wrxmania
Well-known member
From a "key source" today, the engineer giving my new Imbuya Mark IV the once over, he power tested on the scope and checked all my valves and the amp.
He was bowled over by my new JAN Phillips NOS 6L6 WGB's (small bottle) - looking at them on the scope they had a perfect sine wave and great head room. I am running them as a matched pair on the outside. The Mesa's were terrible - not faulty - just terrible. Looking at the Mesa STR-430's on the scope the sine wave was jagged, breaking up very unevenly and too early, not in a musical way althought the match of them was fine. We tested all four of the Mesa valves. He said the Mesa valves were coming through with a rejection rate of 50% with him - not good news - and he HATES the chinese valves. He is very worried about the quality of some new Mesa valves.
Other than that he said my amp was running perfectly, was the neatest wiring job he'd seen, built to old style Mesa standards and styles by "an old hand" and a work of art - I was very happy. I was very impressed by the neatness and quality inside the amp (he said some were a bit like a "dog's dinner") and quality of the joinery work.
But the valves - they were the revelation! I am now about to put the Phillips 6l6's on the inside pair and JJ/Tesla E34L's as the outside pair. Does anyone have this combination on their Mark IV?
I will NOT be buying Mesa valves again after what I have seen (and my last Mesa having 6 sets, yes 6, in the shop before we could find a properly working set
). Not good news for a quality manufacturer. They really need a good valve supplier and a more stringent way of testing their valves.
Brian
He was bowled over by my new JAN Phillips NOS 6L6 WGB's (small bottle) - looking at them on the scope they had a perfect sine wave and great head room. I am running them as a matched pair on the outside. The Mesa's were terrible - not faulty - just terrible. Looking at the Mesa STR-430's on the scope the sine wave was jagged, breaking up very unevenly and too early, not in a musical way althought the match of them was fine. We tested all four of the Mesa valves. He said the Mesa valves were coming through with a rejection rate of 50% with him - not good news - and he HATES the chinese valves. He is very worried about the quality of some new Mesa valves.
Other than that he said my amp was running perfectly, was the neatest wiring job he'd seen, built to old style Mesa standards and styles by "an old hand" and a work of art - I was very happy. I was very impressed by the neatness and quality inside the amp (he said some were a bit like a "dog's dinner") and quality of the joinery work.
But the valves - they were the revelation! I am now about to put the Phillips 6l6's on the inside pair and JJ/Tesla E34L's as the outside pair. Does anyone have this combination on their Mark IV?
I will NOT be buying Mesa valves again after what I have seen (and my last Mesa having 6 sets, yes 6, in the shop before we could find a properly working set
). Not good news for a quality manufacturer. They really need a good valve supplier and a more stringent way of testing their valves.Brian
