Fender Twin tweaks for improved jazz sounds

[Revelation]

I have the Fender Twin with the red knobs. Since I purchased it in the 1980's the only change was putting in groove tubes. In wanting a beautiful clean jazz sound, I did not find this amp to provide me with the sound I wanted. For starters the open back had too much of a loose sound. I also could not believe 2 twelve speakers did not provide me with the rich tone I liked. I tried reducing the treble and and increasing the bass but it fell short. I found 3 ways to give me a closer sound that I was looking for.

1. I hit the lower wattage knob which brought the amp to 25 watts. With the reduced headroom, it offered a little tighter sound.

2. I found the manual that had suggested settings. For "jazz amp" setting they recommend pulling the mid range knob and reducing the mids. Then put the bass on 8 and treble on 5. With the reduced mids, the sound got closer to the tone I was looking for. To clarify, the tone I am looking for is that classic Polytone, Ibanez Whole tone sound.

3. I got a double layered cardboard box and fit it in the open area behind the speakers. (There is still an open area above for the tubes.). This helped remove a little of the loose sound the Twin gives.

[Franz 1997]

I'd be careful about (3) - those 4 6L6s put out a lot of heat & might need some ventilation from below.

[Revelation]

Originally Posted by Franz 1997

I'd be careful about (3) - those 4 6L6s put out a lot of heat & might need some ventilation from below.

Like I said, there is a separate open area above the tubes that is completly open and exposed. I agree with you that tubes need free air movement.

[JZGuitarman]

Thanks for sharing Revelation. I have a 2x12 Carvin SX200 amp, and was trying to get more of a Jazz sound out of it. It has a wattage switch too. I would not have the tube issue, because it's solid state. I'll try the lowered mid range setting.