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Paul[_13_] Paul[_13_] is offline
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Default Does Anyone have a Schematic for a Sound City Joanna PianoKeyboard?

On 5/13/2019 8:45 AM, ChrisG wrote:
On 5/13/2019 6:03 AM, Paul wrote:
On 5/13/2019 3:48 AM, Paul wrote:
On 5/12/2019 3:16 AM, Paul wrote:
Mine looks just like this one:

Â*Â*Â*Â* https://www.matrixsynth.com/2017/07/...ty-joanna.html

The power switch LED turns on, but nothing on the output.

A schematic would sure be helpful....


Â*Â*Â* Oh, nevermind.Â* It works.

I used to successfully employ heavy guitar strings on Farfisa and Vox
organs. They would need to be wound with a metal that could be soldered
though, bronze maybe? I later learned that the original busbars and
springs on better quality instruments were often gold plated, so I
probably caused a lot of destructive wear and tear, but I didnt know
and didnt care in those days. I just wanted the thing to work when I
needed it.
Everything corrodes, but gold on gold is pretty good until it wears
through. If theyre gold, it may be worth transplanting old springs from
the upper keys to the midrange to preserve the busbar, and kludge the
lesser-used contacts.


OK, that sounds like a good idea. Heavy guitar strings. I don't
think these are gold-plated, but I could be wrong.

I just compared them, and the guitar strings are definitely
much stiffer, and less pliant, than the original springs, but it
looks like it should work.

Still, is there a source for the original raw spring material? It
would be better, because the stiffer guitar string would definitely
affect the action and feel of the keyboard a small bit.

But this all answers the question of why there were 10 springs
missing in the first place! They were clearly taken from this unit,
and put into another keyboard. And I noticed on the Vintage Synth
website, that they are selling these springs USED, for about $4 a piece!

Hmmmm....no wonder people like to buy old keyboards for the
parts only!

:/




Â*Â*Â* I just need to clean the key springs, and buy new ones
for the ones that are missing.

Â*Â*Â* But a weird sounding keyboard for sure!Â* Nothing like
that old Italian analog sound!


Â*Â*Â* Ok, can I just go to somewhere like Home Depot, and
get stock spring, to replace the old, worn out key
springs?Â* Like get a long length of it, and cut them
to size?

Â*Â*Â* Here is a picture of similar Crumar key springs:


https://xbs111.files.wordpress.com/2...-springs-2.jpg


Â*Â*Â* Thanks for any advice.