Question on a Mod: SM57

[kfowler8]

I'm trying out the TapeOp mod on the SM57. Essentially removing the transformer. I wanted to try it out first before I decide to remove it permanently. So I unscrewed the capsule and soldered a mic cable directly to the capsule leads therefor bypassing the transformer. (See attached pic)

To test it I ran one xlr cable to he bottom of the mic which goes through the transformer (for stock sound) and another cable as mentioned above soldered directly to the capsule.

As expected, the signal from the mod line running directly to the capsule was about 13 dbs lower. What I was surprised to find is there was no audible difference between using the transformer and bypassing it. Sonically they sounded the same.

So my question is could the transformer still be impacting the line that's directly connected to the module?

 

[Freddy G]

Hmmm....it's not an earth shattering difference in sound. I would disconnect the transformer though to really be sure....it could still be loading the signal.

 

[kfowler8]

Hmmm....it's not an earth shattering difference in sound. I would disconnect the transformer though to really be sure....it could still be loading the signal.

This should help. Here's the test results. The first mic you hear for each section is the stock SM57, second is the modded SM57, and third is a Pyle PDMIC78 (SM57 clone). I adjusted gain for each track to get he same volume level.

Sections are: Snare, Kick Drum, Guitar Amp, Acoustic Guitar, Voice

I'm not hearing much of a difference between the stock and modded SM57.

https://soundcloud.com/kfowler8/sm57-mod-main-file

 

[kfowler8]

Note the recording above used the method in the attached picture. I may go back and just de-solder the whole capsule.

 

[Freddy G]

You're right. I'm not hearing any difference either. It should be noticeable. Try disconnecting the transformer.

 

[kfowler8]

You're right. I'm not hearing any difference either. It should be noticeable. Try disconnecting the transformer.

Got it. I'll try it and see.

One interesting idea I saw was to use a heat gun to remove the transformer and then wire in between two xlr cable. So you could switch back and forth. I want to figure out if it's worth it first.

 

[Batman]

I did the mod on one of my SM57's earlier this year. The results are very noticeable.

I very much prefer the sound of the modded version; it's less middy and nasal sounding and also seems to be a bit less position fussy.

 

[Inland Bagpipe]

Of all the mics to spend the time/effort to mod this would literally be at the bottom of my list. I guess if you're really bored though, why not?

 

[Freddy G]

Of all the mics to spend the time/effort to mod this would literally be at the bottom of my list. I guess if you're really bored though, why not?

Why not? It's a good mod.

 

[Inland Bagpipe]

When a 57 isn't sounding quite right I just throw my i5 on it and give it a try. For mics at this price point that already do such a great job I don't see the point in modifying them. That's just me. Suffice to say I modded the hell out of a CV-12 and that difference was night and day so I'm not against modding things.

 

[kfowler8]

When a 57 isn't sounding quite right I just throw my i5 on it and give it a try. For mics at this price point that already do such a great job I don't see the point in modifying them. That's just me. Suffice to say I modded the hell out of a CV-12 and that difference was night and day so I'm not against modding things.

Well I've never been enamored with the 57 in the first place. I especially dislike it on guitar tabs. So if a simple mod makes it more usable to me it's certainly my worth trying.

 

[Inland Bagpipe]

I actually agree with you on part of it. I find the i5 much nicer on cabs than the 57. Have you ever tried one of those?

 

[kfowler8]

I actually agree with you on part of it. I find the i5 much nicer on cabs than the 57. Have you ever tried one of those?

Have not. Looks interesting though. This $10 Pyle Audio SM57 clone actually sounded pretty good on cabs and male vocals. I have a Sennheiser E835 that I prefer over the SM57/58. I do like the 57 on a snare and certain acoustics.

My favorite mic I've used on a guitar cab was an EV RE-20.

 

[Inland Bagpipe]

Yeah those are really sick. I use an Avantone Cr-14 ribbon mic with my i5 for my home recording gig and they work brilliantly together. I'd definitely recommend pairing a ribbon up with your dynamic when you record. Just be sure to check for phase

 

[Freddy G]

Well I've never been enamored with the 57 in the first place. I especially dislike it on guitar tabs.

Pairing a 57 with the right preamp impedance load will make all the difference in the world.....here's an article:

- Shure SM57 Impedance Modification : Recording Magazine -

 

[kfowler8]

Pairing a 57 with the right preamp impedance load will make all the difference in the world.....here's an article:

- Shure SM57 Impedance Modification : Recording Magazine -

Wow Freddy! Great article. I'm using a Focusrite 2i2 and the mic input is a 2K load just like the article. I'm definitely going to have to try this.

 

[Batman]

Freddy, assuming both my interfaces are 2K (they are) is this something you could do directly to the Mic rather than making up a separate line gizmo?

 

[kfowler8]

FYI, I now hear a difference with the mod. The transformer must have been bleeding off part of the signal. I do like the change.

 

[Pwrmac7600]

FYI, I now hear a difference with the mod. The transformer must have been bleeding off part of the signal. I do like the change.

care to post an A/B clip? I am curious about this mod.

 

[Freddy G]

Freddy, assuming both my interfaces are 2K (they are) is this something you could do directly to the Mic rather than making up a separate line gizmo?

Yes, just solder in the resistor inside the mic