Midlife Messages: 3 Registered: December 2016 Location: GA
Junior Member
Greetings - First of many posts I hope. Just acquired a nearly pristine K-150-1 Bass amp. Pwr switch not working - fixed with zip ties but neither switch illuminates. still has 2 prong power.
stevem Messages: 4733 Registered: June 2004 Location: NY
Senior Member
Hello!
Your amp was born between Jan and June 1972.
The pilot lamp bulbs you need are GE 335 which can be had from many sources , order some spares as they are cheap!
The best way to replace them is to unscrew the mounting bracket that they are threaded on to from the inside face of the amp, then pull the Blue lens off of them and the I use some automotive vacuum tubing to slip over the bulbs to both unscrew them, and install the new bulbs.
Note , I do have new complete switches for these heads but there are 60 bucks before the shipping cost.
While you are in there you should clip out the grounding cap from the polarity switch.
Midlife Messages: 3 Registered: December 2016 Location: GA
Junior Member
Thanks Much! I'm loving this vintage amp! Silly newbie question - why 2 sets of two inputs - what's the intended difference? I looked online for an old manual reprinted or scanned but no luck
pleat Messages: 1452 Registered: June 2004 Location: Belding, Mi
Senior Member
The lower jack on each channel has more gain than the top jack of each channel. Reason might be back in the day you could select either jack, upper for humbucking guitars and the lower jack for single coil pickup guitars.
I know back in the 50's and 60's there were a lot of bands that would share an amp, hence the two independent channels.