Post your Silicon Chip/Jaycar kit questions here!

Posted: 9/12/2005 8:36:25 PM

From: Ottawa, Canada

Joined: 9/12/2005

This may heve been answered already, but just to be 100% clear.
Can I replace the RCA jack with a larger jack that would accomodate a patch cord leading to a guitar amp? Or are there adapters available?

Posted: 9/15/2005 7:43:22 AM
monty cantsin

From: ireland

Joined: 9/15/2005

Hi, I've just built the Silicon Chip theremin using the kit from (no modifications). Everything went fine during construction (especially given the fact that I never used a soldering iron before)..

However the volume is very, very low. I'm currently just using the small built in speaker (I have to get a cable to hook it up to my PC speakers), so I know I shouldn't expect that much from it, but even with the volume knob turned up full, there's barely a whisper out of it.

The volume antenna is working in so much as the sound goes off completely when I place my hand very near to it. The pitch antenna is working.

My voltages are measuring as they should per the instructions.
Posted: 9/15/2005 1:27:27 PM

From: UK

Joined: 2/21/2005

check for any solder bridges near the amplifier section. it's quite easy to do!
Posted: 9/16/2005 4:28:38 AM
monty cantsin

From: ireland

Joined: 9/15/2005

Thanks Abdulkn! A solder bridge it was. Sorted now.
Posted: 9/16/2005 9:48:39 AM

From: Hillsborough, NC (USA)

Joined: 2/13/2005

Ok, Abdul gets the prize for best circuit board debug without even seeing the board :)
Posted: 9/26/2005 3:27:53 PM

From: UK

Joined: 2/21/2005

I know I've made the same mistake many times elsewhere!

I'm glad it's working now! How about posting some recordings?


Posted: 3/29/2006 3:27:06 AM

Joined: 3/29/2006

Hi everyone, I'm very new to all this - I just assembled my Jaycar kit theremin and am amazed I actually get a sound, considering the most I've ever done before electrically is wiring plugs. But I'm finding tuning very difficult, I can't get much range in either pitch or volume - does anyone have any tips? I don't understand anything about how to check voltages either, do I need to get some special equipment? Also the tuning changes a lot if I put the lid on, but there's no way to alter things without taking it off again - they said there was a hole to adjust VR2 but there isn't , should I drill one?
Posted: 4/6/2006 10:46:39 PM

From: Hillsborough, NC (USA)

Joined: 2/13/2005

Check out the schematics page ( for some tips and tricks on making improvements to the Jaycar theremin.
Posted: 4/12/2006 10:40:04 PM

From: Melbourne, Australia

Joined: 4/4/2006

I have just built an SC Theremin. (Actually I have built two with a friend so we can both have one)
I have only started playing around with modifications and would be interested to know people's opinions of how good an instrument I can try to make with the SC design. I am particularly interested in the pitch response as I can only get about 2.5 octaves and the top is still quite compressed after spending some time tweaking by adding coils in series with the antenae. I don't expect to get the 6 octaves of an expensive Moog but can I hope for much improvement from what I hae already.
I also changed my Regulator to 7906. This has made it very buzzy even at quite low volumes. Is this typical? Do Max's timbre mods help with it. (I don't remember reading anything in his modification notes about changing voltage.)
We built from plans rather than a kit. I think this has given us a better and cheaper result as well as a better understanding of the instrument.
I have built the case which I am very happy with - I'll post some pics sometime. So now it looks great it just sounds terrible.

Damian Coutts,
Recently converted Theremin Obsessive.
Posted: 5/17/2006 7:15:14 AM

From: rome

Joined: 5/17/2006

I need to know the MEASUREMENT (lenght and diameter) about the 2 modded ANTENNAE in MAX and ABDUL
Please send me this info at

You must be logged in to post a reply. Please log in or register for a new account.