Mac MC152 Amp

JerryD99

Member
Hello everyone,

Would like to get your opinion on the Mcintosh amp MC152. I have currently a Mcintosh MC7106 100 watt amp at 8 ohmns and it is enough power for now, but it has a problem with a hum that I have had in the shop for repair and the only think they think it is is the transformer, because everything else checks out ok. Transformer is not available. This is a physical hum, not through the speakers. Anyway I am thinking about trading it in on a Mcintosh MC152. speakers will be Phase Tech 3.1 and I think they are either 89 or 91 db. at 6 ohmns. The amp will also be used in 2 channel and multi channel as front mains. However I do plan on using 2 of them and having 1 pair of speaker on the Left and 1 pair on the right.
What do you think?

Thanks for you input..
 
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I also found out today that the MC152 is not a happy camper if it is not running 8 ohm load......Then what is the purpose of the auto transformers?
 
I also found out today that the MC152 is not a happy camper if it is not running 8 ohm load......Then what is the purpose of the auto transformers?

Any idea of what was the explanation of this is? The MC152 has 2, 4 and 8 ohm taps. Hmmmm.


MC152-Back.ashx
 
Exactly who told you the 8 ohm terminals were the only ones to use? That is bogus info. I had the MC152 and used both 4 and 8 ohm outputs with no problems. In fact, I haven't read any negative reviews about this amp.
 
One of the sales guys at AC.... I didn't understand either and when I said it has different taps and was told it does best at 8 and not a happy camper with anything else. Every review I have read, everybody like this amp. I am going to send Mcintosh a email and ask them also.
 
One of the sales guys at AC.... I didn't understand either and when I said it has different taps and was told it does best at 8 and not a happy camper with anything else. Every review I have read, everybody like this amp. I am going to send Mcintosh a email and ask them also.

It's an autoformer amp. They are designed to live happily with 8, 4, or even 2 Ohm speaker loads.
 
MC152 is a 150 wpc amplifier that weighs 75 lbs, output taps for 2, 4 and 8 ohms with full rated power available at each - in the decades-long McIntosh tradition.

I find it extremely difficult to believe the unit is comfortable with nothing less than 8 ohms.
 
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I guess that is always a possibility that I misunderstood, but I don't think so.......Anyway this is what Chuck at McIntosh said....

Hi Jerry,

The dealer is utterly and completely wrong.


Chuck Hinton of McIntosh, Wadia, and Snell Tech Support



That is so good to know, because I have always heard good stuff about this amp.
 
Because new SS Mac amps have a larger current capacity and better transformers and autoformers you can mis match the amps to the load to get a particular sound you prefer, some times. Its evident this gentleman speakers impedance wanders all over the place and they work better with the higher voltage of the 8 ohm tap rather than the higher current of the 4 ohm tap. That doesn't make the amp compromised that means his speakers are.

A 7106 will have a slightly different sound than a 152 with certain speakers as the 7106 is direct coupled and the 152 uses autoformers. Whether you like the difference is a function of the speaker not the amps. I prefer my 207, 206, and formerly 7200's and 7100's without autoformers. Its not the amps fault I like Mac amps without autoformers its my choice of speakers. I fought for years for Mac to make a lower powered amp. The 152 fits the bill and now there is a 2152 to choose from. You could always look back to the MC 162 if you want to stick with direct coupled amps. I always recommend auditioning the amp your interested in in your environment and your speakers. I know its hard to do now days, but thats the best solution. If you are strapping the channels together, maybe you should be looking at a 302 or something similar. I use 207's now days, where would I put seven 7200's or seven 152's.
 
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Is there a difference in sound between the mc7106 and the 207, 206?
Also does your 207 and 206 hum when you put your ear up to the amp?
and yes I hear that some speakers sound better without the auto transformers.....I am running some phase tech PC series 3.1 and will be upgrading to 3.5. 2 speakers per side. They or 6 and 4 ohm load per speaker.

Thanks
 
Yes my 207 like the 8207. Not much. Its mounted in a cabinet so I never hear the hum and the unit is less than 4 ft away. I use two cooling fans with the amps stacked on top of each other wired in series to lower the speed and reduce the noise , But its there if I stick my head over and behind the cabinet. Just the swish of fans. Why does a 207 hum. Well the power transformer is so big, I'm told, that it can't be completely covered by the housing or the potting material. My 206 doesn't hum at all. Only the 207's. They are about equal. I will say the 207 sounds a little smoother in the highs than the 206 and the bass is a touch or 1/2 a shade cleaner. The choice of pre-amp will make a much bigger difference. I found that ought when I replaced my MX 119 with a MX 151. I used to bi-amp the center channel with the 207 on top and the 206 on the bottom. The sound was smoother that way rather than with the 206 on top. . But now that I have. two 207's the center channel is bi- amped by two 207 channels. The left and right are tri amped by one 207. The 7th channel of each 207 run full range pushing each side speaker. The second 207 bi-amps the center and two rear channels now. The 206 now pushes remote speakers and electrostatic headphones. The 2505 pushes Master bed room speakers and also more headphones. . I still have some Crown amps in reserve. Sitting on a shelf gather dust. I guess it will be 10 years pretty soon. Time flys when you keep yourself busy.
 
When I first heard 7106 used with Klipsch speakers I was concerned it was a little to edgy, not like the 7200's I was hearing with B&O and and Mac ML and XR series speakers. Turns out it wasn't the amp but the Denon HT processor he was using. He later upgraded to an MX 134 and the sound was nice and smooth. I Used a 7106 with my speakers while one of my Crowns was being rebuilt by the factory one time. There was a definite difference just as I had heard with a 7200 that I liked. I think the newer amps of today have some differences. I can't really call the 207's new but compared to the others there is a very listenable quality with the right source material. Seems to me that where the biggest difference in sound lies between the different Macs. The latest amps, before the recent introductions could produce more nuances than the older amps. I contribute that to the Quad design and better auto formers. Amps with out autoformers depend on the components of the circuitry more directly. The latest integrated and the 8207 with the self tracking outputs seem to have added clarity in the HF's. Some times that's a good thing unless your HT processor or Stereo pre-amp has issues. My Mx119 and 120 were very easy to listen, too. But the clarity of the MX 151 brought back the defined bass I was missing and the clarity of the C-29 I had been missing when I bought the C-34. I bought a MP100 for MC cartridges and its
known for being a little bright. Well feeding my MX 151 directly digitally was a big surprise. Yes the C-34 being fed by the MP 100 was one revelation using analog signal, the MX 151 being fed digitally by the MP 100 another. The 207's easily shows these differences. Using electrostatic head phones and the 206 or 2505 not as much difference. Yes the 207 is a better mouse trap than the 206. With a great source the 207 and MX 151 are just amazing. But if the Movie and Stereo recording people haven't done their home work the MX 151 will reveal it in a heart beat where the MX 119 and MX 120's I owned wouldn't. They did reveal what I call congestion and depth in staging like a 151. Another thing is using the 151 If I change between the balanced analog out puts of my 861 or 891 and the digital out puts with the 119 or 120 I could hear a difference, preferring the smoother analog sound. I don't hear that difference with the 151. So If I ever get back into a different analog source needing balanced inputs I won't hesitate to give up the analog outputs of the MVP players. What I am trying to say is with my system there can be but not always be a difference between the 206 and 207, depending on the source material and pre-amp/HT processor you use.. And I am still using un balanced out puts of the 151 feeding unbalanced to the 207's because my Electronic crossovers are now un balanced. They were originally balanced using 1:1 input and output transformers, But I removed them because they choked up a bit on the bass, I discovered many years ago when using Crown Amps. If you really want tight bass , to tight sometimes, just use Crown Power amps below 80 HZ. My issue with Crown is above 80 Hz, where they can be come fatiguing from 200 to 5,000 HZ and the highs above that. pretty unrealistic.
 
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