Suggestion to interface a battery pack as pre phono power supply


Hi guys,
I have a Musical Surroundings Phonomena II pre phono.
The carts are an Ortofon 2mBlue (the rookie...) and a Benz Ace L (the master ).

In searching to improve the pre phono sound with a reasonable expense i noticed that the pre phono has a very filmsy wall 12Vdc AC/DC switching power adapter.

Musical Surrounding produces a dedicated battery powered-power supply for this equipment, too.
It is pretty expensive and I'd try to go with some search to check if a DIY solution is viable, instead.
This original battery-based PSU uses NiMH batteries.

Since many reviews of this Battery PSU are very enthusiastic as a true enhancement to my pre-phono performances and since now I coudl not make other significative expenses on this side, I thought that if the original battery based PSU exploits NiMH batteries... it should be a good candidate solution to use this kind of battery as a power supply for this phono stage.

I am guessing: in your experience, is it enough to attach a NiMH battery pack of suitable volts and current straight to the power input of the pre phono instead of using its wall switching power supply or some buffer circuit between the NiMH battery pack and the pre phono are required / suggested ?

I read different infos and threads all around the web about the electrical aspects of the battery packs (high impedance...) when used in an HiFi environment and so I am a bit confused if, to obtain a real improvement, a direct connection is enough or some adapting circuitry is needed..

Some hints on this are very well welcomed !

Regards
Luca
lsfarzo
Teres Audio had a battery upgrade to their motor just like this. All components run on DC anyway, the only difference being how they get their DC. Most run AC through diodes and store the DC in caps. Partly to store power for transients, also partly to smooth diode ripple. 

So you have a phono stage and it runs on DC either from an external power supply or batteries. Same deal, same diff. Phono stage does not know where the 12V DC comes from. Does not care if it is lead acid or NiMH. 

What it DOES care about is any noise riding on that DC. This is the real reason battery power sounds so much better. DC coming off a battery has zero line noise. Only opportunity for RF to creep in is the few feet of wire from the battery to the component. 

UNLESS the battery is connected to a charger. Which for convenience it always is. THEN you must wire it to disconnect from AC during play. Otherwise that AC line noise goes right across the battery and into the phono stage. It was very easy to hear this with my turntable motor. For sure it is there with a phono stage.  

You can use any old car or motorcycle battery. Whatever you want. Mine was a motorcycle battery. You can use any cheap charger. Does not matter. Just wire it with a relay to disconnect whenever the phono stage is on. Phono stages draw so little power it will run for hours and hours if not days and days without charging no problem.  

Do not put anything between the battery and the phono stage. Do put a relay or something between the AC charger and the battery. Simple as that.