24 FPS Crystal Sync Controller Unit for EBM, EL, ESM Motor 16mm MOVIE CAMERA

STL-24 Crystal Sync Controller for Bolex ESM, EBM, EL: An Improved Tobin TXM-24

This unit controls Bolex electronic cameras and motors with built-in crystal sync support. It includes a 7-pin to 7-pin male Tuchel cable for connecting to an EL, ESM, or EBM. The Amphenol-Tuchel right-angle connector does not turn 360 and has it's angle fixed internally using a c-ring. The original Bolex 7-pin to 7-pin male Tuchel cables will work too.

The STL-24 crystal sync unit improves on the well-known Tobin TXM-24 design. It's much smaller. We put the 23.976, 24, and 25 framerates in one unit. Speed adjustment occurs through a ~4mm hole to prevent it from changing accidentally. In addition to the three FPS settings, there is an Alarm setting. It lights up the Alarm LED constantly and slows down the motor as much as possible in crystal sync mode. Our crystal oscillator is temperature compensated (TCXO) to remain consistent between -30C (-22F) and 75C (158F). Its frequency stability is 2.5ppm, removing the need for calibration. We included ESD protection on our circuit board. I've posted a demo video with a Bolex EL Mk3 on YouTube.

Most of the Tobin TXM-24 PDF instructions apply. The Tobin instructions mention oscillator calibration at the end of the document, which isn't necessary with our temperature compensated oscillator. As a result, calibration is not supported.

The STL-24 provides two female 7-pin Tuchel ports. One is on the top, and one is on the bottom. The top port always connects to the Bolex camera or motor to keep sync (and in most cases it draws power). The bottom port must be used for power on the EBM because the EBM only has one port. The power passes through the STL-24 to the EBM. If you prefer, you can use the STL-24 same way with the ESM even though the ESM provides more ports. We do not suggest connecting power to the bottom of the STL-24 when using it with an EL.