JJ 6550s Marshall 1977- mk2 2203 two tubes not heat-n ?

  • Thread starter Thread starter 73 super lead steve
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73 super lead steve

73 super lead steve

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I have a MK2 that just had a complete face lift, new caps/new JJ preamp and power tubes installed 3 months ago from established tech, played it two times and stuffed it away due to what I think is a rare bird, 1977 MK2 master model 2203 double stack (fawn color) set-n behind my avatar pic, hasn't had any body gouge-n away in it to make it sound like it came from outer space except for the tech who put the new tubes in, and he was told no butch-n please Well to make a long story longer, I decided to get it out take the back plate off and to my whore-r, noticed two of the tubes labels where dark and two looked as if they where still brand new Think-n, I'll yank them out, clean and pinch tight all the socket pins, after I drained all the caps think-n that the tech surely would of biased them after the install but now I'm not so sure, anyone kind-a spook on fire-n the reactor back up any hints what to look for?
 
New production tubes are NOT that reliable; If you are turning it on an they are dark/no sound I'd bet they are bunk. Pop in replacements and see (if you have spares around). If you don't get it back to your tech and he better replace at no cost to you. If that's not the problem then the tech F'd something up.
 
-RXR- thanks for the return TXT , I kind-a think the same thing on the dud tubes even though there brand new, just wanted to make sure it wasn't crud sockets first off, it happened to me once before awhile back on my 73 super lead with the same brand tubes just didn't put two & two together quick enough, I got soundwaves come-n out of the 77 mk2, I just happened to see that the two tubes look like they where heat-n up, and the other two stone cold , I wish I could latch onto a vintage tube tester in my area but I down in the woods, I don't see much of them on the interweb
 
PS I like that list you got below of your equipment ,I'm new to this site and haven't yet mastered all the Gims
 
Did you try swapping the cold tubes with the hot ones just to see if the filaments light up? I'd leave it on Standby but just check for heated filaments.
 
The heater supply is serial meaning That the downstream tubes can only get heater voltage if the power section is getting voltage. Are your preamps lit? Aside from tension on the sockets if there were a short the downstream tubes would not get power
 
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