Solid State Guitar Amp Forum | DIY Guitar Amplifiers
Solid State Amplifiers => Amplifier Discussion => Topic started by: Den. on April 26, 2026, 04:28:17 PM
Hi... I'm looking at a Bose L1 model II PA amplifier and I'm looking for help in interpreting a series of voltage measurements. There's a pair of what I think are transistors that look suspicious. On the diode mode these are the readings I got. Can someone help me? Thanks.DSCN2636.JPGDSCN2638.JPG
Those look like voltage regulators.
Clean the schmoo off the top where the "L78" number is so we can read it.
That is likely the part number.