Solid State Guitar Amp Forum | DIY Guitar Amplifiers

Howdy,

I just picked up a KB 300 for a song. The unit is really nice, but the controls are dirty and the cord jacket is cracked just outside of the Heyco grommet. ETA: Cord is fixed.. Had to cut off 1" and re-set the cord in the grommet.

So the chassis needs to come out but I'm not having much luck. I found 4 screws on top (chrome strips) and 4 more in the back that secure the chassis to the case. Also unplugged the speakers & reverb tank.

The chassis can be shifted a bit, but won't slide out the rear.. what am I missing? More screws somewhere? ETA: Got it. Was hanging up on the edge of the chassis.

Also.. this is the early version (no XLR input), built in mid-1983. It doesn't have the pair of 5W resistors on the back of the tweeter horn. Should these be added, for safety? Do you know the correct value(s)?

Thanks!

Quote from: WimWalther on October 28, 2023, 01:15:24 AMHowdy,

I just picked up a KB 300 for a song. The unit is really nice, but the controls are dirty and the cord jacket is cracked just outside of the Heyco grommet. ETA: Cord is fixed.. Had to cut off 1" and re-set the cord in the grommet.

So the chassis needs to come out but I'm not having much luck. I found 4 screws on top (chrome strips) and 4 more in the back that secure the chassis to the case. Also unplugged the speakers & reverb tank.

The chassis can be shifted a bit, but won't slide out the rear.. what am I missing? More screws somewhere? ETA: Got it. Was hanging up on the edge of the chassis.

Also.. this is the early version (no XLR input), built in mid-1983. It doesn't have the pair of 5W resistors on the back of the tweeter horn. Should these be added, for safety? Do you know the correct value(s)?

Thanks!

Regarding the tweeter resistor: for safety, no I do not think it is necessary.  I would need a schematic to confirm this though.  Typically those resistors help to shape what frequencies are going to the tweeter.  If you like how it sounds now, you can probably leave it as-is.

Nothing about a tweeter in the schematic that I could see.