I thought all akai effects were true bypass I think the shred o matic I borrowed was and the akai phaser I've got is. Hope this helps
Actually... Neither the Unibass nor the Deep Impact are true bypass. Bottom line: If there's no power to the pedal, your signal isn't going through it.
It's not going through a Fulltone Bassdrive neither. You may want to find another criteria. Akai claim all their pedals to be true bypass.
To be really anal - you can hear the 'click' of the jumper inside a deep impact when you switch it on and off. I think of the unibass as 'constant-bypass' as it is not strictly an effect, your bass signal remains unchanged regardless of whether or not the pedal is on or off. It simply adds the octave up signal which is either routed separately to your bass signal (effect out) or mixed with it - either way your bass signal is untouched. The unibass manual does not mention being true-bypass nor is it listed as true bypass in their product range and this surely is for the above reason that it doesn't affect the original bass signal. I need to get out more.
The Deep Impact is in fact true-bypass. Failure of the pedal to work when not plugged in is an irrelevant criteria - its what it does (or doesn't do) to your tone when bypassed that is the key.
Any anyway, the signal still passes through when the pedal is unplugged and switched off. I know, I've had to unplug the power to mine when it's started crashing and the bass signal carries through unaffected. Alex P.S. And if the point was that if a pedal needs power to work then it isn't true bypass, then that's wide of the mark too - all it means is that a pedal is active, not passive. And I've yet to come across any passive pedals other than true-bypass boxes. (Or passive tone control boxes if they exist?)