"Tighter" Bass on a Tone King.

[crunchman]

Hi folks, Recently purchased an Imperial (20th ann.) , love the amp overall. I would though like to have less "flub" on the low E and A strings if that can be done

without changing too much. I have read that reducing the cathode bypass caps and the coupling caps can often achieve this. I am trying to

identify the CBC's on the schematic. Is C9 a shared coupling cap ?? I think I see the PI coupling caps as C41 & C42. Any other recommendations

appreciated .........Thanks.

[Chuck H]

C9 is a bypass cap. It is not shared.

You could try changing R5 to 150k and R13 to 180k. This effectively changes the slope resistors for the tone shaping circuits in either channel. The effect should be reduced bass, a lower frequency mid point/cut and an increase in upper mids. Very good for cutting mud. If that's not enough you could try increasing R3 to 1.5k and adding a 1uf cap parallel to it. This will bring the bias for the input closer to center (it's hot now) and increase gain a little in the mid and treble frequencies changing the overall frequency balance.

You could also just dial in less bass when adjusting. Looking at the schem and the way the amp is designed if the amp is farting, too much bass reproduction is being asked of it. Dial in the tone for the max amount of bass without fart. That's all the clean bass the amp can make anyway. If you want more bass beyond that you'll need bassier speakers.

[Jazz P Bass]

As there is not a bypass cap on the first stage, that idea is out.

I agree with Chuck that the bass notes are most probably clipping long before the other frequencies.
That is the nature of the beast.
I see it on Fender Bassman's. (which I have always found odd. BASSman. Duh.)

You could maybe change the .1uf cap, that goes to the Bass control, to a .02uf.

[crunchman]

Thanks for the suggestions !!

[Gaz]

As there is not a bypass cap on the first stage, that idea is out.

I agree with Chuck that the bass notes are most probably clipping long before the other frequencies.
That is the nature of the beast.
I see it on Fender Bassman's. (which I have always found odd. BASSman. Duh.)

You could maybe change the .1uf cap, that goes to the Bass control, to a .02uf.

This was my first thought as well if you are okay with the Lead channel.

[daz]

This was my first thought as well if you are okay with the Lead channel.

I've always found that when i have this issue it is never rectified with a tweak or 2. It usually means changing the circuit quite a bit and likely changing the amp's tonal character in the process. It seems this is just as Jazz said, the nature of the beast. And if you change it's nature you change the beast. In other words, it's part and parcel of that tone you love. There are lot's of current boutique amps that do this. One that comes to mind right away are the PRS amps. Quite pricey and a very flabby low end.

You can reduce bass like chuck mentioned, but the problem is when it's flabby it's not because theres too much bass. So reducing bass doesn't usually help much. If the TK has cascaded gain stages, then cutting bass b4 the OD is generated is the key. But i don't think those are cascaded are they?

[Dave H]

I you want tighter bass on both channels the value of C1 could be reduced. Try values in the 4n7 to 1n range.