Repairs & upgrades

Part

Relay replacement

The original relays in the BeoGram 4000 series wear out with age. I replace them with my own relay PCBs, built around modern Omron relays.

Part

LED tracking sensor

The BeoGram 4002 tracks the groove with an optical sensor lit by an incandescent bulb that dims with age. I replace it with a calibrated LED on a small PCB.

Part

LED RPM adjustment lights

The bulbs behind the 33 and 45 rpm scales on the BeoGram 4002 and 4004 panel have usually burnt out after more than 40 years. I replace them with a warm white LED PCB of my own design.

Speed testing with SpinDex

Every BeoGram 400X I restore is speed tested with SpinDex, an open source RPM logger I designed for the BeoGram 4000 series.

Part

RIAA preamp

A new RIAA preamp for the BeoGram 4002, built around the OPA2134 in the same form factor as the original board. The second SMD prototype is built and tested.

Part

Sledge motor

The original sledge motors in the BeoGram 4000 series can get noisy and unstable, and their bearings can't be serviced. I replace them with a modern Portescap motor, with a Maxon motor as the alternative.

Part

Pickup mount

The plastic tab in the BeoGram 4000 pickup mount can break with wear and age. I replace the mount with my own nylon part and flexible PCB.

Restoring the keypad and chassis on a BeoGram 4002

Decades of use wear through the varnish and black paint on the BeoGram 4002 keypad. I strip it, have it professionally painted and refit it to the chassis.