GE 4BA21A Germanium Mic Pres
- Thread starter RSRecords
- Start date
Help Support GroupDIY Audio Forum:
First you want to see if you care for the sound and noise levels of those particular germanium transistors. Some types are fine, others sound like the wind, and best modern replacements may sound worse. The GE germ I've used has all been fine, but make sure before you waste time.
Drift is a matter for measurement, not shotgunning. Noise is likely more prevalent.
Drift is a matter for measurement, not shotgunning. Noise is likely more prevalent.
RSRecords said:
I don't think so, it's more of an era thing, and some people like to match to type of components used at that time, like having germanium transistors with carbon comp resistors, or having carbon comp resistors in vintage style Fender amps.
Personally I always use 1% Metal film resistors and I couldn't care less about carbon comp resistors. Yes it's true the value can drift over time, also drifts with temperature (the germanium transistors drift much more) , they are also more prone to humidity and have more noise, I think if the manufacturers at the time had Metal Film resistors they would have used that.
Saying this if I had an old/vintage mic pre like yourself I don't think if I would change the original resistors if there was nothing wrong with them, I would definitely change all the electrolytic capacitors without even turning it on.
just my personal opinion, other people will have different points of view, hope it helps
Whoops said:
Yes, definitely changing all of the caps. They were all a bit leaky but who could blame them.
I'll stick with carbon resistors for now.
Also coming up with a plan to mount them. I I was thinking a wooden case with the supply mounted in a chassis beneath. I can add a front panel with +48v and Polarity switches and rear panel for xlrs...I'll draw it up at some point.
