M.Yu
In the Vintage Vanguard
I have a Luxman L-100U, unit A, that I recapped. I had a couple issues after but managed to figure them out more or less. I have recently acquired another L-100U, unit "B". It is very dirty but basically working.
During a closer look at unit "B", I noticed that the Power supply board, PB 647, had a few things missing from it. These included caps, resistors and a couple of diodes. From the look of it, it seems to have been that way from the factory. Also FYI, the Unit A has an A code serial # and the B unit has a B # which I assume means it is of a later production.
You can see the omissions on the edges of Board "B" on the sides.
Also during the recap, of the "A" unit I noticed that the boards on the Power modules, 649, on my unit looked different than the ones I saw online which often had different things attached to the back side such as various caps etc. The same goes for my "B" unit, which in this case has 2 diodes attached to it. Otherwise all the boards themselves both A and B look the same.
Both my A and B unit had clearly had previous servicing done to them but it seems the omissions on PB 647 were from the factory.
My question is are the changes on the Power supply board directly related to the ones on the Power module board? Are any of these boards inter-changeable between the different amps? Any idea why were these done in the first place? And is there any benefit to making one unit more like the other?
Any input is appreciated!
During a closer look at unit "B", I noticed that the Power supply board, PB 647, had a few things missing from it. These included caps, resistors and a couple of diodes. From the look of it, it seems to have been that way from the factory. Also FYI, the Unit A has an A code serial # and the B unit has a B # which I assume means it is of a later production.
You can see the omissions on the edges of Board "B" on the sides.
Also during the recap, of the "A" unit I noticed that the boards on the Power modules, 649, on my unit looked different than the ones I saw online which often had different things attached to the back side such as various caps etc. The same goes for my "B" unit, which in this case has 2 diodes attached to it. Otherwise all the boards themselves both A and B look the same.
Both my A and B unit had clearly had previous servicing done to them but it seems the omissions on PB 647 were from the factory.
My question is are the changes on the Power supply board directly related to the ones on the Power module board? Are any of these boards inter-changeable between the different amps? Any idea why were these done in the first place? And is there any benefit to making one unit more like the other?
Any input is appreciated!
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