Battery Powered Preamps

It would be interesting to hear from some designers on the issue, like Ralph Karsten of Atma-sphere and others. Since I know nothing at all about electronics I may be blind to something critical that makes getting on the grid worth the effort. But I do wonder why so much money and expense in preamplfiers center around the power supply, in some lines (e.g. First Sound)the difference in cost, sometimes significant, is almost exclusively centered around the power supply. If the "grid" is such a problem, that needs so much engineering - why not avoid it in the first place -- other than the fact that you have to recharge the batteries evey 6-12 hours (not a problem for me)? Id rather have improved S/N, no power cord issues, no conditioning required. Seems like an elegant solution; and I can attest that the Dodd sounds darn good. I also notice that the BAM on my Merlin Speakers sound better in battery mode than AC mode.

Dgarretson, do you know if the Dodd is a minimalist tube design? It seems to work well on batteries (4 12volt 5 amp SLA batteries - pretty heavy). Not as strong in the bass as the CAT Sl1 but it does seem very balanced. I wonder if Gary Dodd has overcome the inherent problems you describe through good circuit design or not. On my Merlins which only go to 28hz, the bass seems very good and dynamics seem very strong as well (not to the level of the CAT perhaps which is the most dynamic preamp I have heard)but pretty darn good.

I don't know enough to fully understand Dgarretson's technical explanation, nor whether Gary Dodd might answer "yes, generally true, but...." I do know the Dodd seems to be a pretty effective implementation of battery power and a whole lot simpler than complex power regulation and power supply I've seen in some of the preamps I've owned before. Since there haven't been many battery powered preamps before, I suspect that either battery technology has improved, or new thinking has found a way to deal with some of the issues Dgarretson raised. If that is the case, it would seem battery power holds a lot of promise compared with our traditonal way of designing preamps.

The Dodd uses (2) 6dj8s and as previously mentioned, it only uses 1/2 of each tube (when they get old you switch tubes and the other half of the tube is used). I thought this was a pretty nifty feature for getting double the life from expensive NOS tubes, but maybe part of the decision was based on the battery supplies limitations in terms of driving tubes - don't know. Maybe a well implemented battery power supply is expensive, but nothing like the $10,000K + traditional preamps with robust powersupplies, often requiring a second chassis.

Assuming battery implementations overcome what might be a theoretical issue regarding bass and dynamics (owners of Dodd and RWA seem to think this is not a problem with their preamps)wouldn't battery DC be cleaner and more "perfect" than what complex power supplies and regulation could possibly accomplish? It just seems a lot can wrong in the AC to DC conversion (let alone power cords, and quality of AC in most homes) and delivery versus pure battery power. I ask as an electrical neophyte, but it just seems that simpler is generally better.

Dgarretson, are you thinking battery power frontend electronics, I'm concerned with preamps in particular, is where we are heading for best sound?

Dgarretson, would love to get your impression of the Dodd. SBank also owns Merlins (great minds...) and switched to the Dodd after owning the Atma Pre (he had the MP-3, not the MP-1). In my system I prefer the Atma-Atma combo, but I prefer the Dodd with my Music Reference. I don't understand the theory, but I think Gary Dodd knew what he was up against and obviously came up with a pretty good approach. I wonder if this is Gary's all out approach to a batttery implementation at $3,300, or if more money could have done even better (he didn't spare any expense on the wood chassis or top plate) - there are not a whole lot of parts in there, but maybe as many as necessary and no more. I'm looking forward to RMAF, there seems to be a lot of ingenuity going on out there.