How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Rusty Your Own Question
Rusty, Music Professional
Category: Electronic Musical Instruments
Satisfied Customers: 5905
Experience:  Sound Engineer, Electrical Issues, Tone Consulting
Type Your Electronic Musical Instruments Question Here...
Rusty is online now
A new question is answered every 9 seconds

1989 vintage Bose Ensoniq Piano AWD - very low sound output

Customer Question

1989 vintage Bose Ensoniq Piano AWD - very low sound output thru built in speakers, with high freq hum. Started after long term storage. Internal battery dead as it doesn't store songs. Headphone jack sound is correct / amplified without hum
Suggestions for disconnecting built in speakers (or better) fix for hum ? Would it be related to dead 3v lithium battery?
looks like this
Submitted: 2 years ago.
Category: Electronic Musical Instruments
Customer: replied 2 years ago.
URL didn't show -- perhaps a policy? check out Freedom Guitar Item 8394 similar model
Expert:  Rusty replied 2 years ago.
Hi Bob, my name is Rusty. The headphones and speakers use two different amplifiers. That is why your headphones sound correct, but your speakers do not. You can plug your headphone jack into an amplifier, and it will give you amplification. Bose will have trouble fixing it, due to its age, and they will likely try to sell you something new. Your best bet is to use the headphone output with an external amplifier at this point, unless you can locate replacement amplifiers for the speakers. The battery wouldn't cause the speakers to go out, that's due to long term storage. However, it is recommended that you replace the battery.
Customer: replied 2 years ago.
Rusty. Thanks. Essentially what I had assumed. I was hoping for specific info on how to repair myself - had no intention of sending it to bose. I could find a shop manual online download for $25. Do you know a free source ? saw a YouTube of a similar keyboard disassembly to get at battery. Li battery on mother board. But again, battery is not causing the buzz - just keeps songs from being storedWhat components dry out and fail ? Capacitors? On a good day I could unsolder and replace.That said, too much bother to fix internal amp I'm sure the best route is disconnecting the built in speakers - the subwoofer probably will
work ok and shouldn't respond to the hi freq.Thanks
Expert:  Rusty replied 2 years ago.
Capacitors can go bad when they sit, you'll see white powder leaking from them. That is very likely, and it's worth taking a look. The amp module can also go out. I would recommend opening it up and getting a visual. I don't have a source for a free manual, but it's not a tough job. Remove the screws from the bottom of the piano, and the covers will come off enough to take a look at the circuitry. The PCB you are looking for is attached to the speakers. Check those caps, and if you don't succeed, at least that only powers the speakers, and we can go with plan B, using the headphone output.

Related Electronic Musical Instruments Questions