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 Post subject: Vintage mcintosh gear
PostPosted: Mon Jul 24, 2017 5:59 pm 
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Location: Cochrane, AB, CA
I just purchased my friends vintage mcintosh gear. His father bought it new in Montreal in 1963 or 64. And it is Truly minty or close to it. All the original silk screening is perfect an it all looks great. However, the last time it was plugged in was 1999....so, where does one start? It's an mc-225 amp and an mx-110 z preamp. In the vintage world it doesn't get much better! I am really excited to have them.
In the US they have Terry Dewitt and Audio Classics that specialize in classic mc gear. Do we have an equivalent here is Canada? I am fairily confident doing the power supplies but apart from that I need a good tube tech. Can anyone suggest what I should do? Should I change the power supply caps with authenticap parts and power it up before seeing a pro or do you recommend leaving it to a pro? This is a really nice well kept unit...I want to keep it this way. Any recommendations for tube guys in Alberta?
Cheers
Deek


Last edited by Deekcanoe on Mon Jul 24, 2017 6:30 pm, edited 1 time in total.

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PostPosted: Mon Jul 24, 2017 6:16 pm 
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Location: montreal, QC, CA
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Last edited by byefi on Tue Jul 25, 2017 6:21 am, edited 1 time in total.

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PostPosted: Mon Jul 24, 2017 6:32 pm 
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you have to service the units....even some better local tech should be able to redo the power caps and diodes...Lots of bad caps also in the MX110, but you may do these yourself...check for info online.


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PostPosted: Mon Jul 24, 2017 7:42 pm 
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Location: Calgary, AB, CA
Deekcanoe wrote:
I just purchased my friends vintage mcintosh gear. His father bought it new in Montreal in 1963 or 64. And it is Truly minty or close to it. All the original silk screening is perfect an it all looks great. However, the last time it was plugged in was 1999....so, where does one start? It's an mc-225 amp and an mx-110 z preamp. In the vintage world it doesn't get much better! I am really excited to have them.
In the US they have Terry Dewitt and Audio Classics that specialize in classic mc gear. Do we have an equivalent here is Canada? I am fairily confident doing the power supplies but apart from that I need a good tube tech. Can anyone suggest what I should do? Should I change the power supply caps with authenticap parts and power it up before seeing a pro or do you recommend leaving it to a pro? This is a really nice well kept unit...I want to keep it this way. Any recommendations for tube guys in Alberta?
Cheers
Deek


I'm not sure how far are you from Calgary but Tom of Apollo Electronics should be able to help you. http://www.apolloelectronicsltd.ca/


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PostPosted: Tue Jul 25, 2017 4:10 am 
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Location: St. John's, NL, CA
Ok tube54, I find it weird that you're in Calgary but don't know how far Cochrane is!! That's like living in Toronto and saying you don't know how far it is to Mississauga!!

Generally agree with libor. Get the electronic bits -- caps and resistors -- checked. Probably need to replace most if not all. If they're not bulging or leaking, they'll have drifted so far off their values they really will need replacing.


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PostPosted: Tue Jul 25, 2017 4:14 am 
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If you want to restore it, then I would send it to one of the US Mac specialist noted in your OP. If you want to get it up and running with basic maintenance, then seek out a competent tech in your area.


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PostPosted: Tue Jul 25, 2017 5:15 am 
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Location: Calgary, AB, CA
EL34 wrote:
Ok tube54, I find it weird that you're in Calgary but don't know how far Cochrane is!! That's like living in Toronto and saying you don't know how far it is to Mississauga!!

Generally agree with libor. Get the electronic bits -- caps and resistors -- checked. Probably need to replace most if not all. If they're not bulging or leaking, they'll have drifted so far off their values they really will need replacing.


Oops! My bad...I didn't realize he's from Cochrane, which is basically a dogleg hole from Calgary. As I said before give it to Tom and have them checked out properly.


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PostPosted: Tue Jul 25, 2017 6:39 pm 
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Location: A-Tube-O-Coke, ON, CA
This is a guide only; use at your peril.
Deadly voltages are a slipped finger away.
If you want to do ANY DIY, it's imperative that you get a schematic: Audio Karma is a great resource for that kind of thing: there are more than 17,000 posts in their McIntosh restoration forum, and they're super helpful there. Took me two months to read through the Fisher forum and only then did I think I was ready.
BE SAFE, DONT TAKE ANYTHING FOR GRANTED.
Inspect and replace any bulging capacitors first.
It's just my thing to concentrate on making sure that something is not going to happen that will blow a tube or transformer. Caps, resistors, and wires are cheap. Don't fret over acquiring boutique parts unless you're into that kind of thing, (or you are a high school teacher in Ontario); usually it's not worth the effort of aquiring, except maybe inter stage coupling caps.
Mods can come later as desired.
If it was working fine when last used, it's a good bet that the power and OP transformers are good, but not a bad idea to do a quick check to make sure that nothing is shorted that shouldn't be.
THEN
Connect a pair of garage sale speakers; rule of thumb: OP transformers don't like to be run with no load. You might get away with using headphones but it depends on.......never mind, just use disposable speakers.
If you have a variac, you could slooowwwwwlllllyyy power it up (MOP follows) and shut it down IMMEDIATELY if you hear any creaks, smell anything interesting that you can't explain, let any smoke out, find anything getting hotter than you think it should, ( if you find yourself linking your lips, that's just human nature; enjoy that).

SLOWLY POWERING UP means something like 1 hour when powered up and the variac at 0 volts, then increase the variac 5 volts per hour for the first 4 hours, then 10 volts every two hours, MONITORING IT THE WHOLE TIME. DO NOT LEAVE THE ROOM! I did one over a long weekend speeding things up the second and third day to the point I ended up the day before. At one point if all's well, you might even be able to play music, but DON'T speed up the process if you do (happened at about 75 volts for me).
Use mini clips on a DMM to monitor/measure voltage levels if you want, specifically around diodes and capacitors. A schematic is your bible. Memorize it. Get some forum reading done. A LOT of reading. Don't be afraid to ask questions. Log everything going you do (makes it easier for someone else to troubleshoot, BTDT). :D
Keep your left hand in your pocket. Just do it. (And don't Google to find out why. Trust me.)
If you get the variac up to 115 volts and all is OK, STOP there. You will probably have to find a way to drop it as today's walls can give you upwards of 126vac which can cause problems with things like power switch contacts and tube heaters on a turn on shock.
At this point you have a reference of what it sounds like and what it sounds like after re-vamping the power supply and swapping out electrolytic caps and drifted resistors and such.
If anything goes wrong, then you have something to troubleshoot; that's when the fun begins.
Of course, if you have curious eyes and fingers around, it goes without saying that this all should be done in a lockable room or when they can be supervised.
Very rewarding if you have the time.
Or, you could find someone else to do it. No harm in that, you'd be rewarded one way or t'other. Some people enjoy the destination, I much prefer the journey.
Good luck.

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Lawrence Peter Berra (1925-2015)


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PostPosted: Tue Jul 25, 2017 6:50 pm 
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Posts: 13
Location: Cochrane, AB, CA
Thanks for the advice. I will contact tom in the coming days and arrange an inspection. I am a bit undecided at the moment as what school of thought I subscribe to, but I am leaning towards doing less rather than more. These units have survived over 50 years unmolested so I would like to do the power supplies and rectifiers but I'm not sure about an extensive recap. Some argue that recapping the whole unit to original values as per the original drawings is the best way to honour the engineers that dreamt up this set up in the first place. The other school of thought is changing too much will take away from the mcintosh sound. I have other hifi systems that fulfill my "sound needs" so I think it's ok if my "vintage" system sounds a bit "vintage".
I have a nice period correct rek o kut n33h turntable so now I need to find some speakers that give the right voice. I'm thinking klipsch la scalas that first came out in 63. Ar3s would be nice but they are getting pricy. Any other ideas?
Cheers
Deek

-- 26 Jul 2017 03:02 --

Thanks android. Enjoyed reading your post. I'm not an audio expert for sure but I have built 3 tube amp kits and my job involves working on really old dangerous stuff unattended...so I would free ok working on the amp myself...until I smell that smell and hear that sound and just run out of ideas...and knowledge!
The journey sounds fun too.
Any ideas where to pick up a variac transformer? Maybe b&e electronics? I could google it...
Thanks.
Deek


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PostPosted: Tue Jul 25, 2017 8:18 pm 
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Location: Surrey , BC, CA
if you want to play music with it...you have to restore it...if you want it to have it on the shelf....then whatever...


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PostPosted: Tue Jul 25, 2017 9:28 pm 
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Deekcanoe wrote:
Any ideas where to pick up a variac transformer? Maybe b&e electronics? I could google it...
Thanks.
Deek

Don't know about Calgary area. I would check out electronic surplus type of stores.
Got mine (new) 110 IN 0- 250 OUT at A1-Electronics in Etobicoke ON for about $80. It's an electronic junk supermarket, but he carries new stuff under the counter, and according to his website, he sells online.
Sayal Electronics here, although useful and cost efficient for a lot of DIY stuff, doesn't carry anything suitable for this kind of use, so I wouldn't be surprised if you found the same thing there in places that count on pushing only new parts.
EBay? Craigslist?
Find a member of an antique radio club and ask? Those guys come out of the woodwork and ALWAYS like to chat electronics (and push their addiction). Some of those folks have a few variacs so they an run and work on several radios at once. Might get lucky and find someone who is downsizing.
Mine came bare bones with screw terminals. All I had to do was wire it up to AC plugs and passed the wall cord through a small kit box so I could fuse it (6 amp). A short on the output at the wrong time ever could fry it.
Yes, it's a journey, but I would warn you: it can turn into an addiction, kind of a musical Crack.
I put myself to sleep with visions of matching resistors, or adjusting cathode currents down to within 0.1 ma of target current, or calculating a resistor network that will finally get that heater voltage down from 12.9 VDC to EXACTLY 12.6 VDC.......never ends. Just typing forum posts gives me ideas.........

-- 26 Jul 2017 05:28 --

Deekcanoe wrote:
Any ideas where to pick up a variac transformer? Maybe b&e electronics? I could google it...
Thanks.
Deek

Don't know about Calgary area. I would check out electronic surplus type of stores.
Got mine (new) 110 IN 0- 250 OUT at A1-Electronics in Etobicoke ON for about $80. It's an electronic junk supermarket, but he carries new stuff under the counter, and according to his website, he sells online.
Sayal Electronics here, although useful and cost efficient for a lot of DIY stuff, doesn't carry anything suitable for this kind of use, so I wouldn't be surprised if you found the same thing there in places that count on pushing only new parts.
EBay? Craigslist?
Find a member of an antique radio club and ask? Those guys come out of the woodwork and ALWAYS like to chat electronics (and push their addiction). Some of those folks have a few variacs so they an run and work on several radios at once. Might get lucky and find someone who is downsizing.
Mine came bare bones with screw terminals. All I had to do was wire it up to AC plugs and passed the wall cord through a small kit box so I could fuse it (6 amp). A short on the output at the wrong time ever could fry it.
Yes, it's a journey, but I would warn you: it can turn into an addiction, kind of a musical Crack.
I put myself to sleep with visions of matching resistors, or adjusting cathode currents down to within 0.1 ma of target current, or calculating a resistor network that will finally get that heater voltage down from 12.9 VDC to EXACTLY 12.6 VDC.......never ends. Just typing forum posts gives me ideas.........

_________________
"There are some people who, if they don't already know, you can't tell 'em."
Lawrence Peter Berra (1925-2015)


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PostPosted: Wed Jul 26, 2017 2:40 am 
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Joined: Mon Nov 29, 2004 9:43 am
Posts: 11
Location: Ottawa, ON, CA
Don Sachs in BC restores vintage tube gear and did a good job on my HK Citation II. He has a website which is http://www.dsachsconsulting.com/Citatio ... ation.html


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