U67 de-emphasis network

[OPR]

I did the original test with pink noise and a drum beat. Makes sense what you wrote
Also this is with u87. The NFB circuit is way different.

You're up a bit late! 3:30 am in Norway..

Now when you say the audio Nulls do you mean that the residual gives you absolute silence?
nothing at all?

Can you post the wavs?

What distance from the speaker are you working at?
I have a bunch of 87's here and can repeat your test with the 67 also.

 

[kingkorg]

You're up a bit late! 3:30 am in Norway..

Now when you say the audio Nulls do you mean that the residual gives you absolute silence?
nothing at all?

Can you post the wavs?

What distance from the speaker are you working at?
I have a bunch of 87's here and can repeat your test with the 67 also.

Not absolute silence, it was close to the noise floor. I'll see if i can dig up the files. It's at 40cm, coaxial speaker.