Sutherland PHD

Running a preamp on battery power is no big deal, and has been done for years...the circuits draw little power. The idea of using a signal-sensing automatic turn on also is not new...just about every subwoofer plate amplifier has this feature. Putting these two features together in a preamp is a good idea. It's a clever piece of equipment, and must be fun to own.

All that being said, how does it sound? Good enough to justify the price?

Surprised Twl hasn't stepped in here. He runs his entire system on batteries, although I think they're a little more sophisticated than D cells. I'm sure this gets him cleaner signals and a lower noise floor.

We just put a new 12V halogen light fixture in the room next to our system. Despite the dedicated audio AC circuit and a $2K power conditioner, the hash is still getting through. Anybody got a battery big enough for a 240wpc SS amp?

Except for the need for periodic replacement (which really isn't very often-- the lifespan of those D cells is probably better than most power tubes!!!!), batteries are superior to AC power any day in every way. The currents that are required in a preamp are in the range of a few milliamps, which a battery of this size will just laugh at. They are capable of delivering orders of magnitude more than this.

Hi, yes I also use battery powered stuff. I like it alot. I even use battery power on my power amp. If it is lacking in any transients/dynamics/bass impact, I sure don't know about it. IMO, it is superior to what comes out of the wall any day of the week. I get instantaneous current delivery like you wouldn't believe. Zero grunge. No power transformer hum fields. No rectification or ripple. Pretty damn good in my opinion. I wouldn't go back to wall power again. I'm using lead acid RV/marine type batteries with over 650 cold-cranking amps and deep-cycle capability. These babies rock! And they really keep the noise floor dead quiet. Of course, I'm only powering a 2 watt 45 OTL SET with them that draws 3.8amps at 12vdc, so you could say that I have plenty of reserve power. Probably won't be drawing too hard on those 650CCA anytime. But if they can surge 650a, I think they'll deliver 3.8a pretty freely. My dynamics and bass impact are plenty good. No problems at all.

I currently use the PhD. I am using Grado Statement1 with it and it sounds really good to my ears. The batteries last like forever. I changed it once in the last 3 or 4 years.

I did change the loading on the Grado Statement1 as 47k didn't sound right to me.