he TM3030 is a midi controlled bassline clone that is designed to sound good, be easy to build and use no really difficult to get parts. The design features the same controls as the little silver box we have all come to love: tune, waveshape, cut-off, resonance, envelope sweep, decay time, accent and volume.

Unlike the older Oakley TB3030 and TB3031, this project has its own midi interface on board. This interface has been especially designed for us by Sequentix, the creators of the P3 and Cirklon sequencers and the midibass TB303 midi interface. By careful analysis of the original unit, Sequentix have created a midi interface that allows the TM3030 to behave as a real unit would do if you could feed it midi messages. Slides and accents are faithfully reproduced. Since issue 2 the TM3030 features optional modulation wheel control of filter cut off frequency.

The TM3030 contains no internal sequencer. Of course, part of the sound of those famous acid riffs come from the sequencer, but with careful programming on your favourite computer or hardware sequencer, it is possible to create those wonderful fluid lines that are so recognizable.

The PCB contains, in several key areas, places where the builder can chose to use modern or original Japanese parts. I think that the modern parts I have chosen sound as good as the originals, but the option is there if you can get the original parts and want authenticity.

The front panel pots are Alpha or Alps 16mm devices. These are available from many places and offer long life and feel good. They can be soldered directly to the board to minimise wiring and errors. Special pot brackets are available to allow the PCB to be mounted on to front panels without any further mounting requirements. The board is designed to fit into either a half rack case, or in a 1U rack case. It would be possible to have two TM3030's side by side in one 1U rack.

Like the pots, the LEDs and switch can also be board mounted. Input and output sockets are mounted to the rear of the case and are connected to the PCB with flying leads. Issue 3 boards are identical to issue 2 but now use the THAT300 NPN array instead of the obsolete CA3083 array in the exponential convertor.