After doing some research on the different Vox AC series amplifiers I found the following:
1. The AC 15 was used by numerous British players with great satisfaction. It was a great sounding amp but as venues got bigger more power was needed. Two more power tubes were added hence the AC30/4
2. The EF86 versions of the AC15 and AC30/4 were altered to an ECC83 after "Bass" players complained about microphonics due to their bass frequencies. This was not a guitarist complaint.
3. Along with this preamp tube change a third channel (Brilliance channel) was added since the dual triode allowed it hence the AC30/6.
4. After the preamp tube change, players noticed a change in tone. There wasn't as much gain and clear tone in the new AC30/6
5. To satisfy the complaints on the AC30/6, the treble models were introduced (which had a treble boosting RC at each volume controll)
6. Shortly after that the Top Boost add on kit came out. Eventually the Top boost circuit was made stock in AC30s.
6. Most players of the AC30 amps consider the original circuit with the EF86 to be the best of the series in tone.
After reading all of this, I have decided not to add the top boost components or the 3rd channel to this amp layout It seems to me that the original AC15 and AC30/4 with EF86 were the British gutarists' favorite of all models issued. Of course it was common for guitarists and bass players to share an amp in those days and if the bass players had just had their own amp I wonder if good enough might have been left alone. And of course if Public Address systems had existed back then I doubt there would have been a call for the AC30 at all. So bottom line, I will be building the 1960 EF86 AC15 amp as it was originally issued and the layouts will be in both a combo and head style chassis.
