Yamaha DX-11/ TX-81Z -1988    Weight = Lbs. Number mfg.= ? MRP=$795/?/$599

User Manual: Yamaha
Reset Proceedures: Test mode Note
Operating System code:
MIDI or other control protocol:
Software related Links: N/A
Patches or knob settings: Zicweb for TX-81Z! (Ignore the top 'yamaha sounds' link)
Circuit Overview: below
Scematics/Service Manual:
Common Service Issues/Tips: below
Parts Sources: Keys knobs semiconductors misc
Uncommon chips/modules used: Many
General Info Links: Vintage Synth Explorer

Circuit Overview:
     A digital synthesizer which utilizes special processing chips designed to support Yamaha's FM synthesis architecture. This one having 4 operators but offering 8 part multitimbrality. TX-81Z is essentially the rack version I'm told.

Service Tips:
     Probably pretty robust like others of the series. They have the ridged keys so eventually the contact strip might get worn out. Not sure if that one is available. Ask Yamaha.

While Yamaha normally does not keep parts around more than 5 years or so. I try to stock what I can. Out of dx knobs
Contact Sound Doctorin'

Test Mode Notes

Here is a bit from the manual in case you need to reset one of these machines. From my note to sdiy:

The manual says:

When the test program is executed, the voices in the internal RAM area and voice number in the 96 voice number bank area will be erased. Please be sure to save the voices in the 24 internal RAM area on to a cassette and write down the voice names of the voice numbers in the 96 voice number bank area before executing the program. Also the programmed message that is momentarily displayed when the power switch is turned on will be erased, therefore write it down.

------I say Wow. Well that sounds like fun. What's next? "Put your head between your legs and kiss your tail goodbye"? Hehe. Anyway gotta love early MIDI synths here and there. Anyway it runs you through all the test programs and you need midi in and out connected to proceed there and amp with 10dB gain between cassette in and out jacks and Breath controller hooked up and footswitch. To enter the mode you press 1 and 2 voice select switches while powering on Then it gives you a prompt and you press +1 to proceed but also you can split the tests up by booting instead with 1 and 3 OR 1 and 4 instead of 1 and 2 held down. 1 and 3 will execute only the first 5 tests and the 1 and 4 option will do the remaining ones instead of the first 5 tests. (6 through 9). The moment it enters the test mode all RAM stuff will be returned to factory settings I guess. SO maybe that's the ticket if you don't have any data to save. Otherwise looks like a lot of work.-Bob