What is it with laney amps that makes me forget to photo them?
This Laney amp bias GH100L just needed its bias adjusting to accommodate a new set of EL34s. The GH100L is a fixed bias amp, which means the bias is adjusted (and quiescent current is fixed) by a technician. The opposite of fixed valve bias is cathode valve bias. Confusingly cathode bias is not usually adjustable. For more info, check out this article
If you have a laney repair or a valve amp bias job, please get in touch.