3M M64 Halftrack

[The Ghost of FM]

HAHAHA!! That's sweet, Jeff! Heheh!

Say...can you get me the other "3M" logo meter you got for the photo shoot? Heeheee.

The other 3M logo meter? It basically came from the 3rd dark faced channel which I edited out of the collage. I would have used it but the perspective angle was too low.

Anyway, glad it gave you a smile.

Cheers!

PS, if you take some additional angled shots of the transport, I could build that into a top loader cart design...for fun.

 

[sweetbeats]

Oh I knew you kiped the "3M" logo meter from the darker single electronics unit. I'm just bein' goofy.

Yeah I'm sure there will be more pics at some point...all the stuff is here but I haven't edven opened the boxes yet. I feel I need to get the Ampex stuff boxed up and out of here AND fix my BR-20T before even cracking open the cases. Just trying to exercise some discipline because I know I'll want to tinker with the 3M but I owe my friend his end of the bargain first and I already have a halftrack that is in the midst of being fixed and I think it unwise to open something else. Period. But we'll get there eventually.

 

[ofajen]

These machines came from the factory either mounted in the factory console (see the pics of my original machine at the top of the thread), or naked like this new one for rack mounting, and i suppose you could put them in road cases too but i don't believe 3M had factory cases available for these machine unlike Ampex for many of their period machines.

Actually, they did sell very nice portable cases with internal suspension for use with the 19" rack width units. Mitch Easter has a 4-track M-23 like that that I've wanted to buy for a decade, but he has clients who insist on recording "old school" with a pair of 4-track machines and so he won't sell.

Cheers,

Otto

 

[sweetbeats]

Thanks for the clarification, Otto...i should've asked.

Do you know if the cases were an in-house item or outsourced?

 

[sweetbeats]

Got it...

Its in really good shape considering its age. The headblock is a bit funky, but its functional and the rest of the machine is complete and uncannily clean. And...it is indeed an M-64, so I have a good machine and I can use the original one I got as a parts machine. I don't know if the one I just got is 15/30 or 7.5/15 but I'll find out soon enough. The pinch rollers look healthy...its just a good solid machine. And the electronics are what I suspected: 1 is original to the machine (i.e. M-64 standard issue) and the other two purchased later by the seller are M-23. They are very similar and either will work with the transport. All the modules have all the cards and ALL the cards look strangely un-messed-with. That means there may be some work to do on them (or maybe not) but for SURE I'm not dealing with somebody else's hacks. Same goes for the transport; it just looks...original. The electronics modules are pretty clean too especially the one original to the transport...seriously...I could take about 15 minutes to it and I bet it could be mistaken for new...its that clean. There is an uncommonly low amount of dust on all this stuff.

So it hasn't been powered up yet, but here are some more pics in no particular order. I feel the same way about this transport as I did/do my Ampex MM-1000. I suspect I will be selling my Tascam BR-20T at some point as I believe the 3M is my halftrack.

Shot of the capstan, reversing idler (peeking out), guides, pinch rollers, lifters, etc. The guides and lifters indicate low mileage:

Clean chunky buttons:

More controls...and the 3M nameplate slides over to reveal the output select and power buttons...like a safety cover:

Those aren't scratches on the control escutcheon BTW...its like grease pencil marks or something...rubs right off.

Overall shot...note that the guide/pinch roller covers are off as well as the headblock:

The underbelly...there is just no corrosion anywhere...and again note that there are no brakes on this thing. And that gihugic thing under the cover top center is the capstan flywheel:

Proof of model is in the puddin':

Look at how clean the transport control buttons are from the underside...and I love that thick-thick webbed transport plate casting...the epitome of overkill:

Another shot of the casting with a finger for perspective...and look at the fan...normally that thing would be caked with dust and grime:

This came with it...a 2-track Saki record head. Its big. Too big to fit on the M-64 headblock...I've got a question out to the seller regarding what the story is on this thing:

And the plug-in headblock with Saki erase and record heads and relapped Otari reproduce head. There are funky guide tabs on the erase and record heads...they look suspicious to me. Fortunately I have the stock block and heads on my other M-64 to compare. My understanding is that this block, funky as it may be, is ready to work according to John French and I'm going to trust that, but I may have the stock block lapped and setup at some point, and the repro head may be shot so I may put a Flux head there...or I may do none of that, but the options are there. Intricate block casting, precision locating pins, etc. Just a neat piece of machining:

Found a homebrew extender card in one of the electronics modules...kinda scary.

That's it for now. I'll put up some pics of the electronics later.

Ofajen has been quietly touting his M-23 and the 3M machines for years now. I get it. Very well-designed and engineered. They were ahead of their time and well over-built. Sonically I imagine they are akin to the Ampex machines of the era, but with all due respect my M-64 makes a 440 transport look light-duty, which is not a slam on the 440...I had the same experience when I first laid hands on a 440 transport after working with so many Tascam machines...and that's not a slam on the Tascam machines either. Its just a different engineering standard but me likey over-built stuff so...

 

[ofajen]

Ofajen has been quietly touting his M-23 and the 3M machines for years now. I get it. Very well-designed and engineered. They were ahead of their time and well over-built. Sonically I imagine they are akin to the Ampex machines of the era, but with all due respect my M-64 makes a 440 transport look light-duty, which is not a slam on the 440...I had the same experience when I first laid hands on a 440 transport after working with so many Tascam machines...and that's not a slam on the Tascam machines either. Its just a different engineering standard but me likey over-built stuff so...

Yeah, I used to have an AG-440 along with two M-79s, an M-56 and the various parts of the M-23 lurking in the corner. The AG-440, a perfectly solid machine for many purposes, always struck me as a boy among men next to the 3Ms that were state of the art machines used for studio tracking, mixing and mastering.

BTW, that looks like a very good machine. If you need help identifying cards, send me the numbers and I should be able to look them up.

Cheers,

Otto

 

[sweetbeats]

Thanks, Otto. I'm going to take you up on that. Actually what I'll do is make a list in this thread with the electronics chassis part number and then the cards installed and their part numbers.

I need to go back and look at an earlier post of yours that outlined the purposes of the cards in the modules. It will take a little acclimating because I originally come from a world of one card for all functions, and then it was a shift moving to the Ampex 440 stuff which has 3 cards, and there are 5 in the M-23/M-64 modules. I think I have them figured out as to function but the labeling nomenclature isn't solid for me yet. Top-notch stuff though...serious hardware.

Hey, Otto...do your reel spindles rotate at all eccentrically? Both my M-64 transports have some axial and radial eccentricity and I didn't know if that was normal or not. I'm assuming not, but I'm looking for affirmation to fuel my inclination that I'm going to need to do some shaft straightening like I did on the motors in my Ampex 440-8 way back when.

 

[The Ghost of FM]

I couldn't resist messing around with a couple of the pictures that Cory just posted and decided to try and build a cabinet for them!

Full sized image here;

https://i66.photobucket.com/albums/h250/thefontmeister/3Mtopdownmedium.jpg



I had a problem with the carpet reflections on the channel amps but, oh well.

Cheers!

 

[sweetbeats]

Otto, here is the info for all 25 cards as well as the electronics chassis p/n's...i denoted each chassis with the specific transport with which they came to me just so I can keep track (i.e. M-64 #1 vs #2):

Electronics chassis #1 (M-64 #1) p/n 64059A010
Card "1" p/n 23059B020
Card "3N" p/n 23059B030
Card "4" p/n 23059C040
Card "6" p/n 23059A060
Card "7/9" p/n 23059B090-2

Electronics chassis #2 (M-64 #1) p/n 64059A010
Card "1" p/n 23059B020
Card "3N" p/n 23059B030
Card "4" p/n 23059C040
Card "6" p/n 23059A060
Card "7/9" p/n 23059B090-2

Electronics chassis #3 (M-64 #2) p/n 64059A010
Card "1" p/n 23059B020
Card "3N" p/n 23059B030
Card "4" p/n 23059C040
Card "6" p/n 23059A060
Card "7/9" p/n 23059B090-1

Electronics chassis #4 (M-64 #2) p/n 23059A010
Card "1" p/n 23059A020
Card "3N" p/n 23059A030
Card "4" p/n 23059B040
Card "6" p/n 23059A060
Card "7/9" p/n 23059B090

Electronics chassis #5 (M-64 #2) p/n 23059A010
Card "1" p/n 23059A020
Card "3N" p/n 23059A030
Card "4" p/n 23059B040
Card "6" p/n 23059A060
Card "7/9" p/n 23059A090

 

[sweetbeats]

One of the electronics modules...

First off, Ghost, can you send me the nice little console you built in which to mount my M-64??

Here is one of the M-23 modules that came with the M-64...again, these aren't as clean as the single M-64 module I got, but even these were pretty good for 40+ years old, and the bottom line is that I've got plenty of what I need to put together a couple of very nice modules...The two M-23 modules appear to be for channels 3 and 4 of some 4-track M-23 that is somewhere in the world...or maybe not anymore, but they were at some point because the amp cards in one have "3" marked on them in grease pencil and the other has "4". And the serial numbers are, for all intents and purposes, sequential: 00207 and 00210.

Overviews:

You just can't quite appreciate how gihugic the VU meters are until you can lay your hand on one...they're big:

Tip down the faceplate and there are the amp cards:

Very few elecrolytic caps in this thing...Huge input and output transformers...you can see them in the center flanking the local power supply in the second picture, the one looking down on the top of the module. The input and output transformers are the light grey boxes to the right and left of center. The local power supply doesn't slide out like a little drawer on these modules with the VU meters integrated...I'm thinking in the end I'll probably use the modules that came with the first (now parts) M-64 since that is the a console-mount version with flying meters and therefore no meters on the electronics (and hence the cool slide-out power supply drawers)...I'd just have to moddify the meter bridge that's part of the wider console-mounted machines to be the narrow width of the rack-mount version I have now and fly the meters...A hybrid console/rack-mount version.

 

[sweetbeats]

Ooooo!

And I just compared transport s/n's and they're pretty close which is nice...it means there's a better chance that they use the same parts and assemblies...00249 and 00263.

 

[The Ghost of FM]

First off, Ghost, can you send me the nice little console you built in which to mount my M-64??

I wish I could!

But Photoshop doesn't currently translate its renderings into actual meat world products!

But, at least you have a possible design idea from it now.

Cheers!

 

[ofajen]

Otto, here is the info for all 25 cards as well as the electronics chassis p/n's...i denoted each chassis with the specific transport with which they came to me just so I can keep track (i.e. M-64 #1 vs #2):

Electronics chassis #1 (M-64 #1) p/n 64059A010
Card "1" p/n 23059B020
Card "3N" p/n 23059B030
Card "4" p/n 23059C040
Card "6" p/n 23059A060
Card "7/9" p/n 23059B090-2

Electronics chassis #2 (M-64 #1) p/n 64059A010
Card "1" p/n 23059B020
Card "3N" p/n 23059B030
Card "4" p/n 23059C040
Card "6" p/n 23059A060
Card "7/9" p/n 23059B090-2

Electronics chassis #3 (M-64 #2) p/n 64059A010
Card "1" p/n 23059B020
Card "3N" p/n 23059B030
Card "4" p/n 23059C040
Card "6" p/n 23059A060
Card "7/9" p/n 23059B090-1

Electronics chassis #4 (M-64 #2) p/n 23059A010
Card "1" p/n 23059A020
Card "3N" p/n 23059A030
Card "4" p/n 23059B040
Card "6" p/n 23059A060
Card "7/9" p/n 23059B090

Electronics chassis #5 (M-64 #2) p/n 23059A010
Card "1" p/n 23059A020
Card "3N" p/n 23059A030
Card "4" p/n 23059B040
Card "6" p/n 23059A060
Card "7/9" p/n 23059A090

#1 card is bias amp. #3 is basically a placeholder on NAB machines like ours, and was there for a special card for the Dynatrack machines that used two tape tracks per audio channel to increase S/N. #4 is important as that is the record (eq) card. #6 is just the line driver and 7 and 7/9 are the play (eq) and overdub cards, respectively. A mix machine needs a card in the #7 slot, but not in the #9 slot.

The M-23 manual is less help than I thought it would be. It tells me that the 15/7.5 ips pairing with NAB cards was standard for the M-23 and that other speeds and eq could be ordered. I have 15/7.5 #4 and #7/9 cards with the labels yours have, except that I have no C040 cards, nor any B090-2 cards. So, it's possible that all your cards are 15/7.5. I was under the impression that the belt drive transports of the later M-64 series mainly ran 30/15, but they probably had 15/7.5 as an option, too. Sorry, not as helpful as I thought I'd be.

Cheers,

Otto

 

[sweetbeats]

I've got questions...

• What purpose do the index marks on the capstan serve?
• How do you get the covers off the capstan and reversing idler rollers? Mine are reversed (index marks are supposed to be on the capstan, mine are on the reversing idler).
• Anybody ever rebuild a capstan assembly (i.e. replace the bearings)?

Otto, you're probably the only one who's going to have anything to say about any of these. I have a hunch I should join the 3M group over at yahoo...and I've got a feeling I'll shooting an email to Matt Allen too...need to get an M-64 manual. The 500-series manual I have is pretty good for getting by but the proper manual would be better in order to provide proper care.

This machine is clearly one that can pull 2" tape and is in 1/4" trim...and can gently handle the 1/4" stuff. Pretty cool. The capstan motor, for instance, is the same as is found in the 1" and 2" M-56 machines. I confirmed, BTW, that the motor in my parts machine is a 15/30 unit and the one in the new machine is a 7.5/15 version. I'll be swapping them. Its pretty easy:

Remove the 4 socket-head cap screws from the capstan flywheel/belt cover and remove the cover (exposing the huge flywheel):

Remove the cap screw from the center of the flywheel and gently remove the flywheel and the mylar belt:

You can then remove the 4 philips-head screws that fasten the top half of the cover to the transport and once that's out you can get to just about anything under there.

I've stripped all the decorative stuff off the transport to shine it up and get what little dust or grime is hiding in the internals...just look at that cast webbed transport plate...pretty clean too:

Contrast that with my parts machine which clearly sat for some time with the dress panel off in a very unclean environment:

Another cool thing I noticed is that the entire logic board is plugin and there are only 3 screws that hold it in. Need to get it out? Remove the 3 screws and slide it out. It literally takes seconds to uninstall the whole board:

 

[ofajen]

Index marks are for speed calibration with a strobe. The covers are wedged in and may be glued. Can't recall. Out if town at the moment. I seem to recall my M-23 has lines in both covers. Never replaced bearings, but I replaced the whole idler on the M-23 because it was bent, and replaced the whole capstan assembly on the M-56 to get a new, unworn capstan surface.

Cheers,

Otto

 

[The Ghost of FM]

Love that massive die-cast construction on the transport!

I just hope you don't disassemble it to the degree that you forget how to put it back together again!

Cheers!

 

[sweetbeats]

Otto, I've got an email out to Matt at Allen Sound to get his take on the capstan. I do recall your reversing idler issues.

Don't worry, Ghost...i've gotten really good at utilizing some simple "bread crumb" tactics for ensuring stuff goes back together the same way it came apart, and by virtue of past mistakes being able to recognize the "oops...shouldn't have gone there" before it happens. And, anyway, it won't be getting torn down any more than what you see in that third to last pic in my last post with the exception of trading out the capstan motor and start cap. I believe it is fully functional with the exception of needing a new run out sensor lamp, so what you see accomplishes being able to swap the capstan drive motor assembly and detail the cosmetic pieces which allows deeper access to get whatever dust-bunnies are living "under the skin" and that's as far as I desire to take it at this point. There just really isn't anything else that NEEDS to be addressed at this point. I'm eager to make the capstan motor swap, get it cleaned up and get it racked and then test some electronics. Maybe I'm crazy, but this thing is going to take the seat my Tascam BR-20T has been leaving vacant with its technical issues. There's just too much good in my mind to big fat antiquated space-inefficient vintage discrete electronics. So much easier for me to troubleshoot and fix. I really think the BR-20 machines are fantastic...but the philosophical design nature of stuff like the M-64 and my MM-1000 just fit me better.

So I won't go as deep on this machine because A. I'm a little more wise and B. I don't really have to, which is one reason the previous owner passed it on to me because he knows my tendencies.

 

[Muckelroy]

Those are GIHUGOMOUS traces on those boards!!

 

[sweetbeats]

Oh, Muck, thanks for the new word. I've been limited to ginormous, gihugic and hugantic.

Yeah. The big traces...That's an important part of what I was saying about old large space-inefficient hardware. Yeah, its heavier and takes up more room and yes there are downsides to it too, but good luck getting those traces to lift and fracture when replacing components even many times over. Some "contemporary" stuff that is on glass fiber PC board material is a little better than the phenolic boards in this regard but there's still no comparing to this vintage stuff. I'm reminded of this fact recently with the work on my Tascam BR-20T headphone amp PCB. You'll find phenolic resin PC boards in LOTS of stuff. Its cheaper, okay? Doesn't mean the gear or manufacturer is/was "cheap"...Teac made so many careful decisions in my estimation to meet price points while STILL offering pretty much an incomparable feature-set. You can't build something to the nth degree and still meet an accessible price point and that means some compromise. In this case it was a compromise to me, the end-user tech who's repairing the phone amp board which has shouldered 25 years or so so of some hot transistors. One touch of the iron was enough to damage the solder lands. Then another application putting the new parts in (which were the WRONG parts...my bad) so then two more apps of the iron. Now, if I hadn't erred that would be better, but they were STILL toast from the get-go. This is relatively rare, but the reality is that you always have to take more care with the phenolic stuff. The stuff in my 3M halftrack, Ampex MM-1000 multitrack and MCI mixing desk? My goodness I'd have to work awful hard to damage traces or lands. And that's not an excuse to get sloppy or lazy, its just integrity insurance. And, honestly, I sometimes wonder if there isn't SOME effect on the audio path with all the point-to-point high-quality wiring and big fat traces, etc...the kind of "effect" that some might say effects transparency and others say "sounds better".

 

[cjacek]

Looks great Cory! Can't get over how huge the flywheel is!!