Vintage Maestro Phase Shifter early PS-1 model not working. Some scratching on chassis and needs three ( out of four ) correct sheet metal screws to hold the top to the bottom.The power switch lights when turned on and it does pass a clean guitar signal when connected to your amp.An experienced friend who specializes in tube amps did some testing, and with his oscilloscope we could see the phasing from the op amps. Interesting. He thinks the six pink transistors are probably bad but has none for us to try the repair. He removed the printed circuit board and touched up a few dubious looking solder joints during the testing.Comes with the schematic and ships in a large Priority Mail USPS box.Thank you for looking.