Allo CM board makes a profound difference to the sound of the base Volt+.

The base Volt+ has 1 x 1000uFD to filter/supply both channels of the 3118.
In this configuration, the mid and low bass are very weak.  This is driving
very difficult 2 way bookshelf reference speakers (86db/W/m).

Trying differen SMP bricks, didn't not fix the problem.  I went up to 24V @ 5A SMP,
then went back to 19V @ 10A (which had more resolving power).   People also
seem to be leaning towards linear supplies over SMP bricks.

Then I tried a CM board (2 x 1000uFD) as a pre-filter into the Volt+.

The mid and low bass were markedly improved.   Still not as firm and control
as the amp I was comparing it against (which was 140W AB with 30000uFD
and costing 60x more $).

I'm definitely going to increase the pool up to 7K uFD with fast ESR caps
as the next stage.

Also, the wiring to the speaker output terminals on the Volt+ Step Attenuator
are very lacking.   Very thin wire (which may account for the thin mid/low bass)
and not solder (tension with a screw) which came loose (had to debug this).   

The upper end is spot on.   Imaging of solo vocals and single instruments are very
convincing.

But for the price point,  I really can't complain.

Any benefits to adding external CM board to Volt+.   20000 ufd more
help the sound much?