I just want to know if anyone is using a tube pre amp with ht bypass with a 7500

Tubes Rule, do not be a solid state fool.

Yes, Risky, there are some tube users around the forum. I'm not one of them (my 7500 is paired with a Model 990 in a purely solid state setup), so unfortunately I can't offer much useful input.

A tube preamp with the 7500 would work just fine. The input impedance is high enough so that there would be negligible loading on the tube stage. The benefit would be the same as using a tube preamp with any other power amp.

I bit the bullet today and ordered a dodd audio battery powered preamp and phono stage.

Let us know how it works out, Risky.

I don't see how the preamp could run directly from batteries without some sort of DC to DC voltage step up somewhere inside the circuitry. Looking at the plate voltage requirements, it wouldn't run very effectively at all on the 24VDC available from two series-connected batteries. There simply wouldn't be enough plate voltage to get useful current.

At any rate, I hope it works out well for you.

I was concerned about that myself but after talking to some owners and Gary Dodd I don't for see a problem. Gary assured me it would drive any amplifier on the market. Anyway we will see in about 45 days.

I'd keep the cables from the preamp to the power amp short as possible in any event; under 3 feet if possible.

Assuming they are running the tubes directly with a 24VDC B+, there would only be a couple milliamps of current available. That would rule out a low impedance output stage.

If they are indeed using a DC to DC converter in the preamp to boost the 24VDC up to the usual voltage for this tube, in the neighborhood of 100VDC or more, then the drive current wouldn't be that much of an issue. But having a DC to DC converter would kind of defeat the purpose of running on the pure DC from batteries, wouldn't it!

Well I finally recieved my dodd audio battery pre and phono stage. all I can say is wow!!