Digital piano electrics question

TheOtherDennis · November 2017

Not sure if this should be in here or the other instruments section, because strictly speaking it IS about modding/repairs, but if the mods think it's in the wrong place, I guess they'll move it.

Anyway, I bought myself a Yamaha Clavinova CVP 120 off the evil that is bay. The guy was up front in his description of it, so I've no issue with that.

However, what he was up front about was its age (it genuinely has a slot for a floppy disk!) and the fact that the lower speakers (ie the ones slung under the body) don't work. Only the two that are behind the keyboard work.

For what I intend to use it for, this is not an issue - it works absolutely fine through headphones, which is how I intend to play it, mostly. However, without headphones, it's quite quiet, there's no real volume or depth to the tone and it sounds a teeny bit muffled.

However, I was wondering, if I intend to sell it at a future date (and I will - even if I do get on with it, I'll want to move it on for something better, possibly even a real one), is there anything I can do about the previous-owner-but-one's bodge repair job? He's clearly inserted a replacement amplifier thingy and bypassed the old one. It would appear the old one no longer worked, so he bought himself a new one and installed that instead.

If not, and it's too expensive, is it possible to simply remove the speakers from beneath the keyboard, to lighten the weight and make it easier to manoeuvre?

Here's what I'm talking about -

Image: http://www.bemyguestphotography.co.uk/img/IMG_0600.JPG

The red Kinter thing is the apparent replacement, the gubbins below it are apparently the old one (this is what the guy selling it told me), the speaker on the left is one of the two that work.

I only paid 150 quid, so it's not like I've bankrupted myself for it, but I was just wondering if it's possible to do something about it to make it easier to sell later on.

If not, or it doesn't matter, I'll leave it.

TTony · November 2017

This'll be an interesting challenge for @ICBM ;

ICBM · November 2017

Yes, it should be possible to remove the speakers and the extra power amp.

If that amp is genuinely rated at 500W I would think the speakers might be dead anyway...

TheOtherDennis · November 2017

So how would I do it? Is any soldering (or rather, unsoldering) required, do you think? The speakers underneath have a cover that's screwed on - do I just unscrew this and gently tease the wires to see how they're connected and work from there?

All while the whole is unplugged from the mains, obviously.

ICBM · November 2017

They're probably connected with push-connectors. If not, I would carefully snip the wires a few millimetres from the end of the plastic coating, leaving a small piece of the plastic on the speaker terminals so you can see which way round they were connected, in case anyone wants to put it back.

Don't leave any wires flapping around either, if there are loose ends you should put a bit of tape over them - paper masking tape is fine at this sort of low voltage - although you need to check how the power amp is connected, whether it's mains voltage or if it's from the power transformer - I can't quite see.

TTony · November 2017

TTony said:

This'll be an interesting challenge for

Clearly not a challenge at all.

TheOtherDennis · November 2017

There are so many wires going all over the place, it's really hard to say how the red amp thing is powered - I can say that if you look at the red amp, can you see the connection that's wrapped in masking tape? That heads off along the back of the unit to god knows where on the right hand side. There's another wire that connects to the black spiral flex, and that is connected to the board on the right, with a connection that's underneath that board.

The red amp is loose, and isn't screwed down or fixed to anything.

ICBM · November 2017

Are the connectors on the Kinter labelled? I would assume they are.

The black spiral flex is hilarious! I never spotted that before

.

Nomad · November 2017

12V DC, 5A...

https://www.amazon.co.uk/Kinter-MA-150-Amplifier-Digital-Motorcycle/dp/B007STASSK

Pulling 500W out of that is a pretty neat trick.

TheOtherDennis said:

even if I do get on with it, I'll want to move it on for something better, possibly even a real one),

If not, and it's too expensive, is it possible to simply remove the speakers from beneath the keyboard, to lighten the weight and make it easier to manoeuvre?

You maybe aren't aware that a real piano is significantly heavier than a Clavinova - a typical upright weighs about 200kg.

TheOtherDennis · November 2017

Yes, I am aware that a real piano weighs significantly more than the one I currently have, even I'm not that thick.

I didn't expect a real one to be lighter, that wasn't my point. (A real one, however, has castors. This fucking lump doesn't.)

@ICBM The black spiral thing is the power, the other wires are input and output, they've been wired into a push-in connector, then there are two more standard pin ones (red and yellow) on the other end. Whoever put it in has at least tried to be tidy about it, making sure that similar wires going to similar places are bundled together.

Nomad · November 2017

TheOtherDennis said:

Yes, I am aware that a real piano weighs significantly more than the one I currently have, even I'm not that thick.

I didn't expect a real one to be lighter, that wasn't my point. (A real one, however, has castors. This fucking lump doesn't.)

They don't all have castors - mine certainly doesn't. (And those that do will be pretty crap to move over carpet, should that be what's on the floor.)

ICBM · November 2017

Nomad said:

12V DC, 5A...
https://www.amazon.co.uk/Kinter-MA-150-Amplifier-Digital-Motorcycle/dp/B007STASSK
Pulling 500W out of that is a pretty neat trick.

Ah, the good old "Pure Bullshit Power Output" rating again

.

The good news is that there's no mains wiring involved so it's safe to disconnect it. It also means the speakers may have survived, but you would need to test them.

I would remove the spiral cable - which for what it's worth is extremely unlikely to be rated for 5A! - at the other end wherever it goes to so nothing can short, and simply disconnect the speaker wiring and audio signal inputs and tape them up, just in case someone ever wants to put it back.

TheOtherDennis · November 2017

Ok, thanks for the advice.

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Digital piano electrics question

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