McIntosh Amps-How Often to Service?

[tidmack]

Hey all-

I'm running a Mac 2105 with a MX 113 preamp/tuner. I've had both units for about 2 years and both were serviced (bench tested, cleaned, etc) shortly before I bought them at a local Klipsch dealer in Milwaukee (Flanner's for those of you in the area). How often should I take my equipment in to have looked over?

Thanks

Jeff

[j-malotky]

Hi Jeff

I currently own, and have previously owned many McIntosh amps. Also, FYI, I use the guy at Flanners my self to repair my old McIntosh amps and he is very good.

As a general rule, Mcintosh amps will sound great and last for decades. I only take them in if they sound like they need some work. Over the last 20 years, Out of the 7 amps I have owned, 4 at the present, I have only needed to take 2 amps in for service. One of the two is an amp I purchased at a significant discount on Ebay that was damaged.

I see you are from Milwaukee, we are having a get together or possibly two in August. If you want to be added to the list, drop me an email.

JM

[tidmack]

JM,

Thanks for the quick reply, I'll hold off on taking anything in since I'm not having any problems right now.

Jeff

[tidmack]

JM,

You have mail.

Jeff

[D-MAN]

I've owned my Mc SS stack for about over 8 years now.

They do not need their oil changed, there is no regular

"service" required...

Only when they stop working.

DM

[djk]

I own a MC2100 and two MC2120s.

Caps wear out.

Even when not in use.

This list is for the MC2100, electrically it is the same as the MC2105, just without the meters.

Even though your old amp is still working, you have no idea how much of the music you are missing.

The parts are inexpensive.

Digi-Key is good, Mouser has no minimum order.

Posted by djk (M) on July 11, 2004 at 04:29:36

In Reply to: Re: MC2105 @ $ 100 even @ 20 yrs old is a best buy for me. posted by julian4@telkomsa.net on July 06, 2004 at 14:58:04:

The sound would benefit greatly from replacing a few dried out electrolytics, and adding a few film types here and there.

C301, 302 is the main input coupling cap. It is a Mylar type so it is likely to be OK, upgrading it to a Polypropylene type with give a smoother sound to the high end (0.47µF).

C307, 308 are emitter bypass caps, 100µF 15V. Replace with same type and add a 0.1µF film bypass.

C309, 310 are the output coupling caps for the pre-driver section, 10µF 25V. While a film type would be better, size is a problem. The DC bias across this cap also helps out with its being an electrolytic. Replace with same type and add a 0.1µF film bypass.

C303, 304 are the DC power supply caps for the front end, 470µF at 25V. Replace with same type and add a 0.1µF film bypass.

C1, 2 are the feedback loop caps, 330µF at 3V. The signal goes through these so replacing these with new ones and adding a 0.1µF film bypass really opens up the sound. Go with as high a voltage as what space permits.

C11, 12 are the DC supply caps for the voltage gain stage, 150µF at 50V. Replace with same type and add a 0.1µF film bypass.

C201, 202 are the main filter caps, 39,000µF at 40V. These may be quite expensive new, although I have seen them surplus for very low prices. I would use then unless signs of leakage or amplifier hum are there. Add a 47µF at 50V cap in parallel with each.

C203 is a multi-section cap that will be very hard to find a fresh date code. New caps are small enough that they may be wired to the terminals of the old one, leaving the old one in place. This cap is important as it provides the current for the diff pairs and the VAS. The sections go 80/80/150/50µF with the voltages being 200/200/150/150V. If you measure the voltages 100/95/90/80V are typical, so 200V caps are not really needed, but 100V is not enough.