Vintage Neve BA283 Card refurb/repair
I have some vintage Neve cards that I got in non-working condition/missing some parts. I have most of the work on this card done (I still have to check the bias). I have been heavily researching vintage Neve BA283 cards for the last several years. Finding old catalogues from manufacturers of components used on the vintage units, tracking which components are still manufactured, how the components changed since the 70s. So, it was satisfying getting this card working again. I even went so far as to use the same brand solder that Neve used back in the 70s.
For this card I replaced the transistors on the output stage with BC184Cs I had from another non-working Neve card. I resoldered the R10 resistor, so it wasn't touching the C17 capacitor. I lifted one leg of the R7 resistor so I could test it was working properly. The electrolytic caps were still the originals, so they needed to be replaced. New ones look pretty nice in my opinion.
I got an NOS Motorola 2N3055, which has a matching date code to many I've seen in vintage Neve preamps, to replace the missing one. The mounting hardware took a lot of work to replicate. I couldn't find any suitable heatsink replacements, so I had to make a blueprint then get new ones manufactured. I found a source for the exact type of nuts used on the vintage units. The screws were tough. I had to get the screws custom manufactured to match the vintage ones as exactly as possible.
Here is a before shot (on bottom) then the finished one on top.