I have Analogue Solutions ATT4 passive attenuator.
http://www.users.globalnet.co.uk/~concuss/concussor/att4.htm

When I route for example the clock signal from A-154 or logic high
output from A-166 (10V) through the ATT4, I get only 50% output (5V),
when the attenuator knob is in full clockwise position. However,
with most other sources (including other 10V logic signals) I get
100% output as expected.

I found this, when testing, how my modules would respond to softer gate
signals. I wonder, what is the explanation

Best regards
Jari Jokinen