High End McIntosh C29 Preamplifier Repair!

[@MrCarlsonsLab]

To learn more about electronics, build your own "special" test equipment, and take part in an active electronics community, click here: www.patreon.com/MrCarlsonsLab

[@watershed44]

Mr Carlson's Lab You can tell that this unit was built with pride, and incredible attention to detail, from all involved. Made in the USA too. If only we could travel back in time, while some things are better today many others are not. Are you going to do a follow up video? I know plenty of units made during the 80s and prior have such issue with pots like these. Wow electrolytic caps that are 40 years old and in perfect condition?!?!?! That IS amazing.

[@rbmwiv]

Mr. Carlson, I cannot figure out how to message you on Patreon. I have a NOS 6EM5 tube I have had for almost 40 years. I will never use it since my use of tubes are limited to magic eyes. So I wanted to send it your way. Hopefully you can put it to use. It was part of my light bulb collection from when I was a child. But since this isn’t a light bulb or a rare tube it doesn’t really fit with my other stuff. Thanks for your great content. Keep it up. Look forward to hearing from you. I’m R.b. McBrayer IV on Patreon.

[@j.cheeverloophole9029]

I wonder what type of cleaner you use, & do you use cleaner lubricant or separate? The reason i ask is i have had so much trouble over the years with some cleaners doing more damage than good, eating plastic, dissolving carbon tracks, once i sprayed a dual pot, shaft within a sleeve type & the stuff welded the plastic shaft to the plastic sleeve!

[@friedmule5403]

@@rbmwiv If you still need to know how to contact him, just answer here and I'll write you a message in Patreon on how to.

[@friedmule5403]

Paul is fantastic when it's about electronic but maybe not the best in advertising:-) Because he do not convey how much you really get! Imagine this channel on steroids and then some, I have only been a Patreon for a short time but have gained so much!! :-)

[@editorjuno]

Paul, you are by far the most meticulous and knowledgeable service/modification technician I have ever encountered -- you've got a superb work ethic and engineering-level expertise way beyond any of the literally dozens of professional bench jockeys I worked with and managed over the years before I retired. Your services would have to cost a small fortune for you to stay in business, but had I the scratch I would hire you in a New York minute -- and considering the value of your time, it's incredibly generous of you to keep posting these highly informative, finely detailed, technically impeccable videos. Thanks so much and please keep up the splendid work!

[@MrCarlsonsLab]

Thanks for your kind comment Bruce!

[@rayofcreation3996]

Bruce Morgen that's right. Your said it there. Thanks for the acknowledgement and good luck. 😊👍

[@Marco-717]

Don't ride it too hard or it'll break

[@jerdobi]

Happy you're looking at vintage stereo equipment. As for spending 2 hours cleaning controls, would be nice to see a video on how you cleaned one of these controls and how you flushed out the dual controls grease.

[@robertgray6631]

I’m glad I read your review because I was going to ask the same question. I cleaned my equipment before and just sprayed around the controls front and back when I had the cover and nobs off. It did make a difference.

[@carlpetitt2241]

Totally agree -- not only would I like to see how he did the cleaning, but also how he checked the caps and other internals that he said tested so perfectly.

[@justinmurphy2227]

Why in the world are there any dislikes? This man does this for a living and then spends the time record, edit, and upload these videos. Well I can say I liked it in many ways. And yes McIntosh equipment is very nice. I've been associated with a few pieces of their car audio equipment. When the owner of "Black Betty" decided on the amps when for the highest score ever set record for Sound Quality, he picked the McIntosh MCC602TM.....times four!

[@n7565j]

My buddy from childhood (back in the 70's) older brother purchased a complete McIntosh system. I remember the speakers were taller than I was! (little brother and friend were NOT TO TOUCH ANYTHING!!!) It was extremely loud, and extremely clean sounding!!! I also remember the rep from the place he bought the equipment from spent a couple of days setting up the system and adjusting it for the room it was in. I don't remember how much he paid for the system, but I remember him saying that he could have bought a new car for what he paid for the system ;-) Excellent video as usual Mr Carlson :-)

[@MrCarlsonsLab]

Thanks for sharing your story Brian!

[@jimc3688]

Could of had a race Hemi Cuda.

[@donmoore5716]

I cleaned my Marantz 2500 controls about 10 years ago. It was a big job. I didn't know about doing a second pass. Sure enough, within a few months noise came back. I haven't gone back in, but this tip gives me inspiration to do a better job next time.

[@kevinpeters6672]

Hello Mr. Carlson: I love your video's, from start to finish. Your articulate and savvy with your work on video. I extremely enjoy all aspects of audio / tube equipment you tear into and refurbish new. Please keep up your video's on you tube. It's fun learning with your knowledge. "Thank You"

[@kevinpeters6672]

Thanks Ann C. for your nice agreement. Mr. Carlson has a educated and inspiring gift of teaching and even counts the screws to us viewers for disassembly (PUN INTENDED). Will add to his Patreon soon... "Kevin"

[@elpaso--west7354]

these vids are priceless-------i wish i knew as much as MR CARLSON

[@utGort]

I had a McIntosh receiver many years ago. It was taken in a burglary. :( The insurance agent said "I don't know how you did this but your stereo appreciated in value." That is how good these things are.

[@SantaClaw]

"Man found crushed under piles of electronic test equipment" Runs through my mind every opening sequence :P

[@paublusamericanus292]

clawly: I have thought of that several times. he probably lives right on the quake line in Cali. I really enjoy his videos for many years. some stuff like the 555 scope seem overdone, till I watched eev dumpster diving and found an oscilloscope worth over 300k all he had to do was plug in the plugin inside the case. sheesh. it worked down to nanometers of light travel in a wire.

[@robertcalkjr.8325]

Paublus Americanus I think Paul lives in Canada.

[@richardgoebel226]

I think he lives up in B.C. as he does not celebrate U.S. holidays.

[@bobsoft]

Yes he lives in the lower mainland of B.C. We are in an earthquake zone (Juan de Fuca)

[@harrystevens3885]

Paublus Americanus eev dumpster diving and found an oscilloscope worth over 300k I believe that was an April fools joke by eev.

[@garybevis8691]

I really loved the look of the McIntosh when I was a kid, still do. Great job Paul.

[@Electrolab28Ag]

Those McIntosh are really top quality equipment... I really wish I could get my hands on one but they are very expensive. I am also a Patreon Supporter and I can never get enough of it. I recommend every one to support and join in on the great stuff that is on there. Thanks Paul for another great video.

[@deuteronimus750]

There's a surprising amount of McIntosh equipment out there.

[@Wetboyslim]

@@deuteronimus750 yes, of course :) Potentiometers looks like in a cheap Chinese radio :) Mega Hi-enD!

[@bergarteric5713]

Good morning Mister Another pure gem of science !!! with you Mister i understand many things .... Thanks for all and sorry for my langage i'm living in France and at 62 Years old .... God bless you and your familly Eric

[@MrBillblake123]

I can only say that I have had my McIntosh 1201 Mono Block amps for a long time now and they sound great. .... no issues. .... So,... I think everything you said was right on about quality. McIntosh is HARD to beat! .... Thanks Paul.

[@xray111xxx]

I sold audio for many years and McIntosh always made the best result. I sold other high end makes but this one always pleased no end. It does not surprise me that this device just needed cleaning. It is quality in and out. Unlike today's commoditized junk you throw away. McIntosh is for the generations of music lovers out there. It is an investment. Not just a casual acquisition. I didn't sell allot of McIntosh, and that is okay. It is meant for those who appreciate the finer things. I love your videos. Just so in depth and complete. I am just about ready to start my channel so I learn as much as I can from folks such as yourself. Thank you for this video presentation Mr. Carlson.

[@bryede]

I've fixed a bunch of modern (disposable) receivers and there's two main problems: 1. Cheap electrolytics that fail within 2-3 years and 2. Hot devices tend to crack today's weak solder connections. When you open up older gear, you tend to see fairly beefy "Hershey's Kiss" style solder joints but the new methods of wave soldering seem to use much less metal and leave you with joints that barely rise above the board. Once a power transistor heat cycles a few times, a crack ring forms around the lead. This is only made worse by the brittleness of lead free solder. Vintage gear will always be collectible but it seems like most of what's made today is destined for the landfill.

[@petroldevo9934]

I forget what the company was but do you remember the separate amp and power supply units ? It had a weird cable that went between the two. I used to own that piece of equipment with a vacuum operated record player. Sounded really good !

[@southerner66]

I had a different experience with a McIntosh integrated amp from this same era. Granted, it was not pristine and had been in service a long time. It had blown output transistors and LOTS of problems on the boards including drifted resistors and contact problems where the boards plugged into multi-pin connectors. Getting the output bias stable was a major headache. I don't know how many hours I sunk into that thing. Yes, the case build and all that was excellent, but although I thought it sounded good when done, I don't think it was better than many other HiFi amps I've heard. I will give McIntosh credit for being good to work with and supplying the appropriate replacement transistors, but I was left never wanting to work on one of these ever again. McIntosh tube equipment, yes, but not the mid-70s SS.

[@genestatler2514]

You, Mr. Carlson are a very articulate and knowledgeable perfectionist and I enjoy your videos very much.

[@haskellbob]

In those few seconds of silence at the beginning of this segment I made the mistake of turning my volume up. Then when Mr. Carlson, all chipper, came in with, "Hi, everyone!" I just about jumped out of my seat!

[@robertcalkjr.8325]

Thanks Paul. Man, I never get tired of looking at the opening shot, wow! That McIntosh Preamp is gorgeous!

[@ct5006360]

Watch Mcintosh factory tours here on YT .

[@jameslucas6589]

Thank you ever so much Paul for this restoration. It is so cool seeing what I feel, one of the best of the best pieces of sound reproduction being serviced. When I was 21, I was lucky enough to hear the most beautiful sound reproduction in my life for the first time. For those who have never heard just how amazing music can sound, you need to hear a McIntosh system. It is utterly breath taking. It is like hearing music for the very first time. I must warn you, you will then dream of owning one if not you do not just buy one. McIntosh replicates music so pure. The systems brand new can be very very expensive. I was able to find 2 good MC2105 amps (circa 1965) that I paid only a few hundred dollars for, then serviced, that I will convert to mono blocks. I wanted a good tube pre amp. So I bought a new C222 (which is a tube preamp) which can handle moving coil and moving magnet carts. The sound is pristine. Component systems took a real beating and are still considered by many as non essential in the music listening world today. Thankfully, there are still companies as McIntosh striving to maintain excellence. McIntosh is an investment. It will never be worth less than you paid for it. A clean, well maintained MC250 is worth several times what it cost in the 1960s. It was re- introduced a few years ago for the 50th anniversary costing well over $7000. Many would cringe to pay that for a stereo amp. But it will never go down in value. Finding high end matched tubes for that amp could cost another two thousand. But it will be a piece of usable music reproduction that ones great great grandchildren can enjoy. Parts are quite available; they even offer new glass fronts for the units as many of the older units get damaged. Pure quality end to end.

[@borisdorofeev5602]

You and Applied Science are my favorite KZbinrs. Keep up the great content.

[@disklamer]

8 minutes+ to get the lid off. You sir, are a born suspense builder. I enjoy your knowledgeable rants about every single part and component. I would like to see you do some work, like the cleaning and soldering, and not just be shown the before and after.

[@STR82DVD]

I am literally salivating over that McIntosh. Thanks lad.

[@phillanassa759]

Nothing like Mc. Built with longevity as well as service-ability in mind. Many times Mc gear is passed down father to son//daughter, it becomes a generational thing that the child grows up hearing and loving as much as the parent. I have the C-32, also a C-28 and some others, The 28 and 32 were inherited, along with some early Marantz gear, which is another manufacturer that built beloved audio gear, both tube and solid state. Often times this era of gear needs next to nothing to keep going, at the most some caps like to fail if it wasn't abused. The low leakage caps in the tone controls hold up well, the power supply caps may need replacement at this age. I see the 10v variety essentially fall apart and unroll, going open. Changing failing or weak power supply caps and drifting resistors will typically improve the unit's sound quality by providing it with more stable and cleaner power supply. The mistakes begin with people who use the wrong caps, go overkill with 105c flavored whammy-jammy boutique cryo treated components, increasing many times the original capacitance and/or voltage used. The ratings which the factory engineers spec'd work the best. If it ain't broke don't fix it. Thanks for taking this one in and giving everyone here a look inside a true time capsule. I love to watch guys who enjoy working on both Mc and Marantz stuff, as well as Sansui, Pioneer, Audio Research, Kenwood/Trio, etc. Golden age of audio is what I call this stuff.. Cheers!

[@RiccardoMacri]

Its a pleasure watching the appreciation and repair of a product whose designers had the likes of you in mind. Its so tragic the same cannot be said for most modern consumer products.

[@therepguy1]

Your just conformed my reasoning for preferring the Macintosh brand over all others, I first built my audio system back in the day (mid-sixties) while still in collage (University of Texas). At present I now have the time to set back and truly enjoy my audio system which remains as I first built it way back when. Later!

[@hpelisr]

What a wonderful piece of knowledge and history. I think all americans should get back into this type of learning. Thanks Paul.

[@ZeedijkMike]

Some very good advice there. My old Technics amplifier, bought in the early 80'ies, had some scratching on the volume control (motor driven by remote) and input selector. I gave it a good clean. And it worked for a couple of months. I thought it was a lost case I have lived with the scratching for quite a few years now. But after this video I will give it another go and do it the proper way this time. Thanks for yet another well made and enjoyable video.

[@johnopalko5223]

I lusted after McIntosh equipment when I was a teenager, back in the 1970s. My wet dream was a McIntosh preamp, Phase Linear power amp, Garrard linear-tracking turntable, and a pair of Altec-Lansing Voice of the Theatre speakers. Couldn't afford it then; can't afford it now. Sigh...

[@mfbfreak]

Voice of the Theatre speakers are amazing. A theatre friend of mine owns a set of those. Saved them from the scrap when one of the places where he worked was getting fully renovated. Sadly he didn't manage to salvage the two tube amps that were used with them... They've been in his basement for about 10 years now. The space is a bit too small for the speakers to get to their full potential. But he keeps them, for that one day that he might get a huge house. After all, once you sell them, you're not likely to find a new pair ever.

[@BobPegram]

Convince him that they are dry rotting or wet rotting in there. then he might part with them. I think that's also a pipe dream. 8-( At least get him to throw a block party with them, plenty of space outside! They should be heard again.

[@624radicalham]

@@mfbfreak Is there a brand of speakers called "Voice Of The Theatre"? I'll Google more info if so. And if so, what does your friend being a "Theater Friend" have anything to do with a brand of speakers? A theater friend. Is that a person that you met in a theater and later became friends with ? Is this person an actor in a theater or a critic? Mentioning what your friend's interest or occupation is should not even be relevant in your comment, much less relevant to the brand of speakers you are mentioning, which happen to have the name theater in them . It's just plain weird and strange.

[@mfbfreak]

Why does it bother you so much? Do you require documentation of the events that transpired, formatted as dry as a court record? Anyway: - Voice of the Theatre is a series of speakers, produced under the Altec Lansing brandname. Considering my reaction was to someone who already knows what they are, i am not gonna write down what they already knew. - Anyone who is quite rich can buy a pair of VOTT's on Ebay. But part of what makes the story interesting is the background of the person who happened to stumble upon them, literally saving them from being thrown in the trash. I know for sure the car enthousiasts i know wouldn't have saved them, nor would the sports enthousiasts have done that.

[@highcastle1]

Voice of the Theatre speakers were made by Altec (Altec/Lansing) during the late 50's to mid 60's. They were their top of the line. They were actually used in a lot of theaters because they were so efficient and could project very high sound levels into big rooms. The unfinished version (i.e., no finished cabinetry or fancy veneer) was made specifically for this use.

[@thecentralscrutinizer5105]

Ohh my... This is a real jewel, looks brand new...SWEEEET!! this is the stereo equipment I'm used to getting wrapped up into..... I'm so jelly ;)

[@Penfold8]

My life has found peace. Mr. carlson put out a new video :-)

[@hi-friaudioman]

This is a beautiful preamp! My best friend from childhood inherited his fathers McIntosh setup and it's beautiful! Heavily used, but loved and truly awesome to behold! I don't know what model(s) they are but it's the whole setup, amp, preamp, tuner, eq... Etc, a whole system.

[@BruceNitroxpro]

Recap. Don't be ridiculous about it staying mint... just DO IT.

[@dennylegendre6048]

Absolutely love vintage McIntosh amps and pre-amp. Proud owner of the C26 preamp and MC2505 Power Amp. I just had them serviced alongside the EQ 101. Music bliss.

[@incredifunk]

If it's not too much to ask, what kind of coin did that Servicing run you? Just curious

[@FarnhamJ07]

Great video as always! I'm particularly happy to see McIntosh gear on your bench. Not only are they amazing, they operate here in the city I live in; Binghamton, NY -- it's pretty awesome seeing it on a nameplate in your video. I wish they were a bit more affordable so I could support local business, but I suppose they probably don't need much help at their prices!

[@TheRadioShop]

Love the old McIntosh gear Paul. Best quality from that time. Thanks for sharing with us.

[@ashpowell9451]

Great work Paul and what a classy unit that is.

[@MrCarlsonsLab]

Thanks Ash!

[@NigelDixon1952]

I just revisited this one after originally watching it when you first released it. I thought I'd gleaned all the goodness the first time around, but I was wrong, I've now gained even more great Mr Carlson knowledge! Paul, your videos are so professionally made, but I'm sure there have to be some bloopers in there somewhere. We've been locked down, socially distanced, and had to run to get the last toilet role on sale. Come on now Paul, let's be seeing some of those out takes!

[@reeltorock]

About 10 years ago, I was lucky enough to own a complete McIntosh set from the late '70s including a C29 preamp. I regret selling them....would have been great candidates for thorough servicing and years of enjoyment. They are really fantastic gear - but priced accordingly.

[@larkincrutcher3424]

Nice video. Mcintosh made great equipment. The front panels are glass with lettering on back side. They never are touched so they don't wear out. I was a McIntosh repairman in the 70's. The equipment was usually shipped with the service manual and schematics. They are readily available. I have done restoration on old MAC power amps and the electrolytics in the signal paths usually had to be replaced.

[@incredifunk]

To correct you, Macintosh MAKES great solid equipment to this day

[@heathwellsNZ]

This sort of issue with controls is pretty common so this is an amazingly helpful/instructional piece on troubleshooting and effecting repair! Cheers heaps Paul!

[@maxnix346]

Thanks for showing me where to look on my C29 for flaws. Is there a video showing how to clean the VR? In the day, McIntosh was known to dissect electronic components to ensure that even if they met electronic specifications they also met specified construction specifications. Obtaining classical McIntosh equipment that was produced while Frank McIntosh still owned the company is rather like purchasing a Ferrari while Enzo was the owner.

[@kennedy67951]

Thank you for spending your time with all .Your very skilled and I enjoy watching you work. Again, thank you.

[@mikeburch2998]

Another great video Paul! You must be remarkably busy with this and your patreon efforts. I just don't know how you do it. But I sure am grateful for everything that you do for us and can't thank you enough.

[@royelectrotechnic8711]

Nice video mr Paul as usual, and surprising a good quality preamp neat and solid design. I know that there is a lot trick and Technic that you wouldn't show in this video, but I Encourage all the viewers to join ongoing course on patreon and you'll fine what you're looking for. Thanks so much again sir.

[@PeterWMeek]

I have a pair of MC-60 amps and matching tube-type preamp (stereo), tuner (monaural), and phono cartridge compensator. My grandfather bought them from Picar in Detroit, back in the 1950s. I used to use them, but I haven't fired them up for 30 or 40 years, and now I'm afraid to just plug them in. I need something like your current-limited Variac setup. (I do have a 15 amp Variac, but not the rest of your setup.) I modified a stereo add-on kit to work with the tuner (without modifying the tuner), so I could receive FM stations in stereo.

[@Neffers_UK]

Mr. Carlson, I have found that when it comes to rubber like materials (say, I dunno, buna-n) a very light oil sparingly applied and wiped off of any excess really does help with the longevity of them. It's like feeding leather, almost. Yes, yes before people jump in, some rubbers especially natural rubbers are adversely affected by oil.

[@rebelba42]

Thank you Paul for sharing your incredible knowledge and experience with us. Unbelievable how much we've learned in the last 18 months in your course. I can't thank your enough for helping me to to get access to this great electronics hobby!

[@MrCarlsonsLab]

You're very welcome Ralf!

[@jasonfoster5560]

Mr. Carlson takes some mighty hefty breaths.

[@patprop74]

Do you open up the VR's, or just shoot contact cleaner inside without opening them ?

[@ELcinegatto87]

Awesome!! I personally like the C28 more since it has the center channel output and volume control. I'm a big fan 3 channel stereo, especially if your system is also your tv speakers the center really helps with dialogue making it sound more like its coming from the tv. It really anchors drums and the stage too in music.These older Macs are amazing with vintage Klipsch's too.

[@majordisappointment8692]

Very nice it's a wonder they command such high prices excellent quality. Thanks

[@InXLsisDeo]

hand made in the USA as well, so no surprise here

[@Wizardofgosz]

Interesting. Toward the end of the video you could see the level meter for your audio reflecting in the shiny panel of the Mac, and every once in a while I saw you hitting the red light. Gain that down a little bit! 🙂

[@djhaloeight]

McIntosh and Mr Carlson’s Lab....I clicked so fast! Can’t go wrong! Beautiful piece of gear and a superb cleaning/checking of the gear. Love it.

[@MichaelLloyd]

Every now and then I come across a low time but old electronic device and the electrolytic caps test fine. I'm always surprised. BTW - I'm a Patreon supporter and I can't recommend it enough. There's a lot of great info there.

[@DeadKoby]

On gear that was made with top shelf components.... stuff that runs on lower voltages like 24v solid state amps usually have a pretty long cap life in my experience.

[@adammorris3082]

haha, While you mentioned how easy it is to get into you just brought back a memory from the late 90's of trying to get into a late 70's/early 80's Bang and Olufsen Beomaster, (pegs and wedges,who thought that was a good idea?),It was like an IQ and lateral thinking test in 1 and if you couldn't pass it without breaking something you shouldn't really be trying to fix it lol. Another good, well explained vid. thank you.All the best.

[@TheMB2333]

Oh YEAH DR. CARLSON. Goin' right to the "favorites" for later! Thx!

[@targetheroj5791]

Fantastic video Mr Carlson! Love seeing high end audio gear of the past!

[@richardyoung4616]

I don't have a clue what you're talking about but it's fun to watch.

[@roderickwhitehead]

Proud owner of 2 pieces of McIntosh gear. I consider them as "lifetime plus" investments... something to be handed down along with the guns.

[@volvo09]

I remember distinctly seeing a big McIntosh amp in an audio store as a kid... I had no idea what they were at the time, and had no idea what money meant (and I didn't know the price anyways, so I wasn't just looking at it because it was expensive) but I stared at it like it was the crown jewels... Only later on did I find out it was a truly fine piece of equipment.

[@elpaso--west7354]

used to have an MC-240 AND AN MX-110--GREAT UNITS however the mx 110 was heavilly modified---had to sell both in 1996--------i have regreted it since..i have a real nicedyna 35 stereo and an lafayette amp both sound great-----tubes 4ever thanx

[@roderickwhitehead]

@@elpaso--west7354 - I bought my MX-110 and MC-240 around 2006. Had the MX-110 recapped and modded up at Audio Classics. Love these units.

[@wokada3444]

Thanks for making these videos Mr. Carlson. Always learn something new I never thought about after all these years of working on electronics! Do more videos on Mcintosh gear, bought my first Mc amp a MC275 a few months ago! :)

[@warrenosborne6044]

I caught the input VU reading your voice. Did you have a mike hooked in?

[@glenngoodale1709]

Why did it Hum so bad ..... it didn't know the words lol Thank you for the content you provide ,I like your joking around :)

[@NebukedNezzer]

I have the McIngtosh C22 Preamp in excellent condition.

[@SIXSTRING63]

The machine shop I used to be a CNC lathe programmer for made standoff's for McIntosh PCB's. They were very picky about the quality of just a standoff so you know they are picky about everything else. Great quality stereo equipment. The old tube amps are legendary.

[@coldfinger459sub0]

Every time I watch one of your videos on audio gear and you go through detailed description of what is quality and what special procedures, devices or shielding was used to enhance the quality and it keeps adding Procedures and components To my beginner hobbyist amplifier and preamplifier builds. I caught the never ending perfection bug.

[@wizzkidelectronics]

Way its supposed to be keep it up

[@585585MC]

it's amazing how such a trained technician with so much equipment doesn't have a microphone capable of handling his S's :)

[@rickdauer5179]

Hello Mr. Carlson, what products do you typically use to restore the functionality of pots and switches?

[@robvandendolder3157]

Thanks for an interesting video. We have McIntosh audio equipment and appreciate the quality. You are very accomplished. 👍😎. Cheers from Australia

[@MrCarlsonsLab]

Thanks for watching!

[@faultlessguitarsandamps1116]

Hi Paul . Am I right in thinking that spraying lots of contact cleaner into a VR can flush the lubricant from the shaft and cause contamination from that , and eventually the shaft might seize also .

[@markstratton3924]

This episode is near and dear to me, I live just across the river in Binghamton, NY where that pre-amp was built.

[@stevewodell6183]

Build quality is second to none

[@guyfromsac1]

One of my favorite of your videos. Nice job Paul.

[@jlastre]

Don't think you mentioned it anywhere so I will, but for people not aware Steve Jobs licensed the name "Macintosh" from this company back in 1983. Apple Computing had just come off the Apple Corp. (The Beatles studio) lawsuit couple years back. The company had initially spelt it different from "McIntosh" to avoid infringement. Jobs had requested use without paying but was declined, and offered payment.

[@drde4010]

Amazing program!

[@kedmark]

Hi Paul, more McIntosh please! Regards and 73’s Karl KE3KWE

[@MrCarlsonsLab]

More to come!

[@nicolasjonasson4820]

This is where the motivation to DIY comes from, for many people. A product with this price tag, with about 10 bucks worth of components for the preamp (as far as I can see, power supply excluded). Yes, transformer, switches and case is where the money is spent. Still, a product with this price tag, with a $10 preamp. I think that is funny somehow.

[@kenbouchard7400]

What is to date the oldest and newest repair item you have worked on. For me it was a 1927 RCA Am Radio TRF, with the speaker that looks like an old fan., Electromagnet. And 3 controls in a wooden box with a hinge,. Had it going on the bench and then due to the age, the power transformer gave up. I think it was that I should have measured the wirewound resitor that wired across the filaments. A shame but the cost to get a job done on it was not practical. This was back in 1982.

[@blackwingmaster141]

I remember reading article about audiophiles and how some of them swear that sound is better if you remove top lead from CD player or some other piece of equipment... But hey, audiophiles just have that magical ability to break the laws of physics :P

[@BruceNitroxpro]

Shhhhhhh! You'll let the truth out and deflate a bunch of egg heads if you talk like that!

[@kaiko3206]

Space shuttle?! So cool!

[@mornecoetzee735]

You should do a Mark Levinson. It will blow your mind!!

[@ct5006360]

hand crafted here in CT.

[@mornecoetzee735]

I am a huge fan of Mark Levinson and currently use their No.32 Ref Pre Amp with 33H Monoblocks. I also owned the 380S, 320S and 326S Marvellous stuff 🎶🎶🎶

[@cattythecat9161]

McIntosh is expensive as heck, but you get a really well made piece of electronics for your money, as you see :)) would be proud to own one of their amps. Btw... I love your lab. Looks like a mad scientists hideout, who does his thing. Love it

[@K8XS]

It would be very helpful if you could show us how you clean VR and switch components. Thank you. Fantastic video as usual.

[@waltwimer2551]

I haven't even had a chance to watch this yet, but I know it will be great! Paul + McIntosh = Awesomeness!

[@waltwimer2551]

My interest in electronics started early. Around age 13 I became really interested in high fidelity audio. At that point I was sure I wanted to pursue electronics professionally when I grew up, and my dream was to work for McIntosh! Oh, what might have been! I never lost my love for audio, but in my mid teens I also discovered computers, right smack in the midst of the microcomputer revolution (late '70s and early '80s). So today, professionally, I'm a computer engineer who mostly writes low-level embedded software that controls computer hardware. But in my free time, I "get my hands dirty" in my home electronics lab. Several of my in-progress projects are hi-fi gear. And now I have far cooler tools and test equipment than I had as a kid! Life is good! Hmmm.... I still need to get some McIntosh equipment someday... :-)

[@erikdenhouter]

The grease on the bushes and axes of the VR's is there to give a smooth feel while adjusting. When not so aged, you could flush that grease all over the carbon path, and effectively grease the carbon to be an attractive collector for dirt. And you will also remove that smooth feel while turning, the axe would rattle loosely in its bush. For that reason I try to disassemble the VR as much as possible, to leave the grease where it is, and only tip it with a drop of oil to get it loose. And then with a cotton clear tip and contact cleaner clean the carbon path. Some VR's are not suited for that treatment, they cannot easily be opened. The same treatment is for turning switches. My conclusion when I saw the crackling output on the scope was : the ground connection of the VR has oxidised or broken loose. The fact that the signal would go maximum was evidence for that. If the carbon path was dirty, and no good connection to the carbon runner could be made, the signal would go to zero.

[@nomon95]

I think the vr was bas adjusted to the case and agree the stain problem. and the carbon path

[@hadireg]

a reference in design example for the Right To Repair!! nice!!

[@rsemrad2]

Dielectric grease to prevent contact oxidation. This is a common practice harsh environments but would it be applicable for the VRs and switches in the C29? Would you explain your answer?

[@AMStationEngineer]

Two "darn big" thumbs up!, to a great video! The most remarkable aspect of this pre-amp, is the exceptional attention paid to the prep, stuffing, and alignment of the PCB components prior to their wave soldering, and touch up, is incredible. The perpendicularity of the components, with regards to their positioning towards each other, is unbelievable. No bare copper, indicates a wave re-flow after a flagrantly apparent 'hand trimming, where each lead can be seen', and no "top hat's" are all indicative of first rate quality. This would have passed "MIL STD 2000 Category C" requirements, with only one possible recommendation: build the wiring harnesses in almost the exact same manner, but use an approved brand and diameter of "nylon lacing cord", especially near the 'breakouts'.

[@nakfan]

Thank you for the video. I was a little disappointed that you didn't show som clips from the cleaning, what kind of cleaner, ways if applying it correctly, etc. But hopefully you will make a follow up video about that. BR, Per (Denmark)

[@richardmiranda5357]

Hello Mr Carlson. In this video, right next to your bench, left side, I see the HP 8551/851 A or B spectrum analyzer but it seems it is not working because the power switch is in ON position, with no sign of be actually ON. Do you have in mind the set up, repair or restoration of this "monster" from the 60's? (I call my 8551/851B, "my monster" because weights almost 100 pounds in total). The thing is that after many many hours of work trying to repair/restore my analyzer, still doesn't work the way it should be. I know it could be a tedious project just but wanted to know if you have any plans to do it. Thank you

[@willierants5880]

Well this customer certainly brought their Preamp to the right place!

[@montygore]

Hi Paul. Nice video. What do you use when a peice of equipment needs cleaning what do you use to really wash out heavy nasty. Thanks W5DN

[@josephf151]

It seems you clearly have a lot of audio equipment knowledge as well, any chance we could get an audio setup tour?

[@369gems]

Great video. Very nice equipment. When cleaning vr's; sometimes they are pretty well sealed. If you get the opportunity, with another cleaning, show how you address cleaning vr's that are very well sealed. Thanks.

[@vincedebart]

Hi Mr Carlson thank you for this great informative video as always detail oriented and very helpful. I have a Mcintosh power amp. I’d like to clean the VU meter sensitivity switch in the front. What kind of contact cleaner would you recommend? Thank you.

[@cengeb]

D5 DeOxit cleans and leaves a lubrication, or blue Shower, no residue , but leaving lube is sometime good on stuff

[@cengeb]

Modern chassis tape the mount areas, so there is no painted insulated areas during mfg,. lots of my stuff has unpainted round screws inside chassis to maintain grnd ckts

[@K8XS]

I wish you had shown how you clean the VRs for pass #1 and pass #2. The would have eliminated any guessing on my part. I hope you understand what I mean. Thank you Paul.

[@johnricci4511]

Very cool...I grew up in a McIntosh/Klipsch houuse with Lascalas/Khorns!

[@StewartMarkley]

John Ricci Lucky you. Can’t go wrong with that stuff.

[@LestonDr]

Great timing... have a C23 and MA6100 waiting on the nerve to climb inside...

[@smallenginedude71]

i dream to own a mcintosh amplifier. Id love a MC275. fantastic video

[@kevincampbell8004]

paul...what was the name and number of the MG Chemicals Contact Cleaner with the gold band you use to clean your radio receivers....I think it had a Gold or Red band?

[@orpiv]

I have a C29 and It is as wonderful sounding as its build quality..

[@orpiv]

2205 here too?

[@orpiv]

@Larry Niles Thanks .. You as well!