I forgot to add the like of what the circuitbord looks like:

http://www.tonystrains.com/tonystips/2005/101105.htm

I am trying to install a QSI revolution on the 2-8-0, replacing the old bachmann/lentz  decoder. 

I read many times that for non-bachmann decoders you should remove the C1 capacitor (usually yellow, with a 105 number - micro-farads? -).  However on my circuitboard there is no C1 capacitor, but there are three other small capacitors (C2, C3, C4).  Could they interfere with the new decoder (even fry it) or they just affect the light??

I would like to add a new decoder + sound to all of my spectrum steam locomotives. 

Digitrax has a DH165IP that is compatible with their soundbug SFX004.  Does anyone know if the DH165IP has a socket for the soundbug like the other decoders of the series DH165xx.  From the DH165IP photo I cannot see any socket ...

Also, if there is no socket, can you just connect the SFX004 pins 9 and 10 to somewhere in the tender (if anybody has already done it, a picture would be very appreciated)?

Thanks