Son Of Tascam 58 Story...

Not a 58-“OU”...just a “58”

Not much to report on this project, but the 58 is still around...it’s had to take a seat at the back of the bus in light of lots of competing priorities, life, other projects...sleep...anyway, it’s tucked away in the shop. I’ve been going through some serious thinking about all the gear and projects, and occasionally think about stuff maybe I should let go of, but I don’t think the 58 will ever go. It matches my Tascam “M-__” prototype console, and I think will make a good refurb when I get around to it. And here’s an interesting bit of useless information...all through this thread I’ve been referring to my 58 as a “58-OU”. It’s not. It’s just a “58”. I always thought the balances “OB” and unbalanced “OU” versions of the 58 were introduced simultaneously. Nope. The balanced version came later and when it came to be that’s when the “OU” designation came to be to make the distinction between the two models. So because my 58 is unbalanced I always thought it was an “OU”. I was looking in my manual tonight...doing a little research for another project, and I wanted to look at the schematic for the “In/Out Ampl PCB”, the board that has the input and output balance amps on it. I assumed it would be in my manual because the manual I used to have, which covered the OU and OB models has the technical docs for all the PCB assemblies in it. Makes sense right? So I’m searching and searching in my manual and I can’t find the docs for that PCB assembly. I think “is this manual missing pages after all??” Then I flip to the front, and then start looking through the manual, and there are no pictures or references at all to “58-OU” or “58-OB”...just “58”...like a balanced version doesn’t exist. Then I look in the scanned version of my old manual I had and there’s all the stuff in there about the balanced version, and then also a paragraph at the very beginning I never noticed before, which basically says there was a 58 model that preceded the 58-OU and 58-OB, and it was just call the “58”. I go out to the shop to look at the model/serial number tag on my 58 annnnd:

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Yup. Just “58”.

So this is cool and interesting to me. It means I have a very early 58, and the matching manual, which all must be more rare. And the 58 was touted as Tascam’s first balanced multitrack tape machine, but apparently it wasn’t so from the beginning, which explains why the balance amp board and it’s power supply seem a little kludged into the 58 chassis...the fact there is a separate power supply is a dead-giveaway it all came later. In a way it almost kind of makes my 58 an even better match for my prototype console...they would have likely been made in the same year.
 
I spent a little time working on the 58 last night, mainly driven by the fact I have a small pile of 1/2” tapes that I bought off of lonewhitefly that need to be library spooled for storage.

I started by cleaning up the CS-607 cart that came with the 58...not an exhaustive clean...I’m seeing that the cart and the deck must have been in damp storage...some rusty specks/spots on the finish and especially on fasteners and on the tape guides. Heads look fine. I have. Polish/protectant I usually apply to painted surfaces...that’s going to have to happen later...for now it was the vacuum, and then window cleaner and a rag and some elbow grease...the cart cleaned up pretty good, and later the polish/protectant will remove the rust spots. The cart was really wobbly and that was just the result of it being disassembled at some point and then reassembled without properly tightening all the fasteners, and in some cases fasteners were simply missing. Fortunately I have a bag of various fasteners from other Teac/Tascam gear so I was able to replace/match anything that was corroded or missing. The cart also has the common problem where the spring-loaded stoppers are shot, but I might have a lead on some functioning parts. Anyway, cart is cleaned up and sturdy.

Then I cleaned up the top and sides of the 58...the surfaces that would be somewhat blocked by the cart framework...same thing...quick wipe down, replaced mismatched/missing/corroded fasteners, installed the replacement I got for the missing right side handle...I took the top panel off just out of curiosity...interesting. I’m used to each motor having a single heatsink over it for the motor drive transistor...my early “58” (again mine was made before there were “OU” unbalanced and “OB” balanced models) has one heatsink that spans the entire width under the top panel. This is a pretty big heatsink for just two transistors! Here’s mine:

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And here’s what’s in my parts 58, and non-early model 58-OB:

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Frankly I think the early type has a fair degree more chutzpah. :D

The 58 really has a certain chunky solid feel to it...and I forgot how good it looks perched in the cart...here it is, and after being in storage the past couple-three years it still powers up:

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The capstan still sounds proper, pitch controls work, reel motors are strong (but the takeup motor is noisy...maybe needs new bearings?), but all the transport functions work. I was having a problem with the library wind function in one direction the last time I had it powered, but it seems to be working now. Basically it’s fully functional as far as the transport, but something is far from right with the tensions. More on that below. The bearings in the scrape flutter idler are shot...and the tach roller is noisy and the rubber is somewhat dried out. I think all the bearings in the tape path need replaced. I have brand new Nachi bearings for the tension arm rollers, tach roller, and here is the pinch roller loaded with new bearings fresh from Terry Witt of Terry’s Rubber Rollers:

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Here is yet another whole-hearted plug for Terry...he does beautiful work, has quick turnaround, charges reasonable rates, and, again, the results are worth it. I think this is the 4th roller I’ve sent to him. He’s one of the good guys. I’ll be sending the tach roller to him...yes he can do those complicated grooved rollers too.

So this is the first time I’ve actually loaded tape on the 58. Again, all the transport functions work, all the of the source switching and record arming functions work as well, but in REW or REW library wind mode the supply tension arm bottoms out...there is WAY too much tension. And in FFWD or FFWD library wind mode there is some cyclical lurching of the servo system...like it is stable for a bit, and then it starts to progressively surge like a trailer fish-tailing, then settles down again, and so on. And I think the tensions are off in EDIT mode as well. My first assumption is it is not just tension settings needing checked/adjusted. I can’t get into this right now unfortunately, but when I do I will start by re-seating connections, making sure the tension sensors are clean (and other stuff too...this deck is pretty filthy), the new bearings are installed, brakes adjusted, I’ll inspect the tension arm springs and likely replace them (I think I bought a new set from Teac a decade or so ago when you could still get them...think I bought a new set of guides too...), I’ll degauss the tension sensing hardware, and THEN see how it performs and proceed with the tension check-adjust procedures. Hopefully I can get it sorted out.

Overall I’m finding this 58 has been somewhat neglected, and I can tell it has been opened up, and not by somebody who cares too much about being careful and taking care of things...stripped screw heads, putting any ol’ screw back in wherever...original to the machine or not, etc. Like the wrong size screw in one of the top panel fastening locations...I was able to crush the deformed metal back flat so there was enough material to run a tap through a re-cut the correct threads. Then I was able to put a matching set of four screws in place from spares.

Anyway, I leave you with this pic of reels actually spinning...the tape pack after PLAY spooling the reel of tape is *gorgeous*:

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P.S. I also recently received something in the mail...the Teac YTT-1144-2 test tape proper to the 58...this is one I bought from Beck years ago, and then sold to Blue Jinn after offloading my first 58 project to evm1024...Jinn still had it, wasn’t using it, so now it’s back in my hands for what he paid me when he bought it from me...strange lot we are. :eek: :D
 
I can’t believe it’s been 6 months since my last post on this Story.

Things have been a bit up-ended with a move and renovations on the new place which is smaller...the holidays, and a toddler who is absolutely everywhere. :D

Anyway, been feeling pretty disconnected from audio projects and music...trying to figure out how to play drums at the new place which has close neighbors, but a friend of mine encouraged me to pull my head out and just do *something*...record something, make some music...I decided I didn’t want to do that with the digital rig, but take it back to when I originally learned about and got excited about multitracking and it was embedded in analog recording process and analog tape. All of my stuff is a work in progress. But what is probably closest to being usable is the 58 and the prototype Tascam “M-__” console...get those things working enough to just use them. The console is easy...it’s totally functional but one of the I/O modules is torn apart as last I was doing anything with that console it was exploring upgrades and collaborating on a redesign of the output line amps. We are still totally living out of boxes and the garage is a solid block of boxes and “stuff”, but last night I was actually able to find all the parts to put the module back together and I think I can get to the rack with the power supply and umbilical in it. So, put upgrades on the way back burner and just use the damn thing. The 58 is a little different story...

Back in 2017 I started stripping components off the amp cards in an effort to replace the relays, socket the opamps, recap the boards and also implement some minor upgrades. I think I got halfway through that stripping process. They’re in a box somewhere. BUT...my parts machine is accessible, and I opened up the cardbay and my memory was correct all the cards are in there. So I pulled those out, only to find some gorilla in the past was rough removing and reinstalling the cards...most of the mini Molex connector housings are broken and tweaked. So I’m going to apply a fix I know for that (a little superglue, and then re-flow the solder joints). So there’s that. But then I also discovered the cardbay was a bit jacked up...most of the screws for the bottom panel were missing...other screws too...like the bottom panel which has half the card guides was flopping around at one end, like you couldn’t safely install the cards as the guides were too far apart. Remember this machine doesn’t present like one that was cared for all that well, so it’s pretty dirty and screws are missing or mismatched....anyway I got the cardbay all put together with the correct screws and cleaned up...doing some detailing and general cleaning up of the machine inside and out...*physically* it’s in good shape as far as lack of damage, it’s just dirty and not put together right. All fixable. So it shouldn’t take too much more time to go through it, re-seat connections and clean it up, then I’ll see where the tape handling issues are at, if they’re the same or if they’ve improved...and I can start going through the transport setup/adjust procedures...replacing parts I have on-hand as I go. Hopefully I can get it to handle tape correctly without too much headache. Here it is at one point last evening as I’d finished the cardbay repairs and detailing and had moved up to the arming panel...there were a couple minor repairs to make there too.

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That's going to be a super nice setup, the 58 hooked up to the prototype Tascam mixer. Do you still have the BR20?
 
No I sold that because I have the 3M M64 halftrack...that too is a work in progress of course, but you can see it peeking into the picture in my last post to the left of the 58. One of the coolest tape machines ever IMO.
 
I’m enjoying going through the 58 and getting it cleaned up. It’s been awhile since I’ve had my hands in one of these machines getting it cleaned up and making things “right”.

I kind of forgot what the build was like on a 58. Like, it’s not crazy stout like my Ampex MM-1000, but I recall now like comparing the 58 to the 48, and in the past year I had my hands in several 30 series machines, and all those machines are a lot more “plastic” than the 58...not as much the 48, but the 58 is a considerably more robust build than a 48. Ive talked about this in other threads...the 48 is more serviceable as far as the power supply, capstan and reel servo boards...a smarter layout than the 58, but the 48 uses a reinforced thin electro-galvanized mild steel assembly for the transport plate vs the 58’s 1/4” thick aluminum plate...and the 58’s lifter arm and tension arm pivot bushings are a relatively beefy bronze bushing affair...I recall the 48’s tension arms were far less stout. Somehow the 48 tape path was easier to adjust/setup, but the 58 was just a more beefy machine, and access to the amplifier cards on the face of the machine on the 58 is nice compared to more complicated access on the bottom of the machine on the 48. Anyway...I’m just going through my 58 and getting it cleaned up.

Like this...cleaned tension arm parts on the left, soiled on the right:

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And here’s another thing I’m addressing...it’s not uncommon on plug-in cards on Teac/Tascam equipment from this era, with the mini Molex type card edge connectors, for the connector housing to fail and the little fingers that hold the connector hoisting to the PCB to break, and then you end of with this:

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See the plastic connector sockets are bent up? So I figured out a way to use superglue some years ago...apply the adhesive conservatively and hold with a binder clip. It works.

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And then after the socket housings are secured I go back through and reflow all the solder joints. I’ve had to do this on some of the plug-in cards on a couple of the 388s I’ve owned, and I’ve even utilized the repair on Tascam mixers. People just aren’t respectful with this equipment. You can’t just bang-shift it around. I mean, you *can*, but most of this stuff won’t tolerate a lot of that kind of harsh treatment...doesn’t mean it’s “bad”, it’s just not in that category of robust.

So I got all the amplifier cards’ connectors back in shape...7 out of 8 had bent connectors with fingers broken off.

Then I was starting to look at the headblock assembly...the guides are rusted...the assembly is, generally speaking, nasty and neglected...caked-on sticky shed...one of the guides is bent...The whole machine was pretty dirty...

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I have a spare headblock assembly from my parts machine. I hadn’t looked at it in while so I pulled it out...it looks *really* nice, so I’m just going to use it instead of the one that was on the machine.

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The cleaning continues...
 
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