23/12/2025
Be careful who you choose to work on your equipment, and always do your own research...
This is an invoice for some repair work carried out on a Lumley Reference ST70 power amp.
Firstly, some very bad advice - the correct 'power on' procedure is turn on the right hand mains switch, wait 10 minutes for voltages to stabilise etc, then turn on the left hand switch to fully power up. Switch off process is reversed.
The advice to leave both switches on, and simply turn on and off at the mains plug is awful, and will shorten the life of the valves and could cause damage.
Secondly, he's fitted 4 ECC82S. This is completely wrong, there should be ECC83s in the signal path. They might look similar, but their jobs are very different. A quick look at the schematic tells you this, and no service technician should be working without one.
I have spoken to the owner, who is now ordering some new valves and ignoring the advice given.
