The J.T.30 valve amps. began their life back in about 1982 (when still in London) badged under the  "JAYTRONICS" logo . Later in 1988 I was approached by a small retailer in Tralee ( who also repaired Fretted instruments)  to design and manufacture a Valve amp. chassis , which after a lot of liasing and consideration would be rated at 30 watts R.M.S. output , which we thought was a good happy medium suitable for all sorts of venues . The idea was  I'd supply amp. chassis'  and He'd supply the cabinets loaded with speakers  and retail them through his Tralee shop .  It was short lived  ,  he did a disappearing act  after only purchasing 1 (one) amp. chassis .  To recoup a potential loss  , I made cabs for both 1x12" combo's and  heads , and til the present time the 30watt design is still popular employing 4 EL84 valves in the output stage  , with of coarse varying features decided by the customer  .  A point of fact , my own "JAYTRONICS"  badged  1x12" 30watter is utterly reliable with it's original  late 70's Mullards EL84's in the o/p stage (still to this day) , how many present day valve manufacturers can boast that ? .