The Tascam 238 rocks.

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floid
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Post by floid » Thu Sep 10, 2009 3:13 pm

germaniac wrote:Well, the fix-it guy (Steven) says the caps fail "closed" decreasing capacitance and speeding up the motor. But caps can also fail "open," which could increase the capacitance, and could slow down the motor. So it's most likely the same problem, bad caps.

Regards,
Joe
yeah, think you're right. it's definitely a failing component, leaving it on for a few hours at a time causes it to gradually speed up - in this case, probably a failing cap whose value shifts with temp.
thanks again for that link
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shedshrine
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Post by shedshrine » Thu Sep 10, 2009 3:21 pm

floid wrote:so, speaking of the infamous capstan motor, does anyone have a schematic? digging into the deck, it becomes pretty quickly apparent that the circuitry, not the "motor" itself, is what fails. i keep on putting off shelling out $100 to get a new motor for mine because i remain convinced there must be one of those little dinky resistors or diodes or whatever else is on that board that i could replace for pennies... but without values, nowhere to start :(
germaniac wrote:Actually, I think it's the little SMT caps on the controller board that fail. Here's a guy who done some groundwork and come up with a fix:

http://thesquarewaveparade.com/tascam122.html

Image

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..a monster thread of which the gist is that those same little silver capacitors, when they fail, kill the Dolby S chip, so replace them before that happens, and that that is very fiddly, exacting work requiring a tech experienced with micro circuitry and the precision tools involved.


Image
Tascamwiz of Tascam Forums on Dolby S chip failure wrote:
?90% of the TSR/MSR Dolby-S machines I have worked on (probably more than 20)have problems with the NR in one way or another. Scratcing noises, channels fading in and out, full signal distortion (blowing the studio monitors in the process), just plain dead(no NR at all), etc.....Fostex is not much better, and a whole LOT of Dolby-S cassette decks with malfunctioning NR.....especially the Sony ES and Teac V-8000/8030 series.


Again, it is likely that the issues are caused by tolerance drift of aging circuit components. This coupled with a sensitive Dolby LSI chip causes them to fail at which point circuit diagnosis is impossible. I have tried many different sources for some of these ic's both in the USA and abroad.....no dice. When the chip foundries stop making a particular they apparently do not save the masks and wafer production equipment. There are several different types of Dolby-S NR ic's depending on application and it appears that some major oems like Teac/Tascam had some specific parts made for their machine design.....mainly in bus control and interface logic.

The problem is by the time you hear audible artifacts or notice impaired functioning, the damage to the ic's is most likely already done. The other issue is that unless you happen to live near a shop that can work on these machines, you can rack up $200+ in shipping charges .?

"The interesting thing about Tascam machines in particular is that they can use either the DBX or Dolby-S cards interchangeably as long as they are in the same enable/disable bank. They use the same switching logic interface for both card versions. I had some spare DBX cards for the 238, so I outfitted that particular machine with 4 Dolby-S cards and 4 DBX cards.......worked perfectly fine and the owner was actually happier with the way that worked out. Same thing applies to the TSR/MSR series. If you have one of these machines with bad Dolby cards, you can swap them for DBX cards if you can find them."
witzendoz of Tascam forums on preventing Dolby S failure wrote: "My Machine had the late type boards, the dolby S failed because the caps went out of spec, as simple as that. What I did was find a tech that could solder the micro caps onto the circuit boards. This is specialized work and needs a lot of skill and special tools, as each board failed I got him to fix it. I also had a spare card which I bought to replace the 1st failure (did not know the problem at that time), so I always had a fixed up board on the shelf to keep going. The repaired boards worked fine and the caps were of better quality than the tascam ones so they will probably outlast me.

The components are off the shelf and even the high spec caps are cheap.

Keeping old gear alive is always a labour of love, its like people that restore old cars (and I was one of those once as well), sometimes you have to source parts and workmanship but at the end you get the reward of have a fine piece of old gear.

Cheers

Alan."
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Studio-Integra of homerecording.com said:

"Just replace the SMT caps on the motor PCB..."
Image

"When I got my 238, the capstan motor was also spinning too fast.
I have replaced the caps and it is working perfect now."

http://www.youtube.com/watch?v=3EWNe6sYLu4
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markjazzbassist
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Post by markjazzbassist » Fri Sep 30, 2011 11:49 pm

i'm thinking of downsizing from a 388 to the 238. the 388 is way too big and takes up too much room, i'm hoping the 238 plus a rack mixer will be a lot more consolidated of a setup, should sound pretty close too from the recordings i've heard of the 238.

any suggestions on a rack mixer?

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Post by germaniac » Sat Oct 01, 2011 8:19 am

Hi!

I've got a six-space rack with a 238, a Rane SM82 line mixer, a Neutrik patchbay, and for the moment an Art Dual MP. It's all patched together to work like a PortaStudio of sorts, with the 238 outs normalled to the mixer ins, and so forth. I recommend the SM82 for flexibility, low noise, and neutral sound. The stereo "expand" output makes a usable headphone output for tracking.

I also used to have a 388, and got rid it for size reasons as well. Strictly speaking, I don't think you'll get the same fidelity on the 238 as you will on the 388, but the 238 is very decent sounding nevertheless. I love mine. . . .


Joe

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shedshrine
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Post by shedshrine » Sat Oct 01, 2011 6:09 pm

shedshrine wrote:Similar setup here.
I've got mine currently set up with a patchbay for the 238's inputs, and the 238's outputs go into a 8 channel Soundcraft 200B board.

I use external pres etc. via the patchbay. Watch the levels and gain staging going in, then mix through the board. The 200b channels on mine have the dual swept mids.


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Post by thegreatbear » Mon Nov 07, 2011 3:58 pm

Does anyone have a spare 122 / 238 capstan motor?

I've replaced the caps but the motor still ran too fast I replaced the large BA6411 IC which then stopped the fast running but the motor appeared dead!

I then replaced the BA6303 and I still have a dead motor... I probably lifted a track somewhere but I haven't found it yet...

These motors are getting really hard to find now...
greatbear analogue & digital media ltd - high quality audio and video archive services, tape transfer, restoration and preservation

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Post by thegreatbear » Thu Dec 01, 2011 4:57 pm

We finally got our 238 dbx version working after a long battle with the circuit and Teac parts - neither of which was the ultimate solution!

I've written a blog article here...
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konabuzz
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238 Example....

Post by konabuzz » Sun Dec 04, 2011 8:25 am

Hey all....

Don't mean to hijack thread, but I also really enjoy my 238 (DBX) and have recorded a number of things on the lovely beast. This should possibly go in Listen to My Stuff, but I'm only including it here as it relates to ....the Tascam 238.

http://www.youtube.com/watch?v=IFfLqjz-uDw


The music was a somewhat silly aside, but I think it displays the sonic capabilities of the 238 fairly well.
"Jigsaw Jazz and the Get Fresh Flow"


http://www.youtube.com/user/simpletech?feature=mhee

Teacher's Pet
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Post by Teacher's Pet » Fri Mar 02, 2012 12:57 pm

Hey 239 Experts:

Is there any reason why the 238 shouldn't live in a tilted rack like this?
Does the machine prefer to be level?

Image

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shedshrine
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Post by shedshrine » Fri Mar 02, 2012 2:03 pm

Shouldn't make a difference in functionality. The cartridge door and transport spindles will hold cassettes in place over the heads. Same principle applies to an old Sony walkman.

A record player, another story... :D

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shedshrine
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Post by shedshrine » Fri Mar 02, 2012 2:05 pm

Teacher's Pet wrote:Hey 239 Experts:
Ooooh! The deluxe edition!!

Teacher's Pet
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Post by Teacher's Pet » Sat Mar 03, 2012 6:50 am

Well, mine's one louder, innit?

Thanks,


- Robin

cjogo
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Post by cjogo » Sun Mar 04, 2012 8:32 pm

Just make sure you use short tapes -- get those levels just right ...-- we SMPTE sync'd to a keyboard sequencer .. then had 23 tracks @ mixdown ~!

We ordered 10/15 minute tapes -- never had problems with wow/flutter/etc. It also will save that capstan ...

Made a lot of wonderful tunes with that one ~!
whatever happened to ~ just push record......

bebopcola
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Post by bebopcola » Tue Apr 10, 2012 6:28 pm

Does anyone have an actual user manual , or is the service manual the only thing archived? I only ask because I don't yet own a rascal 238 but am interested

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jonnyh
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replacing the capstan motor

Post by jonnyh » Mon Sep 17, 2012 2:10 am

Just to let frustrated 238 owners know: I tracked down two new capstan motor assemblies from Tascam/Teac US, they we really helpful, the units were about $80 each (they use the same assemblies in some of their dat machines and they do still have stock).

I think rather than bother with replacing caps and chips, its quicker and much less stress to replace the whole assembly. It is actually a fairly easy process for anyone with basic electronic skills.

The real plus i8s that instead of having a repaired capstan motor with thousands of hours on the clock you have a brand new motor ready to roll.
Jonnyh
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