Hi there. thought it better to reignite a thread than start another as I too have one of these mics. Well actually my 414 is the one before the eb version, it's just a 414 circa 1971.
So... Mine has a bit of noise when connected to the preamp. It kinda comes and goes but it's a wise idea to have her serviced before she gets any worse. I don't think that the capsule needs any work luckily but I would like to have it cleaned.
Does anybody know of someone in England UK that does this kind of work short of sending it out to Germany or the US. I'd rather have it done as near to here as possible.
Also... When I got the mic it came with a phantom power unit and I am thinking if it's OK to use it with normal 24-48v phantom. I'm asking this as I took it to a friends place and we recorded some acoustic guitar with it and an SE R1 ribbon. We used the 9v (B46E) phantom power unit that takes a 9v battery and it didn't seem to give the noise that I was getting in my studio the last time I put it up. Probably just time to have it sorted.
So... How would I check if the capsule is in need of a clean and or re-tentioning (replacing).