Tried the MC 7270 in my system

[audiobliss]

Well, after a good cleaning, I posted this beast on a few sites for sale. But, you know in the mean time I just had to try it out in my system. After all that was part of my motivation for taking on the project.

So, you know the saying, " there is no substitute for power " that is so true. I love my 152, but the 7270 just has a ease, bottom end punch and authority that is captivating. All that at low listening levels.
Most noticeable is the full deep bass, I had to turn off my subwoofer which I have been using with my Tannoys.
I thought the 152 drove them well, but the quality of the bottom end has never showed itself like this, and this is with just a quick hookup using a mix of wires and connectors to go from the amp old type binding post screws, to the biwire jacks on the Tannoys.
I am also impressed with how easy and quiet it is to operate for a amp of its age, no pops or clicks on turn on or off.

I think I will be looking to upgrade my 152 to a real BIG MAC. I could just keep the 7270 and sell the 152 instead, but I tend to like NEW. So now my question for you experienced Mac owners is.
Does all the newer higher power amps in the 250 to 300 wpc power range, have those qualities, or is this unique to the 7270 ?

 

[damacman]

It has been my experience that the BIG Mcs have BIG sound ... and plenty of it.

 

[jtee1340]

I love my 7270. It has plenty of power and sounds great. Newer amps, from what I have read are very nice, but do have a different sound compared to the older stuff.
I have both the 7270 and 2205, and I just can't get myself to plop down the kind of chedder these new amps are costing.
Nice setup you have either way btw.

 

[audiobliss]

I love my 7270. It has plenty of power and sounds great. Newer amps, from what I have read are very nice, but do have a different sound compared to the older stuff.
I have both the 7270 and 2205, and I just can't get myself to plop down the kind of chedder these new amps are costing.
Nice setup you have either way btw.

Thanks for the insite, that's what I am kinda worried about, I will sell this beauty, buy 252 or 302, and its not the same.

I wonder how much Audio Classics would cost to go through this 7270 and make it like new ? Maybe I will give them a call.

 

[Logan_Nolag]

Yes the big amps are awesome. My first Mac was an MC2125 it sounded awesome then I upgraded to an MC7300 which is the successor to the MC7270 and it sounded even better. I eventually traded my MC7300 for an MC302 and honestly not a huge difference. From what I understand the MC7270 and MC7300 are very similar and some people even prefer the MC7270 for some reason. I think if you like the MC152 you will be really happy with something like the MC302 or MC312.

 

[Chubba]

I really like my MC-252. Does that count?

 

[audiobliss]

I really like my MC-252. Does that count?

Yeah, there is a guy in California selling a nice one, but he won't ship it. That's the problem with these heavy weights, shipping.

 

[SaturationPt]

The 7270 is a step between the 2255 and the 7300, and an excellent amp. I would say that the 7270 is more like the 2255 (very much so) and the 7300 is the MC300, but anyway it is like buying a Porsche 911 where every year brought another improvement, some very slight and most only apparent on the track, ... for more money every time.

In McIntosh amplifiers you can continue to chase newer and better specs, it will continue to cost money and as many of us found years ago they just don't stop improving and introducing new models.

If you like the sound and power of the MC7270, what would you be looking to improve in a newer model? Trading up to the current MC462 will cost you several thousand more which will get you a shiny new amplifier with warranty, 180wpc more output, and better specs but the question is whether you want to spend the money and will you hear a difference?

Most people's systems have other limitations as well. Yes your ears, but how about your speakers? Can they handle the dynamic peaks of the MC7270 and need more? You're talking about dynamic peaks over 600wpc. How about the s/n ratio? Is your source and preamp so quiet that the amplifier is the generator of that last nugget that pushes it into audibility? Are there things about the MC7270's sound that you do not like?

It appears that the 7270 that you currently posess has had a fairly easy life, probably was never moved (nor vacuumed, but if not used hard no big deal), not run hard, not a party amplifier, so a once-over from a shop will likely reveal little and it's good for decades to come. Buying used gear is usually not that transparent so you'll be rolling the dice, ... of course new will be fine there (although every problem I've ever had in most new items is very soon after purchase).

Let the dust settle (not the real dust you removed of course), listen to the amp for a while, chances are you'll be happy for quite some time. If you decide in a couple of years to upgrade, chances are that the MC7270 will be worth more than it is today, and the current model MC462 will be out of production and available used, if you even want more power. There is also a very real chance that you'll be upgrading other parts of the system first, the 7270 is probably not the weak link.

 

[jlovda]

Trading up to the current MC462 will cost you several thousand more which will get you a shiny new amplifier with warranty, 180wpc more output, and better specs but the question is whether you want to spend the money and will you hear a difference?

I would bet a majority of upgraders will claim their extra two or three grand was worth it even if they don't hear any difference. The emperor's new clothes syndrome plus bragging rights. If an amplifier only reaches 90% of its clipping level how is it worse than a huge amp running at 40% of it's limit? They are both running at 0.005% THD. Maybe I'm deaf.

Caveat: I am an upgrader and amateur restorer. I started with a MC2125 and moved up to an MC2205 and then an MC300 because I got them cheap. My MC300 cost me about $900. I have never seen the PowerGuard lamps on any of them turn on.

 

[damacman]

There are many reasons why you may prefer the 7270 over the 152 - the least likely of those would be output power capability. Unless of course the 152 simply isn't powerful enough for your listening sessions.

 

[audiobliss]

The 7270 is a step between the 2255 and the 7300, and an excellent amp. I would say that the 7270 is more like the 2255 (very much so) and the 7300 is the MC300, but anyway it is like buying a Porsche 911 where every year brought another improvement, some very slight and most only apparent on the track, ... for more money every time.

In McIntosh amplifiers you can continue to chase newer and better specs, it will continue to cost money and as many of us found years ago they just don't stop improving and introducing new models.

If you like the sound and power of the MC7270, what would you be looking to improve in a newer model? Trading up to the current MC462 will cost you several thousand more which will get you a shiny new amplifier with warranty, 180wpc more output, and better specs but the question is whether you want to spend the money and will you hear a difference?

Most people's systems have other limitations as well. Yes your ears, but how about your speakers? Can they handle the dynamic peaks of the MC7270 and need more? You're talking about dynamic peaks over 600wpc. How about the s/n ratio? Is your source and preamp so quiet that the amplifier is the generator of that last nugget that pushes it into audibility? Are there things about the MC7270's sound that you do not like?

It appears that the 7270 that you currently posess has had a fairly easy life, probably was never moved (nor vacuumed, but if not used hard no big deal), not run hard, not a party amplifier, so a once-over from a shop will likely reveal little and it's good for decades to come. Buying used gear is usually not that transparent so you'll be rolling the dice, ... of course new will be fine there (although every problem I've ever had in most new items is very soon after purchase).

Let the dust settle (not the real dust you removed of course), listen to the amp for a while, chances are you'll be happy for quite some time. If you decide in a couple of years to upgrade, chances are that the MC7270 will be worth more than it is today, and the current model MC462 will be out of production and available used, if you even want more power. There is also a very real chance that you'll be upgrading other parts of the system first, the 7270 is probably not the weak link.

Thanks for the reality check. I certainly could live with the 7270 for a few years, I bet as old as it is, it could probably out live me.
Especially since I know its history and it has been living a very easy life.

 

[audiobliss]

There are many reasons why you may prefer the 7270 over the 152 - the least likely of those would be output power capability. Unless of course the 152 simply isn't powerful enough for your listening sessions.

You are correct, there are other reasons. Power not being the least, but that was my first reason I came up with when I heard the fullness of the bottom end and the overall different sound presentation that came at me, at the same sound level that I usually play the 152. Maybe its just putting out more current at a lower level than the 152, that just wakes up the speakers.

The speakers are Tannoy Definition 10T, they are 91db sensitivity, so the 152 should be quite capable of driving them, and I do not listen at loud levels. I have had the 152 driving them for a few years now, and before that I had a 200wpc Rotel with them, and I do remember they had deeper bottom end with the Rotel, but I got the 152 and kept it for other reasons as well, and have been trying to figure out what happened to the bottom end with the speakers ever since. That's why I ended up setting up the system as a 2.1 with a sub.

The 152 is a nice sounding amp , but maybe it was really intended to be used for surround speakers. It has bass, but it seems to roll off much earlier than the 7270. It doesn't seem to wake up the speaker with a smooth response like the 7270 dose.
To feel the punch of the music, you have to turn the volume up more with the 152, and then fatigue sets in.

Other than that, the aesthetics are a plus for the 7270, at least from the front, but I could probably improve the rear with some upgrades also. I am definitely leaning towards keeping the 7270, the 152 will be easier to sell anyway.

 

[audiobliss]

Oh, I forgot to mention, one other piece to the puzzle. When I would visit my relative when he had the system hooked up, and I would go take a quick listen, I was always impressed with the sound of the Vandersteen 3As, it was putting out the same captivating sound I am now hearing with my speakers.
However I always credited it to the 3As, so they were the first things I tried last week, with the 152 inplace of my speakers.

I played them in the system for about 4 days until I gave up and took them out. I was unimpressed and didn't know why. I just thought maybe it was the room. So I hauled them back to the garage. It never dawned on me that the difference was the amp.

A couple days later I couldn't resist trying the 7270 any longer, and summonsed all the strength in me to haul it into the house.
Luckily I have some amp stands I built with wheels to move some tube mono blocs I have in another room, so I used one to roll it, I just had to lift it over the one 10 inch high step into the house.
So now I know that the difference in performance with the two speakers is due to the two different amps used, I am not hauling those 3As back in the house to try them again, because. I may end up wanting to keep them too.

 

[damacman]

The MC7270 is a great power amp, no doubt. I've said many times it's the best value in vintage McIntosh amplification. It has everything you need and nothing you don't. [Interestingly enough, JGH found little to like about it . . . ] I'd be willing to bet that the differences you're hearing can be attributed to the power supply design of the 7270 as compared to the 152. The 152 was Mc's answer to the void below the MC302 wheres the MC7270 had but one peer when it was current - the MC2500. And at the time, the MC7270 was among the first amplifiers designed specifically to reproduce the all new Compact Disc with its improved dynamic range. If I had one gripe with the amp, it would be the cheesy speaker output terminal blocks. Early models had one for each channel, later models had one large one for both channels. Both variations suck.

Personally, I've always liked this particular series of power amplifiers with the DIGITAL DYNAMIC STEREO POWER AMPLIFIER nomenclature and I've owned a lot of them [ (4) 7270s, (1) 7300, (2) 2600 ]. Some have found that the MC7270 is still good enough for them 35 years after it was introduced. Now that's engineering. Sell the 152, park the 7270 in your rig and just enjoy it.

 

[Logan_Nolag]

The MC7270 is a great power amp, no doubt. I've said many times it's the best value in vintage McIntosh amplification. It has everything you need and nothing you don't. [Interestingly enough, JGH found little to like about it . . . ] I'd be willing to bet that the differences you're hearing can be attributed to the power supply design of the 7270 as compared to the 152. The 152 was Mc's answer to the void below the MC302 wheres the MC7270 had but one peer when it was current - the MC2500. And at the time, the MC7270 was among the first amplifiers designed specifically to reproduce the all new Compact Disc with its improved dynamic range. If I had one gripe with the amp, it would be the cheesy speaker output terminal blocks. Early models had one for each channel, later models had one large one for both channels. Both variations suck.

Personally, I've always liked this particular series of power amplifiers with the DIGITAL DYNAMIC STEREO POWER AMPLIFIER nomenclature and I've owned a lot of them [ (4) 7270s, (1) 7300, (2) 2600 ]. Some have found that the MC7270 is still good enough for them 35 years after it was introduced. Now that's engineering. Sell the 152, park the 7270 in your rig and just enjoy it.

A good solution for those crappy terminal blocks is to get some of these types banana adapters: https://www.amazon.com/gp/product/B07XGC6GHX makes it so you don't have to pull out a screwdriver every time you want to change out your speaker wire.

 

[damacman]

A good solution for those crappy terminal blocks is to get some of these types banana adapters: https://www.amazon.com/gp/product/B07XGC6GHX makes it so you don't have to pull out a screwdriver every time you want to change out your speaker wire.

Not a fan of those either ... that's a whole 'nuther thread. I don't mind terminal blocks, but the screws on the 7270 (and late 2500s) have a captive flat that won't play nice when you tighten them.

 

[SaturationPt]

Not a fan of those either ... that's a whole 'nuther thread. I don't mind terminal blocks, but the screws on the 7270 (and late 2500s) have a captive flat that won't play nice when you tighten them.

Agree. I bought a couple of brands of those terminal adapters, all are in a drawer somewhere, ... save a few minutes when changing amplifiers I suppose but putting the correct spades on the end of my speaker wires was a much better, tighter, safer (for the terminal strip) solution.

 

[audiobliss]

The MC7270 is a great power amp, no doubt. I've said many times it's the best value in vintage McIntosh amplification. It has everything you need and nothing you don't. [Interestingly enough, JGH found little to like about it . . . ] I'd be willing to bet that the differences you're hearing can be attributed to the power supply design of the 7270 as compared to the 152. The 152 was Mc's answer to the void below the MC302 wheres the MC7270 had but one peer when it was current - the MC2500. And at the time, the MC7270 was among the first amplifiers designed specifically to reproduce the all new Compact Disc with its improved dynamic range. If I had one gripe with the amp, it would be the cheesy speaker output terminal blocks. Early models had one for each channel, later models had one large one for both channels. Both variations suck.

Personally, I've always liked this particular series of power amplifiers with the DIGITAL DYNAMIC STEREO POWER AMPLIFIER nomenclature and I've owned a lot of them [ (4) 7270s, (1) 7300, (2) 2600 ]. Some have found that the MC7270 is still good enough for them 35 years after it was introduced. Now that's engineering. Sell the 152, park the 7270 in your rig and just enjoy it.

Thanks for sharing your knowledge of these vintage Macs, I never followed Macintosh much until a few years ago when the 152 got me off the amp merry goround.
The rear panel is definetly a modders delight, although I read a tread that suggested if you change the power cord, the amp looses value. I guess that would depend on who wants it.
I would look at it as a upgrade.

So I will be keeping the 7270, but I still would like to have it checked out and make sure its all up to speck. Once I put in the rack, I want no surprises. I just hate to ship it.

 

[audiobliss]

Agree. I bought a couple of brands of those terminal adapters, all are in a drawer somewhere, ... save a few minutes when changing amplifiers I suppose but putting the correct spades on the end of my speaker wires was a much better, tighter, safer (for the terminal strip) solution.

Using good spades are a good idea, and I could redo my speaker cables with some nice ones, but at the very least, I would have to change the binding post screws. The groves in the heads are not too easy to work with. It needs screws with nice deep Phillips heads.
I plan to go in there to see if I can change the damaged RCA, so I will take a closer look at everything.
Thank you also for you guidance.

 

[SaturationPt]

The speaker terminal screws are slotted? They changed the MC2250 & MC2255 to a combination slot/phillips mid-production, I'd expect that the MC7270 being the successor would have the same combination screws.

Yes, I'd change to Phillips-style. I have no love for slotted screws on anything.

Parts Express has several compatible spade lugs depending on your wire size: https://www.parts-express.com/Search.aspx?keyword=spade #8&sitesearch=true