Revox B77 VU meter light replacement?

[Jay Hennigan]

I have a Revox B77 with a burned-out lamp in one of the VU meters. There
is a small rectangular grey socket in the top of the case back, with the
solder lugs outside of the meter. This suggests a small bi-pin or wire
lead bulb inside.

But, there is no obvious way to disassemble the meter or remove the
socket for re-lamping. Any suggestions? Also, does anyone know the
specifications orpart number for the lamp itself assuming I can get this
apart?

 

[Tim Schwartz]

Jay,

Lucky you! To change the bulbs, first remove the case, which I'd guess
you already have. Next you have to remove the lower front panel by
removing all of the knobs, then the 2 screws on each side of the
machine. Lastly you get to remove the 4 screws that hold in the
meters. BE CAREFUL of the toggle switches, the knobs DO NOT come off
them, and they are easy to break if pulled on.

The lamps are listed in the schematic as 24V/1 Watt, and feed off the
21V supply. The Revox part number is 51.02.0142 and as I recall they
are a wedge type. Please note that I'm using a B-77 mkII shop manual
for this info, but as I recall the mk I has the same lamps.

Regards,
Tim Schwartz
Bristol Electronics

 

[Scott Dorsey]

But, there is no obvious way to disassemble the meter or remove the
socket for re-lamping. Any suggestions? Also, does anyone know the
specifications orpart number for the lamp itself assuming I can get this
apart?

As I recall, the body just is pop-fit together, and you can pry it open
with a small screwdriver.

I seem to remember that on the A77 the lamp is soldered in, and can be
replaced with any similar grain of wheat bulb, but it's pretty bright.
Check the service manual, though, and it will have a part number for a
replacement lamp.
--scott