Accu supply for preamp

[hahfran]

With 4 7.2 volts NiCad packs I made a listening test. I replaced
the external power supply for the RIAA preamp ( the preamp sits in an Linn LP 12 turntable in a tight metal box) with these NiCad and without doubt this yields an audible improvement.
I consider whether it is worth to redesign my preamp. A redesign is mandatory as this works with FET cascodes similar to the Akido preamp with + - 25 volts and moreover draws 100 mA per channel.
Any experience out there with accumulator supply for preamps?

Dieter F.

[lumanauw]

There's a commercial manufacturer ASR http://www.asraudio.de/ that uses dry batteries. +/-18V (3*6V cells for each rail). But for powering opamp, not high as 100mA.