Akai mg1214 tape replacement.

D

deslog

Member
Hi there

I have a Akai MG1212 12 track half inch multitrack recorder and a
Akai mg14d which is the rack mounted version using the same tape.

The tape used is in this machine is a proprietary video cassette format( similar to the old Sony beta Tape for video) which uses a 1/2" audio tape.
Apparently the actual tape is TDK-SA, chrome Type II high bias, 70 uS eq.

Other people around the web say that you can re load these with Quantegy 456 but when you try to actually find someone that has and possibly a review of the performance, well I came to a dead end.

A well known technician of these machines said he tried to use and calibrate the Akai with 456 but it could not bias properly. Here is his comment

"As far as Quantegy 456 if it’s the same as Ampex 456 - the overall sound isn’t bad if recording composite music; like from radio or CD, but if recording individual tracks of instruments, the freq response is way off and cannot be biased properly for this tape. The original tape was TDK-SA, chrome Type II high bias, 70 uS eq".
.
Apparently the tape is a Cobalt formula. The original tapes which are no longer made ( Akai MK-20J) are rare and very rarely come up for sale especially new.


Another owner of these machines posted a comment:

"BECAUSE THESE MACHINES USE A COBALT METAL TAPE FORMULA YOU BASICALLY CAN GO OVER THE SAME TAPE OVER AND OVER AGAIN WITHOUT LOSING AUDIO QUALITY". Interesting comment. I wonder how many times you could do this?


I have also heard that some people have used son BETA tape as a replacement.

I am trying to find a replacement so I can refill my cases.

I guess if I try a new type of tape I will try to see if I can get it calibrated to suit if that's possible.

Has anyone got any ideas?
 
Thanks for the advice. I will take a look. Also I wonder about the tape for data storage. Its amazing in this day and age that one of the best archival sorage methods is 1/2" magnetic tape! I wonder what formulation they use and if this could be used also.
 
Data tapes like LTO are likely to be far too thin for the transport to handle safely - you might be better off using SVHS tape or similar. The formulation will also be optimised for storing digital data... biasing it to take an analogue waveform could be interesting. I've never tried it, mind.
 
Normal bias tapes aren't going to work... at least not very well. The tape in the cartridges for the Akai MG machines is high bias like cassette tape or EE open-reel tape. TDK made a beta tape using the SA formulation. It's basically a 1/2" wide Type II cassette tape. Other tapes made for betamax like Sony Pro-X would do as well. People load 456 and similar into the shells, but its not the right stuff.
 
Beck said:
TDK made a beta tape using the SA formulation. It's basically a 1/2" wide Type II cassette tape. Other tapes made for betamax like Sony Pro-X would do as well.
Click to expand...
What is this tape called?

Also the Sony Pro-x? I saw an advert for "Sony Pro Betamax L-500BTPRO L-500 Beta". Would this type work? How would one know the formulation or whether it is high biased?

Is the quote "chrome Type II high bias" something that can be found easly on any given tape?

Thanks for your help. I have sent an email to RMG in France to see if they may have an equivalent. Obviously tape that is still manufactured would be the best way to go.
 
In VHS and Betamax the TDK tape is labeled TDK SA HF. It may also be called Super Avilyn, which is what SA stands for. It depends on what era the tape is from as label styles changed over the years. Tape manufactures loaded the same 1/2" tape in VHS and Betamax shells. VHS tape is labeled in minutes such as T-120 for 120 minutes at SP speed. Betamax is labeled in feet, such as, L-500 meaning 500 feet.

However, I don't think we can say for sure that TDK videotape is what was originally in the MK-20 shells, although it might be and may work just fine. TDK was first on the market with cobalt high bias tape for cassette, open-reel and videotape, but Maxell and Sony soon had their own cobalt formulations. Maxell had XL (Epitaxial) and Sony referred to the Cobalt particles in their videotape as "Vivax."

There's a lot of speculation on the web about The Akai MK-20 tapes and I'm doing some of my own here... but, here's what I know for sure based on Akai literature in my possession:

The tape cannot be Ampex 456 for two reasons. 1) Akai describes the MK-20 tape as being cobalt-based. 456 has never contained cobalt. 2) 456 is too thick for the approximately 375 feet of tape needed for it to run 10 minutes at 7.5 ips. The MK-20 shell is only 6-inches wide and the reel platters inside are less than 2.25 inches in diameter with a center hub of about 1.25 inches in diameter. 375 ft of 456 won't even fit on a 3-inch reel-to-reel. 375 ft of the thinner 457 won't fit either. Here's a pic of an MK-20 tape being loaded into an MG1214, with a 6-inch ruler for reference.

TapeLoading3.jpg

So, the tape is most probably 1/2" videotape, which is thin enough fit the minimum 375 ft inside the small shell and is similar to high bias cobalt-doped Philips cassette tape in performance. It is also most likely higher grade stuff for Superbeta Hi-Fi, VHS Hi-Fi and professional Betacam. These are all 1/2" tapes (12.65 mm). One of the best tapes out there for Beta and VHS is Sony Pro-X. It's a high output backcoated high bias cobalt-based tape. It is different than Sony Pro Betamax. Here's what to look for.


Pro-XL-L-500.jpg


Some notes on the other questions:

Chrome and Type II won't be on the label of cobalt-based videotape. You may see Chrome or something close on VHS and Beta videotape that still used Chromium Dioxide like those made by BASF.

BASF.jpg

CrO2 is the molecular name for Chromium Dioxide like H2O is for water. Chromium Dioxide was used before cobalt for high bias tape. Thus you still see people refer to high bias tape as Chrome or CrO2, and you still see cassette decks labeled with CrO2. People use the terms Type II, High Bias, Chrome and CrO2 interchangeably and though the terms refer to the same tape class and settings, Cobalt replaced Chromium Dioxide many years ago for most high bias tape formulations.

Akai used the VK-30 videotape shell from their own proprietary mid 1970's video recorder for the MK-20J tape shell. It's similar to, but slightly smaller than the betamax and betacam tape shell.

Tape-VK-30_003.jpg
 
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Hello!

I'm not sure if it's any help, but I have loads of new Beta and Betacam cassettes that I'd gladly sell you! I got a bunch of stuff on clearance from a tape warehouse, well over 10 years ago. PM me here if you're interested.
:spank::eek:;)
 
Thank you Beck for the great information.

I was speaking to a guy from a electronic servicing place the other day and he said 20 years ago he used to reload the cartridges with 457 tape.
He said he was able to bias it up properly. He said it is possible to get a run of 457 equivalent from RMG (Pyral France). He said he would make some enquirys for me.
He also mentioned that 457 tape is 1mil thick which is similar to the MK-20J (I think this is the terminology) versus 456 which is 1.5mil. Even if the tape was 1/2 as thick again maybe you could still use it but obviously less length.

Thanks 'A REEL PERSON' for your offer. I will wait to see what the outcome is with Pyral RMG, France before I look at other sources.
 
Yes, any half-inch tape will fit, but the length you can fit in the cartridge will of course depend on tape thickness. And the devil is in the details when it comes to performance. If using a normal ferric oxide like Ampex 457 or equivalent you’ll need the service manual or someone who can tell you how to adjust things like bias and equalization, as well as tape tension for the thicker tape.

Since the Akai MG units are designed for high bias tape the performance will suffer if recalibrated for normal bias tape. It can be done, but you won’t have a machine that lives up to the original Akai specifications. The 3.75 ips low speed for 20-minute runtime would perform poorly. Your best bet if using normal ferric oxide tape is the high speed, 7.5 ips and 10-minute runtime.

The Ampex 457 equivalent from RMGI is LPR35. The 1-mil class in audiotape is closer to 1.5-mil total thickness with the oxide and backcoating factored in. LPR35 is 1.4-mil total thickness. High grade videotape ranges in thickness from about 0.75-mil to 1-mil total thickness.

IMO using normal bias audiotape is the hard way to go because of all the calibration adjustments you’ll have to make and the end result will be sonically inferior to using high bias cobalt-ferric as originally came in the MK-20J cartridge. If I had an MG1212 I would use tape from either Sony PRO-X L-500 betamax tape or Sony BCT-G (20G or 30G) betacam tapes. Anyway, good luck and let us know how things work out for you.
 
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Would this tape be cobalt?

Betacam tape - Fujifilm M321 SP 20 minute ?
- OR - Betacam tape Fujifilm M321SP metal 10M

It's just these are a good buy if they would be suitable.

Also these tapes.....
SONY-BETAMAX-L-500-tapes rather than the Sony PRO-X L-500 betamax tape
 
No, betacam SP is a bit different... more comparable to metal cassette. It's a metal tape, so among other problems the Akai won't bias up to it, it won't erase previously recorded material as completely and will be harder on the Akai heads.

Modern standard Betacam tapes from late 80's and newer are mostly cobalt modified ferric oxide, which is the same as high bias cassette tape. Except for BASF, which used chromium dioxide as I mentioned earlier.

Avoid Betcam tapes with an M, MA or ML suffix because these are metal tapes for the SP format. The box will usually say Betacam SP. There's also digital Betacam, which should be avoided as well. Many brands have a "D" suffix for digital.

For example, the cobalt-ferric Betecam tape you want from Sony is BCT-20G or 30G. The Sony metal tape made for Betacam SP you should avoid is BCT-20MA, 30MA, etc.

Note: In my previous post I made a typo, which I've now corrected. I gave BCT-10G as an example of one of the tapes to look for, but I should have said BCT-20G or BCT-30G because 10G is too short... not enough tape to get the minimum 375 ft of tape you'll need for the Akai machine. 20G is approximately 500 ft long and 30G is approximately 750 ft long, so those would do nicely.

You can try any standard Sony betamax tape, but its best if you stick to tapes in VHS or Beta marked Hi-Fi, or tapes that have high bias cassette counterparts like TDK SA, Maxell XL, etc. The ultra grade type are cobalt modified.
 
OT: Beck, my cousin had once championed mixing to VHS hi-fi. Is this similar? An analog format on video tape, (as opposed to e.g. ADAT?) Just curious.
 
Same kind of tape but totally different technology. The Akai MG machines use heads like a normal reel-to-reel and moves the tape at two standard speeds, 3.75 ips and 7.5 ips, while VHS and Beta machines use helical scan technology (rotating heads) and Audio Frequency Modulation (FM) at very slow linear tape speed compared to stationary-head tape decks.

VHS moves the tape along at 1.3 ips in SP mode. Betamax moves at 1.6 ips, both slightly slower than standard cassette tape. So the linear audio tracks aren't very good quality. But VHS Hi-Fi and Superbeta Hi-Fi have excellent audio specs because the stereo audio is recorded the same way as the video... with fast rotating heads. VHS Hi-Fi has a separate head on the rotating drum for Hi-Fi audio and Beta Hi-Fi uses the same head to record video and audio. The sound is great, and many people used either VHS Hi-Fi or Beta Hi-Fi for mastering in the 80's and 90's... and some still do. I prefer Superbeta Hi-Fi for audio and I still have the Sony Superbeta deck I bought in the late 80's. Superbeta Hi-Fi tapes were accepted at most of the better mastering houses and some still list it as a format they work with.

 
My...

Sanyo SuperBeta Hifi 7250 was outstanding as such, but it's been defunct and needing repair for well over 20 years. I'm not up on, nor necessarily good at fixing VCRs, but I've not gotten rid of this machine. I have some pretty valuable masters that were recorded on it, and much other various Beta recordings. All these years I've been tentative about opening up and repairing this machine, but I've not yet gotten to it, being on a long list of fixit projects that have been sitting for years. I loved that machine, tho!
:spank::eek:;)
 

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I have that long list of things to fix as well. Some day!

Not sure what issues you're having with your Sanyo Superbeta, but the only problem I ever had with my Sony was the tape would load slowly and sometimes wouldn't eject due to a slipping belt. I changed the rubber belt and voilà !!! Now it works like new again.

I once changed the rotary drum in my now defunct Panasonic S-VHS editing VCR many years ago. Had no idea what I was doing when I opened it up, but managed to pull it off and it fixed it for a while. It went south again about a year later, so I think there was just a problem with that model. It was nice while it lasted.
 
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