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Mc2155 vs mc2255

Alguymcgee

Alguymcgee

Active Member
Hey all

I have an mc2105 that I'm looking to upgrade. I have narrowed it down to either an MC2155 or MC2255. My only issue is that I've been unable to find any meaningful differences between the two, besides the obvious differences in wattage and weight. Weight, cost, bang for buck, and repair costs are non-issues. All things being equal, is there anything the mc2255 can offer besides power than the mc2155 can't? Any lil bit helps, thanks!

Alan
 
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2255 is also older and more costly and complex to work on. If you dont need the extra power id look for a 2155. If you like the look of the 2255 id also look at the 7270 or 7300 which have more power and much newer as well as cheaper....
 
The 2155 and 2255 were produced the same time, and equally complex, just one had more power than the other.

If looking for newer I’d skip the (de-featured 2255) 7270, and go straight to my favorite the 7300, which I’ve not seen cheaper than the 2255 but haven’t looked lately either. I’ve had both. The MC7300 (people here know it’s a favorite of mine) is a generation newer and quieter than the 2155/2255/7270 and significantly more powerful with gobs of headroom and balanced inputs to boot.
 
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I loved the 2255 sound, but will agree they didn't hold up as well as the 2205 or the 7300. The 2255 sounded better than a 2205 and the 7300 and 7200 sounded even better. My speakers preferred direct coupled amps for more accurate bass so i chose 7200's after trying all the previous 2000 series amps. 2002 didn't hold up that well either as an early direct coupled amp. the 752 and 754 did very well as efficient monitor speaker amps. Worked well with Klipsch speakers, too. So I would choose the 7300 for most speakers with the 7200 still preferred for my speakers. if you want something more advance you are going to want something like a quad balanced MC 352 or 402. The new MC 152 is a great amp putting out close to 220 watts though it only rated at 150 watts for each channel. MY XRT 28's are pretty in efficient but 90% of the time i stay under 60 watts per channel even though I have close 600+ watts per channel. again using direct coupled MAc amps.
 
Resale value. The MC2255 is highly sought after - much more so than the MC2155, which is quite often overlooked by Mc enthusiasts as quite simply they forget about it. The MC2255 is put on a pedestal due to it being the last of the chrome chassis amps. Plus there is this "300 wpc" category where many Mc buyers want to play. The MC2255 has the highest resale in that category of any of them.

If you do elect to buy one, then pay close attention to the faceplate on it. Mc attached the blue plastic piece (inbetween meters and glass) to the rear of the faceplate with double sided tape. The MC2255 (and MC2205) all suffer the same problem of the tape shrinking over time and pulling the paint off the rear of the glass above and below the metes. This often affects the M C 2 2 5 5 S T E R E O P O W E R A M P L I F I E R script under the meters, pulling the lettering off the glass from the rear. The only fix is a new faceplate.
 
Thanks for all the info guys, this is exactly the kind of help I was looking for! I know my way around a spec sheet, but that only tells you half the picture, so again thank you.

I think I'm gonna go with the 2155. While I acknowledge that I hadn't considered resale, I never met a Mc that you couldn't get your money back from. I really want the 2255 for all the reasons listed above, but when I'm ready for more I think I'll monoblock, which seems much easier to do with a 2155.

Plus, good luck finding TWO 2255s

Now if you'll excuse me, I'm gonna go take a long look at my ear drums so I can always remember what they looked like when they were still intact
 
I was going through an amp purge here a couple years ago and had both an mc2255 and an mc2125 listed. I only wanted to sell one of them and would keep the one that didn't sell. Both had been gone through by AC and were listed at fair prices below what one would find on that auction site. The 2255 was the one that got the most inquiries by far and did eventually get sold for my listed price. Lots of low ballers, tire kickers, trade offers etc. but I didn't budge on my price. The 2125 didn't get much interest and that's fine as it's actually a better fit here for it's purpose of powering my outdoor speakers.
AC's worksheet also had that 2255 listed as producing a prodigious 380 wpc at 8ohms on their bench which far exceeded it's meager 250 wpc rating. I really liked the sound of that amp but oh how I hated moving it especially up or down stairs.
 
Last price of the MC2155 was $2,295 and 1,695 were produced. For the MC2255, the last price $2,995 and 4,699 were produced.

Judging from recent sales, they appear to bring similar money. My guess is the comparative rarity of the 2155 playing some role in that. Both the 2155/2255 & 2150/2250 (non-metered counterparts) are the only McIntosh power amplifiers with the self-diagnostic countdown feature which also likely contributes to collector interest. In actual use, there's just under 3 dB difference between the two when both are driven to their maximum limits which isn't terribly significant. In any case, it would be difficult to go wrong with either- both sonically and in terms of resale value.
 
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motorstereo said:
I was going through an amp purge here a couple years ago and had both an mc2255 and an mc2125 listed. I only wanted to sell one of them and would keep the one that didn't sell. Both had been gone through by AC and were listed at fair prices below what one would find on that auction site. The 2255 was the one that got the most inquiries by far and did eventually get sold for my listed price. Lots of low ballers, tire kickers, trade offers etc. but I didn't budge on my price. The 2125 didn't get much interest and that's fine as it's actually a better fit here for it's purpose of powering my outdoor speakers.
AC's worksheet also had that 2255 listed as producing a prodigious 380 wpc at 8ohms on their bench which far exceeded it's meager 250 wpc rating. I really liked the sound of that amp but oh how I hated moving it especially up or down stairs.
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I don’t move my amps much, if at all so the 100+lb/ea. Doesn’t matter much to me.

When I was similarly downsizing, I decided I’d keep either the MC7300 or MC2255, whichever one sells first goes. I was hoping to keep the MC7300, but it had people quick to make offers. The MC2255 eventually also went away as did its MC2250 rack-mate (fairly rare). Although the MC2255 was more of a collector piece, I decided I’m not a collector, I prefer the best sound over a more vintage / collectible system, to each his own of course.

I’d imagine @Alguymcgee will make his own choice regarding power, collectibility, SQ, and other factors including cosmetics. The used McIntosh selection out there certainly provides a large range.

The only thing I understand to be of any concern in the 2255/2250 is the thermal-tracking transistors (mounted to the power transistor heatsinks) that Chris (RIP) told me have seen some failures and he recommends replacing them. I’m not sure if the 2155/2150 shares these parts or not. At any rate, unless you’re running them constantly in a Mexican disco without cleaning and fans, I’ve never heard of any 2255s failing during their youthful years. They are solid performers.

twiiii said:
Yes a 2255 would put out just over 300 watts an a 2155 just over 200 watts. JUst 1.8 db difference appox. really not all that noticeable.
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As @motorstereo mentioned above, in actual 3rd-party testing the MC2255 produced well over 300wpc at distortion spec at the time the amplifier was new. Might not mean a thing to a user who only requires perhaps 100WPC or less however, more a matter of choice. Personally I prefer to have more than I need, never know what the future holds and as any collector knows, ... you can buy a handful of small-block Barracudas for the price of one Hemi ‘Cuda, ... the big power option is always the safe money. But, ... the 2155 should sound just as good. If you’re a collector though you collect the big options.
 
At first I didn’t like the MC300 with the gain removed from the front panel (moved to the rear). I have since gotten used to the new look and not having adjustable gain, and the older style looks odd to me.

Yes, I’d be just as happy with an MC300 as an MC7300.
 
I'm curious about the upgrade from 2105 to 2155 (or 2255 but we've seen it was a wpc thing? I think?). I'm convinced it's legit, but I've never heard a 2155. Is there a dumbed-down way to qualify it? Asking for a friend with no agenda.
 
nooboy said:
I'm curious about the upgrade from 2105 to 2155 (or 2255 but we've seen it was a wpc thing? I think?). I'm convinced it's legit, but I've never heard a 2155. Is there a dumbed-down way to qualify it? Asking for a friend with no agenda.
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I mean, you can learn a fair amount from spec sheets; low THD, high damping factor is a decent start... but past a certain point you just gotta listen.

Also, stuff comes out in generations, with the basic idea being that each new generation is a little better than the previous one. Of course it doesn't always work out that way, but a little homework on that goes a long way. For example, as much as I LOVE my 2105 for pretty much anything recorded before 1990, it just can't seem to provide the right bass response I want for speed metal and other hard rock. Since that's half my collection, that's kind of a deal breaker for me.. but based on what I've heard it do, I probably wouldn't be trading up if I wasn't such a metalhead.

Beyond that, it's always good to have a grasp of the bells and whistles on your particular unit. There are just too many variables between rooms and speakers and so on. But the quickest check I know of is to crank the volume with nothing on... the quieter the background fuzz, the better.

Ooo! I almost forgot... I pulled the trigger and got the 2155. I'll let you know how it compares after my A/B
 
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nooboy said:
I'm curious about the upgrade from 2105 to 2155 (or 2255 but we've seen it was a wpc thing? I think?). I'm convinced it's legit, but I've never heard a 2155. Is there a dumbed-down way to qualify it? Asking for a friend with no agenda.
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As @Alguymcgee mentioned they learned/evolved in generations where the MC2505 and MC2105 were the first-generation of solid-state (well, there are significant differences between those so really the first generation and 1/2?) and the 2205 started the next generation with powerguard and a new topology. I believe the 2155 is considered similar to the 2205 in amplifier design with an improved Powerguard.

As to the main difference I would say Powerguard. It is also a new topology and has a more stable driver & thermal protection, they are completely different. Sound-wise I will say it’s a matter of preference between the 2105 and 2155, there are those who feel the 2105 sounds more vintage-smooth or other descriptions, so you’ll have to decide on that one yourself if you can audition good examples of both. Dynamic / reserve power is the other big difference, a little more power and just starting to step into the demands of the digital-music era with a little more headroom.
 
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The 2155 is likely the more sensible choice. When I was in my 20s (1995 or so), I had strapped 2300s and wanted more. Now, I have 2300s, 2500s, and 2600s and the needles occasionally reflect peaks of 1/10 of the power. LOL . . . had I had 2600s in my 20s, I would have vaporized my speakers.

Another thing I overlooked about the 2255 is a piece of historical significance. When the compact disc was introduced, most manufacturers slapped a Digital Ready sticker on their units and it was off to the races. McIntosh developed the Spectral Fidelity test, which demonstrated the capabilities of their power amplifiers over the competition as it pertained to reproducing the dynamic range of the CD. This was developed around the 2255. Davey O'Brien demonstrated this during the clinics and possibly even tested competitors amplifiers via this new test (@twiiii would know details). As it was explained to me, the test / demonstration was just lost on consumers as they didn't understand what they were being shown. Somewhere around here I have a full-color pamphlet with the complete story, sent to me by McIntosh in the 1980s when I mailed them a card from dad's popular mechanics magazine.

The 2255 was stripped of features - the 7segment countdown, the chrome chassis, etc., retail price reduced to $2499 from $2995, and became the 7270. The 7270 (and 7200) half glass face units carried the DIGITAL DYNAMIC STEREO POWER AMPLIFIER script across the face, which reflected McIntosh's commitment to be more than just digital ready. 7150, 7300 (both full glass face), and 2600 also have this. This was about the time I became old enough to shop at McIntosh dealers and the 7150, 7300, 2600 were current products.

We McIntosh owners often get flack from those who believe they're in the know . . . but as I type this, I'm reminded that maybe they don't know quite as much as they may think.
 
Yes I can remember the Demo having just seen it once, I was busy traveling so much that I had missed some of Davies visits. Biut a 7300 putting out pulses driving a 4 ohm load from the 8 ohm out puts revealed the amp had a lot of current potential to drive complex loads to high levels without clipping. where other amps that were direct coupled would oscillate, clip prematurely, blow fuses, get over heated and shut down. Amps from Audio Research would oscillate terribly around 200 K even at levels well below their rated output trying to produce high frequencies which would tear delicate tweeters apart and cause premature tube failure. We never had a Audio Research amp meet specs driving 8 ohms let alone 4 ohm from 8 ohm taps. WE had a demo with a TEktronics scope using an impedance measureing bridge and we would take popular speakers people owned rated at 8 ohms and show them how the impedance would drop well below 4 ohms some times. It revealed why it was important that amps have the extra capacity Mac amps constantly displayed. I had a few Crowns at the time and driving 4 ohm loads they would immediately go crazy with high amounts of distortion above 9500 HZ. THey did great below there so i used them has woofer amps very successfully driving 2 ohms loads. When the 7200 and 7100 came along all the crowns were gone and the Macs proved their value again and again never flenching. I use MC 207's for the HT system with two channels still driving 2 ohms the rest are driving 8 ohms. My mc 830's power the XRT 28 which are said to be 4 ohms but dip below that a bit and the amps never over heat or show any sign of stress. But the speakers are in a fairly small room so I never push the amps much over 100 watts each. A Telarc or a Reference recording CD or a Sheffield LP may cause more power to be demanded but its always very short peak power. Pegging the meters on the 830's with out the power guard light flashing was a real surprise when I played Telarc 1812 overture at just the right level, but most of the time like i said 100 watts is about it. which is 102 db at my listening position fast response Z weighted both channels operating. That's about the maimum my old ears will tolerate for extended periods of time.

I remember those clinics very fondly. Davie and Charlie Lucas would take us all out dinner after the last night and I would get a real chance to learn things about Mcintosh at the time. It was never hush hush stuff. just some great stories abput Davies adventures with the company and things that were special about each item I was interested in at the time. Charlie and his sons were the Bozak experts I learned a lot about Bozak, too. They also represented Tandberg, Boston, Telarc, etc. Tube stories were the most fun I thought. People would bring in their MAC amps that hadn't been looked at in years with a layer of dust and they would still meet specs. Davie would pull the bottoms clean them out look them over and replace all the tubes and send then on their way performing even better than new it seemed to me. . mC 30, 60, and 40 owners he paid special attention to replacing caps that he knew would fail eventually, install new tubes and get almost 60 watts out of the mC 40's and just over 90 watts out of the MC 60's. C-20's and C-11's took extra time replacing noisy resistors in the phono sections caps and rectifiers in the c-20's which were a big headache. Switches and volume controls were cleaned and rocker switches retentioned. Its the c-20 with defective rectifiers that started Davie traveling doing amplifier clinics. Davie never said a bad word about others products, he just let the test equipment reveal other manufacturers products short comings.
 
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