Super Find: McIntosh MR 78

Back in the day Michael Fremer purchased one at a garage sale, he sent it to Richard Modafferi for service and updating, he also listed Richard's email address in the article.

Some yrs later I snagged a couple of Mac pieces and was given the MR78 with the understanding it was already sent to McIntosh and returned as unrepairable.

Two different shops stated they could repair it but later returned it as unrepairable. I remembered I had the old magazine so had it in hand when the second shop was trying to return it.

I showed the article to Gary (the service tech/shop owner) and asked if he would send it there. Gary said "you could just send it yourself", my response "you've spent time working on it, send it in and when it's fixed add whatever you think is fair for your time".

Gary sent the tuner to Richard, it was completely fixed and the Modafferi modification was also included, making it most likely "the best" tuner ever made. All for the huge sum of $450, what glorious sound I've never heard from FM before or since.

In case you're wondering, Richard Modafferi was one of the chief designers of the MR78.

Great story. Thanks for sharing!
 
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The picture just doesn't do it justice. It looks about 75% better than when I found it. Also, dusted inside and a did a nice Deoxit application.

I purchased a TERK amplified antenna and plugged it into the 75 ohm coax connector, then sent the RCA connection to an integrated aux input: unfortunately, no dice. :(

So, unless I'm doing something wrong (possible), the device is not working. I'll reach out to my repairman (he is a licensed McIntosh tech) and see what the cost would be to get it up and running. As stated above, spending 1k to have it worked on is not happening. I'm willing to invest something, but...

Anyway, currently, it's the most beautiful nightlight in the world.
 
I thought something went "POOF" and smoke came out?
You don't have to spend $1000 getting it up to spec, I wouldn't spend that either to be honest, it is, stock standard one of the best tuners there is, no need to spend thousands on something that is already the best around.
But do stop powering it up, smoke is usually a sign that something has catastrophically failed, powering it up may cause more damage to occur...
Get it in to a tech and repaired.
 
I thought something went "POOF" and smoke came out?
You don't have to spend $1000 getting it up to spec, I wouldn't spend that either to be honest, it is, stock standard one of the best tuners there is, no need to spend thousands on something that is already the best around.
But do stop powering it up, smoke is usually a sign that something has catastrophically failed, powering it up may cause more damage to occur...
Get it in to a tech and repaired.

It didn't exactly poof; didn't see smoke. Just a burny smell; to me, more of a dusty burn, rather than a catastrophic electrical failure, but what do I know? That's why I took it apart and dusted it out.

No more powering it up until I bring it to my tech, promise! ;)
 
It didn't exactly poof; didn't see smoke. Just a burny smell; to me, more of a dusty burn, rather than a catastrophic electrical failure, but what do I know? That's why I took it apart and dusted it out.

No more powering it up until I bring it to my tech, promise! ;)
Oh, my mistake, sorry, I see now.
Might as well just take it in anyway, make sure its all good,
 
A 78 is a great piece and I thoroughly enjoyed mine though the Kid has it now and I just use my MR80 for FM and the MR 7084 for AM. The 78 is the best out there for receiving weak signals and handling big monster stations close by, which use to be a big problem for me back in the 80's before the two college stations got them selves some decent transmitters and big antennae arrays. But that was then and low power level is not an issue now, I don't have the big stacked Jerrold log periodics on the roof any more, so the MR-80 is my tuner of choice. But if you have issues of extracting the best from an FM station and can have an antennae on the roof with a rotor a MR -78 is the Best Choice.
 
The all green caps are tantalum and most likely a large part of the problem. These should be replaced with Nichicon FG and KL (2 in signal path) caps
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The large green tantalum cap at the upper left hand corner of the board hiding behind the inductor can (bottom left corner of the IC) is the one that can cause damage to the power supply if it shorts.
 
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