LTC1799's HAVE FINALLY BEEN HIT BY THE WORLDWIDE CHIP SHORTAGE. As of July 2022 the manufacturers are quoting a lead time of just over 2 years before they have any more new stock available! All major suppliers are out of stock and prices have tripled or quadrupled anywhere else. Unfortunately this means we have also had to raise our prices and we can't currently sell the DIP6 version. We're not sure how often we'll have these for sale, but we'll have them available whenever we can.
The LTC1799 is a precision oscillator chip from Linear Technology that has many applications, but the main one we're interested in here is its ability to provide a stable and variable digital clock source that can be used to add reclocking / pitching controls to any number of toys, synthesisers, samplers and other noise producing machines. You can use these modules to build a timing oscillator capable of changing the pitch and/or running speed of anything from a gameboy to an Akai sampler, via a huge number of drum machines, FX units, toys and synthesisers along the way.
The actual LTC1799 chip is only available as a surface mount package, meaning its physically about as large as a grain of rice and is virtually impossible to work on without a magnifying glass, a purpose made PCB and some seriously steady hands when it comes to soldering.
As a result we are now selling two versions of the LTC1799 in formats that can be easily used for modding:
The first option consists a complete LTC1799 oscillator module mounted on a tiny PCB measuring 11.5mm x 11.5mm (images 1 & 2). The PCB comes with all the extra components you need already onboard, including a tiny trimmer potentiometer to limit the highest frequency the oscillator will run. All you need to do with this version is to simply wire in a potentiometer and a 5v power supply. When choosing a frequency pot we'd recommend starting with 100K and then going bigger or smaller if it seems like you'd get better results. You will probably find that antilog 'C' curve pots give the most usable response.
This version can be mounted in a 8 pin IC socket using the optional PCB pins.
The second consists of just the LTC1799 chip mounted on a DIP6 adaper (image3), so it can be mounted in a standard IC socket, or used in a stripboard circuit. With this version you will have to supply a couple of extra components, but we do have tutorial explaining how to build the circuit yourself on stripboard at http://tinyurl.com/kust6n6. This is the cheaper version, but it does take up more space with the extra components, and it will take a little more experimentation to find the correct component values.
The DIP6 version is supplied with pins, although they are not soldered to the board.
We have a general guide to installing a LTC1799 pitch control at http://tinyurl.com/khy6mby and a specific guide for a TR505 drum machine at http://tinyurl.com/n68rd6r