Excavated my Laney Pro-Tube Lead 100 watt tube head out of storage. Back when these came out, they were like hot rodded Marshall heads. 4 x preamp tubes split into 2 cascading preamps, All 3 EQ controls have a pull boost feature. Bass boost was just massive! I don't have a cabinet, so used a loadbox to profile it. After about 10-15 mins. of being on and warming up, the volume would start jumping up and down drastically, one of the tubes must be gone or going? So I did a few at a time before it got too warmed up. Anyway, add a comment, let me know if you think any of these are usable.