Fitting A Next18 HM7000 Decoder To A Plux22 Bachmann Class 47

Many people have been disappointed that there was no way to use HM7000 decoders in a new tooled Bachmann model, with a plux22 socket. We have found a way to use a next18 decoder using a plux16 adapter.

You might lose some lighting functions, as you only have access to directional lights and aux1 and aux2. You also need to be mindful of the speaker impedance. You must only use an 8 ohm speaker, if your model has two built in speakers, one has to be removed before you fit the decoder. Don't use any additional speakers unless you remove all the speakers built into the model. More on this below.

In this example we use a new class 47 model. Start by removing the body following the Bachmann instructions. You start by removing the blanking plug and fitting an ESU plux16 to next18 adaptor.

Next you need to make sure you only have one 8 ohm speaker in the model, this model comes with 2 speakers, so I removed the small sugarcube from the top of the PCB. It's important that you do this, otherwise you'll blow the sound decoder.

The screws for the second speaker are under the circuit board so you need to take all the screws which hold the circuit board out to access them. The main speaker which is under the circuit board is left in, and this is the only speaker now in the model.

Once you are sure you just have one speaker, you can fit the HM7000 decoder into the next18 adapter.

I also used the space where the small speaker used to be to add a stay alive.

You can find all the parts you need here.