The No.1 Website for Pro Audio
 Search This Thread  Search This Forum  Search Reviews  Search Gear Database  Search Gear for sale  Search Gearslutz Go Advanced
Bypassing switches in Shure sm7b Dynamic Microphones
Old 1 week ago
  #1
Gear Head
 

Bypassing switches in Shure sm7b

I would like to disconnect the switches from my sm7b and wiring the mic body directly to the XLR connector.
It seems like the black wire goes to pin 3 of the XLR, the white wire goes to pin 2 of the XLR.
How should I wiring the yellow and green wires for bypassing the low cut and the mid boost?

Old 1 week ago
  #2
Lives for gear
 
bgood's Avatar
Why on earth would you do this??
Old 1 week ago
  #3
Gear Head
 

Quote:
Originally Posted by bgood View Post
Why on earth would you do this??
The mic is old and the switches sometimes making noise and since I'm never use the low cut and the mid boost I would like to bypass the switches.
Old 1 week ago
  #4
Lives for gear
Best way is to see how Shure wired it when the switches are off. You can do this with an ohmmeter, or by simply looking at the back of the slide switches.

I'd guess from the schematic that removing the inductor from the circuit will do what you want: black from the element goes directly to 3 on the XLR; leave yellow and green disconnected (from each other, as well as from the switch) and wrap with tape to protect against shorts.

But it's entirely possible that Shure is doing something clever with the inductor to smooth out the element's response... so check the switches first, to see what the "off" positions are.

BEAR IN MIND: this will hurt the resale value of the mic, as well as confuse any other engineer who goes to use it. Why not just clean the darn switches?
Old 1 week ago
  #5
Gear Head
 

Setting the switches to on places a filter network in parallel with the capsule. No audio is going through the switches when they are set to off. Even with a dirty switch, you shouldn't have any crackling in this position - if you do, something else is going on.
Old 1 week ago
  #6
Gear Head
 

Thanks, I've opened the back of the mic again and I found that the connection of the two white wires (one is coming from the capsule and the other going to pin 2 of the XLR ) was badly soldered under the shrink tube.
After solder it properly it seems to operate as it should!
Old 1 week ago
  #7
Lives for gear
 
bgood's Avatar
Quote:
Originally Posted by smilan View Post
The mic is old and the switches sometimes making noise and since I'm never use the low cut and the mid boost I would like to bypass the switches.
Spray some contact cleaner in there!
Old 1 week ago
  #8
Lives for gear
 

Quote:
Originally Posted by bgood View Post
Spray some contact cleaner in there!
That's what I'd. Any electronic tech worth his salt will tell you the exact same thing. Only a fool would go in there and start butchering the circuit when it isn't needed. you easily wipe out a good deal of the resale value the second you attempt something like this.

Be sure you use lubricating contact cleaner too, the kind you use on pots for these type of switches. If you use a non lubricating alcohol cleaner on a plastic slider switch you'll make the problem worse and even make the switch freeze up by removing the contact grease. you want Pot cleaner with silicone or mineral oil so the switches will slide smoothly.
Old 1 week ago
  #9
Gear Head
 

Thanks guys,
Eventually the switches was fine, the problem was a dry soldering point between the two white wires that cause a bad connection. After I re-solder this connection the mic works great!
Old 1 week ago
  #10
Lives for gear
 
bgood's Avatar
Quote:
Originally Posted by wrgkmc View Post
That's what I'd. Any electronic tech worth his salt will tell you the exact same thing. Only a fool would go in there and start butchering the circuit when it isn't needed. you easily wipe out a good deal of the resale value the second you attempt something like this.

Be sure you use lubricating contact cleaner too, the kind you use on pots for these type of switches. If you use a non lubricating alcohol cleaner on a plastic slider switch you'll make the problem worse and even make the switch freeze up by removing the contact grease. you want Pot cleaner with silicone or mineral oil so the switches will slide smoothly.
Seriously... it’s like magic sauce for this sort of stuff!
Old 1 week ago
  #11
Lives for gear
 
bgood's Avatar
Quote:
Originally Posted by smilan View Post
Thanks guys,
Eventually the switches was fine, the problem was a dry soldering point between the two white wires that cause a bad connection. After I re-solder this connection the mic works great!
Cool! Glad you’ve got the knowledge and balls to fix it yourself
Top Mentioned Products
Post Reply

Welcome to the Gearslutz Pro Audio Community!

Registration benefits include:
  • The ability to reply to and create new discussions
  • Access to members-only giveaways & competitions
  • Interact with VIP industry experts in our guest Q&As
  • Access to members-only sub forum discussions
  • Access to members-only Chat Room
  • Get INSTANT ACCESS to the world's best private pro audio Classifieds for only USD $20/year
  • Promote your eBay auctions and Reverb.com listings for free
  • Remove this message!
You need an account to post a reply. Create a username and password below and an account will be created and your post entered.


 
 
Slide to join now Processing…
Thread Tools
Search this Thread
Search this Thread:

Advanced Search
Similar Threads
Thread
Thread Starter / Forum
Replies
sparky88 / So Much Gear, So Little Time
9
edva / So Much Gear, So Little Time
3
Fluency / Low End Theory
4
tubedude / So Much Gear, So Little Time
2

Forum Jump
Forum Jump