some tubes ..even new do have rattles..some don't.. you can pull the tubes and hold them to your ear,lightly tap the glass and listen to see how much looseness or rattles they have.. Power tubes can be microphonic..sometimes really bad. Not alot you can do,but use different tubes that don't have the rattle problems. The Sovtek and EH tubes do have quite a bit of rattle to them..and it gets picked up and you can hear it in the amp. one thing can help..is set the amp head,off the cab..or put a piece of foam under the head cab..this will sometimes help keep out alot of vibrations.. also helps tubes last longer from becoming rattly as they age..
hello there, look for tube dampers on ebay. i've used them with very good success on ef86's. haven't tried them with big tubes yet, but it's worth a shot --they could only help. http://cgi.ebay.com/VACUUM-TUBE-DAMPER- ... dZViewItem
hell there, mark we call them " o-rings" here and, well, they look like o-rings because they are!! i'm not sure if they are made specially for this purpose or have some other industrial purpose that this guy just found a source for or what. but let me tell you the larger/thicker ones work very nicely. if you've paid $$$ for nos mullard el34's or ef86's etc. and they rattle like hell, i don't think it's a hairbrained idea to try to spend a little extra money to make them usable. how much of course is a matter of personal taste and product availability---i can't find o-rings like that at my plumbing store for 50cents ea. (i've looked) so for me these are a good investment and the people i've turned on to these agree. i was skeptical myself at first but thought "what the hell, they're about a buck apiece so i'll give it a shot". so far i've had very good luck with this method of rattle reduction. it may seem silly and relatively costly, but the my experience has been very positive. rh
rhinson wrote:hell there, mark we call them " o-rings" here and, well, they look like o-rings because they are!! i'm not sure if they are made specially for this purpose or have some other industrial purpose that this guy just found a source for or what. but let me tell you the larger/thicker ones work very nicely. if you've paid $$$ for nos mullard el34's or ef86's etc. and they rattle like hell, i don't think it's a hairbrained idea to try to spend a little extra money to make them usable. how much of course is a matter of personal taste and product availability---i can't find o-rings like that at my plumbing store for 50cents ea. (i've looked) so for me these are a good investment and the people i've turned on to these agree. i was skeptical myself at first but thought "what the hell, they're about a buck apiece so i'll give it a shot". so far i've had very good luck with this method of rattle reduction. it may seem silly and relatively costly, but the my experience has been very positive. rh
You know what the more I read about the dampers, the more I am convinced they might help. I am now going to Lowes tomorrow to see if I can find some variation that will work ...after I hit the flea markets to search for some decent 12ax7's. I tweakers job is never finished!
Man.. i have 3 sets of sovtek el34's that rattle so bad its insane.. the good part they arn't microphonic.. the bad part, they are so bad that when i play my dumble inspired amp, i can hear the tubes in my ampeg rattling on the other side of the room...
Hi guys, I finally got a pair of Motorola 6V6's for the Express, (at the wifes request ) and I think I need to reduce my 220K bias resister. I set the negative voltage to -36.83 on pin 5 and popped in the 6v6's and had 100ma between pin 5 and the center tap. Anybody else have to make adjustments to the bias circuit when using 6v6's?
keithrick wrote: I set the negative voltage to -36.83 on pin 5 and popped in the 6v6's and had 100ma between pin 5 and the center tap. Anybody else have to make adjustments to the bias circuit when using 6v6's?
I am such an idiot! I was reading ma from pin 5 to the center tap. I was wondering why the resister was frying. LOL
The motorola's sound great but I still had a rattle problem until I placed the chassis on some padding. No more rattles, other then the walls and my teeth!
i read ken said to put the express on the floor , hehe i boult a clone in a combo where the speakers were right in front of the chassis...you know that was a pain to tune in since the sound shakes the chassis...never again ...comboes are terrible for high gain amps...those el34 winged c power tubes are made in the old svetlana factory and they sound beter than anything ive heard that's new i don't like sovtek anything very michrophonic....groovetubes work but have more gain and sound harsh to me the old rca 12ax7a tubes were excellent closest thing is the jj tesla ecc83s a copy of some older very linear sounding 12ax7 type deal linaer in valves is good it lets all the tone through so you tune the circuit itself to change tone ..i have heard some ruby tubes 12ax7s in fender amps that sounded really good, but the sovtecks all sound cheap to me the last few years.
...after I hit the flea markets to search for some decent 12ax7's. I tweakers job is never finished! 
Anybody else have to make adjustments to the bias circuit when using 6v6's?
