Here is the perfect Vox AC15TBX Superior Valve Kit, using Sovtek valves. These quality Russian valves are the best sounding in this VOX AC15 model.
This Vox AC15TBX Superior Valve Kit contains five Sovtek 12AX7WC, two Sovtek EL84’s and a JJ 5Y3S rectifier valve.
We test every valve we sell and one of the 12Ax7’s and the EL84’s will be hand matched. The specially selected balanced 12AX7WC is for the phase splitter position. We test and match on our suite of Avo testers.
You will receive a test certificate showing the matching info and the test conditions for the matched valves. Sovtek valves are made in Russia and tested to US Department of Defense Mil Std 133 Revison D and the rectifier is made in Slovakia by JJ Electronic.
You do not need to set the bias on the EL84’s so it is literally plug and play.
One important point to note with this amp model is that some of the amps were originally fitted with Philips EL84’s . The El84’s are recessed in the chassis. The holes in the chassis were cut to suit these valves. Unfortunately, all currently manufactured EL84 are slightly wider. The actual spec for diameter of an EL84 is 22mm and they did not take account of the tolerance on the valve width. You might need to use a round file to expand the chassis hole for the EL84. If you find they do not fit, then rasp out the chassis hole with a round file. Take care not to get the metal dust in the valve sockets ! If you dont do this then you face the very expensive option of trying to find narrow matched NOS valves !