Hiow to replace wall wart on step up with battery

RWwear,
Thanks. This sounds almost too easy to be true, but I'll start looking into this
and
Xiekitchen,
I haven't heard them side by side in the same system, but there is a bit of opinion on the two on Ausio Asylum:

http://db.audioasylum.com/cgi/search.mpl?forum=vinyl&searchtext=lukaschek

...always something newer or better....

Thanks for the info on the parameters I should be considering, Herman. A great help. Since the Naim you modified was presumably an AC unit (as is the Lukaschek)and most battery power is DC, does this add an additional parameter I should be looking into?
What I am also considering is a way to bypass most of the DIY aspects of this by using the battery supply of another step up unit, such as, the Phonomena, thinking that replacing only the connector from the unit to the Lukaschek would be easier overall. So, I'm looking for output info on the Phonomena battery pack.
The output to Lukaschek is 24V 250mA, AC.
Thanks for any info or ideas.

Herman,
Once again, thanks for all the info.

But it does leave me a bit confused. The limits of my electrical understanding must have been reached, so if this seems too elementary, bear with me.

I don't understand how the AC to DC conversion is done externally to the Lukaschek if the output from the WW is marked "24V 250mA, AC," rather than "24V 250mA,DC." The Lukaschek case, itself, is marked "24V, 3 VA" above the input connector -- a further confusing item for me.

Many of the WW's I have for, admittedly less complex, devices are marked DC on the output description. That makes it clear to me that these devices operate internally on DC.

I also e-m'd the distributor of the Phonomena and Benz about the output of the Phonomena, and their reply was that the Benz is AC while the Phonomena was DC.

So how does this all fit together? I understand what you have written about battery choice, etc. It also makes sense to me that the conversion from AC to DC for the Lukaschek would take place outside of the unit itself because of its small size. The output info on the WW and what's printed on the case of the Lukaschek, though.... The case of the Lukaschek is metal, and I assume that it is supposed to operate, at least partially, as a heat sink. It stays warm to the touch

I guess it's clear that the background issue is that I am concerned about frying this in some way, and this leads me to proceed with caution in what I might actually be a rather straightforward process.

So, what am I missing?

Thanks.

Herman,
At least, I did manage to learn a good bit from this dialogue. You are right that feeding DC from the batteries directly to the regulators is something tht I don't want to attempt. Seemed like such a good idea, though....