Luxman R-3055 Receiver Before first turn-on?

[jefferylhenr]

I just picked up a mint Luxman R-3055 receiver. Bought originally by an older gentleman and gifted to his son who never used it or even turned it on; in original plastic, foam and box. It hasn't been turned on for at least 5 years. It looks like its brand new...

Question is, should I replace the main electrolytic power caps and others before first turn on? 1976-1979 build dates which makes it at least 40 years old. I am looking at the
Mundorf Capacitor 10000uF 63Vdc MLytic® AG MLGO. Mundorf Capacitor 10000uF 63Vdc MLytic® AG MLGO (partsconnexion.com) or should I go to 15000uf (original is 10000uf). The repair manual just lists the basic individual parts specs but doesn't provide specific make or model which I won't know prior to opening the case.

Or, should I just hook up a dim bulb and wade it as it sets - turn it on without speakers and let it set for a couple hours? See if I can adjust/test the Bias voltages, then hook up speakers and give it a listen before replacing anything if it sounds funny? I do plan on doing a full restoration with best available parts sooner or later. I would rather be safe than sorry... I don't have an oscilloscope but could look for one if that is a must have.

 

[Blue Shadow]

Mine sounds great all original. Last caps to die would be the big ones. The smallest are the ones that have problems

I like the idea of reforming the caps with the DBT. Start with a low wattage bulb for an hour or three then step up to wattage once or twice and then call it good. Set the adjustments and give it a listen. Think about recapping in 2024 or so .

 

[jefferylhenr]

What wattage would you start with? 25?

 

[Blue Shadow]

Yes. That will lower the voltage to something like 70 and limit current. Caps will start to wake up. Proceed to higher wattage bulbs, 40, 60, 75 and 100, using a couple of those. Then if on 100 watt bulb it starts up just fine, check bias and if close go to line level and then set amp operating adjustments. Then it should be just fine.

 

[jefferylhenr]

How long should the unit stay powered up, assuming the bulb dims as it should, at each bulb wattage level? And will this allow for reforming of the capacitors? I am thinking an hour or so. I just ordered an esr meter and should I randomly test prior or after the ramp up?

 

[Blue Shadow]

An hour is fine since we don't reform caps we don't know much about that. The pros do but they are reforming big caps that are new off the shelf.

 

[jefferylhenr]

I found this startup procedure for tube amps. Assume its similar logical steps for solid state. Is there any documentation one has seen specifically for solid state receivers? Amp Startup (robrobinette.com)

 

[Blue Shadow]

Solid state isn't that critical. Most of the time just plug it in and power it up is fine. Going through the reforming procedure is just a bit extra that one can do if they have the needed materials and the time as well as the unit having been asleep for a decade or more. It is just more modern electronics.

 

[jefferylhenr]

That is encouraging to hear. I have never actually had an amp fail, even 60’s era tube amps. But, all I read about on the forums are exploding dried out electrolytic capacitors causing cascading damage. My limited knowledge would lead me to believe that with increasing esr, they basically turn into resistors which would be easily noticeable as reduced output prior to shorting out or hum. This project is my new Rubik’s cube of the moment. I have a tendency to go overboard in pursuit of perfection. If this gear sounded good new, how would it sound with new and better quality parts? Some folks say quite a bit and others not much. Just don’t want to do stupid stuff and destroy parts that are near impossible to source today if I can help it.