Just bought an MCI JH-16 24! Questions about locking up and slowing down.

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Scrappersa

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Hey guys, I just purchased a MCI JH-16 24 Track Machine. It has the JH114 transport but sat inside of a storage unit for about three or four years without being used. I know that this is normally not a good thing for older machines. The machine seems to play audio for about 30 seconds to a minute or so and then the tape starts to slows down and it locks up and makes a big screech sound. I am extremely new to 2 inch tape machines but I am confident in my ability to fix things and solder as long as I know what the problem is and how to fix it. I've cleaned the heads and I am pretty sure that the tape is not sticky because it doesn't seem like it and it is 90's Ampex 456. I haven't been able to calibrate the machine yet because of the problem. Has anybody had this problem before and do you know where to start or how to fix it? What are some troubleshooting steps that I could take to figure this out?
 
Check the rubber parts anyway, but yeah, I've seen sticky tape do things like that.

EDIT: Doubly so if the Ampex tape is pre-1995. Get some RMGI tape and try it with that.
 
Yeah, it's 1990 - 1995 Ampex 456.

The rubber parts feel fine. Not sticky but not hard.
 
Spool the 456 into the trash can and admire your new take up reel. Clean the tape path real well, of course no alchol on the rubber parts. Also dont allow the alchohol to run down the capstan and/or rollers. I have three 2" machines up and running, and I wont even mess with 456. Get yourself some good tape, align the machine to it and enjoy!
 
Spool the 456 into the trash can and admire your new take up reel. Clean the tape path real well, of course no alchol on the rubber parts. Also dont allow the alchohol to run down the capstan and/or rollers. I have three 2" machines up and running, and I wont even mess with 456. Get yourself some good tape, align the machine to it and enjoy!
 
Scrappersa said:
On second thought, it's totally sticky shed isn't it?
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No Doubt!!!

The exact number of people who have encountered these symptoms, searched the web for answers, bought the service manual and taken the machine half apart before realizing it was a problem with bad tape the whole time, is not known… but judging from the cries for help on music/recording forums all over the web… it’s a lot!


Ampex/Quantegy from 1995 to early 2005 is all good, as is 3M/Scotch 206, 207, 986 (The replacement for 226, which is all sticky), AGFA/BASF/EMTEC 468 and BASF/EMTEC 911. And of course RMGI 468 and 911... if you can aford it.

And if you want to go the +9 route you've got 3M 996, BASF/EMTEC SM900, Ampex/Quantegy 499, Quantegy GP9 and ATR.
 
Here ya go…

New 3M/Scotch 206

TAPE SCOTCH 206 BRAND NEW 10 1/2" X 2" REELS FACTORY SEALED - VERY RARE FIND! | eBay

If you can get past the somewhat annoying, breathless, and inaccurate description by the seller, this is great tape…. worth every penny. It was not rare in 1 and 2 inch as the seller believes. It was the high-output tape of its day and quite popular in professional studios. One of my favs. I don't know who the seller is, but seems decent based on the feedback.

He also has a new reel of 207 in 2" for $80.00.
 
Thanks for the advice guys. I'm going to have to buy a new reel to test this out.

Hi Beck, I read almost entirety of the sticky tape thread last night. It kept me up way later then I should have been! If I calibrate my machine with an +6 MRL, can I use +6 even +9 tape? Or is there some conversion process so I can switch between without having to buy a whole new MRL tape?

Was Quantegy 456 one of the sticky shed culprits or had they solved the problem at that point? How about Quantegy 499?
 
No Quantegy has sticky shed problems and no 499 ever did, it's pre-1995 Ampex (besides 499) that will be sticky.

Congrats on your MCI machine! Thank god for the 114 transport or I'd think you're totally bonkers ;)

Get thee over to the MCI Recording forums where there is a forum dedicated to MCI 2" machines. Trust me on this one, before you do anything else, clean and resolder every Molex connector in the thing, all of them, just do it! Also make sure your PSU is sending the correct voltages or you'll have some weird problems. You will find that a re-cap will be on the to-do list if it hasn't ever been done. It will be a substantially awesome sounding machine when you do the usual MCI refurbing stuff to it!

As for the MRL cals, if you have a +6 cal tape you're fine to cal for +9, just crank the meters back 3db. Don't even put the MRL on there until the transport is aligned, correct tension set and the tape path tested, cleaned, de-magnetized and ready to go, MRLs cost a mint and you don't want to ruin it!
 
Yeah, that sticky shed thread has gotten pretty long and involved.

Ampex fixed the problem with sticky-shed tape in late 1994 by switching from a problematic polyurethane binder to a new one. Ampex sold their magnetic tape division to Quantegy about a year later. So the very last Ampex lots and all the Quantegy is good as far as sticky-shed goes. 456, 457, 406 and 407 all had problems before the new binder, but 499 never had sticky-shed even though it was introduced in 1991. For some reason they used a different binder with 499 even before the sticky-shed problem was understood. Just lucky I guess.

If you calibrate to 250 or 320 nWb/m you can use a wide range of tapes. I've found the best results by calibrating to 456 at either of those flux levels and using other tapes like Quantegy 406, BASF 911 and Scotch 206 without altering anything.

If you have a +6 (355 nWb/m) MRL tape, you’re getting a bit hot for tapes like 406 or 206. You can tweak levels and bias for a particular tape for absolute best performance of a certain tape (noise vs distortion), but in practice I’ve found there’s a range of bias settings that will work for a given tape. It doesn’t sound better or worse, but just different. You can use any MRL tape to calibrate to any flux level by adjusting for it. It’s best if the MRL tape you have is the right equalization… either IEC or NAB. You can make adjustments for that to, but IMO the math gets to be a headache.
 
My MRL is actually one of the older ones on Ampex 406 (probably has sticky shed). I have to check if it's NAB or IEC but I think it's NAB. If I wanted to use +6 or +9 tape, would I just crank the meters forward 3db or 6db? I'm heading over to the MCI forums right now. There should be lots of good info! I'll definitely resolder those molex connectors.
 
I just got my dehydrator today. Is there a special way to fit a 2" reel into it? Do I have to cut some of the plastic discs?
 
Scrappersa said:
I just got my dehydrator today. Is there a special way to fit a 2" reel into it? Do I have to cut some of the plastic discs?
Click to expand...


Yes, use wire cutters to cut out the plastic in one or two of the trays (whatever it takes to fit) so you end up with a spacer or two. The trays I have look like this. I cut the "spokes" out as near to the outer edges as possible.

15794006.jpg


Also don’t trust the temperature setting knob to be accurate. You can use an inexpensive meat thermometer. Insert it inside the exhaust vent at the bottom if you have a Nesco Snackmaster or similar.

s_MLV_v_O_f_28578065_8723.jpg


You’re just using the tape to test, right? You wouldn’t want to use it for recording because it will go back to a sticky state within weeks.
 
Thanks for the information Beck. I actually have an MRL tape from 1989 that's on Ampex 406. It seems to have all of the sticky shed characteristics. Hopefully this can restore it enough to use it to calibrate the machine at least once.
 
The tape baking works! Thanks guys.
 
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