Hi

I have no direct experience of the new Mallet, but I suspect the problem lies in the track voltage coming from the MTS control unit. This can be 23-25 volts, which is too high for the installed DCC chip, which then overloads and shuts down.

The solution for this is to place a series of bridge rectifiers between the control unit and the track (see www.atlasrr.com/voltage.htm or www.tonystrains.com/technews/soundtraxx_heats.htm). The rectifiers reduce the voltage reaching the track (which should be below 21 volts) and allow the chip to work normally.

I have a Bachmann K-27 with a QSI sound chip, plus 3-truck Shays which work and sound great on my MTS system. One other thing - the MTS system only supports 14 speed steps, so the CV29 address in the chip has to be given a value of 4 - the QSI chip is probably set up for 28/128 speed steps.

Good luck!

Nick.

Thank you all for your comments. I emailed QSI about the lights problem on Friday and am waiting for a reply. According to the 'voice' of my decoder when first switched on, I have version 7-0-52. Does that make sense?

In reply to Stan, the lights work properly in DC mode but do not work in either forward or reverse when in DCC. My experience with the MTS system is that the decoder does need to be set to 14 speed steps - my Bachmann 3-truck Shay had lights problems until I changed CV29 to 4. However, doing that with the QSI in the K has not solved the problem.

The F0 command is no help with MTS - it turns the controller off.

Nick.

Another 2 pence worth from the UK, and a question..... I have installed a QSI Aristo sound decoder (no. 3010-0) in my K-27. My railroad is controlled by MTS, with the voltage reduced through rectifiers. Control of the K-27 is good, sounds are good, but the front and rear lights and cablight do not work. The marker lights and firebox flicker work fine. All lights work correctly when run on analogue with the dummy board re-inserted.

I thought that the lights not working could be due to a speed-step problem, so re-programmed the QSI CV29 to 4, to suit the 14 steps of the MTS. The lights still don't work! Does anyone have experience of the QSI/MTS combination? I'd appreciate some advice on what else to try.

Nick Hall.

Although you will not need to change the decoder in the Shay, you will need to reduce the track voltage coming from the LGB MTS central unit. This is likely to be 21-25 v (AC) which will cause the decoder in the Shay to cut out. You need to install a number of bridge rectifiers in series with the track feed to reduce this to below 21 v, then the decoder and sound work really well. A circuit diagram and other information is available at www.atlasrr.com/voltage.htm or at tonystrains.com/technews/soundtraxx_heats.htm

Nick Hall