This wasn’t a typical old school vacuum tube amp but a early solid state amp from the 70s. The Amp is a Kustom Kasino 100 watt power head with 8 speakers in the cabinet. When it was given to me the power cable had a few breaks, the knobs were crusty and the power indicator wasn’t working. I’ve been working on this amp off and on for a while. I replaced the power cable when I first got this amp last year. Yesterday I pulled out the power head, cleaned it out and started on cleaning the switches and potentiometers. Contact cleaner does wonders. Now the indicator light is a retro Drake lamp. It uses a typical micro light bulb and since it’s harder to find light bulbs in this special size I converted it to LED. The light bulb used 50volts AC so I have to find somewhere on the circuitry that supplied low voltage DC. I found a lead that goes from the power supply board to the main amp circuit that pushed 9 volts. I tossed in a bright LED with a 220 ohm resistor with some long wire and Bob’s your uncle. I couldn’t be more happier with the results. The indicator lens is blue and the LED was really a bright purple UV LED it makes a super nice royal blue.