Hollis Research GX-10 precision amplifier (internal preamp?)

[Jaythegreen]

Hey fellow bass heads,

I have a Yamaha BBN5-II that I absolutely adore, got it for a steal and has been my go ever since. I have owned this Yamaha for about a year and used it for recording through lockdown (I’m a guitarist mainly, sorry!). Anyway, upon changing the 9v is was curious as to what the little black box was the the batt was powering (an active EQ of some sort I guessed?) and found it to be a Hollis Research GX-10 “ precision amplifier“. I can’t find much in the way of info on it bar that the company was from the Channel Islands and now no longer exist. Any one have any knowledge on said pre amp that can shed some light on it would be most awesome! 

[Jakester]

Presumably you’ve Googled it?

 

First few links suggest it’s an active buffer preamp akin to the Creation Audio Redeemer.

[John Cribbin]

I have a brand new unused one from back in the day (80's?), I'll try and find it with the docs.

[butike]

I just picked up a Yamaha BX-1 bass with a serial dating it to April 2 1987 which has one of these Hollis Research preamps inside. It's my second BX-1, I loved the first one so much that when another one came up in pristine condition just couldn't pass up the opportunity. The first one dates to April 25 1987 but doesn't have a Hollis preamp inside so I'm guessing it was installed by the owner although I could be wrong. Interesting that the original poster had one in his Yamaha bass. Couild this be something that Yamaha was offering as an optional extra from the factory maybe?