Unidyne III 545

milet22 · 25th June 2006, 08:18 PM

(I originally posted in GeekSlutz, but got no respose).

After reading through posts here on mics, I decided to give a Unidyne III 545 (no switch) a try and compare it to my SM57.

The mic has a 4 pin connector (which I've since learned is an Amphenol MC4F). However, the mic came with a cable that has a matching 4 pin connector on one end and what appears to be a 1/4" TRS on the other end and says "Switchcraft."

I tried plugging in the 1/4" to a preamp, and I don't hear anything on when the preamp input setting is 'low-impedence/mic'. When preamp input is instead 'high-impedence/inst' setting, I can hear sound when I tap the side of the mic, but no sound when I speak into it.

So here's my questions:
1) Does it seem like I bought a broken mic, or is it that I don't have the right cable/connector?

2) If it's a cable issue, how do I go about getting the right connectors? I've seen some posts about soldering the necessary 4 pin-XLR cable, but I'm not sure exactly what I need. I would like to use this as a lo-Z mic ultimately.

Thanks for your help...I don't mind building/making a cable, but I definitely don't want a broken mic.

Rob

corworld · 25th June 2006, 09:17 PM

Sounds like the mic is set up for high impedence use. If you have the original instruction sheet, that should tell you about the wiring. On the newer 545s, the switch from low to high is not a big deal. I've never looked at the 4-pin model. You may just want to convert it to three pin for Low-Z use.

What pre are you using?

milet22 · 26th June 2006, 08:09 AM

I found the old data sheet online, and I found what leads are for low and high impedence. I'm going to test the cable to see what it's wired for currently.

I'm using the preamp on an MBox.

milet22 · 28th June 2006, 02:58 AM

According to the data sheet, when using the mic as balanced, low impedence:

BLACK (pin 3) - hot
WHITE (pin 4) - hot
SHIELD (pin 1) - ground
RED (pin 2) - not mentioned...it says this is hot for unbalanced, high impedence so for low Z I guess it's not used.

How should I connect these three leads (hot, hot, gnd) to XLR (hot, cold, gnd)?

Thanks

milet22 · 29th June 2006, 08:40 AM

I found a cable that works (amphenol to TRS) and it's configured for low impedance. However, same problems with the signal level.

I was told that the mic was working before I bought it, and assuming that to be true, any other thoughts?

Thanks...

paulneedles · 29th June 2006, 01:40 PM

that happened to my 545 not that long ago - one of the cables inside had come loose, still worked slightly but with very low levels. open it up - it might be a really easy fix. i thought all the 545s had tuchel connectors? is that the same thing as an amphenol?

Thumper · 29th June 2006, 04:32 PM

Your mic is broke. Give it to me.

milet22 · 30th June 2006, 09:15 AM

Paulneedles,

The three internal wires that connect to the capsule are still connected.

I'm not sure about the Tuchel connectors. I looked up some pictures and they seem to be different than Amphenol.

Thanks.

paulneedles · 2nd July 2006, 02:01 PM

i'm stumped. you need to get someone to look at it for you by the sounds of things.

milet22 · 11th July 2006, 01:45 AM

As a follow-up, I contacted Shure and they said it was either a broken capsule or possibly a broken transformer. For a $55 replacement fee, they'll replace it with an SM57.

Thanks for everyones' input.

Mark Elmore · 14th July 2006, 12:49 AM

Actually....

If it's the old style Mbox you have, the line and intsrument settings only work with the jack input, and the mic setting only works with the XLR input. I hope that helps!

Where online did you find the data sheet? I just picked up a switched Unidyne III with the 4 pin to TS jack cable and I'm looking for more info.

Bob Ross · 14th July 2006, 01:43 PM

Quote:

Originally Posted by milet22

As a follow-up, I contacted Shure and they said it was either a broken capsule or possibly a broken transformer. For a $55 replacement fee, they'll replace it with an SM57.

Just curious: Why wouldn't they replace it with an identical 545SD Unidyne III for $55? Or did you specifically request an SM57?

I've had a semi-non-working 545SD for years & I keep telling myself I'm going to send it back to Shure for repair one of these days. But I've got plenty of SM57's, wouldn't necessarily need another. If for no other reason than it being an idiosyncratic anachronism, I'd rather have a 545. According to Shure's website it's still a current product, so I can't see why they wouldn't replace yours with an identical new mic...or at least repair it.

milet22 · 16th July 2006, 07:58 AM

reply to Mark
--
Thanks for the mBox info. I also checked the TRS cable in a regular mixer with a pre-amp and it still didn't work.

Here's the link to discontinued pdfs
http://www.shure.com/ProAudio/Downlo...inued+Products

reply to Bob
--
When I called Shure they said the replacement mic depended what they had it stock. It could be a 545 or a 57, but it was likely to be a 57.

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25th June 2006, 08:18 PM	#1
milet22 Gear interested Join Date: Nov 2005 Posts: 22	Unidyne III 545 (I originally posted in GeekSlutz, but got no respose). After reading through posts here on mics, I decided to give a Unidyne III 545 (no switch) a try and compare it to my SM57. The mic has a 4 pin connector (which I've since learned is an Amphenol MC4F). However, the mic came with a cable that has a matching 4 pin connector on one end and what appears to be a 1/4" TRS on the other end and says "Switchcraft." I tried plugging in the 1/4" to a preamp, and I don't hear anything on when the preamp input setting is 'low-impedence/mic'. When preamp input is instead 'high-impedence/inst' setting, I can hear sound when I tap the side of the mic, but no sound when I speak into it. So here's my questions: 1) Does it seem like I bought a broken mic, or is it that I don't have the right cable/connector? 2) If it's a cable issue, how do I go about getting the right connectors? I've seen some posts about soldering the necessary 4 pin-XLR cable, but I'm not sure exactly what I need. I would like to use this as a lo-Z mic ultimately. Thanks for your help...I don't mind building/making a cable, but I definitely don't want a broken mic. Rob

14th July 2006, 12:49 AM	#11
Mark Elmore Gear interested Join Date: Oct 2005 Location: Nottingham, UK Posts: 5	Actually.... If it's the old style Mbox you have, the line and intsrument settings only work with the jack input, and the mic setting only works with the XLR input. I hope that helps! Where online did you find the data sheet? I just picked up a switched Unidyne III with the 4 pin to TS jack cable and I'm looking for more info. __________________ -------- Mark

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25th June 2006, 09:17 PM	#2
corworld Gear maniac Join Date: Mar 2006 Location: New Mexico Posts: 170	Sounds like the mic is set up for high impedence use. If you have the original instruction sheet, that should tell you about the wiring. On the newer 545s, the switch from low to high is not a big deal. I've never looked at the 4-pin model. You may just want to convert it to three pin for Low-Z use. What pre are you using?

26th June 2006, 08:09 AM	#3
milet22 Gear interested Join Date: Nov 2005 Posts: 22	I found the old data sheet online, and I found what leads are for low and high impedence. I'm going to test the cable to see what it's wired for currently. I'm using the preamp on an MBox.

28th June 2006, 02:58 AM	#4
milet22 Gear interested Join Date: Nov 2005 Posts: 22	According to the data sheet, when using the mic as balanced, low impedence: BLACK (pin 3) - hot WHITE (pin 4) - hot SHIELD (pin 1) - ground RED (pin 2) - not mentioned...it says this is hot for unbalanced, high impedence so for low Z I guess it's not used. How should I connect these three leads (hot, hot, gnd) to XLR (hot, cold, gnd)? Thanks

29th June 2006, 08:40 AM	#5
milet22 Gear interested Join Date: Nov 2005 Posts: 22	I found a cable that works (amphenol to TRS) and it's configured for low impedance. However, same problems with the signal level. I was told that the mic was working before I bought it, and assuming that to be true, any other thoughts? Thanks...

29th June 2006, 01:40 PM	#6
paulneedles Gear nut Join Date: Sep 2005 Posts: 125	that happened to my 545 not that long ago - one of the cables inside had come loose, still worked slightly but with very low levels. open it up - it might be a really easy fix. i thought all the 545s had tuchel connectors? is that the same thing as an amphenol?

29th June 2006, 04:32 PM	#7
Thumper Gear addict Join Date: Apr 2006 Posts: 408	Your mic is broke. Give it to me.

30th June 2006, 09:15 AM	#8
milet22 Gear interested Join Date: Nov 2005 Posts: 22	Paulneedles, The three internal wires that connect to the capsule are still connected. I'm not sure about the Tuchel connectors. I looked up some pictures and they seem to be different than Amphenol. Thanks.

2nd July 2006, 02:01 PM	#9
paulneedles Gear nut Join Date: Sep 2005 Posts: 125	i'm stumped. you need to get someone to look at it for you by the sounds of things.

11th July 2006, 01:45 AM	#10
milet22 Gear interested Join Date: Nov 2005 Posts: 22	As a follow-up, I contacted Shure and they said it was either a broken capsule or possibly a broken transformer. For a $55 replacement fee, they'll replace it with an SM57. Thanks for everyones' input.

16th July 2006, 07:58 AM	#13
milet22 Gear interested Join Date: Nov 2005 Posts: 22	reply to Mark -- Thanks for the mBox info. I also checked the TRS cable in a regular mixer with a pre-amp and it still didn't work. Here's the link to discontinued pdfs http://www.shure.com/ProAudio/Downlo...inued+Products reply to Bob -- When I called Shure they said the replacement mic depended what they had it stock. It could be a 545 or a 57, but it was likely to be a 57.