The Blackstar also only has one 12AX7 preamp tube. Given that the Blackstar has lots of gain, I can only assume that some (or most) of the sound is solid state generated. I did notice a lot of opamps on the PCB pix linked in the Blackstar thread. Not that it is a bad thing in this case. The Blackstar sounds very good from the clips I've heard. I'm not sure if there is any digital modeling going on in the Blackstar, though.Originally Posted by piebaldpython
The VibroChamp XD is a single ended Class A amp using one 6V6 in the power section. It also has a single 12AX7. It is rated for the same wattage as the Blackstar. It has only one channel.
The SuperChamp XD is a push pull Class AB amp using two 6V6s in the power section. I would assume that the 12AX7 is the phase inverter tube and only contributes a small amount of gain. The gain is most likely generated by digital modeling. It has two footswitchable channels.
The Blackstar is a push pull amp using a 12BH7 dual triode. I'm not sure if the amp uses a 12AX7 as a phase inverter or not. The 12BH7 could be configured as a grounded grid amp (often incorrectly called "self split") This means that the 12BH7 is configured to operate as its own phase inverter and doesn't need a separate tube to perform that function. The end result is that the amp is Class A.
All of this is just pure conjecture on my part as I have not seen any of the schematics.
So to answer your question, I would call the Blackstar a hybrid: solid state preamp/tube output section. Is it a real tube amp? Yes, but not in the sense that a Soldano, or Marshall, or Fender is a real tube amp. It is not *all* tube. But that doesn't make it a bad amp.
tung