Electone
Well-Known Member
I know this is not your typical thread as it is about a musical instrument, but it's a Yamaha and it has audio amplifiers and power supplies just like an audio receiver or amp. I thought it may be an interesting read...
The Yamaha Electone FX-20 was manufactured from 1983-1987 and was the flagship home model based on the stage model FX-1. It cost a whopping $23,000 which translates to $55,000 today . I paid $300 for mine a few years back . This was Yamaha's first foray into digital synthesis technology in keyboards and has both FM generated voices and digital sampling. It also has a massive sound system with 210 watts of power that can shake the foundation of your house. Many of you will recognize the name Yamaha GX-1 as played by Keith Emerson, Stevie Wonder, Benny Anderssen and John Paul Jones. Same family of instruments, except a decade newer.
My plan is to re-cap the massive power supplies and amp board in this beast. There are thousands of electrolytic capacitors in this instrument on hundreds of circuit boards. Changing out each one would be a monumental task.
The FX-20:
The power amplifier power supply unit has 4 Nichicon CE caps. 2 x 10000uf 55v, 2 x 10000uf 65v. Also, it has several smaller caps on the underside of the unit. They have been replaced with Cornell Dubilier SLPX 10000uf 63v & 380LX 10000uf 80v. All smaller caps will be replaced with Nichicon PW. The original Nichicon CE caps were four-lug with the wires wire-wrapped around the lugs. The CDE caps are two-lug and what I did was to install bullet connectors.
PA power supply:
Bottom:
Bullet connectors (male & female) installed on new caps:
Old Nichicon CE and new CDE with female bullet connectors crimped and soldered in place:
Completed PA power supply (notice how much smaller the CDE caps are):
Next up will be the instrument's main power supply. It has two massive transformers and one oddball Nichicon CE cap rated at 28000uf, 16v. I've checked for a replacement and cost is quite prohibitive. So, I tested it and it seems fine. I'm going to leave it for now. The smaller caps on the huge heat sink will be Nichicon PW. Top side of the main power supply:
Bottom side has 2 x 6800uf 35v, 3 x 10000uf 16v & 3 x 6800uf 25v. These will be replaced with CDE SLPX caps:
Third power supply unit supplies power to the panel lights and some accessories. Nichicon PW for this as well:
Main amplifier. Top half is the 90 watt center channel with a STK089. Lower half is the 60 watt x 2 left & right channels with STK085.
Since it's in the general area, I'll recap the expression pedal as well:
This is the now empty lower half of the instrument. The PA power supply sits on the far left, the expression pedal just to the right of the big woofer. Behind it sits the PA and to the right is the main power supply. There is miles of cabling in this thing.
Well, that's where I am right now. I'll post an update when I'm done.
The Yamaha Electone FX-20 was manufactured from 1983-1987 and was the flagship home model based on the stage model FX-1. It cost a whopping $23,000 which translates to $55,000 today . I paid $300 for mine a few years back . This was Yamaha's first foray into digital synthesis technology in keyboards and has both FM generated voices and digital sampling. It also has a massive sound system with 210 watts of power that can shake the foundation of your house. Many of you will recognize the name Yamaha GX-1 as played by Keith Emerson, Stevie Wonder, Benny Anderssen and John Paul Jones. Same family of instruments, except a decade newer.
My plan is to re-cap the massive power supplies and amp board in this beast. There are thousands of electrolytic capacitors in this instrument on hundreds of circuit boards. Changing out each one would be a monumental task.
The FX-20:
The power amplifier power supply unit has 4 Nichicon CE caps. 2 x 10000uf 55v, 2 x 10000uf 65v. Also, it has several smaller caps on the underside of the unit. They have been replaced with Cornell Dubilier SLPX 10000uf 63v & 380LX 10000uf 80v. All smaller caps will be replaced with Nichicon PW. The original Nichicon CE caps were four-lug with the wires wire-wrapped around the lugs. The CDE caps are two-lug and what I did was to install bullet connectors.
PA power supply:
Bottom:
Bullet connectors (male & female) installed on new caps:
Old Nichicon CE and new CDE with female bullet connectors crimped and soldered in place:
Completed PA power supply (notice how much smaller the CDE caps are):
Next up will be the instrument's main power supply. It has two massive transformers and one oddball Nichicon CE cap rated at 28000uf, 16v. I've checked for a replacement and cost is quite prohibitive. So, I tested it and it seems fine. I'm going to leave it for now. The smaller caps on the huge heat sink will be Nichicon PW. Top side of the main power supply:
Bottom side has 2 x 6800uf 35v, 3 x 10000uf 16v & 3 x 6800uf 25v. These will be replaced with CDE SLPX caps:
Third power supply unit supplies power to the panel lights and some accessories. Nichicon PW for this as well:
Main amplifier. Top half is the 90 watt center channel with a STK089. Lower half is the 60 watt x 2 left & right channels with STK085.
Since it's in the general area, I'll recap the expression pedal as well:
This is the now empty lower half of the instrument. The PA power supply sits on the far left, the expression pedal just to the right of the big woofer. Behind it sits the PA and to the right is the main power supply. There is miles of cabling in this thing.
Well, that's where I am right now. I'll post an update when I'm done.
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