the Dodd AUdio DC-Battey powered Vacuum tube preamp is better than any $7k or under preamp I compared this to .Being run purely on 4 small gel cell batterys I get over 18 hours of use before I have to turn it off for a few hours to recharge which takes about 4 hours,being a direct feed to the amp it is a dead quiet background with far superior inner detailwithout all the power supplys and gain stages and noise to deal with.There is only 1 High quality capacitor to deal with in the signal path .I have owner a Cat ultimate signature , Conradjohnson
premier 17, this bettered it in allmost every aspect and at 1/2 the cost .This latest version is even better in the Bass now that all 4 batterys are run in series . The life span for batterys is about a 3 year average and only $65 to replace.