Beogram 4004 Type 5526: Recapping the boards

There are just two boards to replace capacitors on in the Beogram 4004. In addition to the capacitors there are two relays that can eventually fail so I always replace those with a modern sealed relay assembly supplied by Beolover. The relay on the main board is for platter speed selection (33⅓ RPM & 45 RPM).  The relay on the output board is for the phono cartridge muting. There are two trimmer resistors on the main board that I also replace. Those are the platter speed adjustment trimmers. The replacement trimmers are sealed, multi-turn type trimmer resistors.

Here is the before picture of the main board.

Here is the main board after the updates. The 1C10 capacitor was changed from its original 0.33uF value to 10uF. The reason for that is due to the rebuild testing of the DC platter motor. When Beolover rebuilds the motors he tests them for stability using the different 1C10 capacitor values that Bang & Olufsen used in these turntable controllers. On the tests for this rebuilt motor Beolover found the 10uF value to be the best pairing.

Now for the output board. Here is the before shot.

...and the after shot. Note that I added a small switch to the output connector to allow shorting signal  ground to system ground. That shouldn't be necessary when connecting the Beogram 4004 to a Bang & Olufsen amplifier via the DIN plug. However, when connecting to a non-B&O preamplifier there can sometimes be a hum in the signal. The Bang & Olufsen provided adapter cables for DIN to RCA plug type hookups included an external grounding wire for this purpose. The switch makes it convenient to just set the grounding as necessary inside without an extra wire.

There is one reservoir capacitor in the Beogram 4004 cabinet that needs replacing. I replace that capacitor with another Beolover custom part. The Beolover part is designed to mount perfectly in the original clamp.

Here is the new reservoir capacitor installed. It fits perfect and looks great.