Neumann TLM67 de-emphasis

[RuudNL]

Yes, I know, there is no schematic available for the Neumann TLM67. (As far as I know.)
But...is there someone who found out where the capacitor is located that is responsible for the HF roll-off?
Of course I could randomly add extra capacity to several capacitors and listen to the result, but maybe somebody had more or less 'analyzed' (part of) the circuit?
I hope to reduce the HF roll-off a little, to make the microphone slightly brighter, so it will be closer to a U87ai.
Who knows more?
I measured the frequency response of the electronics as it comes from the factory, with the following results:

20 Hz -8,0 dB
40 Hz -1,5 dB
63 Hz -0,5 dB
100 Hz  0 dB
250 Hz  0 dB
1 KHz 0 dB
4 KHz -1,5 dB
5 KHz -2,0 dB
6,3 KHz -3,0 dB
8 KHz -4,0 dB
10 KHz -5,0 dB
12 KHz -6,5 dB
15 KHz -8,0 dB

 

[Kwinn]

@RuudNL
Hi, did you ever identify the capacitor that is responsible for the de-emphasis? Is it otherwise a clean circuit or are there additional sound shaping components involved? Thanks in advance.

 

[RuudNL]

I've lived with it... You can always EQ the microphone.
As can be seen from my first post, the circuit is definitely de-emphasized (as would be expected).

 

[k brown]

@RuudNL
Hi, did you ever identify the capacitor that is responsible for the de-emphasis? Is it otherwise a clean circuit or are there additional sound shaping components involved? Thanks in advance.

Neumann claims the circuit is designed to purposely increase THD as SPL goes up:

 

[pasarski]

Neumann claims the circuit is designed to purposely increase THD as SPL goes up:

Quite an achievement.

 

[k brown]

Quite an achievement.

I could see adding addtn'l 2nd harmonic, but THD?

Plus any tube circuit that did that would have been very poorly designed.

 

[pasarski]

I could see adding addtn'l 2nd harmonic, but THD?

Plus any tube circuit that did that would have been very poorly designed.

Or purposely. My first thought was that it doesn't seem super difficult to achieve with 20th century solid state technology.

 

[Khron]

Or purposely. My first thought was that it doesn't seem super difficult to achieve with 20th century solid state technology.

Tube Screamer, anyone?

 

[bremusound]

It seems that some kind of compression is going on in this circuit.
This is from a review of the TLM 67