Lone star special sounds realllly grainy now PLEASE HELP

[mathieuj]

I bought a lone star special about 4 months ago. Since then my band has played a good amount of shows and while loading back into our practice space I realized that one of my power (el-84's) tubes was bent back.

My guess is when I went to plug it in the power cord snagged it and bent the pins on the tube. So anyways, I didn't realize I had done this at first and started to practice when I realized my clean channel sounded really dull and when I would lay into my guitar harsh grainy distortion came out. My distortion channel sounded just muffled and dull.

I replaced the bent tube and while it fixed it a little bit, it did not fix it back to normal. I have no idea what this could be and I'm sure the 5 year warranty would not cover this.

Has anyone ever had this type of experience or possibly have any ideas?

 

[ricardo loma vista]

mathieuj,

The power tubes need to operate in pairs on the 15 and 30 watt settings, so your bent tube was taken out of the circuit resulting in harsh grainy sound. I have had this happen and have not had any long term problems from it.

Did you replace the bent pin tube, or just straighten the pins? You may have cracked the glass around one of the pins and the tube is dead. You might also replace the other tube in the pair (the two outboard tubes are paired, and the two inboard tubes are paired) and see if that fixes it as it's possible that one is also damaged.

You can test the outboard tubes using the 15 watt setting--only those two are operating at 15 W. Start with switching the inboard and outboard tubes and see if that works. If it does--try one of the original outboard tubes in place of one of the good ones--if it sounds bad, that tube is bad.

If this doesn't work, there are two possibilties--(1) you need a whole new set of power tubes (they do wear out and that may be your problem) or (2) there has been some damage to the amp and you will have to have a Mesa tech look at it (I suspect that amp damage is the least likely scenario)