I am not sure what you mean by jumpers?
Hi, let me try and explain better.....
Here is a picture of a standard "Jumper"
http://www.maplin.co.uk/Module.aspx?ModuleNo=98860They are about 5mm in size, the are used instead of switches to allow options to be selected, these are usually on the Printed Circuit Board (PCB) within equipment.
The BP25 had the option of mps1 or mps2 power supply (maybe only a date related option).
The MPS2 has the additional power supply rail (+12v) that the MPS1 does not,
This jumper I mention is to do with the additional power rail, From your serial number Bryston will know if you needed to remove ths jumper - The details are in the bottom left of the BP25 schematic.
The mps 1 comes in at 29 watts and the mps2 comes in at 100 watts. The mps2 is going to have way better current delivery, and it does.
True that it is able to supply a higher current than the mpsa1 - But this is related to the ability to power four units and the mps1 powers one unit.
In fact 29x4=116, so IF you were loading the mps2 with four devices then the mps1 would offer a higher supply demand ability per unit than a fully loaded mps2.
I know that mps2 has potential for 5 components but every single component can benefit from this larger power supply.
The mps2 will power four units and has remote trigger options for five, you would usually use the related power/trigger for on unit and the additional trigger for amplifiers.
The mps2 needs to be sitting on the bp25, other way around and it doesnt look good imo.
Again I don't think I explained myself well

. If possible try and place the MPS2 to the side of the rest of the kit rather than in a vertical line, same with the amplifier, See if you hear any change.........
I understand this cant be a permenant option for you and may be difficult to try.
My tests with Bryston and other kit have shown excellent improvement.
It reduces the cross contamination of electronic fields.
These are only my opinions and I am very open minded to hear others opinions,
Andy.