This is some of the most extraordinary restoration work on an electronic system I have ever seen.
[This is a huge web page with many pictures, but it's well worth waiting for the slow load.]
Project manager was Phil Cirocco.
It’s a 1934 Hammond Novachord polyphonic synthesizer. The tone generator unit alone contains 146 tubes. Cirocco believes that most are the original Sylvania units, but cannot verify that.
There are links to sound files demonstrating the capabilities of the instrument, and documenting “the first spooky sounds it made”, I take it before tuning. Even that first (rather harsh) recording makes it clear you are hearing a synth, not a mere electronic organ or simple tone generator.
The work included completely stripping the point-to-point wiring chassis and polishing the metal, because PCB and tar capacitors had leaked and contaminated everything. The fabric-covered wiring also had to be replaced because it, too, was contaminated.
All resistors and capacitors were replaced, because they had drifted in value over the decades. Modern parts do not drift nearly as badly. Also, as Cirocco notes in the conclusion:
Thousands of passive components must be replaced. A warning to those who tread in my footsteps. I am not being negative here – just blunt. These are the harsh realities of Novachord restoration. This was an incredibly massive job! Don’t embark on it unless you can handle it. For those of you who think you don’t have to restore your Novachord, keep this in mind – The positive rail is at 300v DC. The negative rail is at -300v DC. With more than 1000 70 year old capacitors across those rails, the failure probability factor is nearly 100%. Keep a fire extinguisher on hand.
Lovely job restoring the wood cabinet, too, although as Cirocco says, “[I am] grateful that I am an electronic tech and not a woodworker by trade – to put it nicely.”
The tube power supplies and amplifiers are just gorgeous.
Power supply before:
Power supply after:
Tags: Cirocco, Novachord, restoration, synthesizer