Bachmann OO 3F Tender 0-6-0 tender engine... possibly one of the easiest to install DCC sound into, within the tender, using a Zimo MX644D 21pin decoder, SugarCube speaker and small stay-alive capacitor - plenty of space!

Above photo supplied by David Brown.

Better speaker in this next one: dual IceCube28X18X10-2W, though the metal weights need to be removed to get this in. A dual SugarCube24X15X07 can be fitted while retaining the weights, which is a good compromise.

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