another new 388 thread...

  • Thread starter Thread starter telenerd
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telenerd

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ok... so i'm sure you guys are thrilled to see another new guy who just bought his first tape machine come on here and ask the same questions, again. too bad, here goes...

first, my back story. so i've been dreaming of getting into this analog recording stuff for at least a year now, and i had my mind made up i was going to go the mx5050-8 1/2" route. and i'm all ready to pull the trigger and i stumble onto this 388 local for $150. a friend of a friend knew a guy who's cousin knew a guy who works for this sound/theatre install company, they go to this ancient studio to renovate, and this guys boss tells him to throw the 388 in the dumpster. thank god he doesn't, he takes it home and puts the word out. he has no idea what the thing is/what it does/if it even works? he makes like $8 an hour pulling wire. anyway, i go check the thing out, it powers up, the meters light up, i pull the right tensioner up the transport functions work, play, FF, RW, i push as many buttons as i can, they all blink/light up, i don't know if it works, what the hell... i buy it. done deal, $150 and now i'm on an adventure.

the fun part... i've been searching and reading and searching and reading. so i'm going to try and make this as painless as possible. i downloaded the manual, i know i have to read that cover to cover. i'll be calling tascam this week to get a belt and a pinch roller. i'll also be ordering a reel of lpr35 1mil and a take up reel. i know to clean the tape path the best i can with 90%+ isopropyl, rubber parts with rubber cleaner, etc.

here are my questions:
when the term calibration is used, are we talking about setting the tape speed and tension? is this something that i can learn to do at home? i know i'll need things like an oscilliscope, etc. if the shit hits the fan there are 3 tascam repair centers within driving distance, so...

can someone recommend me to a good head degauzer for this machine?

is there anything that i am not considering or am unprepared for? i know it's a complicated machine and anything could happen, but i'm friggin determined so any and all advice will be appreciated.

i can't post pictures until i have 5 posts apparently, so i'll be posting pictures in the near future. thanks for any advice in advance, if it weren't this forum, i would already be in over my head.
 
Welcome!

Get a Han-D-Mag. I've gone the other route and tried to save money. Its not worth it. Others will agree. It is the only one to get.

Calibration is basically getting uniform signal levels. What goes in is what passes thru/goes to tape/comes off of tape. It is also related to setting the bias level. Mechanical tape path adjustment precedes the electronic calibration

I was in the same place is you 18 months ago. welcome to the adventure. The 388 is a great machine. We can help you.

The manual you downloaded...is it the full service manual? If not you will need to get it, and I recommend contacting Tascam first.

If you want to do your own full calibration you will need:

* Han-D-Mag
* MRL calibration tape
* signal generator (you can use simple PC tone generator software, but you'll need some way to verify the level going to the 388...you can use a multi-meter, but there are a couple caveats...ask if you go this route)
* Oscilloscope...analog is ideal. There are ways around it...PC oscilloscope, non-oscilloscope methods, but an analog scope is really the ideal.

Post up more questions, and congrats on your find. If the 388 is in good sape and functional, you got a great deal, especially since it was local...no shipping and no risk of shipping damage.
 
...

Tape tension can be set by eyeballing the relative position of the R/L tension arm adjustments. With tape loaded and in Play motion, the center of the tension arm rollers should line up with the bottom of the tack and impedance rollers, as if you could draw a line against the bottom of the tack/imp-rollers and it should intersect the two tension arm rollers. When the positional geometry of the tension rollers are adjusted as such, tension is correct. The proper adjusment of the R/L tension arm positions will also have a tangible effect on the efficiency of the FF/RW functions.:eek:;)

See: Reel/Servo card adjustments.
 

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i do believe it's the full service manual, its got the parts lists, exploded diagrams, and mechanical adjustment procedures. it doesn't use terms such as "calibration " though. it has procedures for head alignment, in which it says my machine requires no adjustment due to semi-fixed record head, and a fully fixed erase head. it also states that tape tension is "precisely factory adjusted, in general [it] should not be readjusted." it does say that i can do a head azimuth adjustment, fast winding speed adjustment, wow and flutter check, and a tape speed adjustment. i'd be lying if i said i was familiar with all of these terms, but i'm sure i'll be quite familiar in the near future.

my list of stuff to get has expanded to this:

belt and pinch roller
tape/takeup reel
head demagnetizer
calibration tape
oscilliscope
tone generator

am i missing anything? any recommendations on an oscilliscope? if i'm gonna do it i'm gonna do it. and a tone generator? i know i will need one in the future, as i plan on aquiring a half track mastering machine, and i know to send analog tape to be mastered for vinyl i need to have put a sequence of tones on the tape, so the machines will sync up. any suggestions on that then? i am determined, so no matter where this machine ends up, it'll be a good experience, i am sure of that.

3 more posts and i can post some pictures. i'm anxious because i have some particular questions once i am able to do that.

thanks for welcome.
 
Sounds like you have been reading up, good man! Don't forget to heed the warnigns about tape - NO AMPEX/QUANTEGY made prior to 1995. I thought I had some good older Ampex 456 tape I had saved, but less than one pass over the heads and I couldn't record at all.

AK
 
I'd agree,...

I'd agree that the heads shouldn't need adjustment. The head plate and way they're mounted is very rigid. You could check it, which is the main maintenance operation that requires a scope. It's more likely the record/play circuits may have drifted which might put your response off 3db or more, and if that's the case would need adjustment. You can tell 'bout how the deck's doing thru some simple testing. Any deck that's been decades perhaps without any calibration is gonna need a little tweaking to be 100%. However, the 388 doesn't require much tweaking and can sound pretty good. Any tweaking could be taken at a pace, but you should be recording right out of the box. When you get reels & tape, that is. Good luck!:eek:;)
 
Wow, I had forgotten which machine wasteh 388..... I remember drooling over these when they first hit the market. Guess now I will have to keep my eyes peeld for a good deal on one, and maybe if I can repair and sell a couple of those consumer decks I got my wife might even let me buy one......


AK
 
I did want to mention I found an awesome (and FREE!) computer based O-scope/analyser etc on the web. It is called VisualAnalyzer (no spaces). Let me see if I can find the link real quick. If anyone is interested, drop me a note and I will email it to you, it is worth a look.
It has a frequency counter, signal generator - heck EVERYTHING. Now if I can just get it to make the coffee right....


http://www.sillanumsoft.org/



AK
 
analogkid, thanks for the link. though i will be needing the real deal soon enough.

my tape should be here anyday, so we shall see what kind of shape i'm in.

areelperson, what do you mean "simple testing?" do you have any suggestions or tips?
 
My simple tests on the 388's I have had (after initial cleanup and de-gunk) consisted of running the same signal thru all eight line inputs, recording them, then playing back thru all eight outputs, then down to 4, then doew to 2.
The idea was to check that all of the signal paths were passing audio, and the meters on all channels were deflecting the same on both record and playback. (visual test)
Then, with a set of headphones, sample the input signal and then the playback signal two channels at a time( left and right ear) and, keeping one the same, punch thru the other seven in the other ear. This is the rough test to check if all channels input and playback at the same level.
(ear test)
This is not as precise as a scope by any means, but at least you will be able to hear if there is a big problem up front.

Whern you get a scope, make sure it is at least two if not four channels. This way you can side by side compare channel inputs, outputs, inpout to output, etc.
 
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