Kalamazoo Model 1...how to make it brighter?

[Triocd]

My 1965ish model 1 has had it's multi-cap replaced. Everything else is original. It sounds great when cranked for crunch tones, but I would like brighter clean tones. I always have the tone knob all the way up. I have a new Jensen C10Q in it so I don't think it's the speaker. Are there any likely parts that could need replacing to brighten it up? Any modifications to the circuit that might bring out some more highs?

[Leo_Gnardo]

My 1965ish model 1 has had it's multi-cap replaced. Everything else is original. It sounds great when cranked for crunch tones, but I would like brighter clean tones. I always have the tone knob all the way up. I have a new Jensen C10Q in it so I don't think it's the speaker. Are there any likely parts that could need replacing to brighten it up? Any modifications to the circuit that might bring out some more highs?

If I recall correctly the Kalamazoo 1 has no bypass cap on its first stage preamp cathode. If this is the case you can zing up the top end with a small value bypass cap here: I'd try 0.1 to 1 uF. Lower values will add some presence to uppermost frequencies, as you increase the capacitance, the boost will reach into mid frequencies. No more than a couple volts on that cathode R, any film cap will do, or a 1 uF electrolytic if you go that far. Select one that makes your ears happy & off you go, easy & cheap. Jensen C10Q is an excellent choice, you'll hear the difference undoubtedly with that speaker.