Hello,
Sorry about the length of this topic but I think it's worth reading it.
Here goes:
My Lonestar Classic - short head, beautiful cleans but unfortunately I was never able to bind with the drive channel. It was simply not possible to reduce the bass as much as I felt it would have been necessary. The perceived sound was without enough drive, pick attack was not there, everything that too much bass can damage was there. As a result the amp didn't get too much play.
However, I have a friend who told me that he modified his Roadster specifically for this reason so I thought I might as well ask the guy if there is a solution for my Lonestar. He called me back and told me that unlike the Mesa Roadster which has a 22nF capacitor at the drive stage entry (which he needed to change because the value was too much - hence too much bass), the Lonestar has a 5nF capacitor at the entry in the drive stage. Nevertheless, he said we should try to change that capacitor for a 1nF. I agreed but not before I told him I don't want the clean channel to be messed with. He told me that capacitor is only for the drive channel, nothing will change in the cleans. Ok.
So I brought the amp to his shop. I tested the amp for the unmodded sound, we agreed that it was way too much bass. Then we changed the capacitor. The original capacitor was the orange type that you see in the Mesa amps, we took it out and put a ceramic 1.5nF, not a 1nF because the guy was afraid that 1nF may be too small. Anyway, time for testing. Plugged in the guitar and... MAGIC!!! With bass between 11 and 12 o'clock, the sound was perfect.
Took the amp home to test it on my cabinet and most importantly with my Suhr Reactive load. Before the mod, I might or might not have lived with the bassy sound through a cabinet but through the Suhr reactive load the sound was simply not ok, it was all over the place, couldn't use it.
After the mod not only the sound is too good to be true, but the perceived drive is bigger. I mean like 50% bigger. The pick attack is to die for, the palm muted notes sound incredible. The guy explained me that if too much bass enters in the drive stage, then the harmonics which get amplified even more will cancel one another resulting in a lifeless tone with a low perceived drive. I am not an engineer, I can only attest for what I hear and feel. Let me tell you it is a different ball game.
Now the amp sounds like in the clips that we all see on youtube, the clips that made many of us want to buy a Lonestar in the first place. I know this happened to me. The BIAS mod didn't do it for me, other mods - the same. But simply changing this insignificant capacitor made may amp sound like the one Andy Timmons demoed on youtube.
To all the guys that have any technical knowledge about this stuff, chime in. It's the 5nF capacitor that on the schematics sits at the entrance of the drive stage in front of two resistors, a 200K and a 1M.
Regards, Adrian