XLR Mod On A Shure Unidyne III 545 Model

[@davestasts1173]

The adapter on the 545 to convert the Amphenol 4 pin screw on connector to a XLR is made by Switchcraft (L3MN) unfortunately Switchcraft no longer makes that adapter. I was fortunate to find 6 brand new ones on eBay 15 years ago. You might be able to find them online but it will take a lot of looking, possibly used.

[@ilikedrums2201]

@davestasts1173 Thank you for this. I have several vintage mics with 4-pin Amphenol connectors and was able to track down some L3MN's on eBay. One thought, since the L3MN is no longer readily available: Switchcraft M3M's are - these have the same male threads as the base of these microphones - fabricating a 13/16-27 female coupler could allow using these in a similar way as the L3MN converter adapter.

[@Cajundaddydave]

The original 545 was dual impedance HiZ/LowZ developed and widely used in the 1960s. Around 1970 they introduced the 3 pin Low Z only XLR version as essentially everyone used it in this configuration. Mic cables were becoming very standardized at this point and the 4 pin connector was a bit of an odd duck. Shortly after the 545 XLR version, Shure introduced the SM 57/58 with low Z modern XLR connector and very similar response to the 545. They soon became the industry standard professional dynamic mic we use today. There are a few of those 1970 545 XLR adapters floating around. A machine shop could fashion you some since you have one example or you could simply create a short pigtail adapter from the 4 pin to an XLR 3 pin and get the same usability. I have three of these mics and they are great for recording drums or guitar amps. Cheers!

[@tordenoglynthorbjrnerlands7606]

Hello i wonder ,do you know the differens between HIZ and Lowz?Is the white cable there to giv more treble ?

[@racl1954]

Hi Ewan. Thanks for sharing this. I know this is an old video post. I am currently in the place of making some custom threaded connectors for my 545 microphones. Same problem as you I need conversion to 3 pin XLR as I won't pay the silly prices that some are asking for 4 pin Amphenol type cables. Honestly you could buy a new SM57 for what they are asking for a cable. Anyhow it will cost me the same to make three or four as it would for one. When I have done the job and tested the fit I will send you one for free so that you can tidy your mic up. I have saved this video to my PC so that I can contact you when I am done.

[@ewanbennettproducer]

Oh wow that's so kind of you! Thank you very much Ricky. Hope the project comes well

[@racl1954]

@@ewanbennettproducer I am waiting for some information from Shure at the moment. I would like the thread and type confirmed before I start using taps and dies. When you consider that even using the inch standard there are four different thread types in the USA alone. Add that to all of the British standards and it really does become confusing. That is long before we consider adding metric to the whole mess.

[@racl1954]

@@ewanbennettproducer Hi Ewan .....Is it just the one mic you need this adapter for ?. I have Shure helping me with the thread sizes etc. I have 2 of these mics. If you have more than one it wouldn't be a big deal for me to make a few more.

[@ewanbennettproducer]

@@racl1954 hello mate, I have 3 if them, but don't put yourself out. I'd be very happy with just 1

[@racl1954]

@@ewanbennettproducer Hi Ewan. No worry. I will do one prototype to test and then make enough to cover us both. It's my way of saying thanks for sharing the video. I would likely have left my 545's in the drawer if I hadn't come across the video you shared on how to convert to 3 pin. I did find proper cables online on a USA site but I won't pay $95.00 for a cable. As you know you can buy a new SM57 for that price.

[@SEOTeamBerlin]

hey thx a lot for sharing this - I've wanted to change my three 545's to xlr for a long time, this is a big help now :) - gtx from the Lake of Constance

[@flownetiko]

can you explain step by step how to change 4 pins to xlr

[@flownetiko]

could you share a diagram or drawing to connect the 3-pin male connector thanks

[@jpanagotopulos]

Sorry to bother, but have you confirmed Blue to Pin 2 is in phase with standard 57? The Shure website seems to have inaccurate instructions. Thanks for posting this!

[@minty_Joe]

He does have it backwards, technically. If your XLR connections are wired Pin #2 positive (+), then the read wire needs to go there. The only time this is critical is if you have 2 of the same mics next to each other (within 6 inches or so) and they're picking up the same sound source at the same time. If one of those mics are wired backwards and the other is in the correct wiring, you'll experience "phase cancellation"; both mics cancel each other out, thus no sound heard. But if both mic are wired the same way, you'll get around 3 dB gain, when the mics are close together. The Grateful Dead used this trick for years during their "Wall of Sound" era, using 2 identical mics of which one was connected in reverse polarity and both spaced 3 inches apart.

[@StellaMoonstone]

Hey! Where do you even find the XLR connectors to solder on?

[@domenicofinizio3363]

Thanks a lot

[@johngaudett8546]

I've just bought a shure unidyne III and I have a yellow wire not connected to anything. Do you know where it goes?

[@happythrasher]

Thanks so much for this. I bagged two of these beauties today and I’ll be doing this tomorrow.

[@happythrasher]

Done. Perfect!

[@ewanbennettproducer]

@@happythrasher that's so good to hear! You're very welcome

[@brokenegg4714]

thank you sir.