Restored for a friend during the most recent national lockdown, this is a beautiful example of the classic Lenco GL78 turntable. These were fairly common in the ‘60s found in standalone form and atop many of the more upmarket all-in-one music centres of the time. This is a 4 speed transcription turntable with variable speed, a heavy idler-driven platter and an arm that was quite advanced for its time though is arguably primitive now.
The deck was pulled from a Dynatron music centre. The primary goal was to build a nice-looking hardwood plinth for it as a departure from the typical stacked plywood constructions that are typically seen in Lenco restorations. A piece of a mahogany doorframe was upcycled to form a plinth not much larger than the chassis itself, though big enough to accommodate a hinged dust cover.
A few parts were provided to me to complete the work, including a new machined idler wheel and a modification designed to reduce bearing noise. Both were fitted, the latter with some small modifications of my own. One of the requirements for this project was to keep the original arm, as the turntable would be used as a testbed for cartridges and as a photographic tool. To that end I disassembled and rebuilt the original arm, before realising that the internal arm wiring had failed.
This proved to be a major stumbling block. The proprietary headshell connector is secured by a tiny plastic pin which is almost impossible to remove without damaging it. Some people have converted the arm to use a fixed headshell, though the common solution when these arms fail is to simply swap them for a better unit, as any arm that uses a Linn mount will fit. The owner decided to purchase a second lento arm which appeared in fine condition and was installed with replacement V blocks in the bearing assembly.
The motor consists of two coils either side of the rotor. For 240V operation, the coils are wired in series. There is a simple switch which is linked to the mechanism and a suppression capacitor across the switch which promptly exploded shortly after I powered the motor up for the first time. A 3900PF safety-rated capacitor is the correct substitute, the Vishay AY1392M61Y5UC63L0 specifically is an ideal replacement.
I thought the result was a reasonably good-sounding thing, though any idler-driven turntable is too noisy for my taste. It sounded quite respectable however and I think it certainly looked the part. Unfortunately the wiring in the second arm also seemed prone to failure, and I hadn’t the inclination to strip the turntable down again. I recommended that a replacement be installed, as the turntable is certainly worthy of a much better arm. Nevertheless here are some pictures of the construction and the finished product.