Can an Etherwave power supply be repaired?

I recently discovered that my Big Briar Etherwave power supply is dead.  They’re out of production and getting very scarce.  Is it possible for them to be repaired?  If so, does anyone know who can repair them?  Can Moog?

Thanks!

Evan Kahn posted this over on FB:

If anyone is looking to replace the (no longer manufactured) power supply for a (pre-2022) Etherwave Standard, this $20 doorbell transformer will do the trick, wired to a male DIN-3 connector. Yes, the AC voltage is a bit higher, but the linear regulators inside the Etherwave should be good for up to 35VAC.

https://www.amazon.com/gp/product/B0CYWPBR96

Edit: I can only speak for US / North America residents here. Don't use these with a 220V wall outlet.

Hi - 
I'm in search of a power supply solution also and was redirected here. 
I've already tracked down a 14VAC adapter - but I don't believe it has a "middle wire" - which I'm assuming is some kind of center tap. I'm curious if this is necessary, since looking at the Big Briar schematic, pins 1 and 2 seem to be connected.

"I've already tracked down a 14VAC adapter - but I don't believe it has a "middle wire" - which I'm assuming is some kind of center tap. I'm curious if this is necessary, since looking at the Big Briar schematic, pins 1 and 2 seem to be connected."  -  billowbay

It's not a center tap, but an AC ground.  Good grounding is critical for proper Theremin operation.

Since the pins are shorted together, I'm confused about how it "works" exactly..  Just to confirm, also, you've used this adapter/modification and it works well for you? 

"Since the pins are shorted together, I'm confused about how it "works" exactly.."  - billowbay

Here's the EW power section:

Pins 1 and 3 bring in AC power, pin 2 brings in ground.  Internally pins 2 and 3 are connected together, which just establishes circuit ground.  The power connections are AC so there isn't any polarity to worry about.

"Just to confirm, also, you've used this adapter/modification and it works well for you?"

No, but I would have no qualms about using this, and I trust Evan.  If anything, that doorbell transformer is overkill in terms of wattage, but that doesn't hurt.

Don’t know about the original Etherwave Standard, but when I was making a clone, I found that the built-in regulators heated up noticeably with voltages of around 18V at their inputs.

I thought this wasn’t a good thing, so I placed two additional +/-15V regulators into AC-AC adapter.
But for this, I had to electrically isolate pin 2 from pin 3 of the connector in order to apply bipolar voltage to pins 1 and 3.

Don’t know about the original Etherwave Standard, but when I was making a clone, I found that the built-in regulators heated up noticeably with voltages of around 18V at their inputs.I thought this wasn’t a good thing, so I placed two additional +/-15V regulators into AC-AC adapter. But for this, I had to electrically isolate pin 2 from pin 3 of the connector in order to apply bipolar voltage to pins 1 and 3.

Ah - that's interesting - did you use the LM78L12 in your clone?  They're supposedly rated for up to 30v. 

My approach would be to hang a 100 ohm ½ watt resistor off of the AC Transformer terminals 0 & 3. This keeps extra heat outside the box. I measured the EWS at about .035 amp current flow.

Christophe S Becker
Old Temecula

"Ah - that's interesting - did you use the LM78L12 in your clone?  They're supposedly rated for up to 30v."  billowbay

It's not the maximum input voltage that you generally worry about, it's the voltage drop across the regulator, which for a linear regulator gets turned directly into heat.  Heat inside a Theremin enclosure is generally a bad thing as it causes drift.  And if the regulators aren't heatsinked (which they aren't in the EW) even if they have internal thermal shutdown (which the LM do) heat will shorten their lives.