Sunday, April 13, 2014

Picked up a couple Turner 500 microphones with native four pin Cannon/XLR plug and noticed an ALARMING LACK OF INFORMATION ON THE INTERNET in regards to refitting these with modern connectors. Tons of data regarding the HAM radio OEM stuff, but hardly a whisper in terms of studio quality stuff Turner churned out before their unfortunate demise.

The original design is actually pretty cool. You have a case ground (black) a high impedance (blue) and a transformer coupled low impedance pair (orange/yellow), so you could cable select impedance. Reminds me of the old SM-57 transformer bypass mod, just so happens to be BUILT IN and optional on these.

That said, sourcing the 4 pin connectors for it now is something of a nuisance, and I want to reach for the low-Z mode anyway, so what you're about to see is an easily reversible disconnect of the high impedance (pre transformer) circuit.

Form factor is identical, I happened to have a couple three pin Cannon male inserts lying around, which turned this into a full "bolt on" mod.

The dirt and crud even lend a period correct feel to these, so as not to bum out the vintage zombies. I jest, partially.

So a bit of heat shrink on the blue hi-Z feed, connect chassis to 1, and I decided to jam orange as "hot" on pin 2 because it's a "warmer" color than yellow. Completely scientific like. Whatever. The mic works, I like the sound, it will get used.

Apologies, I don't seem to have taken a picture of the completed unit. It looks like the connector end of a standard microphone, my guess is that if that isn't explanation enough, this mod might not be for you.


Bill Giles said...

The Electro-Voice 664 was connected the same way, but used a different connector. The only good way to tell how it's wired is to take the connector apart. In the long run, it,s probably better to hard wire the impedance, than to use a selector switch. I prefer the way you have done it.

krivx said...

I tried to do this to some mics with Tuchel connectors, the magic search term is "XLR Insert"