Are 6L6's and KT88's interchangeable?

I replaced the 6L6s in my Mesa Boogie Triple Rec with a combo of KT88's and KT66's (and loved it BTW) Bought the set as a replacement set from Eurotubes - no bias needed just be sure the amp was set to 6L6 on the tube selection switch.

I have freind here in the Philippines that has a Mesa Boogie DC5 and needs replacment tubes and I was hoping I could hook him up with the KT88's that I got for my Triple Rec. Seems to me that if the KT88's will work in my TR then they should work in the DC5 as well correct? I dont want my friend to screw up his amp - anyone know if the KT88's will work in the DC5?

There shouldnt be any problems. I couldnt run the KT88s in my Carvin only because the sockets were so close together. Those puppies are BIG. lol

You need to make sure the that you won't be exceeding the Power Transformer's max heater current rating when using KT88's. KT88's pull approx 1.6A current per tube, whereas 6L6 only pull approx 0.9A per tube.

If that's all ok, go ahead and try them. Like BigBrewtus said, you may or may not run into issues due to the tube socket spacing.