McIntosh C22 Preamp Restoration. Final Checkout On Bench
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- Опубликовано: 14 апр 2020
- This classic McIntosh preamp from the 60s got the works. Replaced seleniums with diodes, all new capacitors, new glass dial plates, new bulbs and more.
#electronicsrepair #stereo #stereorepair #mcintosh 
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amazing job !!!!! congratulations on a job well done!!!! love the channel.
Wonderful sound image.
I just restored a C28 McIntosh equip is a joy to work on. Ive never seen anything built better! your C22 looks beautyful
Thanks, Ron! Yes, they ARE a joy to work on!
You can't get equipment built better than a Mac! Nice resto job!!!!!!!!!
Thanks, Dan!
Beautiful preamp. Wish I owned one but then I'd have to find a place for it.
You did a beautifull job there,and it sounds very nice too
Thanks, John.
old version,want it over 25 years, but poor guy i am
I hope one finds its way into your home someday, Yano.
BTW many of the plate load and power supply dropping resistors ( the carbon comps ) go up in value. I have replaced far more resistors in tube McIntosh equipment than coupling caps. If they get hot they go bad. Been servicing this brand since 1971.
Thanks, Herb. Appreciate someone with your experience stopping by. I’d have to go through my notes to see if I replaced any resistors on the C22. As you said, they can go bad so I make a habit of testing all of them. Off the top of my head, I think all the resistors in this C22 tested fine. I have a more detailed video series up now about the restoration of an MC 2105 amp. There, I found two resistors that measured out of spec and were replaced. Take care.
What size & voltage are bulbs for the indicators? Thanks
Wow what a clean front panel. If original the first owner did not listen to music very often . A well used C22 will be missing some silkscreen.
Herb, this is a replacement glass the old one was worn.
Beautiful! Where did you get the replacement glass panel?
Thanks! I either got the glass from Radio Daze or Audio Classics. The buttons are all original. The bulbs I purchased as a kit on eBay.
Is there a video on the restoration of this classic piece? I was hunting around the channel looking for more videos on this. I have a C11 that I absolutely love.
John, sorry no. I have some video footage and stills of the restoration, but I never put a video together. I do have a resoration series on a McIntosh MC2105 amp, though, that you might be interested in.
@@FluxCondenser Saw that one. Loved it.
A beautiful job. It looks great. I have a question about the restoration. There is that one can on top, on the right, next to the transformer, which has MFD values 20-20-40-1000. I have a bunch of Mallory caps in the shop, but wasn't able to find a match. Were you able to find one? Or were they in good enough shape that you felt replacing them was unnecessary? I'd be grateful for your advice. // D.
Hi, yes, all the electrolytics were replaced. It’s been a while since I worked on this one, but looking over my photos, it appears that I was able to replace at least two of the multi-section capacitors with new ones and another I left the old one in place and replaced it with new separate caps under the chassis using a terminal strip. Hope this helps. There are suppliers for multi-section caps, but they can be hard to come by. Check out the web site antique electronic supply and hayseedHamfest.com . Good luck!
@@FluxCondenser Thanks for the reply. I'll be done with my rebuild hopefully just after thanksgiving. Looking forward to hearing it.
shotgunned the coupling caps I see. Those Sprague film caps rarely go bad, did you find some that were bad?
Great question. The unit had issues with left/right balance so I made the decision to just recap the whole thing and skip the diagnostics. You’re right about the Spragues, though. I didn’t test all of them, but the few that I did check were fine. No leakage and in-spec. If someone wanted to keep things as original as possible, it wouldn’t be a bad idea to just replace all the electrolytics and get rid of the seleniums. If all sounds good, leave the Spragues alone. If not, narrow down the bad caps and just replace as needed.
For me, I’m not a big believer that capacitors possess magical sound qualities. If they test the same, they sound the same. So I don’t really have an affection for the old Spragues. Others may disagree of course, and think yanking them was a mistake. To each their own. I save everything I ever remove from all of my repairs (and I mean everything!), so the Spragues can be reinstalled in the future if I desire.
@@FluxCondenser Sprague 160P are Difilm (polyester-paper dielectric), super reliable and often still have insulation resistance of a new capacitor. Liikely did not need replacing. A pity.
...and buttons?