Question: Shure Unidyne III 545L ?

Pier Calacino

New member
Hi guys,

I came across some Mics that I had put away some time a go and had forgotten about. Anyway, they are Shure Unidyne III model 545L. They all have a 1/4" plug at the end, and when I unscrewed the back part of the Mic to expose the electrical connections, I noticed that two of the connections on the cartridge have been jumped together and wired to the two wire 1/4" plug. (the cartridge has three connections)

Can these Mics be modified and fitted with an XLR plug or even a 1/4" stereo plug to make them a three wire Mic and more useful? Are they OK wired as the are?

Are these Mics any good and for what application?
What would they be worth if sold?

Thanks
Pier
 
I was just gong to ask about this microphone myself.

As far as I can tell, it evolved into the SM57, but I don't know the details. It may be the same microphone.
 
Hi Bongolation,

Have you used it for anything? How is it compared to the SM57 or 58?

I wounder if it has the same cartridge or similar cartridge ?

Thanks
Pier
 
I honestly don't know, which is why I'm asking.

The Unidyne III was pretty much the top-of-the-line Shure stage microphone thirty, thirty-five years ago and it looks just like the SM57. SM57 ad copy seems to suggest that they are essentially the same microphone.

I had a pair of these, but one went bad in storage (it's sitting here on my desk) and I can't find the other one at the moment. I suppose I will eventually send it back to Shure for a rebuild, and I imagine it'll come back as a SM57.

But I'm just guessing.
 
I have got about 6 or so of these maybe more that are doing nothing!

Do your's have the 1/4" plug on the bottom or are they hard wired ?


Pier
 
Hi Pier
The oldest one I have says Unidyne III,has a brushed chrome finish with an on-off switch on the barrel.Probably 60s or early 70s.Next in line is the one I mentioned that says both Sm 57 and Unidyne III on it.Black matte finish,no switch.Probably late 70s or so.Next I have a SM 57,black matte finish ,no switch.Pretty much modern.All have 3 pin XLR plugs.I do have a Unidyne I with XLR that is not balanced (like the 1/4" you mention).
 
Well, it sounds to me like my assumption was right - having Unidyne III and SM57 on the same microphone would seem to clinch it.

Anyone know what the flat-rate Shure rebuild cost is on these?
 
In my heart of hearts, I wish I knew what the "flat-rate Shure rebuild cost" is/was on these.
 
The "Unidyne III" is from my understanding the mic element, and since the 545 and SM57 not nly shares the same mic element, but the same capsule (they look identical, at least) they should make the sound pretty much the same.
 
The Answer [I hope]

Firstly: I visited this forum whilst searching for info on how good the Rode NT1 is.

Secondly: This is because I hve just got a nice presmp and had just upgraded my Shure unispere and my

UNIDYNE 3 B545 .... which I have had for most of my life.

Only two days ago I was looking at the original instruction book which is Copyright 1969.
And working out how to connect it to the XLR lead I had just bought.

AND, looking inside the connector, was noticing how it was not twin lead connectoin.



I am going to now describe the connector wiring diagram.


When wired high-impedance, AS SUPPLIED, then pin 1 is for the shielded cable and pin 2 is for the conductor which will lead to the tip of the 1/4 inch jack plug. This is what I found when I looked inside mine. So I confirm the info on the leaflet.

The other configuration is low impedence ... AS NOT SUPPLIED:
Pin 1 is still for the sheild.
Pin 3 and Pin 4 are for the conductors.

So far so good. I left the original cable-end and adaptor that screws onto the end of the mocrophone, and shortened the original lead to about 30centimetres. and fixed an XLR three-pin plug on it. This now clicks into the standard XLR socket of my modern cable and that plgs into the XLR socket of my pre-amp.


I hope this is useful. If you need more info, then PM me .... and I'll be very happy to photocopy the instruction leaflet and send it to you or to answer any questions you may have.

To me, this is such an amazing co-incdence. Indeed ..... it was a miracle that I had the original instruction bookelt. I bought the mike second hand about THIRTY years ago. About a year ago, the green foam that held the mike in the plastic box had perished so much that I just HAD to remove it .... and there was the booklet ... I had never seen it before. It was like finding a treasure chest.

Anyway, enough of that.


Best wishes

:)
 
Thanks for your reply everyone I really appreciate it.

Zenda,

So from what I hear, the 545L is very similar to the SM57. Is this correct ?

If its not much trouble I would love to have a photo copy of the instruction leaflet.

I am going to try an fit these mics with Standard XLR connectors, and an actual wiring diagram would be useful.

What transformer should I install ? What one does the SM57 use?

you can try and send it to my work address at pcalacino@orbtek.com

That would be very helpful.

Thanks alot everyone

Pier
 
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I happen to have a number of these mics. One still had the screw in, 4pin adaptor on it with a 1/4 stereo on it. I was able to make a 1/4 stereo to XLR adaptor, it it sounds great.

What I need to get are more of the 4 pin screw on adaptors, what are they called, model number, or other info, to help me locate and order some.

Any help would be useful.

Thanks,

Sam
 
I didn't even know that anyone knew about these things!

I've got two of them (the Unidyne III's) and back when I first started recording and was on a really tight budget, a buddy of mine gave them to me.

I've used them on guitar cabs, for vocals, the two of them as drum overheads (though I had to crank a good bit through them), and I'd say that they're definitely comparable in sound and versatility to the 57's of nowadays.
 
I didn't even know that anyone knew about these things!

I've got two of them (the Unidyne III's) and back when I first started recording and was on a really tight budget, a buddy of mine gave them to me.

I've used them on guitar cabs, for vocals, the two of them as drum overheads (though I had to crank a good bit through them), and I'd say that they're definitely comparable in sound and versatility to the 57's of nowadays.

Heck yeah! I love my 545 on my guitar cabs. I also found an EV623 at a yard sale for $5 bucks. It's EV's mic of the same style era as the Shure 545S.

I took some pics and posted a recording made with the $5 EV here:

http://www.spottedmuse.com/

(There are other files there, the EV 623 sample is the last link on the page.)
 
....is it me or does the gls have more body than the Shure :confused:
$30 buck a pop huh? ....viva la 5yr old thread
 
The Shure 545 is NOT the same as an SM 57, to start with the 545 has a copper voice coil. Many old school engineers actually favor the 545. They certainly sound different on snare drum and guitar.
 
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