Spires & Amp Comparison: Mac 402 vs 275

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daveneumann

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I am posting this review here because I believe that the comparison of amps is all about the amp-speaker interface versus the amps in isolation.

Before I jump into the review, first a bit of background. When I was in the market for speakers to replace my Quad 2805, I auditioned the Spires at Audio Solutions in Indy. I first heard them with a solid state amp and before the first song could finish I asked them to turn it off. The speakers sounded ragged and I was ready to move on to a different speaker. Then we hooked up a Mac 275 (which is the amp I owned and used with my Quads to very good effect) and ahh! that was closer to the sound I was looking for. Much sweeter, relaxed, and three dimensional. I bought the speakers and have enjoyed them immensely with my Mac 275 for the past 7 months.

But as I continued to listen I began noticing some congestion and smearing on complex music and softening of dynamic peaks. After reading reviews and getting advice from others, I bought a Mac 402 new (cashed in on the great discounts you can get now).

After several hundred hours of breakin I did careful A/B/A comparisons of both amps. I used 4 Ohm output taps for both amps, and the rest of my system is described below.

In the 275, the input tubes are Siemens 12AT7, Telefunken 12AX7, and Gold Lion KT88 reissues all with Herbies dampers.

Music included Amercian Beauty and Workingman's Dead on vinyl, Allison Kraus' New Favorite on vinyl, the White Album on vinyl, Jeff Beck's Porkpie Hat on vinyl, and several cuts from the 5 Songbirds CD (Barber, Jacintha).

In most cases the differences between the two amps were clear and repeatable. The 275 is a great amp and I find it to have an overall character of being more relaxed, a little dark, and softer with a very nice midrange, especially with female vocals. For example, female vocals seemed to emphasize the mouth noises more versus the 402 which emphasizes the breath more.

The 402 surprised me throughout the comparison. I have had tube amps exclusively for many years and have always enjoyed them immensely. But overall I have ended up preferring the 402.

The first thing I noticed is by comparison the 402 has much better dynamic punch and initial attack. Guitar strings, drum heads, bass snap, all have more impact, and in some cases MUCH more. By comparison, the 275 seems to soften the initial attack.

I thought that the tube amp would have better tone, and be better with the middle and end of notes. But the 402 holds its own here as well. Anyone who says the ML Spires can sound "thin" must not be pairing them with the appropriate electronics and front end. It is easiest for me to use guitar string tone as a benchmark and I think it is a toss up between the two amps on the quality of tone.

The 402 presented better detail and with clarity throughout the soundstage. Voices, instruments, background sounds all had an increased level of clarity and detail that I was not hearing with the tube amp. The soundstage was wider with the 402, although both had equal depth which is about 5' behind the speakers in my set-up.

There was no noticeable congestion or smearing with the 402. Even on the loudest peaks and most complex passages, each instrument maintained a clear and distinct place in the soundstage and just seemed to stand out more than with the 275.

This next difference is kind of getting "out there" on describing the music, but as I look back over my listening notes it appears more than several times. With the 402 in the system, there was just more intentionality to the music. Voices had more of a "pay attention to me" quality to them. For example in "Dire Wolf" Garcia seems to have a real urgency in his voice when he sings "don't murder me". By comparison, with the 275 the same song had more of a laid back and stoned "oh well, whatever" attitude. Instruments had that same intentional quality. It is as if the players were saying, "hey listen to this" with the 402. Whereas with the 275 backing instruments and vocals were just that...in the background and did not exist as strongly on their own.

On piano and some female vocal, the 275 could sound glassy or have a bit of glare over the music. I heard no glare or glassiness with the 402.

I'm not a bass nut, but the 402 has noticeable tighter, deeper mid-bass and deep bass. This surprised me, since the Spires have built in amps for the subs. I'm not an engineer, but my guess is that the signal passed through the 402 carries more bass information whereas through the 275 it does not, even though neither amp was actually driving the bass cones of the speakers. I'm open to others' explanations here...

In conclusion both are great amps. They both have excellent build quality and work flawlessly without issue, idiosyncracy or hiccup. The 275 is a real gem and matched with the right speakers is wonderful. I really enjoyed it with my Quads and never felt I was missing a thing. But with the Spires, I prefer the 402 and it is going to stay in the system. The 402 has seemed to take my Spires to a new level of performance and I'm even happier with my speaker purchase with this amp-speaker combination.

Comments, suggestions, further explanations welcomed!

Dave
 
I'm not a bass nut, but the 402 has noticeable tighter, deeper mid-bass and deep bass. This surprised me, since the Spires have built in amps for the subs. I'm not an engineer, but my guess is that the signal passed through the 402 carries more bass information whereas through the 275 it does not, even though neither amp was actually driving the bass cones of the speakers. I'm open to others' explanations here...

In conclusion both are great amps. They both have excellent build quality and work flawlessly without issue, idiosyncracy or hiccup. The 275 is a real gem and matched with the right speakers is wonderful. I really enjoyed it with my Quads and never felt I was missing a thing. But with the Spires, I prefer the 402 and it is going to stay in the system. The 402 has seemed to take my Spires to a new level of performance and I'm even happier with my speaker purchase with this amp-speaker combination.

Comments, suggestions, further explanations welcomed!

Dave

Hello Dave. Thank you for the very thorough review. Many of the same aspects that you mentioned when comparing the two amps were similar if not exactly my thoughts was well. Of course I audtioned the MC275 against the Ayre V-5xe, but many of the same areas you noticed were the differences that I experienced. I also had aftermarket reissued tubes in mine which did sound much better than the stock, but when I put it up against the Ayre there was not much debate as to which one my wife and I preferred. As for the bass, it appears that the quality of signal that is delivered to the built in Martin Logan amps do make a tremendous difference. This was another area that sold me on the Ayre. I too enjoyed having the MC275 in my system, and it was extremely nice to look at but the Ayre just completely won out to these ears. Thanks again for sharing and enjoy!!!!!!!

Glen
 
when you first auditioned the Spires at the dealer, what
was the solid state amp you referred to?
 
As I have written elsewhere in this forum, I really love the MC-402. It does seem to do everything well. I'd never claim that you cannot find a better amp (especially for a price), but it is hard for me to imagine ever being dissatisfied with the Mac. It just sounds so natural. I have it paired with a tube preamp (BAT-VK32SE), but I know several people who seem equally pleased pairing it with a solid state pre.
 
Mantana

It was a Mac 252. However, I wonder if it was hooked up correctly, on the wrong output tap, or even warmed up properly...

Dave
 
Thanks for a well-written and informative review/comparison of the Mac amps. I, too, have usually preferred Mac's SS amps to their tube amps for driving ML speakers.

Anyone who says the ML Spires can sound "thin" must not be pairing them with the appropriate electronics and front end.

I wholeheartedly agree with this statement. If they sound thin, then there is a room acoustic or system synergy issue.

I'm not a bass nut, but the 402 has noticeable tighter, deeper mid-bass and deep bass. This surprised me, since the Spires have built in amps for the subs. I'm not an engineer, but my guess is that the signal passed through the 402 carries more bass information whereas through the 275 it does not, even though neither amp was actually driving the bass cones of the speakers. I'm open to others' explanations here...

Having experienced this myself, I actually asked one of the engineers at ML about this very issue. He basically said that the quality of signal you get out of the powered woofers was directly related to the quality of the signal you fed them. Different amps will feed them a different signal and produce noticeably different results. Another reason why system synergy is so important with ML speakers.
 
Thanks for a great write up Dave! I recall reading awhile back you were going to try this.

I also tried a pair of 275's versus the 501 and the 501 became my favorite. You were able to put into word that I could not but I have to agree with you on every point.

Just out of curiosity, did you try both at the same time perhaps with the 275 on top and the 402 on the bottom?

Thanks again!

Gordon
 
Gordon

Thanks for your comments on the review. To answer your question, no I did not try to bi-amp the Spires with the 275 on top and the 402 on the bass.

My guess is that the results would have been the same. My preference for the 402 has to do with the entire frequency spectrum. The treble extension, the detail, dynamic impact, instrument separation, tone, etc. were all preferable across the bass, mids and treble using the 402.

It's been a little interesting to see some of the issues I have stirred up over at AK on the McIntosh forum. There are some diehard tube-o-philes there who also use ML speakers.

This comparison has been an interesting lesson and reminder for me...trust MY ears and how things sound in MY system. I used to prefer tubes over SS amps. But now I am more of an agnostic and tend to think it is really a matter of amp-speaker matching versus one technology over another.

Regards.
 
Dave, I saw the "tubes rule" bias there on your thread as well as other sites I frequent. While some good points were made as far as speaker wire goes, which I am looking into myself, the tube/ss debate will never be over. It's all good!

Gordon
 
Thanks for your comments on the review. To answer your question, no I did not try to bi-amp the Spires with the 275 on top and the 402 on the bass.

My guess is that the results would have been the same. My preference for the 402 has to do with the entire frequency spectrum. The treble extension, the detail, dynamic impact, instrument separation, tone, etc. were all preferable across the bass, mids and treble using the 402.

It's been a little interesting to see some of the issues I have stirred up over at AK on the McIntosh forum. There are some diehard tube-o-philes there who also use ML speakers.

This comparison has been an interesting lesson and reminder for me...trust MY ears and how things sound in MY system. I used to prefer tubes over SS amps. But now I am more of an agnostic and tend to think it is really a matter of amp-speaker matching versus one technology over another.

Regards.

Hi,
I think this comparison is a little unfair,75 watts tube and 400 watt SS.
We should try a 200 watt to 400 watt tube amp see how that goes.I know how 600 watt tube sounds with prodigy,s unbeatable.Regards Victor.
MY SYSTEM.
http://www.avsforum.com/avs-vb/showthread.php?t=1136036
 

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