I also have been using Yamaha instruments among others....for a very long time, Acetone top 1, Electone D2B, Electone E 10 AR, then Hammond X66, Hammond B3000, X66 again, Roland E20, D20, Ensoniq SQ1, Yamaha DX 100, Yamaha Electone FX1, Yamaha Electone HS6(2) with all the modules CVS 10 AVS 10 and MDR3, Korg X3, Yamaha Electone EL 90, Roland VA7, Ketron X1, Ketron SD1, SD1Plus, Yamaha PSR 3000, Korg PA500, PA800, Roland BK 5, PA 600, Yamaha Tyros 2,3,4,5 Genos, now I also have other 2 Hammond X66 just to be enjoy at my place...no gigging with those....I am to old to carry all that weight.
One thing for sure, when I purchased the VA7 did not like it at all, I sold it less than 3 months from the date I purchased, at the time, I was living in Mexico and could not test the instrument before I made the purchase...But, when you have the chance to test it several times, and did not like it...why buy it?, and if you do, you already have a negative predisposition, aptitude or bad expectative. I know that X brand is not for everyone, perhaps W or Z....
I feel bad for the guy, and I agree with Gary, is very probable that the AC is not as stable, I did deal with that long time ago(around 42-43 years ), when I went to perform with my Hammond X66 ( it had a motor for the tone generator and another for the scanners/vibratos), I did play in a small community out of my town, and they had a line of light bulbs around the court, and every time I push the expression pedal, the lights dimmed and the tone of the organ went down....could not play very loud, so, to say the least, it was an interesting lonngg evening....!!! A friend of mine was playing with a Roland in another place more recently, and when the voltage drop below 110 W. simply the Roland turned off.
In my case, I am glad that I really like my Genos, and to my 51 years as a Pro musician, is a treat to use it, besides the perks I get collaborating with Yamaha making some of the Expansion Packs.
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mdorantes