LSS issue. Help Required!

[Quattroste]

Hi All,

I was just playing my LSS in 5 watt mode. I switched up to 30 watts to give it a bit of a lashing and now the 30 watt mode is all that works on both channels. The 5 and 15 watts gives me nothing!! Any ideas? :?

 

[nemesys]

I don't know much about the LSS, but on Mesa's site it says that a feature of the amp is that you can use 1, 2, or 4 power tubes for 5, 15, or 30 watts respectively. I would guess (though someone who knows more about the amp would likely have a better answer for you) that the power tube that services the 5-watt mode (according to the manual, the far left one facing rear) has a problem, which would cause the 5 and 15-watt modes to stop working. It's probably not the other one in the pair, or the 5-watt mode would work, and the 15-watt mode wouldn't. The 30-watt works because it still has a good pair, though without the second pair, it's probably running at reduced efficiency.

In any case, it probably won't hurt your amp to swap some known-good tubes in to see if that is the problem.

 

[Talus]

I haven't had a LSS for a while now, but if I remember correctly 5 and 15 watt use recto tracking while 30 uses diode. Hence, your rectifier tube is blown.

 

[Quattroste]

Great :x

I only changed the pre and power tubes last Thursday. I didn't get a rec tube because I didn't think I'd need it. Is there any way to tell for sure if the rec tube is blown? Does anything cause the rec tube to blow?

Bit of a tube newbie so thanks.

 

[drunkdolphin]

Your 5Y3 is gone. Grap a sovtek replacement and you'll be fine.