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Does anybody sell pre-made resistor "gizmos" for sm57/58 mics?



 
 
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  #11  
Old September 15th 20, 10:46 PM posted to rec.audio.pro
geoff
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Default Does anybody sell pre-made resistor "gizmos" for sm57/58 mics?

On 16/09/2020 9:42 am, geoff wrote:
> On 16/09/2020 5:43 am, Roy W. Rising wrote:
>> I can't seem to find a suitable XLR F/M barrel, how about a 2' cord
>> with a 1% 600 ohm resistor in one end?* Send me an email, it's yours
>> for $10, including shipping.* ~ Roy
>>

>
> Here's one. A bit expensive. A little googling should find one for much
> cheaper.
>
> https://www.digikey.com/product-deta...048-ND/1290432
>
>
> geoff



Here's a cheaper one. This is from a New Zealand distributor, but I'm
sure equiv available anywhere in the world.

https://jansen.nz/product/signal-ada...etal-1842.htmx
( that is about US$3.50).

geoff
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  #12  
Old September 15th 20, 11:52 PM posted to rec.audio.pro
Scott Dorsey
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Default Does anybody sell pre-made resistor "gizmos" for sm57/58 mics?

Roy W. Rising > wrote:
>I can't seem to find a suitable XLR F/M barrel, how about a 2' cord with a 1% 600 ohm resistor in one end? Send me an email, it's yours for $10, including shipping. ~ Roy


Beautiful, Roy! I was going to suggest he drop by a local makerspace with
a cable and a resistor.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."
  #13  
Old September 16th 20, 07:46 AM posted to rec.audio.pro
Trevor
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Default Does anybody sell pre-made resistor "gizmos" for sm57/58 mics?

On 16/09/2020 3:43 am, Roy W. Rising wrote:
> I can't seem to find a suitable XLR F/M barrel, how about a 2' cord with a 1% 600 ohm resistor in one end? Send me an email, it's yours for $10, including shipping. ~ Roy
>


Wow Roy pretty generous, that's less than the cost of parts and shipping
surely!

  #14  
Old September 16th 20, 07:54 PM posted to rec.audio.pro
Roy W. Rising
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Default Does anybody sell pre-made resistor "gizmos" for sm57/58 mics?

When I started in TV sound in '65, I was told the mic preamp input impedance should be "2K or greater" to avoid loading ribbon mics, which lose HF performance when loaded. Dynamic mics generally "care" less about loading, with the exception of the SM57/58 as discussed here. EV co-founder Lou Burroughs told me that as of the "Research Engineering" era, EV dynamics would no longer use transformers for impedance selection. The successor to the EV 666 (with transformer) is the RE15. Lou said that inline attenuators' loading would not affect performance and that a true 150 ohm load would only lower the level by 6dB. With all of the variables surrounding mic performance, I decided to step beyond the esoteric practice of "mic selection". Instead, I started using RE15s on "everything", in part because EQ on every input was appearing. My other reason was that mixing TV orchestras amounted to mixing leakage. The RE15 is flat from all directions, hence "better" leakage. I have a matched pair for my desert island gig.
  #15  
Old September 16th 20, 08:11 PM posted to rec.audio.pro
Scott Dorsey
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Default Does anybody sell pre-made resistor "gizmos" for sm57/58 mics?

Roy W. Rising > wrote:
>When I started in TV sound in '65, I was told the mic preamp input impedanc=
>e should be "2K or greater" to avoid loading ribbon mics, which lose HF per=
>formance when loaded.


And see, when I started in the seventies, I was told the opposite, that
ribbons wanted to see a lower impedance. Roy is correct, and Olson backs
him up, and what I was told was wrong, but apparently a lot of people
believed it at the time.

> Dynamic mics generally "care" less about loading, wi=
>th the exception of the SM57/58 as discussed here. EV co-founder Lou Burro=
>ughs told me that as of the "Research Engineering" era, EV dynamics would n=
>o longer use transformers for impedance selection.


If you want microphones that are efficient and have high output, you get
tight coupling and live with loading changing the response. If you can
make the magnetic circuit lossy, they won't be as sensitive to load.

One of the things about the SM-57 is that it uses a very low-Z winding with
a few big turns, going into a step-up transformer. The later EV dynamics used
higher impedance windings without the transformer, which was a win sonically
but might have made them less rugged.

> The successor to the EV=
> 666 (with transformer) is the RE15. Lou said that inline attenuators' loa=
>ding would not affect performance and that a true 150 ohm load would only l=
>ower the level by 6dB. With all of the variables surrounding mic performan=
>ce, I decided to step beyond the esoteric practice of "mic selection". Ins=
>tead, I started using RE15s on "everything", in part because EQ on every in=
>put was appearing. My other reason was that mixing TV orchestras amounted =
>to mixing leakage. The RE15 is flat from all directions, hence "better" le=
>akage. I have a matched pair for my desert island gig.


The RE15 is an unsung hero, alongside the Sennheiser 441. Both sound pretty
good when you're standing behind them. Try THAT with an SM-57.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."
  #16  
Old September 17th 20, 12:03 AM posted to rec.audio.pro
geoff
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Default Does anybody sell pre-made resistor "gizmos" for sm57/58 mics?

On 17/09/2020 7:11 am, Scott Dorsey wrote:
> Roy W. Rising > wrote:
>> When I started in TV sound in '65, I was told the mic preamp input impedanc=
>> e should be "2K or greater" to avoid loading ribbon mics, which lose HF per=
>> formance when loaded.

>
> And see, when I started in the seventies, I was told the opposite, that
> ribbons wanted to see a lower impedance. Roy is correct, and Olson backs
> him up, and what I was told was wrong, but apparently a lot of people
> believed it at the time.


Surely all passive ribbon mics have output transformers, and the optimal
loading would be dependent on that, which could be different for every
model or brand ?


>
> The RE15 is an unsung hero, alongside the Sennheiser 441. Both sound pretty
> good when you're standing behind them. Try THAT with an SM-57.
> --scott
>


And the AKG D224E, not omni, put freq response pretty similar all angles.

geoff

  #17  
Old September 17th 20, 06:25 PM posted to rec.audio.pro
Roy W. Rising
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Default Does anybody sell pre-made resistor "gizmos" for sm57/58 mics?

On Wednesday, September 16, 2020 at 4:03:58 PM UTC-7, geoff wrote:
> Surely all passive ribbon mics have output transformers, and the optimal
> loading would be dependent on that, which could be different for every
> model or brand ?
> >

Let me repeat: Microphone preamp input impedances should be 2K ohms or greater to *avoid* loading ribbon mics. "Optimal loading" would be NO loading whatsoever.
  #18  
Old September 17th 20, 07:56 PM posted to rec.audio.pro
Don Pearce[_3_]
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Default Does anybody sell pre-made resistor "gizmos" for sm57/58 mics?

On Thu, 17 Sep 2020 10:25:58 -0700 (PDT), "Roy W. Rising"
> wrote:

>On Wednesday, September 16, 2020 at 4:03:58 PM UTC-7, geoff wrote:
>> Surely all passive ribbon mics have output transformers, and the optimal
>> loading would be dependent on that, which could be different for every
>> model or brand ?
>> >

>Let me repeat: Microphone preamp input impedances should be 2K ohms or greater to *avoid* loading ribbon mics. "Optimal loading" would be NO loading whatsoever.


There is an equally important impedance requirement in the other
direction. To achieve the lowest possible noise level the microphone
impedance as seen by the pre must be about right. Typically this is
about 150 ohms. This is determined by the balance of voltage noise and
current noise in the preamp. Many of the top mixers are pretty poor in
this regard; something that was not very important until the new
generation of ultra-low self noise mics came along.

d

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  #19  
Old September 18th 20, 12:18 AM posted to rec.audio.pro
geoff
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Posts: 1,673
Default Does anybody sell pre-made resistor "gizmos" for sm57/58 mics?

On 18/09/2020 5:25 am, Roy W. Rising wrote:
> On Wednesday, September 16, 2020 at 4:03:58 PM UTC-7, geoff wrote:
>> Surely all passive ribbon mics have output transformers, and the optimal
>> loading would be dependent on that, which could be different for every
>> model or brand ?
>>>

> Let me repeat: Microphone preamp input impedances should be 2K ohms or greater to *avoid* loading ribbon mics. "Optimal loading" would be NO loading whatsoever.
>


Let me repeat - FAKE NEWS !

Input impedance that a ribbon mic works into should be whatever is
specified optimal for the specific model of ribbon mic. They have either
a transformer (which should reflect the specified load optimally to the
ribbon), or an active preamp will will isolate the ribbon element
totally with a known and controlled load, and have its own specified load Z.

A passive ribbon mic with its inherent transformer may have markedly
different response into normal range versus very-high-to-none-at-all
loading.

But I could be wrong - Scott, Don ?

geoff
  #20  
Old September 18th 20, 03:08 PM posted to rec.audio.pro
Mike Rivers[_2_]
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Default Does anybody sell pre-made resistor "gizmos" for sm57/58 mics?

On 9/17/2020 7:18 PM, geoff wrote:
> A passive ribbon mic with its inherent transformer may have markedly
> different response into normal range versus very-high-to-none-at-all
> loading.


This is true for any microphone with a transformer. It's not about
impedance matching of the microphone element with that of the preamp, it
has to do with the inductance and resonance characteristics of the
transformer.

This is a _system_ issue, not a component issue.

--
For a good time, call http://mikeriversaudio.wordpress.com
 




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