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[ALLEN WRENCH]

Junked capstan motor... this stupid thing's making noise!

[Tim Gilles]

http://www.blevinsaudio.com/

Talk to Randy Blevins.

Tell him what you did, and what you're hearing.

Cleaning the capstan on the JH series is something ya gotta be very careful with.

I try to use a limited amount of cleaner on the 'scrubbing' Q-tip and rotate several  'blotting' Q-tips at the base of the shaft, watching VERY carefully as to where and how much moisture is attempting to migrate into the machine.

As you scrub away... The 'blotting' Q-tips will have to be rotated and replaced, as they can get soaked pretty quickly.

I have never killed a motor doing this, but somebody explained to me(about a zillion years ago it seems... LOL) that this was a possibility if you didn't keep the moisture out of the machine.

Good luck with it.

Tim "Rumblefish" Gilles

PS. A very interesting link to an old article on the Blevins site listed above, with Jeep Harned(The main dude behind MCI)... It's pretty amazing how many 'standards' for analog audio design were pioneered and or/popularized by this guy.

[ALLEN WRENCH]

Cool Tim.  Actually I shot off an email Blevins last night.  I talked with him on the phone a few months ago  when I ordered a manual from them and they seemed super cool.  I?m also going to grab a batch of their used tape.

Also, after pulling the motor out, I found a rebuild sticker from Precision Motor Works, who had rebuilt the motor back in 1990.  So I?ve also got an email off to them.

The REALLY fun part about all of this is that I?m right in the middle of this fucking record!

I?ll keep everyone updated on who?s the coolest and fastest with an AMATURE home studio recording idiot!

If anyone else has any capstan repair resources, let me know!!!

[thedoc]

This company is outstanding with tape machine motors...


http://www.athan.com/  

[David Schober]

Blevins is great and can help a lot.  But there's a very, very experienced guy in the SF Valley that can come out and help you.  Charlie Bolis of Vertigo Recording Services has been doing independent maintence since the early 80s and can take care of you.

He's a great guy...no BS, no hyped repairs.  I'm looking for his email, but can't find it right now.  I'll  have it up either later tonight or or tomorrow.  In any case, here's phone # (818) 907-5161  He's in Sherman Oaks.  If you're just starting out he can help you get that MCI in good shape, make sure head alignment, etc is spot on.  
A poorly setup analog machine will sound bad, analog or not.  It would be worth the money IMHO.

[David Kulka]

Charlie and his crew do outstanding work.  He may not service MCI capstan motors, but contact him, it's worth a try.

You guys are gonna flip when I tell you how I clean the ceramic shafts on these motors.  I pull the motor and take it into the bathroom, then mix together a little Ajax and water, making a thick paste.  Using a paper towel with a little of the paste on it AND HOLDING THE MOTOR UPSIDE DOWN, I clean the shaft several times until it's spotless.  Then, STILL HOLDING THE MOTOR UPSIDE DOWN, I rinse and clean many times with water, making sure I get it clean and dry.  I have probably done this 200 times over the last 28 years and it has always worked perfectly.

When installing an MCI capstan motor (or even just putting one back) you nearly always need to shim the underside, to set it's azimuth.  This is kind of fun, and there are two reasons for it.  One, the tape deck and motor are not perfectly machined so if you just bolt the thing in, it will usually tend to pull tape slightly up or down as it exits the headstack.  Two, gravity.  Even if everything is perfect, the weight of the tape may tend to cause it to "fall down" across the headblock and the capstan.

My trick for this little task is to install the motor with no shims and put it in play.  If the tape path grossly crunches down, the motor needs to be shimmed to lift it up slightly, which means placing a shim between the left side of the motor and the deck plate.  Generally, a small strip of plastic leader, or something thinner, is about right.  If the tape tends to pull up (rare) you put the shim on the right.

If the tape path looks ok without any shims, reduce the supply tension and see what happens.  (The supply tension is what keeps the tape path stable, so reducing it reveals misalignment in the tape path.)  Turn down the tape tension, or just use your hand to gently spin the supply motor counter clockwise, reducing the hold back tension.  Now what happens to the tape path?  If it remains stable for a second or two with almost no back tension the motor is perfect, leave it alone.  It the tape creeps down and starts wrinkling, try a very thin shim (aluminum foil or glassine type paper) on the left.  If it creeps up, place a very thin shim on the right.

Carefully observe the tape path across the 3 heads and the 2 guides.  It should be perfectly centered and stable all the way across.  It's tricky and definitely a trial and error process but if you want to give it a go, these pointers might help get you there.

A further thought.  For all the talk of the awesome tape sound, blah blah blah, I wonder what kind of shape some of these machines are in.  Even when they were new, keeping 24-tracks shipshape and working right required a lot of TLC.  If you're in love with the smooth top end of your 2" recorder, be brave and record a few minutes of 15 kHz.  Do the meters read close to zero, and not bounce too much?  In many cases the answer will be  "oh, geez".  Head geometry and tape path are a big deal.  If those things are out of whack, and that happens very easily, audio quality can take a big, big hit.

[ALLEN WRENCH]

Hey David K.  that?s cool that you posted because after pulling out my motor there was a small piece of plastic on top that I couldn?t figure out how it had gotten there!  Now I?m hip to the shimming.

I talked to Jeff Gilman from Precision Motor Works and it looks like my capstan motor will cost me about $450 and about 4 weeks of precious down time.

A friend of mine has a pro studio (Rich Mouser / Mouse House Studio ? Pasadena) and uses a repair tech named Scott Holderman? have any of you guys ever heard of him?  But I?ll probably end up calling Charlie Bolis also at some point.

An interesting thing with this whole modern tape machine thing? is the situation of armatures/idiots getting a hold of them for home/project studio use.  

I would think that in the past? if someone was to lay down $ 30,000 - $ 40,000 on a machine they would have an idea of upkeep, servicing, alignment and things of that sort.  

But now with the price drop in tape machines due to ProFools, I think you?ll see a few more idiots like myself getting curious and taking the plunge into the wonderful world of analog.

Hey, My  used  MCI JH-16 cost me about $ 1,000 more than an ADAT machine I bought a little less than 10 years ago!

[bobkatz]

As long as we're in the good advice camp, I can add that almost no one pays attention to HEAD CENTERING (also known as wrap, but these are technically two different things). You can get considerably more life out of a head by making sure the center of the gap is at the center of the wrap.

And zenith as well, make sure there is equal wear pattern at top and bottom of head and across the gap.

I do this by painting the head with a sharpie. I know some people cringe at this, but I never ruined a head with that so must be doing something right.

On an old Studer you have to take the headstack off, make a tiny change on the centering, adjust, lather, rinse, repeat if you're not lucky. But you'll gain thousands of hours of additional sond quality by optimizing centering and zenith.

BK

[David Schober]

David Kulka wrote on Thu, 07 April 2005 07:48

A further thought.  For all the talk of the awesome tape sound, blah blah blah, I wonder what kind of shape some of these machines are in.  Even when they were new, keeping 24-tracks shipshape and working right required a lot of TLC.  If you're in love with the smooth top end of your 2" recorder, be brave and record a few minutes of 15 kHz.  Do the meters read close to zero, and not bounce too much?  In many cases the answer will be  "oh, geez".  Head geometry and tape path are a big deal.  If those things are out of whack, and that happens very easily, audio quality can take a big, big hit.

David is totally right.  While I admire your bravery to attack your machine on your own, if these machines aren't setup right they won't sound good.  As one who started out on a MCI just like yours I gotta say, these kinds of machines are more of the "don't try this at home" variety.  Even with full time, experienced staff these babys are a bit neurotic and need lot of attention.  (ever own a Weimaraner?)  Just realize that with the advent of ADAT, DAW's and Mackie consoles, lots of folks grew up without having a regular maintenance staff to keep their studio running.  If you're  jumping into the analog world, you'll need that.

The shims should be a bit of a lesson for you.  Those are essential to making a tape cross over the heads at exactly the right angle.  Screw them up and not only will you find at best, the top end being funky, more likely the tape will be mangled as it goes thru the pinch roller.  Tension on both sides of the heads is critical, as well as what Bob alluded to, which is the wrap of the tape around the head.  Additionally, the heads may be worn and need to be replaced or relapped.  (you may or may not know about that yet)  If that's the case, that will be your next expense.  Otherwise the machine can't play high frequencies properly  


Even though I grew up on this stuff and understand a decent bit of it, if I were to purchase a machine for my use I'd always have a guy like Charlie to keep it running.  In reality, he should have been  your first call...before you bought the machine.  Think of it like buying a 1968 Mustang.  It's a cool ride, but a mechanic needs to check it out to make sure it's running right.  I dont' mean to rain on your parade too much.  I hope for the best and it's a cool ride.

[ALLEN WRENCH]

  Hey guys thanks for all the info!  And yes, I REALLY wish I would’ve been a little wiser before buying my machine from those wonderful people at Pro Audio Designs.  Now I’m a little more hip to the ‘tape machine broker’ concept.

I’m glad to see the input from Bob Katz!  There have been two books I’ve really been into over the last year… one was ‘Mastering Audio’ – Bob Katz, and the other is a really great book everyone should check out called, ‘Mixing With Your Mind’ – Michael Stavrou.  Stav’s spilling all the beans on pro recording concepts and tricks!

Once my ears ‘woke up’, the digital formats have almost become unlistenable, that and the low prices of 2” machines were what pushed me towards going full bore with the 2” analog set up.

Once my machine arrived (9 months late after paying for it in full and with no manual or head report – Thanks PAD!) I soon realized I needed a lot more knowledge than I currently had to get this thing going.  But hey, not knowing anything didn’t keep me from doing my first 2 records, why should it now!

[Brian Roth]

One trick I picked up somewhere is to have some glass blocks made up suitable for the task at hand.  I had a local glass shop make me some out of 3/8" thick material by 1 1/78" wide.  I had several lengths made up.

By placing the appropriate block so it "spans" between two adjacent tape contact points you can tell if everything is "squared up".

The critical points on an MCI machine (and most others) are:

1. Input guide at left end of the head block.

2. Erase head

3. Record head

4. Repro head

5. Output guide at right end of head block

6. Capstan

Bri

[thedoc]

Have you been able to find a manual?

[ALLEN WRENCH]

Yes, I got a manual from the handy... Randy Blevins.

www.blevinsaudio.com