-10db pad to lf cut filter conversion

[rodrigo salvatierra]

Does anyone know how to convert an OKTAVA MK012 -10dB pad to a low cut
filter? The pad has a small capacitor to ground.


thanks

[Peter Larsen[_3_]]

rodrigo salvatierra wrote:

> Does anyone know how to convert an OKTAVA MK012 -10dB pad to a low cut
> filter? The pad has a small capacitor to ground.

You can not - in the real world, I'll leave theory to someone else - insert
high pass functionality there. It may be possible to fit a stack foil
capacitor into a jack plug and use it as high pass filter by inserting it in
the mixer or preamp insert, if any. The actual roll-off will depend on the
actual impedances in the actual insert-point.

What actual problem is is you are trying to solve?

> thanks

Kind regards

Peter Larsen

[Scott Dorsey]

rodrigo salvatierra > wrote:
>Does anyone know how to convert an OKTAVA MK012 -10dB pad to a low cut
>filter? The pad has a small capacitor to ground.

You can't, really.

But it's easy enough to add a low cut filter AFTER the electronics. Look
at the Shure ones.

It would be impossible to add it BEFORE the electronics.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[rodrigo salvatierra]

On Jun 18, 6:35*am, (Scott Dorsey) wrote:
> rodrigo salvatierra > wrote:
>
> >Does anyone know how to convert an OKTAVA MK012 -10dB pad to a low cut
> >filter? The pad has a small capacitor to ground.
>
> You can't, really.
>
> But it's easy enough to add a low cut filter AFTER the electronics. *Look
> at the Shure ones.
>
> It would be impossible to add it BEFORE the electronics.
> --scott
> --
> "C'est un Nagra. C'est suisse, et tres, tres precis."

Thanks. What I would like to know is if it is possible to turn my
-10db pad, that I have never used, into this:
http://www.zenproaudio.com/oktavalowcutfiltersilver.aspx
which is something I would. ¿possible?

[rodrigo salvatierra]

A filter for the MK-012 does exist though, that goes between the
capsule and the preamp. Since it is similar in size, I wanted to use
the -10dB pad, which I do not use, to make a low cut filter, by
changing its components. is that possible?

[Sean Conolly]

"rodrigo salvatierra" > wrote in message
...
> A filter for the MK-012 does exist though, that goes between the
> capsule and the preamp. Since it is similar in size, I wanted to use
> the -10dB pad, which I do not use, to make a low cut filter, by
> changing its components. is that possible?

IMHO, having anything between the capsule and the mic preamp is going to
degrade the signal. Maybe not much, but needlessly since it's so easy to
plug something after the mic preamp.

But yes, you can make a passive filter that will give you a modest amount of
low cut. The question is finding the components that will fit in the space
you have, and still be effective AND sound tolerable. It'd be a lot easier
to just buy the Oktava filter if you really want that.

Sean

[Don Pearce[_3_]]

On Sat, 18 Jun 2011 15:16:21 -0400, "Sean Conolly"
> wrote:

>"rodrigo salvatierra" > wrote in message
...
>> A filter for the MK-012 does exist though, that goes between the
>> capsule and the preamp. Since it is similar in size, I wanted to use
>> the -10dB pad, which I do not use, to make a low cut filter, by
>> changing its components. is that possible?
>
>IMHO, having anything between the capsule and the mic preamp is going to
>degrade the signal. Maybe not much, but needlessly since it's so easy to
>plug something after the mic preamp.
>
>But yes, you can make a passive filter that will give you a modest amount of
>low cut. The question is finding the components that will fit in the space
>you have, and still be effective AND sound tolerable. It'd be a lot easier
>to just buy the Oktava filter if you really want that.
>
>Sean
>

There is a huge mechanism for signal degradation putting a low cut
between mic and pre-amp. The noise level in a pre-amp is dependent on
the loading effect of the microphone's impedance. When you unload the
preamp input by interposing a capacitor, the noise increases at the
same rate. In the normal way, he 1500 ohms (approx) of the preamp is
shunted by 150 ohms of the mic capsule. With the cap in place that
1500 ohms is left unbypassed, and the LF noise will rise by 10dB. Not
good news, and you need yet another highpass filter down the line to
get rid of it.

d

[Peter Larsen[_3_]]

rodrigo salvatierra wrote:

> A filter for the MK-012 does exist though, that goes between the
> capsule and the preamp. Since it is similar in size, I wanted to use
> the -10dB pad, which I do not use, to make a low cut filter, by
> changing its components. is that possible?

Yes, back in the analog days it was a great idea to use a first order filter
before tape when recording vox. Today the great idea is to use a 4'th order
bessel - example: via scientific filters in audition 3 and earlier - and
adjust it to fit the noise in the actual recording. It plain sounds better
and you get rid of the mud without getting rid of the fullness of the voice.

In my opinion anything but the simplest clean recording is folly or - to be
polite - technically a suboptimal solution.

Kind regards

Peter Larsen

[Scott Dorsey]

rodrigo salvatierra > wrote:
>Thanks. What I would like to know is if it is possible to turn my
>-10db pad, that I have never used, into this:
>http://www.zenproaudio.com/oktavalowcutfiltersilver.aspx
>which is something I would. =BFpossible?

Yes. That's just an RC network in there. The problem is that it doesn't
work worth a damn; the distortion goes through the roof and the high
frequency response is altered also.

Mind you, the shunt capacitor "pad" is just as awful. It's worse than
useless.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Mike Rivers]

On 6/18/2011 2:09 PM, rodrigo salvatierra wrote:
> A filter for the MK-012 does exist though, that goes between the
> capsule and the preamp. Since it is similar in size, I wanted to use
> the -10dB pad, which I do not use, to make a low cut filter, by
> changing its components. is that possible?

You really don't want to mess with the design of the mic in
the high impedance path. You don't have the facilities to
test what you've done. It might be possible to add a filter
in the low impedance part of the mic (near the output) and
switch it with the built-in switch, but there are two
problems with this.

The first one is obvious - there may simply not be enough
room in the case to put the parts that you need. Unless
you'll be satisfied with just 6 dB/octave (and you shouldn't
be), you'll need more than just a capacitor of the proper
value.

The second is less obvious. By putting the filter between
the capsule and the impedance converter (which is what mic
designers who know what they're doing do), you're keeping
the high amplitude low frequency energy from overloading the
impedance converter or eating up most of its headroom. So
that's the right place for it, but it's something that's
integral with the mic's design, not a simple add-on.


--
"Today's production equipment is IT based and cannot be
operated without a passing knowledge of computing, although
it seems that it can be operated without a passing knowledge
of audio." - John Watkinson

http://mikeriversaudio.wordpress.com - useful and
interesting audio stuff

[Sean Conolly]

"Ty Ford" > wrote in message
al.NET...
> On Sat, 18 Jun 2011 15:16:21 -0400, Sean Conolly wrote
> (in article >):
>
>> "rodrigo salvatierra" > wrote in message
>> ...
>>> A filter for the MK-012 does exist though, that goes between the
>>> capsule and the preamp. Since it is similar in size, I wanted to use
>>> the -10dB pad, which I do not use, to make a low cut filter, by
>>> changing its components. is that possible?
>>
>> IMHO, having anything between the capsule and the mic preamp is going to
>> degrade the signal. Maybe not much, but needlessly since it's so easy to
>> plug something after the mic preamp.
>
> Sean,
>
> The good pads are put between the capsule and electronics of the mic. To
> put
> the pad after the electronics opens the possibility of overloading the
> electronics before the signal leaves the mic.

Understood, but at that point it's time to switch to a different mic.

Sean

[Arny Krueger]

"Sean Conolly" > wrote in message
...
> "rodrigo salvatierra" > wrote in message
> ...
>> A filter for the MK-012 does exist though, that goes between the
>> capsule and the preamp. Since it is similar in size, I wanted to use
>> the -10dB pad, which I do not use, to make a low cut filter, by
>> changing its components. is that possible?
>
> IMHO, having anything between the capsule and the mic preamp is going to
> degrade the signal. Maybe not much, but needlessly since it's so easy to
> plug something after the mic preamp.

True in a way, but you've missed the point. What is the difference between
degradation and optimization? The difference is based on what is the right
thing to do at the time.

If the signal is too loud or has too much bass, then *degrading* it by
dropping the level or rolling off the bass is a good example of optimizing
the sound. The purported degradation will make your recording sound better,
and that is all that matters! Don't go all golden ear audiophile on us! ;-)

[Scott Dorsey]

Arny Krueger > wrote:
>"Sean Conolly" > wrote in message
...
>> "rodrigo salvatierra" > wrote in message
>> ...
>>> A filter for the MK-012 does exist though, that goes between the
>>> capsule and the preamp. Since it is similar in size, I wanted to use
>>> the -10dB pad, which I do not use, to make a low cut filter, by
>>> changing its components. is that possible?
>>
>> IMHO, having anything between the capsule and the mic preamp is going to
>> degrade the signal. Maybe not much, but needlessly since it's so easy to
>> plug something after the mic preamp.
>
>True in a way, but you've missed the point. What is the difference between
>degradation and optimization? The difference is based on what is the right
>thing to do at the time.
>
>If the signal is too loud or has too much bass, then *degrading* it by
>dropping the level or rolling off the bass is a good example of optimizing
>the sound. The purported degradation will make your recording sound better,
>and that is all that matters! Don't go all golden ear audiophile on us! ;-)

Problem is that doing this does a whole lot more than just drop the level
or roll off the bass. The high-Z capsule/electronics interface is a touchy
thing in the best of circumstances.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Ty Ford]

On Sun, 19 Jun 2011 13:05:00 -0400, Sean Conolly wrote
(in article >):

> "Ty Ford" > wrote in message
> al.NET...
>> On Sat, 18 Jun 2011 15:16:21 -0400, Sean Conolly wrote
>> (in article >):
>>
>>> "rodrigo salvatierra" > wrote in message
>>> ...
>>>> A filter for the MK-012 does exist though, that goes between the
>>>> capsule and the preamp. Since it is similar in size, I wanted to use
>>>> the -10dB pad, which I do not use, to make a low cut filter, by
>>>> changing its components. is that possible?
>>>
>>> IMHO, having anything between the capsule and the mic preamp is going to
>>> degrade the signal. Maybe not much, but needlessly since it's so easy to
>>> plug something after the mic preamp.
>>
>> Sean,
>>
>> The good pads are put between the capsule and electronics of the mic. To
>> put
>> the pad after the electronics opens the possibility of overloading the
>> electronics before the signal leaves the mic.
>
> Understood, but at that point it's time to switch to a different mic.
>
> Sean

Not necessarily. The better mics are padded this way and have stood the test
of time.

Regards,

Ty Ford



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