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MC2105 Restore Kit

ChoppieChops

ChoppieChops

New Member
Hey guys, I've been toying with the idea of selling my MC2105 and C29 and keeping my C30 and looking for a nice tube amp, maybe MC240 or MC230. Looking at the prices on those, I've given up. Now I'm on the mission of getting what I have tuned up nicely. I'm looking for a kit to do a restore on the MC2105. I see one on ebay for around 375.00. If I'm going down this path, I'm doing the full kit, not going to REVISIT THIS PROJECT AGAIN IN MY LIFETIME...

I watched a 9 part youtube series where a guy went all the way and made his MC2105 perfect again. He mentioned that not all parts are the same for all the MC2105 amps and that it all depends on the SN number of the amp and just what version it is....

If I post my SN here, can I get some help in locating what I need.....

Thanks everyone....awesome forum going on here...
 
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Do you mean Mc240 or Mc225, there is no Mc230 (there is a MA230 integrated). As far as help from AK members, help is always given to those who ask.
 
I hate to be a "Debbie Downer", but buying some kit, and hopes of any of that doing the trick is in essence a lot of good money just thrown to the wind.

Playing a Craps Game, and tossing the Dice.

In a nutshell it ultimately comes down to replacing parts that didn't need replacing, and not replacing the parts that did. Then doing further tune in adjustments, bias, etc, etc.

In the Mechanical world, I would refer to that as a "Brown Bag Mechanic". Meaning some dealer goof who runs to the parts counter all day long swapping out different parts on a wild guess to fix some problem.

Find a highly competent tech, and go from there is the best bet IMO.
 
McIntosh used top quality components, which in addition to their engineering is a prime factor in how long this equipment reliably sounds outstanding. The eBay kits? Who knows where the components are sourced.

Better, in my opinion, is to go make a list of what you need from the service manual and hit up Mouser, Newark, or Allied for quality components.

Best, in my opinion, is unless you see a failure, evidence of capacitors leaking, or deteriorating sound is to leave it alone - or, as noted above, seek out a good tech. Audiokarma is full of threads where guys have embarked upon a probably unnecessary recap only to cause other problems and are now seeking help.

Pursuit of "better" is often the ardent enemy of "good enough".
 
If you're looking at the kits from hifiaudio please look for reviews on these forums regarding him and his previous captanfantastic handle. I would recomend against it.

As above, I agree that an MC2105 is only good if it is left alone, or properly restored. An ebay kit restoration is not going to improve its reliability.
 
Background on me;
I'm the type of person that becomes "intimate" with any newly discovered hobby; I can tell you everything you could possibly want to know about back yard beekeeping, and I've only been doing it for 9 years, for example. Took apart a small block chevy engine, one year later had it running 450 horse power...twisting a drive shaft in half when I was 22 years old. When I was 18 I had a nice Marantz receiver and a Tequneques turn table in the late 70s, then went into the NAVY for 12 years....now I'm 60 and finding myself wishing I was 20 again...and loving the simplicity of that time... I work for a custom home theater company...been in business since 1974... I've got about 20 NICE receivers that were pulled from upgrade jobs...Denon, Yamaha, Integra, Lexicon,...all way too complicated for me...I like the simple gear. Trying to find a consignment shop in the West Palm Beach area to dump it all...I might get 40 bucks a pop for what once was a 900 dollar unit.... Everyone wanted to add HDMI switching..which some of these didn't have... Now we're moving to 8k bandwidth HDMI cables.

When I get attached to a "new found hobby" I research it forever...

I've watched all the vintage audio gear restoration videos from the guys that its their life messing with this gear. Two if my favorites below;

Flux Condenser Vintage Audio Electronics

Mr Carlson's Lab

The resounding theme across them all...is....REPLACE THE OLD CRAP that is KNOWN TO GO BAD because when it's pushing 40 PLUS YEARS OLD....and if your in there already.... DO IT using higher quality parts! These guys do this for a living for MANY years, how is it that they could be wrong? Asking for a friend...(just kidding) but you guys get the idea...

The only kit I found on ebay is

The seller has over 5,900 transactions with a 99% rating...

Deluxe Refurbish Kit McIntosh MC2105 MC-2105 Amplifier

This is the description

This Introduces our own line of high quality can capacitors. In this case the 13/8 High voltage can Unavailable new. 105C operating temperature. These are custom made and fully tested.

All NEW PARTS. NO OLD JUNK OTHER KITS HAVE. We Test all capacitors for ESR, Capacitance value and Leakage during HiPot.
Note:
The large Filter Cans we supply vary by what our supply chains can provide. We only buy from reputable vendors. They vary in height from 3.5" to 4.25". Diameter is 3" on all. Values vary from 41000 to 56000 all at 50V DC. (The orignal caps are under rated).

FREE TECHNICAL SUPPORT WITH KIT PURCHASE

From the original suppliers of refurbish kits. We started it and continue to offer them. We are always adding kits so please follow us.

If you have purchased a McIntosh MC 2105 and have not changed the power supply or audio capacitors, the amplifier is not performing to its full capability.

Please read the Disclaimer below before purchasing.

Our MC 2105 Refurbish Kit includes All power supply twist lock and screw terminal that fit physically into the space of the originals. No drilling no clamps. The screw terminal capacitors are higher capacitance than originals. Bass response is tight and fast.

We supply all Audio capacitors and sub power supply capacitors as well. Only the finest polypropylene electrolytic and non polarized electrolytic capacitors are supplied. Thermistors included. Power supply resistors included

We also include heavy duty diodes for the high voltage section. (4)1866 and (4)1888 bulbs are included. Led bulbs just don’t cut it for the original look. We restore these regularly so we know what’s needed and supply unlimited technical support.

Everything needed to fully electrically restore your MC2105. The best Solid State amp McIntosh ever made.

For those not qualified to install the kit we offer a restoration service as well. Only buy this kit if you are experienced. If you need instructions you may not be qualified. Don’t be fooled by competitors kits they are not complete like this kit
 
w3jn said:
McIntosh used top quality components, which in addition to their engineering is a prime factor in how long this equipment reliably sounds outstanding."..
Click to expand...

Top quality electronic components from 1968? Compare them to medium quality Japanese equivalents in 2023? 50 years of R&D and new materials being engineered and used and proven 100 times better in all regards? Just my logical opinion...

I AM a purest, 100 percent! If I could set up some 70's McIntosh gear with a nice turn table and a DVD player on AUX one, and my computer on Tape one.....and know all the STUFF inside those nice boxes is running just fine, not perfect but just good and will for the remainder if my life....I'd be happy....but they're 50 years old....and it doesn't seem it would be so. I'd like to (set it and forget it)!

Being a purest, I will 100 percent save ALL THE REMOVED ORIGINAL caps and such and store them in a small cardboard box with model number and SN and date they were remove from said unit.... sandwich bag would seal in the leaking gasses and could speed up the decay of the original caps....should some one 80 years from NOW decide to put them back and enjoy true purism....

I understand the "if it ain't broke don't fix it" mentality, but I'm of the mentality of replace the timing belt while your in there replacing the water pump.....and get that UP COMING MONKEY ON YOUR BACK....OFF your back....and don't look back

Anyway, if anyone has any specific information regarding specific parts needed for re-cap based on SN number or version number of MC2105, would love it if I can be pointed in correct direction...

thanks guys.
 
Not sure what prompted the aggressive response, but I think you've misunderstood my point. I'm not proposing keeping old components for the sake of being a purist; rather, the high quality components McIntosh used demonstrably last years and years, with very few failures.

The skills and tools involved in rebuilding a Chevy 350 are different than working on this gear. Do whatever you like with your gear, I'm just trying to steer you with the benefit of 50 years of doing this.
 
Ebay doesn't charge for words, and negative feedback can be removed, caveat emptor

This vendor might be very good and I have no idea who it is nor do I care, just do your own research and don't depend on how many widgets he has sold over 20 years without looking into it a bit, all I'll say on that subject.

I agree with @w3jn that there are components that don't need replacing, I have verified proper operating condition of many components in vintage McIntosh amps and left them in place, some items such as the Sprague flim caps really don't need replacing for example unless they're damaged. Transistors if still operating correctly and matching (if you can curve-trace and test under load) can be left in place, etc. If it doesn't need to be replaced it's your choice whether to do so anyway.

I also have gone completely through amps, just because, and replaced pretty much everything with the correct replacements (which is another discussion as so many Techs today feel that they can use different type resistors, capacitors, etc. and it'll be "better") and then keep the original in a box, ... and I like the result.

I've also had more new tubes and transistors fail than old ones, so there's that.

Your equipment, your choice, don't need to justify it here.
 
Agreed. New incandescent bulbs and glass fuses just SUCK in comparison to stuff you could buy 10, 20, or 30 years ago. So then, why would we think new capacitors would be any different? Standards? Lol ... it's all about cheap and profit.
 
I'm just gonna throw my hat in the ring here...those kits on ebay are all trash. Source your own parts from Mouser, Digikey, and Newark. Use high quality Nichicon PW KL or Panasonic FC series for small caps and United Chemicon E36Ds or CDE for the main filters. I've been doing this for well over a decade and can't tell you the number of times a customer has brought me a captain fantastic kit from ebay and I've told them to send it back or throw it in the trash.. the components were all over the place, wrong values, mixed brands, mixed specs, no thought given to quality. Additionally, I purchased one of his volume pots for a C27 restoration....it was an absolute pile of flaming garbage that did not even fit properly (shaft too long, D cut too shallow, clocked wrong, power switch not metal or able to be shielded) The left/right tracking was abysmal...one channel would be blaring before the other was even audible. I ended up ordering a used pot from Mc labs and made it work.
 
SaturationPt said:
Ebay doesn't charge for words, and negative feedback can be removed, caveat emptor

This vendor might be very good and I have no idea who it is nor do I care, just do your own research and don't depend on how many widgets he has sold over 20 years without looking into it a bit, all I'll say on that subject.

I agree with @w3jn that there are components that don't need replacing, I have verified proper operating condition of many components in vintage McIntosh amps and left them in place, some items such as the Sprague flim caps really don't need replacing for example unless they're damaged. Transistors if still operating correctly and matching (if you can curve-trace and test under load) can be left in place, etc. If it doesn't need to be replaced it's your choice whether to do so anyway.

I also have gone completely through amps, just because, and replaced pretty much everything with the correct replacements (which is another discussion as so many Techs today feel that they can use different type resistors, capacitors, etc. and it'll be "better") and then keep the original in a box, ... and I like the result.

I've also had more new tubes and transistors fail than old ones, so there's that.

Your equipment, your choice, don't need to justify it here.
Click to expand...

One thing I have to disagree with here. I've been having a flood of vintage gear come through my shop with transistors that test just fine but are either horribly noisy or intermittently noisy. As our gear is aging, there is an increasing rate of transistor failure due to black leg disease (silver impurities) creeping inside the die. I've had on a number of occasions a McIntosh 2105 or similar that would have intermittent static that was coming from one of its original high quality Motorola transistors that had gone noisy at random intervals. Changing them all out for a modern low noise equivalent made the amp be quiet with a much lower noise floor. Using NOS off the shelf transistors isn't going to do much good either as it is mostly an age related oxidation and internal impurity issue. YMMV of course and not all situations are the same.
 
Thespeakerdude8 said:
One thing I have to disagree with here. I've been having a flood of vintage gear come through my shop with transistors that test just fine but are either horribly noisy or intermittently noisy. As our gear is aging, there is an increasing rate of transistor failure due to black leg disease (silver impurities) creeping inside the die. I've had on a number of occasions a McIntosh 2105 or similar that would have intermittent static that was coming from one of its original high quality Motorola transistors that had gone noisy at random intervals. Changing them all out for a modern low noise equivalent made the amp be quiet with a much lower noise floor. Using NOS off the shelf transistors isn't going to do much good either as it is mostly an age related oxidation and internal impurity issue. YMMV of course and not all situations are the same.
Click to expand...

I'd have to say "truth be told". There's lots of tricks and foolios out there, just not only with old components not good, the wise know neither is some of the newer. Hard choices.

And to sift through who really knows all the differences, and who doesn't?
Sad for many that it becomes a Hail Mary event, and pray for the best.
 
Sounds like you want to do the work yourself. Cool...I like to do my own work too. There is a learning curve to everything but if you are careful the mistakes you make can be mitigated to things like:
  1. taking too long (but your labor is yours so no big deal)
  2. Making multiple orders and paying extra shipping as you get deeper into it
  3. doing things twice
But that does not mean that you can't end up with a great job and the satisfaction of doing it yourself, and doing it right in the end.

Don't buy the kit! There are always part choice and availability issues. Don't let someone selling a kit make the hard calls for you. you will learn a lot less and you will get some cheaper parts for more money than if you bought them yourself. Digikey, Mouser, Hayseed Hamfest, McIntosh factory, are better options.
See:
https://audiokarma.org/forums/index.php?threads/mc2105-rebuild.894616/

https://audiokarma.org/forums/index.php?threads/mc2105-restore-to-former-glory-parts-list.992160/

You can also search for posts on the MC-2100 as the circuit is the same except for the Meters.

Start with downloading schematics for all the versions you can find, then cleaning and figuring out which schematic matches yours. By the time you do just that you will know a lot more about the amp.
Good Luck! and keep us posted.
 
I bought one of those kits years ago from ebay for my MX113. The parts were all lowest cost stuff and after doing the power supply, I chucked the rest and did what I have done with all the rest of the gear I've restored... I use a caliper to measure size and lead spacing of components and buy the best I can find from Mouser or Digikey to replace for exact fit. You'd be surprised how inexpensive capacitors and resistors are. What I've found for the most part, it's the smaller electrolytic capacitors and high value resistors that are out of spec but it doesn't take much longer to do a complete job. Read the threads here on Audiokarma and get an idea of capacitor and resistor brands/types and really do it yourself. For the can caps, there are some replacements available, or if you're like me, you can empty out the can caps and fit discrete components inside for the look.
 
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