Changing output Valve?

[Sully807]

Oh and I agreed, in regards to most amps he certainly is right, but not with the SL5, maybe it was because as Santiago says there's no guarentees of a good sound and marshall didn't want people hearing the amp with an inferior tone? Who knows, personally I've found marshall "helpdesks" to be quite frustrating at times when wanting to find out specifics about something, but if you go direct to a designer or specific employee they can be pretty helpful, The v30mf speakers come to mind. Just the way they like to do things I guess

[Anitoli]

Im glad Surf was able to clarify this issue, Thanks.
As Surf said it doesnt say anything about the tubes in manual and i did look at that first. Also coupled with what the tech support(?) here said and never having seen any of the marketing material i erred on the side of caution even though ultimately i was wrong.

Now, as far as the tech support is concerned, i went to the official site, followed the links and thats where i was directed to. Maybe this needs to be addressed so people can get the proper help?