A "U867" microphone

[LevinGuitar]

Any advantage of using a BV12 transformer and its deemphasis over a standart BV13 and U87 way of deemphasis in a Fet microphone? The ratio is a bit lower but there could be gain stage adjustment to match it.

 

[abbey road d enfer]

Does the BV12 really have deemphasis? Do you have a link to this (dis)information?

 

[soliloqueen]

The way the u67 does deemphasis is finnicky and they dumped it just about as soon as they could. Advantages? Like sonically? I don't believe so

 

[Delta Sigma]

Does the BV12 really have deemphasis? Do you have a link to this (dis)information?

I believe the OP just means the separate secondary winding that is used for the de-emphasis feedback path.

I'm assuming, they mean "is there any advantage to tertiary feedback in a FET mic for capsule de-emphasis over the de-emphasis in a U87"

 

[abbey road d enfer]

I believe the OP just means the separate secondary winding that is used for the de-emphasis feedback path.

I'm assuming, they mean "is there any advantage to tertiary feedback in a FET mic for capsule de-emphasis over the de-emphasis in a U87"

Thanks for the translation.

My take on the subject is that all current and past "deemphasis" sytems are equally wrong, because1st-order "deemphasis" is inadequate for compensating the capsules resonance,, which is a 2nd-order phenomenon. I don't think there's an existing mic with proper capsule resonance, except some that exist in their own ecosystem, such as Slate and Sphere.
I may be wrong since I don't know every mic in existence.

 

[LevinGuitar]

I believe the OP just means the separate secondary winding that is used for the de-emphasis feedback path.

I'm assuming, they mean "is there any advantage to tertiary feedback in a FET mic for capsule de-emphasis over the de-emphasis in a U87"

Yes, that was the question, thanks

 

[Moby]

Thanks for the translation.

My take on the subject is that all current and past "deemphasis" sytems are equally wrong, because1st-order "deemphasis" is inadequate for compensating the capsules resonance,, which is a 2nd-order phenomenon. I don't think there's an existing mic with proper capsule resonance, except some that exist in their own ecosystem, such as Slate and Sphere.
I may be wrong since I don't know every mic in existence.

I don't think deemphasis by feedback winding or passive U87 deemhasis is used to tame down the capsule resonances. As far I know, capsule resonance is tamed down mechanically or say acoustically inside the capsule itself. Deemphasis in U67 and U87 was used to linearise the shelwed high frequency curve of the k67, k87 capsules. And yes, Bv.12 deemphasis "system" sounds diferent from the "more classical deemphasis circuit" used with the U87's.

 

[kingkorg]

Deemphasis in U67 and U87 was used to linearise the shelwed high frequency curve of the k67, k87 capsules

And reduce noise of the electronics, Dolby NR style. Also to limit upper HF extension and prevent distortion of high frequencies in radio broadcasting. It's often forgotten there is also low end roll-off as well. It is as important to nail this part. Most focus only on 220pf range cap in u87.

Roll off just the high end on a k67 it will sound boomy. Roll off the low end as well, and we get typical mid focused u87 sound.

Using this feedback network also lowers THD compared to simple rc filter which in my experience always increases it.

Feedback from the tertiary in Manley Ref C. brings 12ax7 THD so low you wouldn't believe it's a 12ax7.

Not that i doubt you knew this already, just throwing it out for others who might not be aware.

 

[Moby]

And reduce noise of the electronics, Dolby NR style. Also to limit upper HF extension and prevent distortion of high frequencies in radio broadcasting. It's often forgotten there is also low end roll-off as well. It is as important to nail this part. Most focus only on 220pf range cap in u87.

Roll off just the high end on a k67 it will sound boomy. Roll off the low end as well, and we get typical mid focused u87 sound.

Using this feedback network also lowers THD compared to simple rc filter which in my experience always increases it.

Feedback from the tertiary in Manley Ref C. brings 12ax7 THD so low you wouldn't believe it's a 12ax7.

Not that i doubt you knew this already, just throwing it out for others who might not be aware.

Thanks for adding more detailed explanation. I was too lazy to do it . LOL

 

[Recording Engineer]

For a few years now, I’ve had a new Flea F9 capsule I bought to play with. Still haven’t, but I’ve thought… Hey, what would happen if I put it in a U67-type circuit?

 

[Moby]

For a few years now, I’ve had a new Flea F9 capsule I bought to play with. Still haven’t, but I’ve thought… Hey, what would happen if I put it in a U67-type circuit?

F9 (M9) is omni capsule withouth any need of deemphasis. So, F9 + U67 is not what you want.

 

[Recording Engineer]

F9 (M9) is omni capsule withouth any need of deemphasis. So, F9 + U67 is not what you want.

Right. Obviously, that’s not how the system was designed, but is that not a massive linear rise in the M9 design?:
http://recordinghacks.com/microphones/Neumann/CMV-563
Hence… My curiosity.

 

[Moby]

Right. Obviously, that’s not how the system was designed, but is that not a massive linear rise in the M9 design?:
http://recordinghacks.com/microphones/Neumann/CMV-563
Hence… My curiosity.

Please try and share the result with us. Generally speaking, everything is doable. Right?

 

[abbey road d enfer]

I don't think deemphasis by feedback winding or passive U87 deemhasis is used to tame down the capsule resonances. As far I know, capsule resonance is tamed down mechanically or say acoustically inside the capsule itself.

That's the midrange resonance; of course it is damped to provide a flat-ish response. But the HF resonance, combined with the diffraction boost, is a 2nd-order resonance that can be corrected only with a 2nd-order EQ.

 

[Moby]

That's the midrange resonance; of course it is damped to provide a flat-ish response. But the HF resonance, combined with the diffraction boost, is a 2nd-order resonance that can be corrected only with a 2nd-order EQ.

Ok, so how do you explain the flat U67 response. We all know that k67/87 capsules has the emhasis. Right?

 

[abbey road d enfer]

Ok, so how do you explain the flat U67 response. We all know that k67/87 capsules has the emhasis. Right?

I don't know. I just know that every capsule has a HF resonance that may appear as a peak or as a low-pass response if it's too damped.
It's just physics.

 

[Moby]

I don't know. I just know that every capsule has a HF resonance that may appear as a peak or as a low-pass response if it's too damped.
It's just physics.

True but the question is does U67 has the deemphasis. Yes, it has and it's achieved by unique approach. DC polarisation voltage on the backplate is mixed with the AC singnal derived from the transformer winding.

 

[abbey road d enfer]

True but the question is does U67 has the deemphasis.
Yes, it has and it's achieved by unique approach. DC polarisation voltage on the backplate is mixed with the AC singnal derived from the transformer winding.

That's correct.