the jrdg model 8 is no longer in production (altho it's listed as a "current" product on thier website). hence, unless the seller already has a battery unit, they may be hard to come by. the battery unit does lower the noise floor and provide a "blacker" background. i've never purchased a battery for my modified 8ti, tho, because its use cuts in half the power output and i need the 400 watts/channel the "ac-powered" amp produces into my speakers' nominal 4 ohm load. -cfb
