Post by RandomHero on Dec 4, 2006 10:34:37 GMT -5
My cousin's late father had this now 50-year old Wurlitzer electric piano. He knows he could find a great value for it if it were professionally restored as an antique, but in respect for his father he would much rather restore it to working order himself and use it in his music. There are three fundamental parts to it.
The mechanical piano action resembles a normal piano. There are a couple of snags with it, but nothing I can't fix, for the most part it's in surprisingly working order. It's shown here with the keys removed for the purpose of cleaning under them.
Mounted in place for the hammers and dampers is what seems to be a combination electrostatic pickup/sustain block/acoustic element. The hammers strike and damp tiny metal rods, each having an amount of what appears to be solder on the end, filed to a certain mass to resonate at the desired frequency. Here's a closeup of the reeds.
I'm not entirely sure how this thing works, electrically speaking. There is what seems to be the equivelant of "ground," the chassis of the assembly, which was electrically grounded to the amplifier circuit in many places before its' removal. The only piece attached to the amp that seemed to be "hot" was the metal plate shown here, which I have a patch cable attached to.
With the cable plugged in, this generated an -extremely- weak signal, but enough for a gain-cranked guitar amp to reproduce the sound. Of course, the input gain of the tube amp in the piano is probably a bit higher, to accept an electrostatic signal instead of an electromagnetic one, right?
Speaking of the amp, here it is. It's tube, and seems to have two 6V6's, a 12AU7, a 5Y3, and another smaller tube which I can't identify. Every one of them is fried.
I'm assuming by the age of the thing that fried tubes isn't the only problem, but for now I want to see if I can identify these and replace them, And perhaps I'll get lucky and it'll work then.
The piano has an internally mounted 6X9 speaker, which is unmarked. I'll be acquiring a digital multimeter soon, to test it.
The mechanical piano action resembles a normal piano. There are a couple of snags with it, but nothing I can't fix, for the most part it's in surprisingly working order. It's shown here with the keys removed for the purpose of cleaning under them.
Mounted in place for the hammers and dampers is what seems to be a combination electrostatic pickup/sustain block/acoustic element. The hammers strike and damp tiny metal rods, each having an amount of what appears to be solder on the end, filed to a certain mass to resonate at the desired frequency. Here's a closeup of the reeds.
I'm not entirely sure how this thing works, electrically speaking. There is what seems to be the equivelant of "ground," the chassis of the assembly, which was electrically grounded to the amplifier circuit in many places before its' removal. The only piece attached to the amp that seemed to be "hot" was the metal plate shown here, which I have a patch cable attached to.
With the cable plugged in, this generated an -extremely- weak signal, but enough for a gain-cranked guitar amp to reproduce the sound. Of course, the input gain of the tube amp in the piano is probably a bit higher, to accept an electrostatic signal instead of an electromagnetic one, right?
Speaking of the amp, here it is. It's tube, and seems to have two 6V6's, a 12AU7, a 5Y3, and another smaller tube which I can't identify. Every one of them is fried.
I'm assuming by the age of the thing that fried tubes isn't the only problem, but for now I want to see if I can identify these and replace them, And perhaps I'll get lucky and it'll work then.
The piano has an internally mounted 6X9 speaker, which is unmarked. I'll be acquiring a digital multimeter soon, to test it.
