rating) and in turn 15A circuit was the limiting factor when the meters were showing approximately 12A, 110-115?V and 500?W on one amp.

Every situation is different, the room the speakers are in, the distance the listener is at, the speakers that are hooked up to the amps and the material the listener is playing. This all factors in how much power is required.

The only constant is the amplifiers themselves. McIntosh knows what kind of power they are capable of. And putting the bigger amps on 15 circuits work; but you will never be able to realize the full power of those amplifiers.

 

[damacman]

I am a home builder and I've had extensive conversations about electrical needs for stereos with my electrician who's excellent. Large circuits as explained to me simply isn't necessary. Most amplifiers just don't draw that much power. In most cases a 15 amp shared circuit is more than sufficient. When I built a room on my house we ran a single 15 amp circuit. The single circuit was more to eliminate any potential noise. When we wire homes, we will split receptacles and lighting circuits. In my basement that's how it's wired and I have 2 tube amps, 2 SS amps, a AVR, and all the sources and I've never tripped a breaker. When we tested it with a meter, with everything fired up and running there was a voltage drop of half a volt.

You'll love this. In a spec home with builder grade outlets & switches, and stab-ins . . . I figured - let's see just how much amplifier power I can plug into a single 15A circuit . . . not knowing where in the circuit that outlet lies (was it #1 or #8 in the room - stab ins IN on one side of the outlet and OUT the other to feed the next outlet - yep, this whole house is built that way. [AZ is home to the world's shittiest home wiring.]

(2) MC2600, (1) NAD 218THX, (1) Integra DTA-70.1 (9ch)

Try as I may, I was simply unable to flip the breaker. Dim the lights - sure. Cause voltage to sag from 123VAC to 105 - sure. Flip the breaker - nope.

Now, I have a sub panel that supplies the room. It's supplied with 4/3 with a ground from the main panel and the outlets are Hubbell hospital grade with 10 AWG THHN supplying each (on separate 20A breakers). No lights dimming and voltage is rock solid. I can't tell an audible difference but I do feel a bit safer when the room is pressurized.

 

[Snappahead]

You'll love this. In a spec home with builder grade outlets & switches, and stab-ins . . . I figured - let's see just how much amplifier power I can plug into a single 15A circuit . . . not knowing where in the circuit that outlet lies (was it #1 or #8 in the room - stab ins IN on one side of the outlet and OUT the other to feed the next outlet - yep, this whole house is built that way. [AZ is home to the world's shittiest home wiring.]

(2) MC2600, (1) NAD 218THX, (1) Integra DTA-70.1 (9ch)

Try as I may, I was simply unable to flip the breaker. Dim the lights - sure. Cause voltage to sag from 123VAC to 105 - sure. Flip the breaker - nope.

Now, I have a sub panel that supplies the room. It's supplied with 4/3 with a ground from the main panel and the outlets are Hubbell hospital grade with 10 AWG THHN supplying each (on separate 20A breakers). No lights dimming and voltage is rock solid. I can't tell an audible difference but I do feel a bit safer when the room is pressurized.

We measured the draw with a meter on my 2105 playing at about 50% volume. It drew .33 amps. I find it hard to believe that any amp, even the huge 2.1's would draw anything near 15 amps.

Using a heavier wire would definitely help with voltage drop so you did the right thing. I don't believe than anyone can hear a difference with better grade wiring or power cables but that's another story.

 

[62caddy]

According to the owner's manual, a single MC2KW draws a maximum of 12A @ 120V per module or 24A per pair, per channel. I'm guessing the unit is also capable of near 2,700W factoring in McIntosh's typically conservative output ratings. Of course the 12A/24A may be erring on the side of caution for liability reasons.

The MC2.1KW should be slightly higher but McIntosh doesn't seem to have the owner's manual for the 75th posted on its webpage. I agree that special dedicated wiring would be necessary in order to take full advantage of the unit's maximum output capability. This side of the most extreme demands, the user could probably get away with his existing home wiring but that would defeat the whole purpose of buying this model in the first place. Draw at idle is 35W per module (70W per channel) or 0.58A.

 

[Snappahead]

According to the owner's manual, a single MC2KW draws a maximum of 12A @ 120V per module or 24A per pair, per channel. I'm guessing the unit is also capable of near 2,700W factoring in McIntosh's typically conservative output ratings. Of course the 12A/24A may be overstated erring on the side of caution for liability reasons.

The MC2.1KW should be slightly higher but McIntosh doesn't seem to have the owner's manual for the 75th posted on its webpage. I agree that special dedicated wiring would be necessary in order to take full advantage of the unit's maximum output capability. This side of the most extreme demands, the user could probably get away with his existing home wiring but that would defeat the whole purpose of buying this model in the first place. Draw at idle is 35W per module (70W per channel) or 0.58A.

It that's accurate, anyone who purchased a pair would need (2) 15 amp circuits to power a pair. I'd be curious to know if anyone who owns these actually has 30 amps of dedicated power.

 

[62caddy]

It that's accurate, anyone who purchased a pair would need (2) 15 amp circuits to power a pair. I'd be curious to know if anyone who owns these actually has 30 amps of dedicated power.

The owner's manual states that each power module needs to be connected to a dedicated 20A circuit (x4) while the output module is to be connected to a separate third circuit which may be shared with other source components. The second output module may also be connected to the third circuit.

AC connections are covered on p. 4 of the pdf.

I would imagine anyone prepared to drop this kind of coin on a rig will likely follow these guidelines.

https://www.mcintoshlabs.com/-/media/Files/mcintoshlabs/DocumentMaster/us/mc2kwom02.pdf?rev=a942af20455e401a9833896a088e4477&revision=a942af20-455e-401a-9833-896a088e4477