I've been repairing, refurbishing and modding a lot of multi track cassette tape portable studios lately. I very much enjoy recording music to cassette tape, as it has a very agreeable texture and quality, and it's just fun and archaic! However, I find that four tracks is just too few. Sure you can bounce, though it gets too complicated for me (Just too much planning really)
There are a few 8 track Portastudios, TASCAM 688, 644, 488, a few 6 tracks also, (these are fairly elusive, from Vestax, Sansui, AKAI) The thing is though the readily available ones are large, and the mixer is fixed. The mixer is reasonable, sometimes very good, though never really GREAT. Plus it's only ever THAT mixer, you can't change the mixer.
So when I found out about the TASCAM 238, which is rack mounted, and simultaneous 8 track, I was very interested. You can change mixers over time and still keep the same deck, and it has a really great recording head (the same as the 688 Midistudio)
Unfortunately the 238 suffers from the classic leaking capacitors of the early 90s. SMT (Surface mount Technology) parts were still pretty much in their infancy, well ok adolescence at this point. Although good quality parts were used, some capacitors leak on the motor control PCB, damaging the speed control circuit components and causing the deck to run at an extremely high speed.
Happily enough it's fairly straightforward to fix. I think some users have found it really quite tricky though. I think they miss the zener diode, which is right in the path of the leaky caps. Corrosion will enter the diode package and destroy it internally. Also there are traces which can become damaged by corrosion as well, making a point to point wiring fix necessary. You can only find these by beeping out all the traces.
The 238 is a direct drive system, which is unusual for a multitrack cassette deck (it's the only model I know of which has a direct drive motor) With the appropriate TASCAM sync box (ATS-500) you can have two decks synced together, one will chase the other until they are in sync. They still need to be striped with timecode on one track. See this clip from another youtube user: https://www.youtube.com/watch?v=UNGRONFxoc4
It's also possible of course to use tape sync in the standard way, where the tape deck is master, and everything else slaves to the tape deck. With a direct drive of course, there is no belt to change, ever! Bonus.
I found a 238 on ebay, which I bought after confirming with Denis at 238pro.com that it was a good price. Denis gave loads of tips, advice and part numbers, enabling me to fix the machine more quickly than if I'd been doing it all myself, thanks Denis!
The 238 was missing the shuttle knob. I found I had a suitable replacement in stock, which I'd pulled from another tape deck which I'd bricked in the process of trying to speed mod it (don't worry it was only a Philips shoebox recorder) The original knob is very hard to find, it was not used on (m)any other TASCAM products (unlike the other knobs, which can be interchanged with the M-xxx mixer range knobs) I like the slightly oversize replacement knob. It's too much effort and $ to find an original, for me. Though if you have one spare, email me please: artworkfromewaste at gmail.com
Looking inside, you can see it's a really professional machine. Each track has its own dedicated REC/RP card in a cage at the rear. Massive power transformer and plenty of filtering caps on the PSU card. Accessing the mainboard and the front panel LEDS is fairly lengthy. I decided to only replace all the front tact REC select switches when one goes out of service (normally I'll just do every tact switch on a machine, they have a limited life)
To be expected that some parts are hard to access when you have this much going on in a 19 inch rack case. I think they did really well with the layout:
The FF/RW 12v motor was hanging off for some reason. I would reattach this later. It was easy to reattach, somehow the retaining bolts had let go and fallen into the case. You need to remove the cassette blind to insert the bolts from the front of the transport.
First I recapped the power supply, reflowed the power converters and rectifiers, applied fresh heatsink paste, and replaced the transport tact switches. (this is standard when I'm refurbishing a machine)
Also necessary was deoxit on the dbx switch and the cassette sensing switch (another common issue is for the CSS to become oxidised, the deck then stops, because it reads this information like the cassette has reached the end of the reel)
Then I desoldered the faulty caps and diode, cleaned up the capstan board and soldered the new parts on. I did buy SMT components to replace with, though I ended up using through hole parts which I had in stock. This was because the PCB was already a bit damaged from the corrosion (one pad came off a cap point during work) and I found it a bit tricky to get the right angle. Later, I found how to get a better angle! I considered redoing it with the SMT parts, though decided against it: it worked, so I thought, just leave it. (this took me about three or four days to let it go! : )
Because I had removed the capstan PCB (this is not necessary) I then needed to adjust the end gap of the motor. Direct drive motors have an end gap, which is (basically explained) the space needed behind the motor magnet, for it to be able to spin properly. Using the big flat screw head I adjusted the end gap until the resonant squeaky noise stopped.
The deck is now working great, recorded some audio, it sounds really good indeed. Now I'm looking for a mixer with 8 group outputs, so I can record to it properly and easily. Using DBX I'm going to have to be able to use EQ on the way in to tape, to boost the highs. 8 outputs means I can record all 8 channels at once (something not all 8 tracks are capable of)
After looking around for a while I've settled on the Fostex 812, I'm currently trying to source one! I used to have a Soundcraft Spirit 16/8/2, which I really enjoyed. However, I like to try new things, and the Soundcraft is also a huge beast, even in the 16 Channel version. At some point I'd love to have an ex-broadcast desk like a Calrec, maybe a live desk like an early Midas. Pinnacle would be some cassette module German/Austrian broadcast mixer like Telefunken or Siemens. Right now, the 812 seems ideal for what I want.
The Fostex 812 is modular in build, so if one channel goes out of service or needs recapping, it's easy to remove one channel at a time and still use the mixer. 8 Groups, with nice routing options, fairly compact, 12 channels, sub input. Tidy.
It took me a few days to carry out these repairs. I had put some groundwork in reading up on the issues, ordering parts etc as well. This it was an enjoyable refurb, not too challenging or head scratching.
I thought at first that my machine was missing the bottom panel, as there is not one. However, this is standard for the 238. I made a bottom panel so I can increase the life of whatever surface I put the 238 down onto, until such time as I have a rack to put it in. I had a Roland DEP 5 bottom panel knocking around. I put some new holes in rubber feet on, and attached to the base:
Here's a gallery of some other pics of the interior:
Hi. I just ordered my 238, and it has the jet engine issue, of course. I'd like to recap with the more traditional type components like you used. I have basic soldering equipment so it might be easier that way. Did you use any SMD parts on the repair? I saw the 238PRO site, and Denis names the parts needed. Do you happen to have the simplified list of parts needed? Non SMD type. Also, did you twist off the bad caps to get to the pads? I saw a YT tutorial that shows that being an easy way to get them off without a heat gun.
Anyways, any tips would be appreciated. I'm excited to get this project starte…