Scooter B
New member
I have a 1960 Kalamazoo (Gibson) Model One 5 watt tube amp that has some pretty awesome tone and perfect for my home recording volume wise. All 100% class A desong with three tubes....the budget part of this Gibson line is the cabinet is made or particle board.
The only weak spot is the speaker wich while good for reproducing more vintage sounds starts to break up a little at higher volumes.
Personally I prefer the distortion in the tube gain and not from the speaker its self for more modern tones. Also the paper cone being 40 years old and of unknown history (recent e-bay find) may not be long in life when cranked. The serial numbers on thses are printed on the speaker backing for some reason so I would prefer to keep this speaker in good shape and add an external jack that switches the internal speaker off when a 1/4 inch speaker plug is inserted.
I found some recomended mods here and plan to do the grounded plug and the external speaker jack projects (yes I know to discharge the caps first) here.
http://www.rru.com/~meo/Guitar/Amps/Kalamazoo/Mods/speaker.html
External Speaker Jack
As an alternative, you can leave the current speaker permanently wired, with a jack that switches the internal speaker out when an external speaker cabinet is used. This is an even better alternative, because it doesn't provide a chance to run the amp without a speaker (which will unusually fry your output transformer).
Wire the OT and speaker grounds (return) to the ring (outer connector). Wire the other OT lead to the tip connector. Wire the other speaker lead to the switch connector. When no plug is in the jack, the switch will close against the tip connector, letting your internal speaker work. When you plug in the cab, it opens that switch, disconnecting the internal speaker, but leaving voltage across the tip and ground, where the cab's plug is connected.
The directions are not very specific to me as someone who knows just a little about wiring but knows how to solder etc. But the attached diagram shows wires going to a jack with a tip and ring (I assume this implies a female TRS jack?).
While looking at the female TRS jacks at partsexpress.com they have "swiching" jacks and "non switching" jacks.
1. Do I want the switching jacks for this purpose?
This seems to make sense but I have not used swithcing jacks before.
2. If this uses a TRS does the sleeve get wired to anything?
I am assuming form the description that the sleeve does not get wired but they may be assuming I know more than I do and would be crazy enough to do this myself if I didn't.
3. Lastly the internal speaker wire is wired to the switch? Is this seperate from the sleeve?
Thanks
The only weak spot is the speaker wich while good for reproducing more vintage sounds starts to break up a little at higher volumes.
Personally I prefer the distortion in the tube gain and not from the speaker its self for more modern tones. Also the paper cone being 40 years old and of unknown history (recent e-bay find) may not be long in life when cranked. The serial numbers on thses are printed on the speaker backing for some reason so I would prefer to keep this speaker in good shape and add an external jack that switches the internal speaker off when a 1/4 inch speaker plug is inserted.
I found some recomended mods here and plan to do the grounded plug and the external speaker jack projects (yes I know to discharge the caps first) here.
http://www.rru.com/~meo/Guitar/Amps/Kalamazoo/Mods/speaker.html
External Speaker Jack
As an alternative, you can leave the current speaker permanently wired, with a jack that switches the internal speaker out when an external speaker cabinet is used. This is an even better alternative, because it doesn't provide a chance to run the amp without a speaker (which will unusually fry your output transformer).
Wire the OT and speaker grounds (return) to the ring (outer connector). Wire the other OT lead to the tip connector. Wire the other speaker lead to the switch connector. When no plug is in the jack, the switch will close against the tip connector, letting your internal speaker work. When you plug in the cab, it opens that switch, disconnecting the internal speaker, but leaving voltage across the tip and ground, where the cab's plug is connected.
The directions are not very specific to me as someone who knows just a little about wiring but knows how to solder etc. But the attached diagram shows wires going to a jack with a tip and ring (I assume this implies a female TRS jack?).
While looking at the female TRS jacks at partsexpress.com they have "swiching" jacks and "non switching" jacks.
1. Do I want the switching jacks for this purpose?
This seems to make sense but I have not used swithcing jacks before.
2. If this uses a TRS does the sleeve get wired to anything?
I am assuming form the description that the sleeve does not get wired but they may be assuming I know more than I do and would be crazy enough to do this myself if I didn't.
3. Lastly the internal speaker wire is wired to the switch? Is this seperate from the sleeve?
Thanks