Possible problem with the tubes on Lonestar

[Vovka]

Hi to all,

I recently bought a 1 year old 10/50/100 Lonestar in mint condition. It sounds great. The problem I’m having with it is that after 30 minutes of playing a strange sound comes out the combo. It gives a sensation that someone put wood on fire. It’s not too loud but it sounds like it is burning. Could this be that some tubes are dying? I looked behind the combo and nothing strange happens. It’s just this strange sound coming out of the speakers no matter which channels or 10/50/100 mode I’m using. And another questions is - should the fan be always on?

Thanks in advance!

 

[plan-x]

The fan can be turned off in the back. I think someone had this "Crackling" issue before. But I can't recall it off the top of my head. Try a search with "Crackling" maybe?

 

[Vovka]

Thanks plan-x. I'll try find it.

 

[Vovka]

Apparently the problem was in the pre amp tube. I changed them and problem is solved. I was looking also to change the power tubes but what I noticed is that there are 2 types of Mesa tubes – yel and red. I was wondering which ones should I use in the lonestar? I play more hard rock type of music. Is there a tonal difference between two of them? Thanks.

 

[Charles Reeder]

Vovka:
In regard to the power tubes. It is OK to have both reds and yellows in use. For best results....make sure they are 'paired-properly'. The 2 outside power tubes make a pair and the 2 inside tubes make a pair.
The yellow 6L6's are hotter in the LSC than the red 6L6's. Use the yellows as your outside pair...where they'll bias out at between 33ma and 37ma. (35ma being a popular recommended setting). Use the reds as inner tubes. They'll be colder (don't remember exact readings).
Using them this way...you'll be able to get some nice natural tube saturation (mild output distortion) at 50-watt setting. Switching to 100-watt setting....the colder reds will give you a bit of clean headroom.

Charles

 

[Vovka]

Thanks Charles!