Tascam 238 Story...

  • Thread starter Thread starter sweetbeats
  • Start date Start date
Wow JP....I'm just watching the following video on 'synchronous reluctance motors' and the thought of the four coils came to mind....look at the following video (it's all very interesting but the bit in question is at 6mins 45secs).

 
Hey There.
Do you still have the old complete capstan motor and servo assembly?
I'm buying the old complete capstan motor and servo assembly from you if it's cheap!

By the way, what's the phone number to call to get a brand new complete motor and servo assembly from teac?
How do you buy from teac?
sweetbeats said:
I'm calling this project done.

After cleaning the heads, demagging the tape path, getting the pinch roller out of the machine and giving it a good cleaning, this thing is recording and playing back nicely on all 8 tracks, levels are pretty flat. And it sounds good. Was using Jeff Buckley's "Everybody Here Wants You" as a test track. Let the haters hate...I think it's pretty amazing how good these tiny little tracks can sound.

This 238 is 100% operational and functional, nice to look at, has the RC-88 remote to go with it, and has a brand new complete capstan motor and servo assembly...not a refurb but brand new direct from Teac.

Done.
Click to expand...
 
I do not have any Tascam 238 parts on-hand at this time.

My understanding is Teac ran out of stock of the 238 capstan servo/motor assemblies years ago, but maybe it’s worth check to see if they have more these days? You just call Tascam Parts in the US, (323) 727-4840 Monday through Friday 8 AM to 5 PM pacific time.
 
sweetbeats said:
I'm calling this project done.

After cleaning the heads, demagging the tape path, getting the pinch roller out of the machine and giving it a good cleaning, this thing is recording and playing back nicely on all 8 tracks, levels are pretty flat. And it sounds good. Was using Jeff Buckley's "Everybody Here Wants You" as a test track. Let the haters hate...I think it's pretty amazing how good these tiny little tracks can sound.

This 238 is 100% operational and functional, nice to look at, has the RC-88 remote to go with it, and has a brand new complete capstan motor and servo assembly...not a refurb but brand new direct from Teac.

Done.
Click to expand...
Can I ask if you ever came across a copy of the 238 Serial Connector protocol? I want to control a 238 from my DAW system.
 
campbellr said:
Can I ask if you ever came across a copy of the 238 Serial Connector protocol? I want to control a 238 from my DAW system.
Click to expand...
I’m not sure I understand your question…the protocol is serial. To synchronize the 238 to another tape machine, video machine or anything with some sort of time code you need a synchronizer capable of working with serial protocol. So it’s not something you come across per se. It’s serial protocol, you acquire a synchronizer capable of interfacing with your DAW’s time code output, which is typically MTC over MIDI, or maybe you’re striping SMPTE timecode to a track in the DAW and outputting that through your audio interface, but regardless you need a synchronizer like a TimeLine Micro Lynx or something like that in between your DAW timecode interface and the 238. The synchronizer reads the audio SMPTE timecode from the DAW, or the DAW MTC via a MIDI OUT port on your DAW interface, and reads the timecode from the tape track on the 238 striped with timecode (track 8), and via a specialized interface cable connected between the synchronizer and the 238, controls the capstan of the 238 and other transport functions in order to stay locked to the DAW. Does that help?

In other words you cannot and do not control the 238 directly from the computer-based DAW. You hav to have a device in between the DAW interface and the tape machine in order to read the reference timecode from the DAW and control the tape machine.
 
Thanks for the explanation. I probably didn't explain what I'm trying to do very well.
I would use a Tascam ATS-500 Synchronizer to allow the 238 to be slave locked to my DAW (Cakewalk) which would provide the master LTC timecode source.

However, what I want to do is also control as many of the 238 functions as possible from Cakewalk, so all of the functions which the RC-88 can do, so all tape transport (whether sync'd or not), the eight record arms and the various locate functions.

I have been able to do this with a Fostex R8 8-track but this has a MIDI interface for this purpose.

So I'm looking for any information about the RC-88 to 238 remote protocol, which I assume is serial based. I can use a PIC controller to do the actual interfacing from Cakewalk (MIDI via AZ Controller) to 238 (some kind of serial protocol).

All help would be appreciated.
 
Well I doubt anybody here has that information. Tascam didn’t publish it. I’d suggest reaching out to Tascam to ask if they have any documentation on it, but I’m fairly certain they don’t. That doesn’t mean it’s not worth a try. Outside of that it’s looking in the service manual that is available online, following where the 8 pins of the remote mini DIN connector go on the schematic (most of which go to an LC7800 chip which I believe is a microprocessor chip U2, and an LB1213 transistor array chip U4). Here’s the LB1213 datasheet:

https://datasheetspdf.com/mobile/391335/Sanyo/LB1213/1

Unfortunately, so far I can only find a Japanese language version of the LC7800 datasheet. But you’ll have to do some reverse-engineering of the pin function on the ICs to which the RC-88 pins connect; what type of signal do the IC pins expect in terms of voltage type and waveform, etc.

A guy with 1. a 238, 2. an RC-88, 3. a good copy of the service manual, 4. a good scope and 5. some time on their hands could figure this out. I lack #s 3 & 5. You’d obviously have to do this with the RC-88 connected and the 238 under power because the RC-88 does nothing unless powered. And then you’d have to find where/how to access the pins internally in the 238 in order to probe them and then start building a table of what happens on each output pin when each control is actuated on the remote…voltage, waveform, frequency, etc. it would also be helpful to have a service manual for the RC-88 as far as what’s going on in there electronically and what microprocessor is inside…find the datasheet for that, etc. outside of that a guy would have to pull their RC-88 apart…I’ve never seen a service manual for the RC-88. The 238 service manual is very not high on my list of good service manuals.

So your inquiry is pretty complicated IMO.

But that’s just my opinion. Who knows…somebody might jump on here and go “oh it’s this.” I don’t know.
 
Okay I made some progress!
Whilst the RC-88 remote port on the Tascam 238 could provide one way to access the machine for remote control from my DAW, I found out from Tascam that the Accessory2 port on the 238 (and all later Tascam Multitrack Machines) actually contains two comms circuits on the 15 Pin DIN. Some of the pins are allocated to the 'controlling circuit' which deals with the capstan control for sync purposes. The other pins are for what's called a 'communication circuit' which is a standard RS-232C serial port and that's the port which does all the machine remote control. I believe that is the serial port used by the MTS-1000 MIDIIZER for remote control of Tascam Tape Machines.

So far Tascam have found me a cope of the CD Controller protocol (attached) which provides a lot of useful information on the serial port but NOT the correct codes for tape machine control.

I have asked them to look again but if anyone reading this has a copy of the serial control protocol, possibly as part of a Tascam Tape Machine Service Manual, or perhaps within the MTS-1000 MIDIIZER documentation, then please let me know.
 

Attachments

And more progress!
I found a guy who is doing a similar project and has uncovered the Tascam Accessory2 port commands for remote control. Have a look to https://github.com/bgencarelle/Tascam-MIDI-bridge
When I get time, I'll write up the list of codes (which are hidden away in a software programme in the project I have pointed to).
 
Any work on this?? I'd love to just have the simple remote functions that a rc-88 could provide.
 
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