Welcome, Guest. Please login or register.
Did you miss your activation email?
August 08, 2020, 09:48:44 PM
Home Help Search Login Register
News: Check out the photo gallery link above or >click here< to see photos of recently announced products!
+  Bachmann Message Board
|-+  Discussion Boards
| |-+  Large
| | |-+  2-6-6-2 QSI and MTS help please
« previous next »
Pages: [1] Print
Author Topic: 2-6-6-2 QSI and MTS help please  (Read 1096 times)

View Profile
« on: April 26, 2009, 08:58:25 AM »

I installed a QSI sound module in my 2-6-6-2 and it does not appear to work with my MTS system. Does anyone know if they are incompatible. I was aware that the sound system in the 3 truck Shays would not work with MTS and I wonder whether this also applies to QSI modules.

I know I need to ditch the MTS but I am reluctant to throw away the investment.

Thanks for any help.
Nick Hall

View Profile
« Reply #1 on: April 28, 2009, 06:01:32 AM »


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 or 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!

Pages: [1] Print 
« previous next »
Jump to:  
Powered by SMF | SMF © 2015, Simple Machines Valid XHTML 1.0! Valid CSS!