A while back, a customer came to me with two pieces of equipment he wanted to have restored – a gorgeous Luxman M-4000A power amplifier and a matching Luxman C-5000A preamplifier.
I restored the M-4000A here. This post looks specifically at the C-5000A, a rare and beautifully built preamplifier, from the somewhat enigmatic manufacturer, Luxman.
The Luxman C-5000A is indeed rare, so rare in fact that, despite extensive searches and contact with the Luxman Yahoo group and the Luxman Vintage Audio website, there are literally no service manuals available for the ‘A’ series models. There is service data available for the M-4000 and C-5000, but these are quite different so that data is not of much assistance.
The only thing any of us could find was a hand drawn (not drawn by Luxman) schematic of most of the M-4000A, but with no information identifying the functions or settings of the various trimmers in either piece was ever located.
Anyway, this meant I had to proceed blind with the Luxman C-5000A. Intuition guides me to a certain extent when servicing equipment, cleaning, replacing parts and so on. The problem is that both these pieces had been worked on before and parts had been replaced. Without factory service data, one can never really be sure that the replaced parts are of the correct values and I have found that often they are not. The other issue is that again, without factory service data, setting the equipment up correctly can be very difficult.
The C-5000A is built in a way that most modern gear is not. The preamp is completely modular, with a chassis, in which the various modules reside, as plug in cards. This approach is more akin to that found in test and measurement gear and is only rarely found in consumer audio equipment. Accuphase is one other such manufacturer which has always used this form of modular construction. This form of construction makes servicing and repairs both easy and hard – easy because the boards just unplug from the backplane inside the chassis; bad because you really need extender cards to allow you to make measurements and adjustments.
This particular C-5000A was much like the M-4000A in that it was old, dirty, had poor replacement parts in places and really needed some TLC. The following images document my service and restoration of this lovely old piece of equipment. You can of course find more about the C-5000A at The Vintage Knob.