Has anyone put Hornby TTS in an 00 classes 68 or 70? I am considering putting something like a Hornby Class 60 TTS chip in a Dapol Class 68 or Bachmann Class 70? Alternatively I might wait until the Class 66 TTS are available. I think if I do this then I will upgrade the speaker, so has anyone experience of the improvements to a class 60 of TTS with a better speaker? Many thanks Paul