Tascam 58 Question

tremichael

New member
Hey all,

I recently acquired a refurbished Tascam 58 from a reputable tech in the NW. I was excited to have a balanced 1/2” 8 track for all my tape stuff - I do a lot of tape laybacks of chosen tracks while mixing records (in pro tools), and occasionally do a bit of recording on machines as well.

I say “I was excited” (which sounds a bit dramatic, but hear me out haha) only because I came to find out once I picked up the package and brought it back to my studio, that this 58 didn’t actually have balanced I/O - just the unbalanced RCA connections.

I had never received a photo of the back of the deck - which I feel silly about now - but I had never seen one without XLR so I had no reason to think otherwise...I thought that was part of the 58 appeal! Since I do so much transferring of tracks between digital and tape, the balanced circuitry is really nice for me to not have to do a lot of padding, make up gain, etc.

So, anyways, now I feel a bit stuck. I have a very dialed in 58 on my hands that I got for a good price - although I thought it was for one with balanced connections…which I suppose would increase the value? Anyhow, I’m imagining the tech I bought it from would be amenable to taking it back, as bad as I would feel. But, these are hard to come by, and I’d like to make it work.

Is there anyone out there with hands on 58 experience that wants to convince me of a -10 life? Is there a way for me to mod it for balanced I/O without breaking the bank?

Thanks !!
 
It's possible you have a 48 with the wrong faceplate which is the exact same machine minus the +4 in/outs. The performance of the 2 machines should be identical. If you must have it operate @ +4, matching outboard matching devices are available.
 
It's possible you have a 48 with the wrong faceplate which is the exact same machine minus the +4 in/outs. The performance of the 2 machines should be identical. If you must have it operate @ +4, matching outboard matching devices are available.
What??

No.

The 58 and 48 are entirely different machines. Almost nothing is compatible between the two, Rick. I’ve owned and tore into both machines…highly dissimilar. They use the same heads, and the R/P amp circuitry is similar, but completely different PCB assemblies, the tape path is completely different, the chassis and metalwork completely different…no cross compatible PCB assemblies at all. I think the only common parts aside from hardware would be the reel adapters, the heads themselves (not the headblock assemblies), and maybe the feet on the back…the round ones for when laying the machine on its back. Oh, and the XLR jacks and reel motors are the same. But that’s IT.

@tremichael the 58, when originally introduced, was unbalanced -10dBv only. It was just the “Tascam 58”. I have one of those early versions. The manual is different than the second generation machines. A key telltale sign of an early machine is the scrub wheel has no finger detent in it…this thing:

A14F00EA-BF6F-4327-831D-C2AF31C10D9E.jpeg

I don’t think the 1st generation lasted long though because Teac was gunning for a foothold in the professional video production market. That’s really what the 58 was developed for as far as the marketing folks were concerned…for video sweetening…had chase-lock sync capability to sync with VTRs, the available full-function remote for install in the machine room and full control at the console, but the early version was unbalanced only. Then with the 2nd generation we see the advent of the model designations “58-OU”, for unbalanced, and “58-OB” for balanced.

The 58 is all unbalanced -10dBv internally, so the balanced I/O circuitry simply branches off of the same I/O that feeds the unbalanced RCA jacks. There is a balance amp PCB assembly, a separate regulated power supply for that PCB, and of course the rear panel is punched for and has the XLR jacks mounted; conceptually simple.

I have the balance amp PCB assembly and power supply here in my spares, as well as the punched rear panel. No jacks. But here’s the thing…or actually a couple things…though you could kludge the balance amp guts into a 1st gen or “OU” 58 just like Teac did (no disrespect meant, but that is what it is…the additional guts are tacked on and make it hard to get to everything else inside the 58), I don’t know why anybody would do this. For one, keep in mind balanced audio doesn’t make the audio sound better. Okay? You understand that, yes? Unless we are talking about a problem you are having with environmental RF or UHF “noise” being induced into your interconnects. Then balanced interconnections DO make your audio sound better because, if implemented correctly, the balanced circuitry mitigates the unwanted noise. But that is all balanced signal does or is designed to do when implemented correctly, is mitigate induced environmental electronic noise. The concept comes from the telephone industry where it was developed…it was necessary with thousands of miles of wire. The concept was carried forward into the audio world many decades ago in professional studios, video and broadcast production environments, where you have hundreds or sometimes thousands of feet of audio cabling going from room to room or often spanning multiple-story buildings. Induced noise was unavoidable, so it had to be mitigated. Plus the higher nominal signal level standard helped with any signal loss in those long cable runs. But balanced circuitry, whether active electronic (like differential amp circuits) or passive (transformers) actually can have a detrimental impact on the signal quality because you are passing signal through additional circuitry or components…additional amp stages and coupling capacitors…resistors…additional noise and distortion is the result…or through transformers which impart non-linear artifacts on the audio. Granted some folks like those non-linearities, and for others the detriments are outweighed by the benefits of the noise abatement because they have a long cable runs or an exceptionally “noisy” environment as far as RF, UHF, etc., or both. Just look at the 58 specs. The frequency range goes up to 25kHz using the unbalanced I/O, but it is 22kHz using the balanced I/O. Is that a deal-breaker? Nah. But it’s important to be aware of it, and to realize that if your environment requires cable runs under 25’, and you use good quality shielded cable, you really don’t *need* balanced audio. And actually, at least on paper, the performance is better on the 58 at the unbalanced jacks. Of course the better the quality of the components and circuit design, the less of an issue it is having the signal traverse a more complex path. But that comes with a price…fancier “better” circuits typically cost more. Of course there are also times it’s just easier to interface devices together if most everything else in your studio is +4dBu standard, but I rarely run across a device that can’t accommodate unbalanced -10dBv signal.

So now you just have to ask yourself what YOU want to do…determine what you actually need. And if you need the balanced I/O, I think you should not monkey with your nice 58…leave it as it came from the factory. Sure I could sell you all the guts and the jacks are readily available…you’d have some wiring to do and some modifications in order to mount the power supply and balance amp PCB assembly, but, again, why do all that? The 58 is a relatively rare, interesting and desirable vintage 1/2” 8-track machine…I wouldn’t cut into it. As @RRuskin stated, there are a number of outboard boxes you can get that will do the balance/unbalance -10dBv/+4dBu conversion for you…get a couple LA-40mkII units, or an LA-80 and an LA-81…mount them close to the 58, get the shortest good quality pair of 8-channel snakes you can get to interface the boxes with the 58, done…the HOSA snakes have been a good bang for the buck as far as good shielding and construction…reliable…those above noted LA series devices are probably cleaner than the OEM balancing circuitry for the 58-OB. They have lower headroom. This isn’t an issue for most folks. It’s not that they have “low headroom” per se, it’s just that the 58-OB, since it was designed for video production and broadcast work, was capable of interfacing with the +8dBu standard of those markets, so the power supply and amp circuits have some greater oomph to them. But this is usually not needed in a typical audio production environment. If you want the headroom of the original 58-OB balancing guts, then you can look for a pair of 1st gen LA-40 units…harder to find but the amp circuit is almost the same as the 58-OB circuit.

Hope that helps.
 
I'd agree with Sweetbeats - provided you use reasonably short connections and a sensible grounding scheme, there is little point in using balanced connections in a home studio where you have time to make things work. Balanced connections are useful in a studio where the gear has to work under a wide variety of circumstances. I've not used a 58 but I do have a collection of -10 multitracks as well as a big MTR90 which is fully balanced. I actually set up the desk to work at +4dBu to match the MTR90 but accepted that the levels would be lower with the other machines. Even with this compromise, the noise floor of the desk is far lower than the noise floor from the tape.

With my last tape machine purchase I ended up with 24 channels of +4dBu balanced to -10dBV, unbalanced matching electronics which has just sat in a corner unused.
 
Hey everyone!

Thanks for the generous replies - especially @sweetbeats! I do understand balanced/unbalanced cabling and such but thank you - I imagine others searching for similar topics will land here and find your reply quite useful : )

Like I mentioned previously, I do a decent amount of transferring between the computer/tape. That is the main reason I want balanced connections on the tape end. Less fuss when sending to and from my converters so I don't have to do much adjusting in between. I do quite a bit of remote mixing for folks these days so it's nice to have a really quick workflow to bounce tracks to tape and back when I want to!

So anyhow, thanks to everyone's suggestions and a from some correspondence with Jim Williams, I'm most likely going to get a balancing rack or two. The tascams a re bit hard to find, but Rane makes one and I'm also looking at this one. Jim also suggested just adjusting the in/out trims, which seems smart, but I'm prone to leaving the machine as is for a moment since it was just refurbished and set up.

As a treat, here's my machine !

IMG_3552.jpg
 
Nice lookin’ 58! And I see you have the rare RC-50 transport remote too. Nice! And yes I do believe you have there the more rare 1st gen 58…pre-“OU/OB” delineation. You can also tell by removing the top panel…early generation 58s have a heatsink that spans all the way across the top above the reeling motors and main power transformer…2nd gen 58s have smaller heatsinks just over each reeling motor. Again, the easy-to-see giveaway is the scrub dial without the dimple for your finger. Did you get the manual with it?

Oh and it looks like there’s a good selection of Tascam leveling amplifier units on eBay. Just search “Tascam LA”.
 
Yup remote works great too! No manual unfortunately, but I'm sure that's floating around online...

Ended up ordering some of the Rane units - found a well priced pair on ebay so I went for it! Ordered a couple hosa snakes, too. Looking forward to checking out how it sounds early next week : )
 
…No manual unfortunately, but I'm sure that's floating around online...
I think you’ll be hard-pressed to find a free Tascam 58 manual download, at least I. Any quality you can read at the schematic level. And betcha it won’t be the manual that matches your early generation machine. The later generation manual should work fine, just don’t be surprised about some differences between your machine and what’s in the manual. There are OEM Tascam 58 manuals on eBay in original binder…you can possibly le order reprints from Teac directly. Lots of options…just don’t know what you’ll find for free. I have both manuals…hoping to make a scan of the 1st gen manual at some point.
 
This has been an interesting thread - I always assumed the "OB" designation meant "Outside Broadcast", i.e. it was intended for use in a mobile recording van or something.
 
I just checked HiFi Engine, and it appears that they have a copy of the owners/maintenance manual for the unbalanced version. The Exploded view shows a massive heatsink for the top, which is what Sweetbeats references.
 
I just checked HiFi Engine, and it appears that they have a copy of the owners/maintenance manual for the unbalanced version. The Exploded view shows a massive heatsink for the top, which is what Sweetbeats references.
Oh that’s amazing. I haven’t checked there in awhile…so cool…yep! That’s the 1st gen manual…and it looks like the quality is good enough you can see the necessary detail when you zoom in on the schematics. That’s where it’s usually a problem…the quality of a pdf scan. But this one looks alright! Wow check THAT off my list lol! So the 1st gen manual p/n is 570039301. The 2nd gen manual I have has p/n 570039303. So the manual on hifiengine will work perfect for the OP…the service instructions are in a strange order so I usually reference the later manual for that, and of course there’s no information or reference to the balanced I/O, but that works for the OP. Cool! Thanks @TalismanRich !
 
I just saw on Reverb a 570039300 manual version. That’s probably the original. 301 that’s scanned to HiFi engine was the first revision, but still pre OU/OB…I’ve not seen a 302 version, but maybe that’s the first revision that goes with the 2nd generation with the OU/OB models, and the 303 manual I have was a revision to that.
 
Awesome thanks for the manual info! That’s super helpful.

Been a busy couple weeks at the studio but finally got my rane balancing racks + cabling. Look forward to hooking it all up and finally trying it soon!

Anyone with this machine or similar use a rolling rack cart for theirs? I’ve been looking at the readily available “griffin” ones but I’m actually not quite sure it’ll even fit…doesn’t seem to be much out there that’s a slight step up from there except for K&M which is very expensive!
 
I had my first 58 in one of those generic rolling tilting racks like this:

https://www.ebay.com/itm/3944235179...le5cs0tQ9u&var=&widget_ver=artemis&media=COPY

It worked. It was strong enough and rolling nice enough and I didn’t need to tilt it all that often, so…it worked. But I didn’t like the fit and finish…definitely a budget rack…and I despise the pop-in square but setup. I get why it exists, I just don’t like the chore when it comes time to reconfigure. You’re correct there’s not a lot between that level and really expensive stuff. I e owned three different Tascam racks and they are much nicer, but, of course, the price has come up on those on the used market.

Sorry that’s probably not very helpful.
 
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