MKII Q88 not sending MIDI to TG100

[ceddm]

I had this beautiful vision to have a lightweight 88 key keyboard to play vintage sound modules with. And just as that dream was about to come true, the TG100 and powered speaker all warmed up, the MKII dropped a turd on my musical utopia. I know what you're thinking "You fool! You didn't use the recommended 9V/500mA power supply (not included) when connecting this device to an external sound module." But you'd be wrong. I did use the recommended 9V/500mA PS and the TG100 just laughed in its face. "You call THAT a midi signal?" it said. And the MKII just whimpered and shrank into the corner of the room where it apparently rightfully belonged.

"No no no!" I thought. There must be some mistake. The MKII is sending strong enough signals, they're just probably slightly different signals than the TG100 is expecting. So I ran it through MIDIOX and the dim reality began to dawn on me. Note on and Note off messages on channel 1 of various velocities--EXACTLY what the TG100 craves to be delivered to its rear midi port. My worst fears were coming true. The MKII is a p***y and can't raise its 2022 manlet voice loud enough for the chad TG100 to hear. "Did you say something?" the TG100 mocked without turning face.

I still refused to accept reality at this point. I went into my closet and dusted off the ol' ship's anchor 68 key yamaha from the 90s. One of those children's ones. There's no way this piece of s**t can do what a $220 midi controller from the future can't. Right? R-r-right?

I hurled that sack of s**t onto the stand like I was dumping a body into the Hudson. A new wonder of the world was added to include the fact the power adaptor happened to be alongside it in the closet. I connected all the cables. I switched it on and watched its putrid blue screen flash in greeting. With trepidation I pressed a key. SOUND! SOUND from... the 90s! It was all there in its cheesy glory. The TG100 turned its head and winked at me as it said "Oh that's what you wanted? Why didn't you say so?" And I just stood there with a thousand foot stare wondering how it all got to this point.

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Okay real talk I bought a $220 midi controller and its signals are apparently so anemic they can't communicate with a sound module from 25 years ago. Like bro, that's your entire job. You produce midi signals. How did this make it out of the design room? I get I'm doing something a little niche but c'mon. I'm just salty about it and there are apparently no products for my use case. I just need to vent. We live in such a throwaway culture and I try to be scrappy and bring new life into old things but this world won't let me. Apparently the only way to do that today is to become a f***ng engineer and design or mod products that will interface with new and old.

Am I the only one who's tried this? If not please commiserate with me and wallow again in your sorrow.

[Eddy Deegan]

The MKII is sending strong enough signals, they're just probably slightly different signals than the TG100 is expecting. So I ran it through MIDIOX and the dim reality began to dawn on me. Note on and Note off messages on channel 1 of various velocities--EXACTLY what the TG100 craves to be delivered to its rear midi port.

If MIDIOX can see the data coming from the Alesis then so should the TG100 (or any other module, for that matter).

Whatever the problem is, if you're seeing data from the Q88 then it's nothing to do with 'weak' or 'slightly different' signals. The Q88 is a MIDI controller and, barring a hardware fault, will meet the required specs.

You don't say if you're using DIN or USB for the MIDI. Presumably to get notes to the PC running MIDIOX you are using the Q88's USB output (or are you connecting the DIN to a MIDI interface on the PC?) and to connect directly to the TG you're using the DIN output, but glancing through the manual there appear to be some settings which may affect whether it sends MIDI out of the DIN socket or not, one of which means it can be configured to be a USB->DIN bridge (see page 9 of the manual) in which case it might only relay MIDI sent from the PC out through the DIN port. I don't have a Q88 so I can't test that for myself.

Have you tried controlling anything else with it or recording MIDI from it into a DAW? Also double check the 'Input/Output Options' section on page 8 of the manual.

[Hugh Robjohns]

As Eddy suggests, this feels like a configuration problem, rather than a design failure!

[N i g e l]

The Yamaha TG100 from 1992 ?
I would suggest that a hardware problem is more likey to be in the 30 yr old unit rather than the modern MKII.

MIDI Rx circuitry requires an LED opto coupler and these can become less efficient over time and become out of spec, especially ones from last century !
[in 1990, things like LED TVs or house lights were not technically feasable. ]

[Wonks]

If it works from another keyboard, then it's not likely to be the TG100, which logically wouldn't work with either of them.

[N i g e l]

If it works from another keyboard, then it's not likely to be the TG100, which logically wouldn't work with either of them.

not necessarily true because the two keyboards may have different drive strengths (due to tolerances).
If the Rx is marginal one kb might be over and the other under the threshold.

[Wonks]

I still think it is more likely to be the configuration issue Eddy mentioned.

In this document https://mitxela.com/other/ca33.pdf, the change to 3.3v from 5v power (and 3.3v is what the Q88 is most likely to have) can mean that there are certain instances where a MIDI spec compliant 3.3v transmitting system isn't compatible with a legacy 5v receiving system. But looking at the TG100 circuit diagram, the TG100 both a) has an optocoupler and b) doesn't take power from pin 4, so both the mentioned possible incompatibility issues are covered.

Remember that it's a current loop rather than a voltage sensitive one. The receiver circuitry is the same on both the 5v and 3.3v power circuits. It's only the transmitter circuit that's got different value resistors in, but both standard transmitter circuits are designed to provide 5mA+ current to the same receiver circuitry.

But we really need the OP to respond first before speculating further.

[N i g e l]

I still think it is more likely to be the configuration issue Eddy mentioned.

I am not saying its more likely, just that its an option that cant be ruled out without further info.
I have recently added MIDI out to a Korg Volca so I am aware of the 3.3V / 5V MIDI spec. I was a bit surprised that the MIDI spec Resistor values were so low, compared to the ones I had worked out from actual gear measurements [into a modern Nord]

Then I thought - backward compatibility with last century !
I think the standard 3V3 design has been thought through to include the old gear, as to be expected.

Remember that it's a current loop rather than a voltage sensitive one. The receiver circuitry is the same on both the 5v and 3.3v power circuits. It's only the transmitter circuit that's got different value resistors in, but both standard transmitter circuits are designed to provide 5mA+ current to the same receiver circuitry.

But we really need the OP to respond first before speculating further.

All the resistor values are different
Modern resistors are probably 1% tolerance whereas in the 90's it was 5% or even 10% ?
Dont forget the volts drop across the opto LED. It will probably be greater on the older opto. In the 90's, there were no LED TV Screens or LED household lighting, the technology has advanced greatly .

If youve got the circuit, what opto does the TG100 use ?
these things deteriorate with time, even transistors.
I replaced a transistor on the sustain pedal input of my alpha juno because it had lost its gain and stopped working.

[Wonks]

It's a 6N137 (diagram doesn't state a manufacturer).

The MIDI spec states ±5% tolerance for the resistors for both 5v and 3.3v transmitters. so even the 90s ones must be at least that. But the notes section on the diagram doesn't specify the resistor tolerance at all, so you'd have to look at the bands on an actual resistor to find out.

I can only find a picture of the top of a TH100 circuit board and there are no resistors in sight. Must be at least a double sided board (if not multi-layered) with the resistors on the underside.

Here's where I found the service manual.

https://elektrotanya.com/yamaha_tg100_s ... nload.html

There is a loopback MIDI test you can perform if the unit is put in test mode, but as it works from another keyboard, I expect it will pass that test OK. (refer to the TG100_SM2_C pdf).

[Hugh Robjohns]

Modern resistors are probably 1% tolerance whereas in the 90's it was 5% or even 10% ?

I was using 1% resistors in the 80s, so I doubt that would be an issue!

[N i g e l]

Perhaps I should have said standard use run of the mill resistors.
Indeed 1% and better were available then but whether the extra cost would have been justified in their use as standard part in a commercial design is another matter.

[Hugh Robjohns]

Perhaps I should have said standard use run of the mill resistors.
Indeed 1% and better were available then but whether the extra cost would have been justified in their use as standard part in a commercial design is another matter.

Possibly... but not relevant anyway as the resistance value isn't that critical in the MIDI drive/receive circuitry.

[Eddy Deegan]

Perhaps I should have said standard use run of the mill resistors.
Indeed 1% and better were available then but whether the extra cost would have been justified in their use as standard part in a commercial design is another matter.

Possibly... but not relevant anyway as the resistance value isn't that critical in the MIDI drive/receive circuitry.

Configuring the device not to send data out of the DIN port, on the other hand ...

[ceddm]

I read all of your replies and frankly you guys are on another level above me in terms of analyzing schematics and the evolution of voltage in the midi protocol. I have nothing meaningful I can contribute in that line of inquiry.

That said I have made some progress diagnosing this and I may indeed be wrong that it's a midi signal strength problem. Since I wrote the OP I've been able to hook up a sound card to test the midi out of the MKII from that. And surprisingly I was not able to read any midi signal through it. When I then hooked up that kid's keyboard from the 90s it has no problem sending midi through the card.

I mean I guess it still could be a midi signal strength problem but this sound card is a 1st gen scarlett 8i6 that was manufactured around 2015. It was outside the realm of possibilities for me that a brand new keyboard would have a busted midi out. Even the barest of QA should catch something as obvious as that, right? And I don't want to get too conspiratorial but this keyboard doesn't come with a power supply (and alesis doesn't manufacture one either so you have to just go 3rd party and pray) which the manual demands you use if you choose to control an external sound mod. Would they really cut corners on their midi port assuming their customer base won't likely use it (or at least not before the warranty is up)? I probably just got a lemon and I hope it's only that...

[James Perrett]

Have you tried a factory reset? From P13 of the manual...

Factory Reset
1. Power off Q88 MKII.
2. Hold down the buttons "+" and "-" simultaneously, until step 4.
3. Power on Q88 MKII.
4. Release the buttons.
The Keyboard is now back to the factory default settings.

[ceddm]

That was one of the first things I tried actually. And just to be sure I tried again now with the same results. I don't see how it could be anything other than a bad midi port at this point.

[James Perrett]

In which case, if you bought it from a retailer, it needs to go back to be replaced. If you bought it used then you've probably found out why the seller didn't want it.

[ceddm]

It was new from the Alesis seller on Amazon. It'll be returned to get replaced and I'll post an update when I get the replacement.

[James Perrett]

That's one good thing about Amazon - they are excellent with returns in my experience. I returned a faulty item last week from a third party seller and the refund was in my account as soon as they saw the item was in the post.

[ceddm]

WOW -- Just received and tested my 2nd MKII. This one was used, "Like New" and is in *pristine* condition. THE MIDI OUT DIN PORT DOESN'T WORK ON THIS ONE EITHER!! Like previously I tested against my old 90s keyboard which had no problems outputting midi via DIN using all the same cables and equipment.

And not only this but something strange happened before this keyboard came in. When I couldn't get the DIN port to work on the first one I immediately called the Alesis customer service. The technician couldn't help with my case so I was told a "level 2" technician would call me back within 1 business day to help resolve my issue. They never called back. That's not the weird part though. Yesterday I was on amazon and I noticed the price of a brand new Q88 MKII from the Alesis seller on amazon DROPPED $50!! That's an almost a 25% discount OUT OF THE BLUE. After seeing this 2nd keyboard's DIN port not work I've gone full conspiratorial and I think they're trying to get rid of as many of these as they can before word gets out that they're all defective.

All this is such a shame too because it's otherwise a great design and I really wanted it to work. There isn't another lightweight (10 lbs) 88-key keyboard with a minimal interface, decent key-action and accessible price point. But I don't know how any of this could have gotten past QA. I think it's reasonable to assume that this is an issue with every single Q88 MKII. Did Alesis try to pull a fast one to save money expecting their customers to never test the DIN before the warranty expired? I just don't know how this could possibly happen unplanned.

[Wonks]

I don’t think you’ve said whether you’ve configured the MIDI output to go to the DIN port as previously mentioned. If you don’t it won’t work.

[James Perrett]

I don’t think you’ve said whether you’ve configured the MIDI output to go to the DIN port as previously mentioned. If you don’t it won’t work.

As I understand it, you have to configure it to NOT send the MIDI output to the DIN connector. If you do a factory reset the DIN MIDI output should automatically be sending data from the keyboard without any further configuration. That's why I suggested a factory reset in my post above.

Or is there a software bug that means that the factory reset doesn't reset the DIN output to its default?

[ceddm]

I don’t think you’ve said whether you’ve configured the MIDI output to go to the DIN port as previously mentioned. If you don’t it won’t work.

From the manual in the "MIDI Out" section: "By default (when you switch the unit on), all controller data is sent out via the MIDI output as
well as the USB out."

I have also done numerous factory resets on each of these to ensure it is operating with this default.

By all means order an MKII yourself and prove me wrong that their DIN ports work. I'd love to get another person to corroborate (or disprove!) what I've found. I've tried everything I can conceive of to get anything out of these DIN ports.

[Wonks]

OK James, I see what you mean now.

Did your external 9v 500mA PSU have a centre-positive connector? If you got the appropriate Alesis one then fine, but a lot of generic 9v PSUs are centre negative and it's an easy mistake to make.

[ceddm]

Did your external 9v 500mA PSU have a centre-positive connector?

Yep, center-positive. And as far as I'm aware Alesis does not sell any official power supply of this kind. They demand you buy 3rd party if you wish to use the functionality that requires it (such as using the DIN port to message an external synth/module).

[Mitchell1234]

Hi I just bought a new Q88 MK II and I am having same problem. I am going into an older QSR rack module and it won't work out of the midi out, but if I run out of the usb out through my Kenton midi USB host interface into the midi in on QSR, it works perfectly. I have tried my other keyboards with the midi out from them and no problem, changed cables etc. Have you had any luck figuring this out, or is this midi out on the Alesis not working?

[resistorman]

Hi I just bought a new Q88 MK II and I am having same problem. I am going into an older QSR rack module and it won't work out of the midi out, but if I run out of the usb out through my Kenton midi USB host interface into the midi in on QSR, it works perfectly. I have tried my other keyboards with the midi out from them and no problem, changed cables etc. Have you had any luck figuring this out, or is this midi out on the Alesis not working?

Is it possible MIDI thru is enabled?

[Mitchell1234]

Do you mean midi thru enabled on my rack synth? I don't think so, if I use another synth or piano with midi out, the rack synth receives controller info perfectly.

[sonics]

I just read this entire thread and didn't see any mention of MIDI wiring. There could be an issue there. Not all MIDI cables (or devices) are wired the same (or correctly)! I've seen pins 1/3 linked to 4/5 and then 1/3 grounded on a device = no MIDI.