Vintage Luxman L-450 crackle and hum


Hi All - I'd be very grateful for your thoughts on a disturbing new development. This morning, after a nice and not very loud listening session, I stopped the last song and noticed that all was not quiet. The amp, a Luxman L-450 in pretty good shape, was making a kind of static-crackle hum, not very loud or low — like maybe middle C on a piano. I turned the amp off and back on: still there. I switched between all of the inputs (aux, phone, tape, etc.) and it was still there. Volume and tone controls had no effect. (It did not get louder when I turned up the volume.) What could it be? And what's the right way to repair it? I really like my Luxman and I want it back in shape!
brooklynluke
Many of the problems on the Luxman units of that vintage were due to the thermal breakdown of integrated circuit modules (DML's) that are no longer available. There is a guy in, I believe, Holland named Hans Hilberink that makes replacement modules that are supposed to be better than the originals.

One of the best guys in the states for Luxman repairs is Tom Ishimoto at Northridge Audio in California, but Hans probably knows of someone closer to you. Hans posts on the Luxman Yahoo group, and is a goldmine of info.
http://www.hilberink.nl/codehans/luxman.htm
Hello all, I have an update and a question after one year. I took my Luxman L-450 to Jude at Pro Audio Repair in Crown Heights as recommended, and he was great. The unit sounds terrific now and is everything I could hope for. Except for one recurring problem.

Every few days, the right channel will cut out. The left channel still sounds great, but the right channel is just gone. (Not dead silent, but almost.)

One clue as to what is happening is in how I get the right channel to start working again. I am running my source (an Auralic Altair) through the Aux input. If I flip to another input, then turn the volume WAY up, I can hear a little bit of noise bleeding into both channels. And if I then turn the volume back down and flip the selector back to Aux, I now have the right channel back. This works pretty consistently, but it is irritating!

It seems like there is some kind of power problem in the preamp stage, and blasting it resets things for a few days, but I don't really know if that even makes sense.

I took the unit back to Jude for a look, and he cleaned everything up and sat with it for a few weeks, trying to reproduce the problem, but he couldn't make it happen. We finally gave up. (No charge from Jude! He is really great by the way.)

What does this sound like? And how can I remedy it? I'd be grateful for thoughts!