EHX bass big muff sucking signal when bypassed

[SSCBA]

That's the problem,

AFAIK, the bass big muff is true bypass, but I'm noticing a very big difference when the pedal is bypassed than when I connect the bass directly to the amp. Lows and higs get reduced, as well as overall perceived volume from the bass.

The signal path is bass > big muff > amp, and I've tried each cable individually and I get 'full' signal from both when connecting directly to the amp.

The problem comes when I connect the big muff between bass and amp bypassed.
The bass is a passive jazz bass btw.

Could be possible that the extra lenght of cable in the signal path (when using the bbm in bypass mode) is causing such a notorious decrease in signal quality?
What's your experience when bypassing the bbm?

[Laurent]

Sounds like a low batterie or a defective pedal.
Cable longer than 12 feet will start sucking tone.

[SSCBA]

Thanks, is there any way to verify that the pedal is defective before sending it for warranty?
Wouldnt a true bypass pedal work bypassed even without battery?

[walterw]

i'd suspect the switch itself, those mechanical switches can and do break.