Express with KT66s and 12AT7s?

[Rouse94]

I would love to have an Express that isn't so high gain but still does the clean to mean stuff just as well. I know the 12AT7s would tame the gain but would they destroy the clean to mean volume compression? And would effects such as delay work better now that the gain is lower?

[funkmeblue]

I built one with 6sl7's and I really like the sound with kt66's. Still does the clean to mean thing great just never gets as mean. Nails that early AC/DC tone.

[M Fowler]

I have not found that by using 12AT7 which is a PI tube, the 12AY7, 12AU7 or 5751 is of much use at it takes away that great compression in my experience. But I only use current production tubes.

Mark

[Cliff Schecht]

The amount of compression that you get from the Express really is a function of the amount of gain that the amp has, especially being that it's fixed bias. I find the Express doesn't have a whole lotta compression in the cleans, it's very touch sensitive in that region which is pretty much the opposite of what compression does. To really get that singing compression and sustain, you have to push the power amp well into distortion. A lower gain tube in the phase inverter, where the magic happens along with the PA, is definitely going to change the sound and lose some grit. Perhaps try a lower gain tube in V1 or V2 positions..

[Rouse94]

Besides the changing of preamp tubes, what would be a good way to keep the gain down and and not loose the clean to mean effect?

[dave g]

Tweak R7/C8. Try 33k/0.01uF or 22k/0.015uF.

[funkmeblue]

what if you add a fast/gradual switch?