Etherwave --> ??? --> Diamond Speaker

Posted: 9/30/2019 1:33:52 AM

From: Halifax, Canada (east coast)

Joined: 7/28/2019

Let's say one was theoretically that I wanted a genuine looking diamond theremin speaker like this:

Possibly using this as a guide:

Now we see this is just a speaker and if I just hooked it up to the Etherwave it wouldn't be very loud.

What would you recommend for an amplifier for this? 

Also, is it a really dumb idea? Would it sound terrible?

Posted: 9/30/2019 2:24:07 AM

From: Northern NJ, USA

Joined: 2/17/2012

"What would you recommend for an amplifier for this?"   - DanielMacKay

Plenty of modular and plate amps at Parts Express:

"Also, is it a really dumb idea? Would it sound terrible?"

Open backed speakers can lend a lot of resonance and room ambience to your sound.  You might try your Theremin through an open-backed guitar amplifier to try it out.

Posted: 9/30/2019 2:32:33 AM

From: The East of the Netherlands

Joined: 6/18/2019

Just hooking a speaker up to an Etherwave won't work, there needs to be an amplifier beween the theremin and the loudspeaker, which on the input side doesn't distort the relatively high (line) level signal, and an output impedance that roughly matches the impedance of the loudspeaker and a wattage that is not higher than the loudspeaker can handle. Personally I'ld prefer a small tube amp like maybe a guitar amp modified to have less input gain than what most guitar players want, or a mono line level tube amp. Otherwise a keyboard amp with output for an external speaker.

My own current amp(s) & loudspeaker(s) setup is a Fender Greta with a lower gain preamp tube and an upgraded internal speaker, usually going into a 1950s vintage open back radio extention loudspeaker cabinet and/or a Vox Lil' Night Train with a lower gain tube in the phase inverter stage, going into its matching front ported closed back cabinet with a 10" guitar Celestion (?) 16 ohm loudspeaker (and at least a diamond patterend grill cloth). The loudspeaker in the vintage cabinet is also around 10" and the impedance probably 8 ohm (DC resistance ~ 5 ohm). The Etherwave's audio out goes into a preamp with level adjustment, then sometimes an effect pedal, then going into a Vox Valvetronix Tonelab modeller/multiFX unit and from there into one or two amps, or one of the amps gets directly connected to one of the outputs of the preamp. The Greta and Lil' Night Train are both not in production anymore, but could perhaps be found for sale 2nd hand.

If the Diamond speaker is in good condition, it should not sound terrible (ok, that depends much on the playing as well, but just the sound in itself should be good, just as my 1950s cab sounds good with a nice acoustic quality to it).

Posted: 10/1/2019 3:37:25 PM

From: The East of the Netherlands

Joined: 6/18/2019

I've uploaded some pictures of my setup that show the small tube amps and speakers I'm using.

DreadVox Photo Albums

Posted: 10/1/2019 4:56:52 PM

From: Halifax, Canada (east coast)

Joined: 7/28/2019

Thanks guys! I think I'll hold off on the diamond speaker for now.

I wonder what "Doc" Theremin used in his? Maybe the amplifier was built into the RCA theremins?

Posted: 10/1/2019 7:19:23 PM

From: 60 Miles North of San Diego, CA

Joined: 10/1/2014

Daniel, you are in the fun period of theremin exploration. Almost from the beginning my interest was in how someone creates the best theremin sound. That one guy does it for $5000 and so as one would imagine this knowledge does not come easy. For ten years I have shown how $5 in simple parts gets my sound which is analog and naturally that did not catch on with the misguided bit-shifters with their latency issue.

Here is some data I collected on the RCA 106 which was intended as a main amp speaker for an early AM radio. Modern diamond back speakers I think are an alternative to a pitch preview approach. You would not need more than 5 watts mono as only “you” need to hear it. Many amplifier modules are on the market today to fill your need for under $10.


Posted: 10/2/2019 1:38:53 PM

From: Brooklyn, New York

Joined: 11/25/2005

RCA Theremins have a single ended triode (171-A) for the amplifier. The 106 speaker is really only good for an RCA Theremin, not modern theremins.

Evidence from the only known surviving diamond speaker (Clara's) shows that it likely had a RCA 106 Loudspeaker installed (currently has a modern speaker and a matching transformer mounted inside the RCA cabinet).

At some point in the future I will be making more diamond speakers that will be authentic replicas of Clara's, as Floyd had to make a few guesses since he only had a small amount of time to measure and document it. I got to spend 2 full days with the speaker and the modified RCA.

I'll post when I will be taking pre-orders for the replicas. They will not be cheap, but if anyone is interested, let me know here or send me a message. I am thinking that I will have different tiers for different speakers/no speaker.


Posted: 10/2/2019 10:58:27 PM

From: Halifax, Canada (east coast)

Joined: 7/28/2019

wow, amazing, thoughtful thoughts guys!  thank you!

Posted: 10/18/2019 9:12:45 PM

From: Pittsburgh, Pennsylvania

Joined: 1/1/2011

Here's the one I made along with the amp.  It has way more volume than I would ever need at home. The speaker is a 12" rebuilt speaker that I got from a guy in New York on Ebay but I don't remember his name.   



Posted: 10/19/2019 12:44:18 AM

From: Halifax, Canada (east coast)

Joined: 7/28/2019

wow, very interesting bisem, thank you.

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