Yahoo Groups archive

Vintage Simmons Drums (UK) Users Group

Index last updated: 2026-03-30 01:08 UTC

Message

Re: [Simmons Drums] Musicaid Claptrap schematics

2013-12-16 by chris@chriswareham.net

On 16 December 2013 at 03:13 Michael Buchner <buchnerelectronics@...>
wrote:
> This is the schematics of the Mark 2 (analogue Simmons ClapTrap), the
> humaniser is already built in. It was a great idea to use the AC frequency
> from the PSU to modulate the VCO. A free LFO! This is the Simmons spirit!
> Also bad, that the LM566 (VCO) is so expensive these days. Back in the days,
> you could buy it for a few cents. Now they want 15 Euro or more.
>

There's an interesting thread on the Electro Music forum that suggests the
NTE994M as an alternative to the LM566:

http://electro-music.com/forum/topic-12642.html

It also mentions an interesting drum voice that can be built around those chips.
Something for the Christmas break perhaps ...

Chris

Attachments