Fast/Grad VS Fat/Gain switch

[Rimy]

in both builds i had a fast/grad switch installed, but i didn't really like the sound of the grad position.
too much muddy bass and the noise/hiss was quite a lot, but i didn't know better because i couldn't
compare to a real wreck for the amount of noise/hiss, so i thought it can't get better.

finally i took the fast/grad switch out and there you go... the hiss was gone!

after that i was looking for a different gain reduction and i found in the
tw-file section the schematic of the A8a blues express plus.
i thought i give it a go and tried a bit different way to keep my original specs.
i've ended up with a incredibble mod, wich sounds awesome!!!

in the middle position the switch is off, wich means all original.
in the low position there is less gain, more headroom and less bass response.
in the top position there is less gain, more headroom and a huge bottom end.

and still no noise/hiss...

one more thing.
the fast/grad allways had a very loud switching noise (pop).
the fat/gain switch is dead quiet.

[RJ Guitars]

Nice job, and thank you for the good schematic. This sounds like a really good set of options for an amp.

rj

[Nigel Tufnel]

Cool tweak, I like to do something functionally similar. I use a smallish value resistor in series with a pot wired as a variable resistor to ground for v2's grid load. The ability to change the corner frequency and gain on the fly makes the amp very flexible with different guitars and pickups. I use different coupling cap and resistance values depending on what I'm after. Your setup looks very nice for a fatter more bluesy tone at the flip of a switch.

[Richie]

There is also a chart that was posted of the cap value/resistor frequency.
Also Dana and Allyn had the fast gardual, noiseless switching board made for the Komet,that would also work.
As i'm sure there are others that sell boards that use different switching methods, or it can be manual switch.
And still maybe put a pot on the back panel for a more like trim pot fine tuning adjustment. Probably lots of things could be done,or have already.
Might also set up a click type or multi setting cap switch, and resistor switch,with pot to trim adjust.
What you might run into if you look at the cap/resistor chart is, many different values can give almost the same effect. So you might want to experiment to see what might give the same tone/frequency, with same amount of similar gain. Like the .0047/68k might give the same amount of gain and frequency as the 150k.002. But one may sound like it has less hiss or something.
I think the chart had 68k 100k and 150k used.
I'm sure other values could be calculated is someone wanted to. Like 120k
The other thing is, there is going to be a more fine line between cap values to how it sounds. Meaning the values will not be huge in the differences.
Where going from 150k .002 to .003 .004 etc.. you'll get to a point where the amp may start to lose definition or muddy sound on the bass.

Another thing someone might like experiment to just have a switch to bypass the extra gain section,for a more clean sound.