Williams True Blast Diesel Sound Unit compatibility with Postwar Lionel diesels

[trainyardjp]

JP of Acton MA, USA writes,

Not sure if I have asked this in a previous post, but would a Williams True Blast Diesel Sound Unit, be compatible with a Lionel postwar diesel, completely replacing the postwar factory installed buzzer / buzzer solenoid / battery bracket?

Would the Williams sound unit have to be connected to a motor, for accurate engine 'rev up' / 'rev down' sounds, or does the sound unit produce the 'rev up' / 'rev down' sounds, automatically / electronically, based on voltage?

Any info would be greatly appreciated.
Thanks.
-JP
Direct replies can be sent to jpstrainyard@yahoo.com, Subject: "Replying to your Bachmann Forum post"

[Len]

I've installed both diesel and steam True Blast and True Blast II sound units in Post War Lionel locos. Depending on the loco, the biggest issue is sometimes finding space for the speaker. On diesels it will fit where the 'buzzer' used to be. For steamers with whistling tenders, locate the speaker over the whisle opening. The red wire should connect to the pick-up roller and the black wire goes to a chassis connection.

I don't know about 'revving' sounds. All the True Blast and True Blast II boards I've installed just had horn or whistle and bell sounds.

Len

[trainyardjp]

JP of Acton MA, USA writes,
Thanks for the info.
I looked at the product description on the Williams by Bachmann website, and there are Prime Mover sounds (which I assume is the diesel engine sound), along with the horn and bell sounds.
-JP

[Len]

Ok, I was looking in the 'Order Parts' listings. What you're talking about, the True Blast Plus modules, are in the 'On Line Store' listing for some reason. The PC board is about the same size as the True Blast II board, and there's only a two wire hook up, the same as the True Blast II. So, since the horn and bell are triggerd by a DC offset on top of the AC track voltage, the same as the True Blast II, the rev level pretty much has to be tied to the AC track voltage.

Len