SM57 Impedance Gizmo
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CJWall
Member
dreamcatcher
Raising the Knife
Glenn Fricker
Very Metal &Very Bad News
dreamcatcher
Raising the Knife
OzNimbus said:
Ain't got one, can't find one.
It's an old Tascam M-30.
NVM found a different vendor for manuals
Haha, exactly what I asked for in my other thread!
I was talking to my broadcast/electrical engineer at work, and I told him about this. He told me that in the strictest electrical terms, an impedance matching transformer is the right way to go...instead of a resistor. He's a VERY by-the-book guy though.
I don't have enough money to buy a UA, Groove Tubes, or Great River pre...so I guess I'm going to have to try this.
I was talking to my broadcast/electrical engineer at work, and I told him about this. He told me that in the strictest electrical terms, an impedance matching transformer is the right way to go...instead of a resistor. He's a VERY by-the-book guy though.
I don't have enough money to buy a UA, Groove Tubes, or Great River pre...so I guess I'm going to have to try this.
could someone take a picture of this? How should I connect this to a preamp? Do I just solder the resistor IN the Male connector? that's it?
Keiffer said:
Lol, yeah I don't know. The guy is very smart when it comes to all sorts of technical stuff. He regularly tears apart our massive 263,000 watt analog transmitter with the biggest vacuum tubes I've ever seen...so I'm pretty sure he knows what he's talking about.
He started babbling off with all sorts of in-depth technical jargon when I asked him my impedance question...I told him to simplify it and he showed me an inline XLR thing that had an impedance matching transformer in it, which he told me to use instead.
I have very little experience with electronics, so I'm not sure which way is the right way...and I don't really care if this little gizmo works.
There is no 'right' way - there are lots of ways to alter impedence, and they all have their place. Sticking a resistor in the connector is damn easy and dirt cheap, but you have to do the math beforehand and pick a good average value (unless you only intend to use the cable on one preamp) - whereas the transformer route will (I believe) match itself accurately to the loads either side, so you can use to on a wide range of preamps and it will be bang on with all of them.
However, if you know the Z of a particular preamp and a particular mic then you can get a resistor that will be almost as good a match, and the difference will be pretty small - certainly far less then the difference of not having any impedance correction at all.
Any electrical type will tell you to use a matching transformer because it's more accurate and it's designed specifically for that job - plus it saves them having to do any maths
In acoustic terms though, the accuracy isn't that important.
Steve
However, if you know the Z of a particular preamp and a particular mic then you can get a resistor that will be almost as good a match, and the difference will be pretty small - certainly far less then the difference of not having any impedance correction at all.
Any electrical type will tell you to use a matching transformer because it's more accurate and it's designed specifically for that job - plus it saves them having to do any maths
In acoustic terms though, the accuracy isn't that important.Steve
Ben Johnson
SSSSSSSSSSSSSS
Glenn Fricker
Very Metal &Very Bad News
For the record, the Great River uses different windings on the transformer to adjust impedance. The new Presonus/ADL tube pre (not a cheap unit), on the other hand, uses resistors. I believe both methods are viable.
BTW, I built a unit today & tried it out on my Vintech dual 72. So far, the results are pretty interesting. Besides dropping the level about 3 db's, it does seem to smooth out the extreme top & bring the mids a touch more forward.
Remember guys, when conducting these experiments, make sure to level match your tracks when A/Bing. VERY important.
-0z-
BTW, I built a unit today & tried it out on my Vintech dual 72. So far, the results are pretty interesting. Besides dropping the level about 3 db's, it does seem to smooth out the extreme top & bring the mids a touch more forward.
Remember guys, when conducting these experiments, make sure to level match your tracks when A/Bing. VERY important.
-0z-
KeithRT99
BOOSH.
Another thing mentioned in the article is... *drumroll*... transformerless mics!
Even cheaper than another cable, and simpler than figuring out impedance, is unscrewing the mic body, taking the body (not capsule) and removing the wires from it, boiling it to melt the glue and remove the transformer, and rewiring the fucker so you have a clearer, fuller SM57. Am I the only one on this board who has spent much time with this? Drives me nuts - the transformer is going to screw up the sound if you've gotten one recently, as they haven't been putting in the best by any stretch, and if you yank the bugger out your impedance will be much closer to where you'd like it anyway with most equipment. Yeah, this is a great article and will be very helpful for dynamic mics with transformers that are worth keeping, but you can probably do better just taking out the transformer.
Jeff
Even cheaper than another cable, and simpler than figuring out impedance, is unscrewing the mic body, taking the body (not capsule) and removing the wires from it, boiling it to melt the glue and remove the transformer, and rewiring the fucker so you have a clearer, fuller SM57. Am I the only one on this board who has spent much time with this? Drives me nuts - the transformer is going to screw up the sound if you've gotten one recently, as they haven't been putting in the best by any stretch, and if you yank the bugger out your impedance will be much closer to where you'd like it anyway with most equipment. Yeah, this is a great article and will be very helpful for dynamic mics with transformers that are worth keeping, but you can probably do better just taking out the transformer.
Jeff
Gnash
Lefty
I think I'll try this. The cover on my snare 57 just cracked, so this might be the one!JBroll said:
Suicide_As_Alibi said:Any electrical type will tell you to use a matching transformer because it's more accurate and it's designed specifically for that job - plus it saves them having to do any maths
Steve
Yeah, like I said...I don't know much about electronics. I just go with what I hear from people.
I think that was his point though, to use a transformer that was intended for matching impedances.
Eh, oh well.
Keiffer
Member
- Apr 14, 2006
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Fucking A... 
I'm talking a cable with a resistor in it. it's just an option... yeah transformers will work, so willl the resistor. to pick a value it's best to know the preamp impedance you're going to use it with.
comparing $1K+ preamps to this cable is... well absurd. the preamp has a lot more going on than just loading the mic.
as for your technical buddy... he's right. but you've totally missed the point. FWIW, I have a EE degree of 25 years and have done this shit for years even longer.
you don't have to use the cable, but it's a very good and dirt cheap option.
and no, transformers do not auto match. transformers are basically inductive and have an impedance.
as for removing the 57 transformer, here's a clip comparing with and without.
57 with - 57 w/o - i5
I'm talking a cable with a resistor in it. it's just an option... yeah transformers will work, so willl the resistor. to pick a value it's best to know the preamp impedance you're going to use it with.
comparing $1K+ preamps to this cable is... well absurd. the preamp has a lot more going on than just loading the mic.
as for your technical buddy... he's right. but you've totally missed the point. FWIW, I have a EE degree of 25 years and have done this shit for years even longer.
you don't have to use the cable, but it's a very good and dirt cheap option.
and no, transformers do not auto match. transformers are basically inductive and have an impedance.
as for removing the 57 transformer, here's a clip comparing with and without.
57 with - 57 w/o - i5
