Hi Laurie, Yes, the output stage of the KCP is based on the AC30, but with a couple of tricks thrown in, one for the master volume design, the other to make the amp run cooler. The preamp design for channel 1 was not based on Vox and was designed to be more versatile, but can have a similar sound. Channel 2 was the early Vox EF86 design, more or less, but did not have a brilliance switch. Regards, Charlie
Hi there. I could not stop my fingers from writing when I saw you guys talking about EF86. My experience of this is, the EF86 produces a softer sound then a ECC83 / 12XA7, it is very hard to describe the different it just is there and what it is is difficult to say. I have built Amps with both types, I prefer EF86, to me it sounds more musical then 12AX7 / ECC83 especially when it is hard driven. That can be one part of That Sound a other part can be the use of speakers Goodmans Audiom 60 or Rola Celestion Blue speaker they sounds a lot different.
Hi 26rednef, The EF86 has much higher gain than a triode like the ECC83, so the EF86 has less headroom. The way it overloads is different and I think that is what makes it sound softer. Pentodes like the EF86 also have different transfer characteristics ie. the way they distort, than triodes. Regards, Charlie
Yes there are lot of things that differ between a triode and a pentod from signal point of view. The pentod make the life easier for the Amp designer, it simplifies the preamp down to one tube step in most cases as in VOX AC15/EF86, witch also will have a positive impact on the sound, less components in the signal path with negative influences on the sound, fewer trade offs to make and so on. The problem with it back then was it couldn't take the tough environment in a Guitar Amp it braked down to often, it had to be changed to the more robust ECC83/12AX7. In my opinion from the musical point of view a degradation .......... uuups.
Hi Just as info. The book 'That Sound' written by Roberto also came with a CD. Roberto had recorded a few tracks with his Gretsch which he claimed Hank had with his Gretsch, Apache being his favourite claim. It was done for the listener to make a comparison.
The CD is interesting to listen to and a few people have said no way did Hank use a Gretsch on those tracks, but others have said, not sure. I make no 'public' judgement.
The article can be found in "PIPELINE Magazine" [# 46 (1999)] and the bock is referenced in Shadsfax, #28/2000, the bock "THAT SOUND" was offed for sale by Leo's Den. I don't know if it is still on the market.