"Hey everybody! How about this for another "turn up for the books!"
Coming through the workshop recently for a service/check-up from a music shop, and coincidentally yet another Champ-Amp, designed and completely hand-built by myself (including the transformers) way back around 1972!!
I remember doing a few of these back then. It is a 200-MP (multi-purpose) amplifier; 200 watts from 4 x EL34's.....yes 4!! [Trust me, you can get 100 watts from a pair of EL34's (200 watts from a quad) if you run them with 800 volts plate (anode) and 400 volts screen (grid 2); fixed bias of course as with this specimen.] Most companies wouldn't actually push them this hard but the specifications to run them in this way are actually available in Mullard's original data sheets. I have used these specifications many-a-time with excellent results and success.
Apart from just one EL34 that had blown itself apart, the rest of the amp was absolutely fine and has surely seen plenty of use over the past 30 years or so, as can be seen in the photos. The owner of the amp tells me he would never sell it as it sounds superb on bass guitar.........as my amps and designs always did!!
I will point out that I actually remember doing this particular amplifier as I had previously taken an order on a PA version which was actually never made. As I already had made the case for the PA version, I ended up fitting this one into the PA case and filling in the large front panel hole of the case with a grill instead!!
Great memories, thanks for all your interest."