Biula
Well-known member
- Joined
- Mar 24, 2023
- Messages
- 57
Maybe you are referring to selenium rectifiers... Well, as stated earlier:Back in the 40's and 50's many German/Austrian/Swiss mic manufacturers used rectifiers that consisted of coated metal(steel?) squares stacked up. in their power supplies. These rectifiers worked well and were in some of the finest tube mics ever made, but, it would not take much moisture to make them corrode and fail(short). While it may be worthwhile to preserve totally original mics, in the interest of reliability, it is probably better to replace the whole power supply with an aftermarket supply, or at least have a spare one on hand. When you have session with 85 musicians coming in at union scale in NYC and have no spare M50's they probably need to work. Amazingly, as an emergency move, a high voltage modern diode will do in a pinch. The circuit design of these power supplies are pretty simple and conventional. Easy to understand and repair. Especially compared to modern switching supplies. (just throw it away and get a new one)but, original parts are almost impossible to find, like the V-14 tube. As a practical matter, modern components can successfully replace them. But, not all changes should be considered progress,
So, better a well mainteined original power supply than an "aftermarket" one (BTW, Telefunken Elektroakustik crap power supply IS considered NG47 aftermarket substitute!!!), especially if you are dealing with such important events... if you do not trust an original NG47 how can you trust the venerable 1940 VF14? It was meant to work flawlessly for 10.000 to 20.000 hours, and so does its power supply.I've serviced many original U47 and never had any issues with the NG PSUs. Even the selenium rectifiers seem to work forever.
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