tube questions

[Bigfknbang]

whats the hardness rating on tubes? what does the #'s 1-10 mean? does a tube being harder make it sound different? i just got a crate bv120 halfstack for 500$ and it needs new tubes, the tubes in it are like 5 years old. im pretty much new to tube amps. i've only had one other tube amp, a laney aor pro tube lead and i never changed the tubes on it before i sold it. well any way, the crate has 4 6L6's and 4 12ax7's which brand of tubes should i put in her? i want the heaviest sound i can get out of this thing. thanx for any info [img]/images/graemlins/headbang.gif[/img]

[slayer]

Re: tube questions

That hardness level is very confusing for sure. I don`t buy mine that way, I just buy the power tubes based on their Bias #, my amp is biased at 39 with EL34s. if you buy it, get it biased to the power amp tubes and forget about that hardness stuff. Jack.

[Guest]

Re: tube questions

Are looking at Groove Tubes? On GT's, the lower the number, the earlier the tube breakup. 1-4 has a lower headroom, early breakup. 5-7 is medium or average breakup, and response. 8-10 have the highest amount of headrom, have to driven hard to breakup as they are generally the cleanest.

The rating effects compression, response, even tonality. There should be some info similar to this on GT's website.

Mesa has a rating system for their tubes as well but I forget offhand how theirs are rated, by bias, hardness or both.

[peedenmark7]

Re: tube questions

I would agree with jack...once upon time I used to buy my usa made 6550 tubes from GT... I always wanted a 6 or greater rating... today that rating means little because with import tubes packed under low vacuum you are replacing them 3 to one over the older usa made ones and after several hours on the tubes that rating changes anyway.....I am told the sec [original svetlanas] are pretty close to our old american 6550 in longevity and power. can anyone confirm this ?....
I like my '77-78 single channel marshalls bright and tight and would rather drive them to the max than get that fake low volume break up....I also like 7025 preamp tubes they last longer and put up with more physical abuse than the 12ax7 tubes, if you saw my marshalls you'd understand.. after 20 years on and off the road they do get used and abused.....
I also heard GT was tooling up to do 6550's here in the states, did this ever come about ? I am sick of paying carzy money for old tungsols......anyone ?..john

[CZSER]

Re: tube questions

I found a pair of NOS Tung Sol 6550 (grey plates with holes) here in Argentina for u$s85. So I moded my self-made SLO clone, wich I originally loaded with Krappy sovtek 5881WXT. The TS6550 have truly huge tone, but starts to break up only at vol=8. They are the cleanest tube for high gain/vol. Not for my beadroom. FOR ARENAS ONLY [img]/images/graemlins/headbang.gif[/img].
BTW, I find 6550 Sexies [img]/images/graemlins/drool2.gif[/img](what a Tubeneck) [img]/images/graemlins/laugh.gif[/img]

[CZSER]

Re: tube questions

John: If you have developed a taste in 6550/kt88, U should check "JJ KT88". They are known to be the best actual 6550/kt88 tube.