There was a Dual Rec on e-bay not too long ago that was modded to accept 6550's and KT-88's. To run the KT-88 you need more room between the sockets than I would think you have in the Mark III. If you have the space it would be a mod having to be done to use them. Then it would be absolutely brutal slamming you off a wall sound. Forget the light chest pounding, that thing would rip your head off and throw you against the wall.
The guy that sold it lived in La Mirada. I wanted to go try it but never got around to it before it sold.
KT-77's are EL34 replacements. Not much change. KT-88's make for more wattage and headroom. Running KT88's in a Marshall would require a mod not unlike the one to change from EL34's to 6550's. In fact KT88's can be used in the place of 6550's in some case like the KT77's and EL34's.
There is however another step....
KT100
The KT100 is even moreso the kill you and eat your children tube. I read something that Bob? had written regarding this tube. I know a guy at a local shop that suggested the tube also if a KT88 wasn't enough.
Just imagine the depth a Rec would hit with 6550's, KT88's, or even KT100's. It would be insane. I am almost considering trying a 6550/KT88 mod on my Mark IV. I think I am liking my sound right now too much to jump at it though. I would hate to risk losing what I currently have going on. Too bad they don't have a fourth channel mod to add a rectifier and deepen the voicing to that of a Rec.
I believe it is because he changed the rectifier in use to the GZ34 instead of the typical 5U4G and steps partially back with the 6V6's. That would allow for the KT's. I would think that the KT88 would need a mod but with the rectifier change it may not be necessary.
The Mark amps sockets are too close together to get a KT in there typically. The KT77 looks like it will fit. It is a drop in replacement for the EL34 so it should work but the KT88 is a little fat like a 6550 so they probably just don't physically fit.
Those big KT's might be just what the Dr. ordered. The problem still lies in getting them to fit. Maybe an extension board that fits in the sockets and allows you to plug in the tubes at a remote location? Think like a side draft carburetor? Or even just relocated slightly further out but still pointing down to keep from interfering with the bottom of the cabinet or speaker in the case of a combo. The only problem would be getting the relocator/manifold to be stable and keeping the tubes out of harms' way. I think that would be a killer bolt-on. Maybe make a shroud for it to protect the tubes. You could even put a toaster grill on it to warm your coffee or make toast... :lol:
KT100 doesn't equal KT88 or they would be KT88. Imagine the possibility though. You could have the first one and maybe set a trend and even market it. Just remember to give me a cut.
I use KT66's in my Simul-Satellite, and let me tell you... ****. I just retubed the amp, and its crazy loud. They are big, but they sound big too. I think they need a minor re-biasing. My amp is all clean, no gain channel, but I can still get a Mark III sound out of it. The old 6L6 tubes i had before sounded like crap in comparison.
Tool is probably my favorite band, but I listen to so much music its hard to pin point one. It is what I am going for in my music tho, dark, melodic, and aggressive. I prefer their older albums...Aenima is awesome...
::edot:: as for tubes yes, I will try EL34's on the outside once i get em! I wonder if the EL34's can work with the KT66 i just put in there.