Double Bass Barcus Berry 3000A preamp, in/out which one turns battery off?

[MDH]

Hello, just got one of these used with the 3150 screw/clamp-on bass pickup. Found a brochure online that says battery life 1000 hours but can't find any specifics. I assume either the RCA input or the 1/4" output jack turns the battery power on/off? Or how does it work, thanks

BarcusBerry.com redirects here: Shop by Brand - KMC Music, I gather they changed hands.
Brochure [with what appears to be the 'owner's manual'] https://www.fullcompass.com/common/files/15831-BracusBerry3125MUserManual.pdf

 

[Francois Blais]

The 1/4 inch output jack has power the switch.

 

[MDH]

The 1/4 inch output jack has power the switch.

ah! OK, that makes sense, as one of the installation options is to leave the pre-amp clamped to the tailpiece, you'd presume with the pickup/rca plug left plugged into it. So far using at home I have an rca extension cord running to the 3000A on a desk next to the bass.
thanks!

 

[Francois Blais]

I meant "has the power switch" but you already guessed that.