ANY idea what this is? Tab AK5 filter

[adamasnan]

TAB AK5 FILTER

I got it for peanuts, in the hope to use the NTP M100C to replace a bad one elsewhere, but what is it?

Thanks!

 

[Michael Tibes]

A very wild guess: a 90 degree filter. If I understand it right these devices shift the phase of the mono input signal something like +90 degrees on one side (or is it +/- 45?) so that it feels like 'stereo' but it doesn't collapse if summed to mono. Correct me if I'm wrong on that description...

Michael

 

[[silent:arts]]

Michael, a 90 degree filter would have two input(s)(transformers) and one output(transformer).
Looking at the transformers I would say the AK5 is mono in and mono out.

 

[analogguru]

My bet is that it is a low-pass-filter for telephone- (3,5kHz) or studio- (16kHz) lines.