lonewhitefly
Active member
that machine is a real work of art !
sweetbeats
Reel deep thoughts...
Gutting the parts transport out...
M
Muckelroy
Member
Nice transport. I feel moved. Transported even.
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.
O
ofajen
Daddy-O Daddy-O Baby
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
jpmorris
Tape Wolf
Is there anything actually amiss with the audio circuitry, or were they just removed to help isolate the transport problems?
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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sweetbeats
Reel deep thoughts...
Goodness…over five years since I posted anything on this thread. I, naturally, still have the M64. It still needs going through. But I’m prepping to send the two headblock assemblies off to John French for evaluations and some advice on what to do. One assembly has original 3M heads, likely have been relapped at least once, and the setup wasn’t done by John and I’m not going to name the vendor but it was a terrible setup…wrap is off on all the heads I believe and significantly so on one of them…and the zenith is off on at least a couple of them. So I don’t even know if they can be relapped if that’s the set to use. See, I’m trying to determine which set has better performance potential. So there’s the OEM 3M assembly with the jacked-up setup and significant wear, and then there’s an assembly with SAKI erase and record heads and some unknown make of reproduce head…maybe Nortronics? It’s a small head…and it’s in a fancy little carriage so it can mount properly to the 3M base. It has a JRF sticker on it, so I know whatever it is it’s proper, but it looks like something somebody did as a quality but budget solution when the original heads reached the end of their service life. SAKI was an OEM provider for a number of companies. They make quality heads and the two that are in my assembly are ferrite type, so longer wearing. But the repro head is going to have some sonic limitations because of the smaller size and therefore limited tape-to-head profile. The SAKI heads look really good…I’m thinking the SAKI assembly is probably overall the winner, but I’m also thinking a different repro head will need to be part of the equation. Anyway, all TBD at this point. But I’m going to send them both off to John and see what he says.
It’s been awhile since I opened up the transport…the dress panel and a couple other bits come off in order to remove the plug-in headblock assembly. Can we all just take a moment to appreciate the beef of this transport? Look at the precision cast transport plate…it’s 1.5” thick…
And I’ll leave you with an overhead shot of the two headblock assemblies…
It’s been awhile since I opened up the transport…the dress panel and a couple other bits come off in order to remove the plug-in headblock assembly. Can we all just take a moment to appreciate the beef of this transport? Look at the precision cast transport plate…it’s 1.5” thick…
And I’ll leave you with an overhead shot of the two headblock assemblies…
sweetbeats
Reel deep thoughts...
So, many moons later…
I sent both headblock assemblies to John French…there were issues with both. I’ll talk about the assembly with the original 3M heads first. That’s the one on the left in the picture of the two assemblies in my last post. I was right…significant wear, significantly poor setup or it was setup right and somebody messed it up…anyway, real shame because it’s all original but it just didn’t make economic sense to invest in the OEM 3M assembly, which I expected. The wrap angle was so far off on one of the heads, the amount of lapping required to refresh the surface and correct the profile, coupled with the existing wear, would have left very little tip depth. So that assembly is back here and it goes in the parts drawer. Now for the SAKI assembly…again, SAKI made good quality OEM replacement heads, and was an OEM supplier for a number of companies, including 3M. The erase and record heads on my assembly are ferrite, which are much longer lasting than metal core heads. People say they can’t be relapped. But John French can do it. Remember in my last post I said the reproduce head was a small unknown make of head in a carriage to adapt it to the 3M assembly, and it had a JRF sticker. John looked in his records and couldn’t find the job order, but because of the address on the sticker it was a long time ago…previous location. And when I talked to him he was surprised it had a JRF sticker because he basically felt like pulling a small aftermarket repro head off the shelf and putting in an adapter like that on a 3M Mincom halftrack is not something he would do. So we figured it was probably a situation where John had a reasonable/typical recommendation for the scenario and the customer demanded a very budget solution. I told John we needed to reverse that. He pulled it apart and discovered it was a Panasonic head. I’m sure good quality, but “pro-sumer” grade and a really small coil in terms of the profile compared to the OEM head…which would really limit LF response. So John set to work to find something there that would work. Ultimately he found a matching SAKI reproduce head. The problem was it was for an M79…same size and type of head, but different mounting pattern. I don’t know what he did, but he was able to adapt it to the M64 assembly with zero hinky-factor. The existing erase and record heads had very little wear, but the wrap on the record head was slightly off, and there was a little bit of pitting…so the best thing was to lap them and dial them in…done. The repro head is new, the erase and record heads are around 75%, and, again, ferrite heads last much longer than metal core heads. Here it is…glad to have it back and have the M64 back together:
I sent both headblock assemblies to John French…there were issues with both. I’ll talk about the assembly with the original 3M heads first. That’s the one on the left in the picture of the two assemblies in my last post. I was right…significant wear, significantly poor setup or it was setup right and somebody messed it up…anyway, real shame because it’s all original but it just didn’t make economic sense to invest in the OEM 3M assembly, which I expected. The wrap angle was so far off on one of the heads, the amount of lapping required to refresh the surface and correct the profile, coupled with the existing wear, would have left very little tip depth. So that assembly is back here and it goes in the parts drawer. Now for the SAKI assembly…again, SAKI made good quality OEM replacement heads, and was an OEM supplier for a number of companies, including 3M. The erase and record heads on my assembly are ferrite, which are much longer lasting than metal core heads. People say they can’t be relapped. But John French can do it. Remember in my last post I said the reproduce head was a small unknown make of head in a carriage to adapt it to the 3M assembly, and it had a JRF sticker. John looked in his records and couldn’t find the job order, but because of the address on the sticker it was a long time ago…previous location. And when I talked to him he was surprised it had a JRF sticker because he basically felt like pulling a small aftermarket repro head off the shelf and putting in an adapter like that on a 3M Mincom halftrack is not something he would do. So we figured it was probably a situation where John had a reasonable/typical recommendation for the scenario and the customer demanded a very budget solution. I told John we needed to reverse that. He pulled it apart and discovered it was a Panasonic head. I’m sure good quality, but “pro-sumer” grade and a really small coil in terms of the profile compared to the OEM head…which would really limit LF response. So John set to work to find something there that would work. Ultimately he found a matching SAKI reproduce head. The problem was it was for an M79…same size and type of head, but different mounting pattern. I don’t know what he did, but he was able to adapt it to the M64 assembly with zero hinky-factor. The existing erase and record heads had very little wear, but the wrap on the record head was slightly off, and there was a little bit of pitting…so the best thing was to lap them and dial them in…done. The repro head is new, the erase and record heads are around 75%, and, again, ferrite heads last much longer than metal core heads. Here it is…glad to have it back and have the M64 back together: