11 comments on “Yamaha SY99

  1. Hi, same thing happened to the end cheeks on my sy-99. I think they are pretty prone to this damage. I am thinking of putting wooden end cheeks in. Separately, my 4zone aftertouch has failed. Do you know anything about this? I reckon it’s mechanical rather than electric and perhaps I should take the whole keybed out and check it out.

    Re the ac/dc power supplies – I just picked up a fizmo cheap because someone thought it was faulty and they were running it of a dc psu when ac/ac was required

    Kind regards
    Ps great site and great projects

    • Thanks!The aftertouch on the SY99 is a plastic strip that is attached under the keybed. The end of it plugs into a small PC board near the power supply. The connector may have come off or the aftertouch needs adjustment (on the small board).

    • The part numbers are VH809500 and VH809200. They are called the left and right end blocks. Unfortunately they are not available from Yamaha US and Japan has stopped manufacturing them. Other countries local Yamaha service centers may have some left, though.

  2. I just bought an SY99 on eBay and didn’t think to ask about a power supply until it had already shipped. It turns out that it will not have one included when it arrives. I don’t see any listings for a power supply specific to this model online. Can anyone give me a recommendation?

    • The SY99 power supply is internal – was it removed prior to you buying it? Yamaha no longer makes this power supply, but I succesfully cloned it, although I had to make a mounting plate for the toroidal transformer that I used.

    • There is an adjustment for aftertouch, on a small board next to the power supply. I’ll have to fire mine up and check it (haven’t powered it on in a couple of years…)

      • “…d check it (haven’t powered it on in a couple of years…)”

        I know what you mean, it weighs so much and its quite unwieldy but it does sound fantastic. Better than the Fs1r somehow. I think my aftertouch sensor is the problem because i do not get degrees of aftertouch if i adjust sensitivity. I think i need to peel the sensor away from the felt and clean it.

  3. Hi, fixed my AT. At the end the carbon and worn away very slightly and because the molex header has hardly any surface area to make contact it was failing. I cut the carbon back and jumped it with some wires directly to the the aftertouch pcb. Details are on my blog

  4. This might be useful for other people owning an SY99. The original transformer that used to be available through the consumer audio division (it was also used on audio amplifiers. you could get it at best buy part department) is no more available. However there is a company based in New York who makes a 35W transformer matching the Yamaha specs and that is a drop-in in the sy99. The company is signal transformer (www.signaltransformer.com) and the part number for the sy99 transformer is : MT-7-12. take a look. I upgraded an sy99 from japan using this transformer to bring it to support 117V. I just needed to replace the power cord to a UL spec cord for 35W and it was good to go.

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