I would like to hear the new sound system on the GP30. Is a sample of the sound system available online somewhere? The loco LOOKS great by the way!

The circuit board puts resistors inline between the wheel electrical pickup and the electric motor. These resistors limit the current that passes through to the electric motor. I am making an assumption that this is to protect the motor from high current from a short circuit, such as might occur in a derailment, but Mr. Bachmann, or one of our more electrically expert group members, might provide a better reason for the resistors.
The circuit board is not necessary if you convert Thomas to DCC by soldering in a DCC decoder. I would think it would be a good idea to keep the circuit board in your Rosie conversion, pending more expert comment from Mr. B or a more expert group member.

Thomas' circuit board is mounted to his cab roof. The cab roof lifts off fairly easily with a gentle pull and wiggle. Red and black wires come from the wheel electrical pickups. The electric current passes through resistors mounted to the circuit board and orange and gray (or maybe brown) wires take the electric current to the motor. My guess is that the resistors are to protect the relatively small electric motor from damage due to any high voltage surges from a short circuit.

The circuit board does not control eye movement. Eye movement is mechanically driven by the same electric motor that drives the wheels. Eye speed changes directly with engine speed.

The motor for the N 0-6-0 w/tender is available on the Bachmann web site for $10.00 plus shipping.

http://estore.bachmanntrains.com/index.php?main_page=product_info&cPath=66_70_115&products_id=307

Hi,

On the mid-bottom of the loco you will see 2 small Phillips head screws. Undo these and the plastic fuel tank comes off.

Once the fuel tank is off, this exposes 2 more Phillips head screws (in deep sockets) that hold the body to the frame. Remove these and you can lift the body off. You might have to wiggle the body end-to-end to get the coupler boxes past the ends off the frame.

I have used the NCE Bach DSL decoder in the B23-7 with good success. This decoder is designed as an "upgrade" for other "DCC Onboard" Bachmann diesels, but with a little creativity it works well in the "Non-DCC" B23/B30-7.

I have the CSX B30-7 with decoder installed for sale on my web site. I have included a couple pictures. I have a Conrail B23-7 w/DCC in stock also. Contact me off the board if you would like a price for an install in your loco.

Best Regards,
Steve K.
www.skingtrains.com

Hi,
    After reading this thread today, I decided to open up a Bachmann Thomas to investigate the DCC installation. I happened to have a Digitrax DZ123 decoder floating around from a never completed N gauge DCC conversion. This is a rather small decoder which made things pretty easy in terms of finding room for the decoder. It turns out that Thomas has a small circuit board fastened to his cab roof and this is the place to solder in the decoder. Thomas' cab roof can be removed by gently squeezing the front and back windows and lifting gently. Anyway, in less than 2 hours Thomas, programmed #0001, is whirring around my test track with a Hornby Annie and  Clarabel, and a Brake Van (also Hornby) in tow. Thomas with DCC is an even MORE useful engine!
    I operate an online train shop and would be happy to do this work, at a reasonable cost, for anyone who might be interested. I can provide the decoder and installation in your locomotive or provide a brand new locomotive with decoder installed. Contact me directly at [email protected] if interested.

Thanks,
Steve K.
www.skingtrains.com

Hello,
I have recently upgraded my older HO Bachmann Spectrum 2-8-0 to DCC with the Bachmann 44915 Decoder. All works well except the headlight is very dim. Can I reprogram the decoder to send more voltage to the headlight? Or should I replace the headlight bulb with an LED when using this decoder?
Thanks,
Steve K.