Advice to evaluate used audio gear - XLR mics, field recorders, accesories

[hojomo]

What advice do you have on how to evaluate this equipment?

Aside from obvious audio problems to look for after determining there's no operator error, how do you know a quality (say 500USD+) xlr mic is ok to buy? Do they either work & sound clean on a quality pair of headphones attached to a working recorder with good pre-amps - or they don't work at all? Do you have to boost the gain over time, or does the noise floor increase over time before they fail altogether?

Does the same kind of thing apply to XLR adaptors for DSLR/mirrorless cameras & field recorders?

 

[paulears]

You plug them in and listen. Old mics can sound equally good as a brand new one, Common real faults are crackles, or low frequency rumbles and other noises, but these faults usually relate only to condenser mics. The fault is usually capacitor based. The test is always simple. You plug them in and just say one two - test test or whatever phrase you use on other microphones. You listen for things that should not be there. Spit bound mics with blocked internal foam might sound lacking in top, but my own test is just a bit of speech with sibilance to check the top end and then I go in very close and rub my thumb against the side of my first finger - that's very HF oriented sound. If I can hear it, the mic has normal gain and HF.

I like to buy classic mics if they come up on internet sites, and bought a couple of rare Shures - one from the US and one from Norway. I asked the seller if they were OK, they said yes, I bought them. . 500USD seem high to be considered by somebody unsure of how mics age? You'd be better buying new with a warranty.

If you buy second hand, then my own rule is never spend more than you can afford to lose. I personally don't agonise over this.Ask the seller questions, pay with credit cards where possible so if they say it's a perfect mic with no marks or noise and you get a bucket of bolts, there is some protection from VISA or whoever. If you buy from ebay - you pretty much get a refund when something is not as described or faulty.

Microphones in general stay the same. One of my SM57 mics was bought new in 1976. I have no idea which one it is. I have 3 AKG 451 condensers of similar vintage and one is prone to crackles. It's the screw on capsule and the centre pin is a little oxidised and the cure is a clean before using it. I have a Crown boundary mic that is noisy. The capsule is permanently charged and I think it's dissipated a little over the 30 years I have had it. XLR adaptors and all the other electronics can have poor performance, but usually, fault are simply silence and obvious.