SM7a/b humbucker coil

[CoolCat]

more pictures of disassembly -

The stand nut screw was weird- a square screw, the new SM7b with standard Phillips much easier, but this is the old one a button head screw with 4pt "square" screw.
Pic 1-5
Backplate and EQ and capsule wiring
following pictures- noted inner body is painted and wiring colors.

 

[rob aylestone]

That's really good for identifying how it should look! thanks for this.

 

[CoolCat]

Its one early version at least to note a bit. Outside the no-humbucking coil and the humbucking coil there's not a lot of difference seen.

Looking at the newer SM7b's I have there are good improvements imo, over the original ones.
1.Putting the XLR in the front seems to be popular (which can be done with any model of these)
2.The mic stand is now a Phillips/cross screw instead of this old weird square screw.

Seems most everything is still to the same spec/design and interchangeable from old to current. Some decal/label changes, nothing important.
As with old vs new in sound? gets crazy....the capsules and magnets etc, and age seems to be the "sound" difference debated forevermore. For gear collectors the old ones will go up in value

Shure has a number for the tiny screws pn 30D443E but they don't seem to sell them. Not much info on them I could find. But then another Shure Product seemed to have used the screw p/n and there were details its M25, and that's a o.08 size! 80 thousandths of an inch, so many people seem to lose them. To be honest 2qty hold the back plate/EQ plate fine but 4qty is the full set. I found that interesting as I need to order some. $7 for 10 of them or something.
UPDATE: Seems the tiny tiny backplate screws are technically called "2-56 x 5/16" , ( .086 dia x .31x Long ), the ones I got were too short in length so don't buy the 1/8/.11.

I also found the XLR shield wire intentionally not connected, with the black and clear wire going to the mic PCB. Because the pin 1 is connected to the case of the SM7, shield wire. There is a fine wire jumper from Pin1 to case ground. Inside the mic there's no green wire from the XLR. Anyway the old one works and noise was identical to my new SM7b.

In the picture it shows only black and clear going into the mic body and the XLR shows the pin 1 green with heat shrink on it? wierd. It works fine!

 

[bouldersoundguy]

Is the noise the same when near a powered up wall wart or fluorescent light?

 

[CoolCat]

Just having the mics setup sitting idle, I didn't see any difference.

Thats the thing, my setup/room doesn't have a hum buzz issue.
I can only assume the engineers of Shure got it right.
Some mention in the older days of tubes and amps and radio station setups/rooms the humbucker -coil was needed.

My original curiosity was if the humbucker-coil changed the sound but if the humbucker coil is only active in the presences of noise, seems its just docile when not needed.
In guitars humbuckers and single coils sound different, so I wondered?
I haven't done anything in depth of the sound thing. I am impressed the old mic works fine and isn't too beaten up. Interesting history of the SM7...SM57 on steroids the Shure article said.

I don't know anything about setups in the 1970's or 1960's that would not only drive the SM7 but also the humbucker-coil being added.

 

[drtechno]

Just having the mics setup sitting idle, I didn't see any difference.

Thats the thing, my setup/room doesn't have a hum buzz issue.
I can only assume the engineers of Shure got it right.
Some mention in the older days of tubes and amps and radio station setups/rooms the humbucker -coil was needed.

My original curiosity was if the humbucker-coil changed the sound but if the humbucker coil is only active in the presences of noise, seems its just docile when not needed.
In guitars humbuckers and single coils sound different, so I wondered?
I haven't done anything in depth of the sound thing. I am impressed the old mic works fine and isn't too beaten up. Interesting history of the SM7...SM57 on steroids the Shure article said.

I don't know anything about setups in the 1970's or 1960's that would not only drive the SM7 but also the humbucker-coil being added.

The humbuker is just a counter-wind tied in series. so they act like a small inductor filtering way past the audio range and counteract proportionally when electro magnetic radiation imposes on the mic coil. But since the inductance is small they don't interfere like they do with guitar pickups.

Since the "presence" filter is a useless cut, I removed mine and installed a TAB-58 transformer because it needs a step up transformer. That made it well compatible to plug into any mic preamp. About a year later, a young guy who was an intern with the local public radio was impressed on how it sound when I played through it and bought it off me. Which later I found out, that kid, Bryan Carlstrom, made a lot of platinum albums with it.

I made a couple of more for my own use, when I find someone to play with from time to time. They still freak the sound guys out because they think they are not going to work. Then when I played through them they freaked out because they decided to turn the mic gain up too much.

 

[CoolCat]

interesting. I looked for a picture of a bucker-coil wire, it must be tiny. The wire is so tiny, so I might assume the hum-180 coil wire is the same gauge?

modding a SM7abd , the TAB58 seems is 1inch x .7inch pretty large but the SM7 has more room I suppose somewhere in the body. Any pictures?
Bryan , wow...I was just listening to Americana this week, love Offspring, the guitars and vocal "sound" screaming tube compression vibe, good article in TapeOps.

 

[drtechno]

interesting. I looked for a picture of a bucker-coil wire, it must be tiny. The wire is so tiny, so I might assume the hum-180 coil wire is the same gauge?

modding a SM7abd , the TAB58 seems is 1inch x .7inch pretty large but the SM7 has more room I suppose somewhere in the body. Any pictures?
Bryan , wow...I was just listening to Americana this week, love Offspring, the guitars and vocal "sound" screaming tube compression vibe, good article in TapeOps.

I'll dig one out and take a picture when I have time this weekend. But the hardest thing was figuring out a way to mount it.
The last time I saw him was a couple of months before his accident and he was using it in this one corner space area that was enclosed on one side with a glass sliding door. He was distant micing a Marshall stack with using a modified marshall amp that had a bogden SRPP input stage made by a like minded modder. That later I modded again to clean it up more.

I tried to share my mod and even offer to sell ones on Gearslutz years ago. But they were more into pushing the cloudlifter which isn't a true fix for the microphone. Putting a step up transformer in it is the proper solution.

Long ago, I researched and tried out different preamps to find what kind of preamp that would interface it correctly. Which I found that it was DC coupled mic preamp channel. First one I found was from a sadies broadcasting board that is used in television and radio studios and others like a harrison (can't remember which model) and an AMEK M2500 were the other ones that worked instantly with a stock sm7.