Yahama MT8X Mk1 | Tear Down | 1 | Open Case, Remove Transport

[@justinriley158]

Although I will never own all of the machines you’ve provided rare info on (I can’t think of any other resource that even comes close…), I very much appreciate your efforts. 🍻

[@brendanhayter3869]

Hell yeah man! I have an MT8XII at home with a dead master bias oscillator - meaning it does everything BUT actually record music into tape. Through much effort I learned that Yamaha created a proprietary bias oscillator that only exists in the MT8X and MT8XII machines, apparently. So…if you ever have a dead one of these laying around for parting out, lemme know if you wanna sell me an oscillator! \m/

[@Tetrakan]

Not my machine unfortunately...above my pay grade to blithely suggest this but I'd have thought you could Jerry rig a new master oscillator? Any LC oscillator which produces 85khz would do, you could probably build something on Vero board for buttons?

[@sequentialcircles]

Very happy to have stumbled upon your channel. I got one of these in a swap about a decade ago for a graphic equalizer. I finally decided to do a deep dive into it and remembered there was a reason for me not using it. The major issue with it seems that after 5 or 6 seconds or so the tape will just stop. When I take the tape out a little tape will be hanging out of the bottom of the cassette. Not sure if it's a belt or motor issue. Or something else entirely.

[@tab2072]

I’ve got exactly the same issue with mine, did you get to the bottom of it?

[@CarlDidur]

@@tab2072 That is the wee belt that lifts the heads up. Quick fix. $.50 part

[@CarlDidur]

small belt!

[@tab2072]

@@CarlDidur any idea on the part name/number?

[@CarlDidur]

​@@tab2072 If you can take the machine apart and remove the tape transport you will see a motor with a very small square profile belt, about the diameter of a quarter. It drives a post with gears on the bottom which in turn lifts up the heads. When the belt gets just A TINY BIT stretched it can't pull the heads up and the machine can't "sense" its state and auto-stops. The belt never even looks bad but a new one always cures it. I have seen a half dozen (I am a tape tech as well). Lots of good vids about it! You can do it. A batch of generic small belts 25 - 40mm from Amazon will have something suitable. I don't have a dimension or part number for you since I eyeballed it from my box of belts. It is possible to get at the transport without unseating any wire harnesses as there is enough clearance to move the lid to the left, exposing the tape deck. Fiddly, but no special tools required. Someone more diligent than I will have the specific info now that you know to look for it. Best of luck!

[@SpringySpringo]

Hey, I ordered this machine used but the tape heads are now stuck in the engaged position. Not sure what to do now because i figured it was an issue with the belts because it did have the 8 second problem, but i cant completely open the back because the heads are blocking the way. Do you have any advice?

[@SpringySpringo]

nevermind

[@andrewfoley3808]

Recently purchased a yamaha mt4x, do you know if the internal components of the mt8x differ greatly from it? Cheers

[@Tetrakan]

It's been a while since I had one if those, but the transport is definitely the same as a Tascam 424 mk ii or mk iii, so have a look at my tear downs on those models...the MT4X is a similar size and layout to the later 424s so there may be other similarities?

[@andrewfoley3808]

@@Tetrakan thanks. It's a solid device, really respectable mixer section. Do you have any experience using the midi timecode sync capababilties of 4-track recorders?

[@Tetrakan]

Not yet. I mean, I understand roughly what is involved, but other than using the sync out with pocket operators and volcas, using the sync out on tape multitrackers something I've experimented with, musically.

[@michaelgrossman7361]

Hello, I have an mt8x that I bought used. Changed both belts and it worked great for a few months. All of a sudden, Channel 8 records but only plays back through cue and a few days later channel 3 no longer records and channel 2 records at super low volume. Input levels are fine. Heads were cleaned/demagnetized routinely. Any thoughts?

[@Tetrakan]

Probably aging capacitors or solder. Very occasionaly I'll actually need to replace an opamp. It'll probably require some troubleshooting to figure out exactly what tio replace. Here's a video where I go thr9ugh that process, allbeit on a much smaller multitracker. kzbin.info/www/bejne/nIfWYXSCrqqIg7s

[@travisraab]

Oooh i've been thinking about these guys. What do you think about the sound and build quality on these vs the portastudios?

[@Tetrakan]

The foam they used as a dust guard had rotted, the felt used in tascams is a better choice, were it not for that I'd say the build is as good or slightly better. I'm skeptical that tape recorders sound significantly different....like, tapes sound different, tape speeds sound different, noise reduction schemes sound different, preamp designs vary quite a bit so you can get a significantly different sound by hooking up an external mixer, but unless the calibration is off or there are bad components in there I would expect a 488 and an MT8X to be hard to distinguish in a double blind test.

[@travisraab]

@@Tetrakan great info!! Well said good to know.

[@josephmajor8580]

hey man - really helpful videos! I have an MT8x and I'm experiencing an issue where recording an overdub on track 2 will record over track 1 and vice versa. Same goes for tracks 5 and 6. Any other configuration works fine. Might not be an issue specific to this yamaha unit, but do you have any ideas why this could be happening?

[@Tetrakan]

Sorry for late reply....possibly a previous owner connected the erase head to the wrong sockets....open it up and check?

[@richardsmith4992]

...no supermonobloc???

[@Tetrakan]

It's still my psuedo surname (psurdonym?) but I've seen the spelling slaughtered in forums and the like, so in the interests of shorter URLs more referrals and suchforth I've abbreviated it.

[@richardsmith4992]

@@Tetrakan Can he fix it? Yes he Tetrakan...but sometimes Tetrakant....;)

[@Tetrakan]

I'll take that strapline under advisement