McIntosh MR78...As good as it gets?

Charles Peterson <charlesp@...>
 

I finally bought something I've wanted for more than 20 years, a McIntosh MR 78,
and I love it. It's a superb tuner in every way, the best I've ever owned
(unseating both my Sansui TU-9900 for DX'ing and my Kenwood 600T for sonics).
It's a super DX tuner and a super audiophile tuner in one well-designed box.

I went the whole number and got a unit in "near mint" condition (recently
cleaned by a perfectionist Mac dealer) and with the Modafferi Update (done in
2000). I haven't yet gotten the paperwork for the Modafferi Update, and I have
no way of comparing the unit before and after. But I can tell you that with the
update, it's great. I'm sure part of that has to do with it having been aligned
recently by Modafferi himself. This is probably better than if you bought an
MR78 brand new. Considering they cost as much as $1600 new in 1976, the one I
got for $1200 on eBay with a recent Update is a great deal in my opinion.
Without the update, they sometimes sell for under $800, which is also a great
deal in my opinion. After the MR 80, McIntosh stopped even trying to build "the
ultimate" in super tuners because they would have gotten too expensive to sell
to enough people to make money. (One such estimate of price was "5 figures.")

The MR 78 sensitivity and selectivity are outstanding. Even in the widest IF
mode, I've been getting stations that required the narrowest mode on other
tuners (100 and 200 miles away). In the Super Narrow mode I've been picking up
stations all over the dial I've never heard before. Unfortunately, with my
kitchen wall mounted whip antenna, none of those new stations are actually
listenable, but I have great hopes for what can be accomplished with a high gain
yagi which I hope to put up in the next year or so. I have the good fortune of
living in San Antonio where the troposhere is amazing, which is why I can get
far away stations even with a nondirectional indoor antenna.

My favorite local station, a public radio station with 24 hours classical music,
sounds quieter and better than it had sounded on my 600T. I would have thought
I was getting full quieting with the Kenwood (the meters read 61dBf and no
multipath) but somehow the MR78 is even quieter and yet has equally extended
high frequencies (if not more extended). Even when lightning knocked the
station down to auxiliary power yesterday (with a more than 20dBf loss), it was
still coming in noiselessly on the MR78 while a CT-1010 in another room was
becoming very noisy.

The seems no lack in bass, midrange, or highs with the MR78, and it even has a
certain "liquidity" (from lack of high frequency noise and distortion?) that I
was not expecting. By comparison the Kenwood 600T has a very fine grain, and
the Kenwood KT-7500 has boulder sized grain (in which many musical instruments
no longer sound like real instruments). The tubed Fisher KM-61 also sounds
grainless, but seems far less defined, like there is some stuff missing (though
you get what's most important).

I'm sure that when I get the performance measurments made by Modafferi it will
show essentially flat frequency response and vanishingly low distortion. I have
serious doubts that it gets much better than this. I believe it must be pretty
close to perfection already. Even if there are tuners with slightly better
measurements, they are probably not better by enough to be audible in a blind
test, so why spend big money chasing after them? (I'm thinking about those
spending $2,600 for a TU-X1 for example...and I have serious doubts than any
particular TU-X1 is even going to be better in the first place.) Those who have
denounced the sound quality of the MR78 are clearly wrong. It is audiophile
quality. It is the best sounding tuner I have heard, and I also own a few of
the ones they recommend.

The controls are great; the selectivity control is much easier to use than on
the Kenwood 600T because it's big and turns easily. Every control operates
without making any noise or short cut-out. The center tune meter is somewhat
more sensitive, and the multipath meter is much more sensitive than those on the
600T. I like the way the stereo light shows that there is a stereo pilot
whether you have stereo enabled or not (though there could be another light for
stereo enabled, as there are for filter and muting).

The glass front is nice, the only slightly dated look comes from the rectangular
plastic grill around the dial. With lights off, however, the unit is very
beautiful, and all the legends for the controls are lighted (in blue) through
the glass. It's wonderful to bask in the cool blue glow in a dark room. It's
also cool to look through the wire cages in back, where you see the labeled (in
gold) and enclosed filter modules, and a nice blue fiberglass-epoxy circuit
board. It's like audio jewels in a custom terrarium.

There are no 200Khz tick marks as on some other tuners, but with all other the
tuners I have the dial is off by about 100Khz or more anyway. (I think Mac left
the tick marks off so as not to require annual tweaks by perfectionistic Mac
owners.) With my MR78, tuning is about as close as you could guess by eyeball
between the evenly spaced 1Mhz tics. I'd rather the "log scale" had been
left out...another part of the slightly dated look.

I do miss having a calibrated signal strength meter and modulation meter (as
on the Kenwood 600T), but I'll take the better performing and sounding tuner
any day.

Many people think of the MR78 as lacking filtration for the 19Khz pilot and
38Khz carrier. That was true of the earliest production, units AD1001-AD5164.
The later units, AD5165 and beyond, and CG1001 and beyond, did have a 19Khz and
38KHz filter. I think of the later units as "MR78 B" though McIntosh choose
never to label them that way. My unit, AD7xxx, is clearly in the later series.

In addition to the added filter in the later units, there is also an emitter
follower to drive the output. The variable output adds only a 10K pot (not an
extra stage as with the Kenwood 600T). If you wanted to tamp down the high
frequencies a tiny bit (you will not want any more highs, IMHO), you could use
the the variable output and adjust it anywhere from full to -3dB. The effect
will also depend on how capacitive a cable you use. It will be a very subtle
effect; I think of this as an extra "audio pallette" control, not a high filter
per se. (The MR78 already has two very effective high filter settings for noisy
stations.) Modafferi puts new gold jacks on the fixed output, so it's clear
which output he wants you to use. I'm very happy with the fixed output.

Charles

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