Ok guys I have a question about output. When I plug into channel 1 the volume knob is set on maybe #2 and it will deafen you. When I plug into channel 2 I have to turn the volume knob to 3 1/2 or 4 to get the same volume. Is this normal??? or should they both be close to the same. Now channel 1 has that select tone switch which channel 2 does not.
stevem Messages: 4742 Registered: June 2004 Location: NY
Senior Member
If you plug into the number two input on channel 2 is it then louder and more like channel one, or lower still?
If not then one of two possibility is that late in the 1971 production run of the K150s and 250s Kustom made a change to add more gain to the preamps and this in turn would make them louder for any givin volume knob setting, in short may be your amps channel two never got that late 71 mod, or that channel has a failing bypass cap in the circuit.
If I plug into the lower input of channel 2 it does get louder. I enclosed a pic of what my settings on the volume dial are to be somewhat equal. The lower input of channel 2 is louder than the top one... What do you think???? Normal????
stevem Messages: 4742 Registered: June 2004 Location: NY
Senior Member
If that's the case then the amp has been worked on and the jacks simply reinstalled in the wrong position.
The number 2 input on these metal face amps just like on Fender and many others is 1/2 the gain of the number one input of a given channel.
And by the way in seing the course tuck and roll on your amp in that picture means that your amp has the factory gain mod in place that I posted about before.
One other note that I just tested. I have another K-250-4 same vintage as it has that xlr connection for the foot switch, if that is any indicator of age. I tested it just a few min ago and it does the exact same thing. The exact same settings on the volume and all. And the bottom input of channel 2 is louder than the top. Could 2 amps be backwards???I know anything is possible when you don't know what has been done to it.
pleat Messages: 1452 Registered: June 2004 Location: Belding, Mi
Senior Member
The lower input jack on the slant metal face amps should be louder than the upper input jack.
Kustom described the input differences as to an instrument using single coils could use the lower input jack for a gain closer to a instrument using humbucking pickups in the upper jack.
With your amps having the XLR jack for the lighted footswitches, the amps may have been produced prior to 11-1-71 when the dealer mod was issued to change the gain of the PC5066.
pleat
Thank You Steve and Pleat for the info. I can rest at ease.
Ya know I would have thought that Channel 2 would have been the one with the most output because it is the channel that has ALL of the effects. But then again I am no amp engineer.
BTW serial numbers for my 2 K-250-4 are 82610 and 90346. If that helps