SC/Jaycar kit-Maxie's mods advice wanted

Posted: 4/10/2010 3:31:25 PM

From: Mexico

Joined: 3/18/2010

Working properly now, i´ve replaced the regulator 7805 for an 7806, i´ve removed the speaker and i´ve conected the theremin to an amp. Now i just want to change the sound a little bit, please help me Thierry, thank you so much .....
Posted: 1/14/2011 12:15:57 AM

Joined: 1/14/2011

I'd like to know about the difference between the article and circuit diagram on Max's Jaycar mods, too.

The article says "a 100 k trimpot in series with the 0.1 uF capacitor", but the circuit diagram has a 10k trimpot in series with a 1uF cap.

I've searched the forum and can't find an answer, any advice?
Posted: 1/14/2011 5:00:09 AM

From: Colmar, France

Joined: 12/31/2007

The time constants of both variants (100k/0.1uF and 10k/1uF) are identical. So you may decide on what you find.
Posted: 1/14/2011 11:30:03 AM

Joined: 1/14/2011

Great thanks:)

The 10k pot in the original Jaycar kit is logarithmic, so would I be right to assume that the trimpots mentioned in Max's mods are also logs?
Posted: 2/19/2011 12:51:41 AM

From: Melbourne, Australia

Joined: 4/4/2006

I have an old jaycar theremin, well from the jaycar design but built from scratch, with some of the mods mentioned in this forum. It is not a great instrument but playable. I was exited when my neighbour siad he had the new MKII Jaycar (2009 project) I have put it together and it seems OK so far. However when I put the lid on the volume gradually drops away. It looks like a bad design having the speaker magnet so near the coils. Has any one seen this problem? Does anyone have any comments on the MKII design?

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