YAMAHA RA100 Keyboard Amp Leslie Thing. HELP!

[greenstax]

Hi all,

I've recently bought an old Yamaha RA100 Keyboard combo with a view to repairing it. three quick questions really,

1) When I turn it on, the horns at the top start spinning, the light comes on but when I plug anything in there's no sound. When I turn it off, there is a mains thump/pop through the speaker(s) (hope you know what I mean) that seems to happen with all solid state amps. Does this sound like a simple fault to anyone or could it realistically be anything? The fuses look ok but I'm not sure where else to look / where to start.

3) short of buying one of ebay, does anyone know where I can get hold of a service manual for this amp? The net seems a bit light on information, but maybe I'm looking in the wrong places (being a simple guitarist!)

2) Does anyone know anything about these amps / have one / have an opinion on whether they're any good or not?

Any help / advice / info greatly appreciated

Cheers

[Enzo]

used to order manuals right from Yamaha. They tended to cost $15 or something, but they were very thorough and well done. Can't think of anyone who makes better manuals.

The power thump means the power amp is probably working, and the lack of sound means no signal is getting to it. See if the preamp power supply is getting to it. The trace a signal through the preamp. APply some signal - even just noise - to the power amp and see if it comes through

[Peter Naglitsch]

I have one of those. I got it a few years back to run my Rhodes and my Hammond X2 (I think X2 is the name) solid state 70’s Korg rip-off (sounds really good thou). It has the advantage of being able to run in Leslie mode fast/slow and in some “full range” mode. Perfect for a E-piano and an organ. Real small, light on weight and the sound is OK. On the negative side; You cannot upgrade the treble horn (would be nice) a really boring solid state pre/power amp means you need some extra tube preamp, the bass speaker doesn’t pulsate at all (have been thinking about some mod, but I’m to lousy with electronics). Anyway, it was a bargain and worked fin until it started to behave exactly like yours. I solved it by bringing out my guitarport, use the Leslie mode in that and running it directly to the PA. Also we got ourselves a “real” keyboard player, so now I concentrate on the guitar.

[vintagekiki]

I have schematics for RA100
send me your email on
vintagekiki@yahoo.com
vintagekiki