Kit: Zimo MX649 with Minnow4 Speaker and SACC16 kit with 2x 330uF Tantalums for stay-alive
Pretty little B4 model from Dapol. Careful as you take it apart though as everything disassembles and drops out! Once you've removed the
screws for the keeper plate and dropped the chassis out, screw the keeper plate back in to save the mechanism from dropping out while
you are working and testing.
Neat PCB with 6pin socket provided, but no good for sound. Model also provides 2 LEDs for firebox light which is a nice bonus - we'll
reuse those with the DCC Sound installation.
A little extra room to play with in the nose, but not much, so some careful planning required.
No extra space at the rear to speak of.
Here's the kit we will attempt - MX649 (hard-wired of course), Minnow4 speaker and stay-alive using SACC16 board and a 330uF Tantalum (flat one):
Snip off the original PCB supports to give us more flush space for the decoder...
Looking at the profile, I reckon we can actually fit a pair of 330uF Tantalums (flat versions) to the SACC16 board to double the
stay-alive... let's give it a go...
Hard-wire the motor and pickups, then join in the firebox lighting. Note everything is directly wired to the decoder so no wire joins
as this would take up too much space. We split off BLUE (common positive) from the SACC16 input, via a resistor to the positive pad on
the B4's firebox lighting PCB. The 2 LEDs are controlled by AUX3/FA1 and AUX4/FA2 outputs on the decoder so we can control them
Now test, and a case of getting everything neat and balanced so that it does not interfere with the motor or fly-wheel.
Minnow4 speaker fits in the top of the nose, secured with some Black Tack - don't want that falling down!
Some squishing and squeezing to get it back together, but done, and runs sweet! Our sound project is a variant of the Andrew Barclay
project with modified whistles to suit the B4.