The No.1 Website for Pro Audio
tape loop in Yamaha MT3X 4 track recorder
Old 8th December 2018
tape loop in Yamaha MT3X 4 track recorder

Hello all.
I'm trying to make tape loops work in my Yamaha MT3X but the auto-stop function keeps making the tape stop after a few seconds.
Does anyone know how to disable autostop on these decks?

I appreciate any input!
Old 14th February 2019
Here for the gear

I would also love to know how to disable this.

I did read somewhere it is to do with the take up spool not rotating - indeed when I manually rotated the take up spool the tape look would keep playing.

I'm not really able to read a schematic but if someone knew it was a matter of snipping a few wires or installing a switch I'd definitely have a go. I guess it's a case of providing a signal to some sensor, so I feel like it should be possible.
Old 14th February 2019
Yeah there is an optical sensor that picks up some white dots on the shaft of the supply reel. I dont know how to bypass it at all.
I thought I could just connect the legs of the sensor. Nope, that fries a resistor.

If anyone knows how to disable these optical auto stops, please let us know!
Old 14th February 2019
Here for the gear

Well you're a lot further along than me if you got that far. I'm afraid I'm no use to you - I opened it up and promptly put it back together. It's well beyond my limited capacity to work on such things.

I decided in the meantime to work on making a tape loop in which both spools rotate but even that is proving irritatingly tricky.
Old 14th February 2019
I have a few different lengths of these:
If I could get them to work it would be super sweet. They can be over 1min. Long!
Old 14th February 2019
Gear Guru

On most tape machines that I have used, the auto-stop is a lever that falls down when there is no tension on the tape.

your loop is probably "too long" for size of your machine

As are most loops recorded at high speed. So the lever falls down and shuts off. You need to have enough tension on your loop so that the lever stays up. No more than that, but some tension.

What we always used to to was to tape a pencil to a chair or nearby shelf in such a way that the tape loop had to run out to the pencil and back again. Move the deck or the chair or the pencil to get the tension correct. I would leave the empty reels on the deck. They will spin away, but they will help guide the tape back across the heads again.

EDIT: I see the deck in question is a cassette. Still, I would still try the tensioning thing. I don't know how the optical sensor plays into this, but maybe try painting out the white dots?

Last edited by joeq; 14th February 2019 at 09:12 PM..
Old 14th February 2019
Hey Joeq,
Thanks for the response. Unfortunately this is one of the later 4 track cassette decks that uses the optical electronic circuit and not a mechanical stop.
If the photo sensor doesnt see motion, it initiates auto stop function. I'm unsure of how to take the autostop out of the circuit without interrupting other transport functions. There are a lot of ICs in there.

Old 14th February 2019
Gear Guru

In this video he shows what part of the circuit does the stop function. Maybe there is something in there that could be useful to you. He does not tell you which wire to cut, unfortunately.

At about 2 minutes he talks about how some alcohol dissolved the dark paint. He said something about repainting it to "fix" the auto-stop, but it wasn't clear to me what he was fixing. i.e. is he fixing the fact that it no longer stops or fixing the fact that it stops for no reason.

I guess it depends on whether it wants to see high voltage or low voltage or just a change in voltage. Maybe you could stick a small flashing LED light in there opposite the photocell and spoof it.

Old 15th February 2019
Here for the gear

joeq - Thanks very much, there's some interesting stuff there. And as you say a flashing led might just do it.

standingwave - However, in the absence of an electrical solution, would a mechanical one possibly work? I've tried placing a rubber band around the two shafts of the spools, sort of underneath the teeth (or behind the cassette), and the take-up spool does rotate and the rubber band doesn't seem to be in the way of anything else. I think it would be a matter of finding a band with enough tension to ensure the take-up spool rotates but it doesn't drag on the motor, but I think it might be a possible temporary work around.

I guess one thing with tape loops (if yours are as lofi as mine) is that they're not exactly dependent on perfect playback speed
Old 15th February 2019
Thanks Joeq
I actually watched that video. Unfortunately it is how to fix the autostop. The blinking LED is an interesting concept and would probably work.
I'm going to try the rubber band first! If that works, itll be a brilliant and easy solution.

As far as tape speed: I myself am recording onto the deck as an effect, or using it as an instrument; I modulate the tape speed a lot anyhow. This ain't no Bruce Springsteen record.
Old 15th February 2019
Thumbs up

I got it working! I used a small hair elastic.
I tried a few sizes bit this one is perfect: Goody brand for fine hair.

I can just leave it in there and forget about it.
This was a perfect solution.
Thanks for all the help guys!
Attached Thumbnails
tape loop in Yamaha MT3X 4 track recorder-2019-02-15-15.56.15.jpg   tape loop in Yamaha MT3X 4 track recorder-2019-02-15-15.56.32.jpg   tape loop in Yamaha MT3X 4 track recorder-2019-02-15-15.57.04.jpg  
Old 16th February 2019
Here for the gear

Aw yiss! I tried exactly the same sort of hair tie yesterday, but underneath the top cover, and I was a bit downcast when it would rub and end up tangling around one of the shafts. But your method, with the rubber band on the outside the top cover, works perfectly. Excellent work.

That said - if any electronics genius is reading this thread, I'd still be interested in an electronic mod to disable the autostop...
Old 16th February 2019
Completely disabling the autostop would be best for sure. The LED with and LFO would probably work: I'm lazy now though.
I'm just super stoked that I can make some funky loops now!
Old 16th September 2019
Here for the gear
NordMode's Avatar

I'm posting this after a bit of a research of this MT8X 8-trakker.
There is Cassette Mechanism test mode which does not limit use of the unit but only disables Auto-Stop mechanism for testing purposes.
You can enable this mode by pressin PLAY button + Track 1 button while powering on this unit. REMAIN will flash on display when this mode is on No need for rubber bands or Leds with LFO or
Just got my first tape loop done this way.

You are welcome.
Old 16th September 2019
That's awesome! I didnt see anything about this in the manual. I'll try it on the 3X later today.
I really appreciate you sharing the discovery!
Old 16th September 2019
Here for the gear
NordMode's Avatar
How did it go with MT3X?

This info was in service manual.
Was looking for knowledge here, when I signed up for the forum.
Just bought 2 of these mt8x's, both defect.
One I got working quite fast, a bit of adjustments in cassette mechanism.
2nd I could not power on so had to refer to service manual.
Funny I stumbled on this information by accident. Karma I guess.
Old 17th September 2019
Hey I'm actually just in front of my MT3X right now. This model actually does not have buttons for track selection.
There must me some combination of buttons to press if other models in the same line have that function.
Either way, it was way cool of you to add to the knowledge base about these aging recorders.

If anyone reading this has a service manual for the MT3X, please have a look for us!
Old 17th September 2019
Here for the gear
NordMode's Avatar
Here is a link to MT3X service manual. On quick search I could not find this Cassette Mecha test mode, but only made a glimpse on it.
Old 17th September 2019
Thanks for the link. I looked through the manual as well. Unfortunately it looks like were stuck with elastic bands for now. Its not as graceful of a solution, but it does work without much of an issue so far.
Again, the input is appreciated.
Post Reply

Welcome to the Gearslutz Pro Audio Community!

Registration benefits include:
  • The ability to reply to and create new discussions
  • Access to members-only giveaways & competitions
  • Interact with VIP industry experts in our guest Q&As
  • Access to members-only sub forum discussions
  • Access to members-only Chat Room
  • Get INSTANT ACCESS to the world's best private pro audio Classifieds for only USD $20/year
  • Promote your eBay auctions and listings for free
  • Remove this message!
You need an account to post a reply. Create a username and password below and an account will be created and your post entered.

Slide to join now Processing…
Thread Tools
Search this Thread
Search this Thread:

Advanced Search
Forum Jump
Forum Jump