lonewhitefly
Active member
that machine is a real work of art !
3M M64 Halftrack
- Thread starter sweetbeats
- Start date
sweetbeats
Reel deep thoughts...
Gutting the parts transport out...
sweetbeats
Reel deep thoughts...
Once everything is removed from the transport casting (the 2" thick webbed aluminum casting) I'm going to mount it to the wall in the studio as a knick-knack shelf.
Everything is really, really nice on this transport. Grossly over-engineered in every way, ultra-high quality components, and lovely and innovative design engineering. I love that it possesses a very effective mechanical constant tension system and wow and flutter specs that best even the most modern of transports, and note 3Ms method of measuring included record and playback wow and flutter! If you look closely or dig deeper you'll find in most cases wow and flutter specs of a machine are based on playback only (using an ultra precise wow and flutter test tape...3M published the spec of tone recorded to and reproduced from the same machine). And this is a machine made in the 60s...and actually im not sure how far back it goes as far as when the M-23 was produced. Brilliant. So, lovely transport, and it is coupled with some amazing electronics...I/O coupled by HUGE transformers, all discrete, relatively huge dedicated power supply for each channel, and the amp design actually has heritage in a mondo-mojo brand/model. I have information from an individual that was in engineering and design with this line of 3M machine who cites from where the amp design was "borrowed".
Everything is really, really nice on this transport. Grossly over-engineered in every way, ultra-high quality components, and lovely and innovative design engineering. I love that it possesses a very effective mechanical constant tension system and wow and flutter specs that best even the most modern of transports, and note 3Ms method of measuring included record and playback wow and flutter! If you look closely or dig deeper you'll find in most cases wow and flutter specs of a machine are based on playback only (using an ultra precise wow and flutter test tape...3M published the spec of tone recorded to and reproduced from the same machine). And this is a machine made in the 60s...and actually im not sure how far back it goes as far as when the M-23 was produced. Brilliant. So, lovely transport, and it is coupled with some amazing electronics...I/O coupled by HUGE transformers, all discrete, relatively huge dedicated power supply for each channel, and the amp design actually has heritage in a mondo-mojo brand/model. I have information from an individual that was in engineering and design with this line of 3M machine who cites from where the amp design was "borrowed".
sweetbeats
Reel deep thoughts...
And and AND...3M did it with NO scrape flutter idlers. The tape path is so simple.
sweetbeats
Reel deep thoughts...
Yes.
It's been almost 4 years since I posted to this thread.
But the M64 has tagged along through all the moving, and sits in different corners or closets since there's no room for it in the bedroom that's combined office, crafting, games, drums, guitars, and electronic vomit that's in various states of repair/disrepair.
And the M64 remains in a various state of disrepair. I recall back in 2013 threading tape and it wasn't working right. I have a video somewhere of the problem...I'll have to watch it to refresh my memory, but I think there was a loop that would keep developing on the takeup side. Somehow I got ahold of Dale Manquen (who passed away not too long ago
...RIP Dale), and he watched the video and directed me to check a couple electrolytic caps on the logic board that control the timing of takeup tensions and such. When I pulled the logic board I could see for one of the caps there were two caps piggy-backed...the cap is supposed to be one 250uF and these two caps were 50uF each (in parallel so 100uF total...not enough), so I ordered replacements for both of the lytics and then life got nutty. I finally put them in last eve.
I still really like this machine.
The logic board is easy to pull out...there are three screws to remove on the back of the chassis and then the board unplugs and out it comes.
You can see the two orange piggy-backed caps above the relays there...
When I removed them I could see somebody tested the caps before putting them in and wrote the actual capacitance measured at the time on them, but that only totals 135uF...still not enough...not sure what the thinking was there.
Anyway, new caps are in...I need to find a 1/4" NAB takeup reel and a reel of 1/4" tape in all the hodge-lodge here to try it out now and see if it's any better.
It's been almost 4 years since I posted to this thread.
But the M64 has tagged along through all the moving, and sits in different corners or closets since there's no room for it in the bedroom that's combined office, crafting, games, drums, guitars, and electronic vomit that's in various states of repair/disrepair.
And the M64 remains in a various state of disrepair. I recall back in 2013 threading tape and it wasn't working right. I have a video somewhere of the problem...I'll have to watch it to refresh my memory, but I think there was a loop that would keep developing on the takeup side. Somehow I got ahold of Dale Manquen (who passed away not too long ago
...RIP Dale), and he watched the video and directed me to check a couple electrolytic caps on the logic board that control the timing of takeup tensions and such. When I pulled the logic board I could see for one of the caps there were two caps piggy-backed...the cap is supposed to be one 250uF and these two caps were 50uF each (in parallel so 100uF total...not enough), so I ordered replacements for both of the lytics and then life got nutty. I finally put them in last eve. I still really like this machine.
The logic board is easy to pull out...there are three screws to remove on the back of the chassis and then the board unplugs and out it comes.
You can see the two orange piggy-backed caps above the relays there...
When I removed them I could see somebody tested the caps before putting them in and wrote the actual capacitance measured at the time on them, but that only totals 135uF...still not enough...not sure what the thinking was there.
Anyway, new caps are in...I need to find a 1/4" NAB takeup reel and a reel of 1/4" tape in all the hodge-lodge here to try it out now and see if it's any better.
sweetbeats
Reel deep thoughts...
I'm very sorry to hear that Dale has passed away. He was a great resource for those using the 3M machines. Also glad to see that you still have the M-64. I sold my last 3M a few years back and now have only a pair of little Otari machines, and I'm sure both machines wish I would record stuff more often.
Otto
Otto
sweetbeats
Reel deep thoughts...
Finally tested the transport to see if the caps I replaced on the logic board helped with the tape handling problem...it’s definitely improved. There is still work to do, but I’ve done nothing yet as far as setting up the transport on this machine and I think the issue that remains as far as the momentary tape slack on the takeup side when I hit PLAY has to do with adjustments in the timing of the pinch rollers and when they each engage the capstan. Short video here:
YouTube
YouTube
sweetbeats
Reel deep thoughts...
No they're complete and in very clean and very original condition. I'm just trying to get the transport working tip-top first so have not connected them to the transport. Everything is there...all the cabling, cards, etc. Have lots of spares too. I know they will need to be recapped because they have a number of the old Beaver brand paper can electrolytics on them that were not so good when new, and these are now pushing 50 years old...notorious for leaking/drying out. I even have some good guidance from emails and notes from phone conversation I had with Dale Manqeen before he passed away a few years ago regarding the recap...beneficial changes to some of the cap values that can be accommodated with more modern caps that are physically smaller in size relative to capacitance value...he was a brilliant man who used to work for 3M...was integral if not the primary innovator in the development of the M56 for instance...
sweetbeats
Reel deep thoughts...
Not much of an update per se, but I like this sort of thing...found an original M64 manual in original 3M binder on Reverb for a reasonable price. Rare as “hen’s teeth” I suppose. I have good quality PDF versions of the 400-series manual (aka M23) and 500-series manual (aka M56) which are extremely similar to the M64, but there are differences and I’ve never located a PDF of the 410-series (aka M64)...or hard copy for that matter! The seller indicated the one I bought is complete, unmarked and in excellent condition...I’m happy I stumbled upon it.
sweetbeats
Reel deep thoughts...
Sometimes its the little things...I got the manual this past weekend. It is indeed in excellent condition...like, were it not for the yellowing of the paper (which is to be expected at nearly 50 years of age), I wouldn't know this manual didn't just come out of the carton of a brand new machine. Absolutely no marking on any pages, all pages accounted for, not even a dog-eared page to be found...the binder, after a little sweetbeats treatment, is spotless, and the binder hardware shiny chrome. This is the cleanest vintage manual I have ever seen:
Check it out...it even has the original warranty registration card still intact!
And this manual has the LONGEST fold-out schematic page I've ever seen...how am I supposed to scan that in as one page?!
Anyway, just thought I'd share...very pleased to have the matching manual to my M64.
Check it out...it even has the original warranty registration card still intact!
And this manual has the LONGEST fold-out schematic page I've ever seen...how am I supposed to scan that in as one page?!
Anyway, just thought I'd share...very pleased to have the matching manual to my M64.
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