Need help tweaking OD

[dogears]

I am running the 390ohm as well. Mine blooms like crazy so something is wierd! Try changing the OD2 grid to 150k. You'll hear it.....

The midboost will dramatically fatten up the PAB tone as you will get much more bass when in PAB mode. I'd change the SM or ceramic .002 to a PS series .002 Also, measure your 390pf ceramic treb cap. Make sure you have a full sized one. If it is small, like some are, you will lose fullness in PAB mode.

You can also change the OD1 cap to a .0025uf PS series. They have them at tubesandmore.com What does your OD drive pot measure? Is it low? If it is 230k for example, you will need to raise the cap since the knee will be too high.

Try changing the OD2 grid resistor to a 150k. That will restore some highs.

I am alarmed that you needed to so dramatically alter your NFB loop. That is way way suspicious. I have a 50w Marshall output in my Glaswerks and 4.7k is perfect.

I just went PS to ceramic on the .002 mid cap, but I will put the ps back in and check the 390. With NFB, I havent actually measured the trimmer at its current setting (75%), but I think 4.7 would sound good too. I tried it halfway up and it sounded about as good as at 75%. Pretty much anything over halfway is doing it for me, but I should be more scientic (less lazy) and desolder/measure. Also just to verify, i have NFB on the 4 ohm tap. I still have only 390 on the PI tail (across the 2k pres. pot). Should I up that to 1K? like some suggest? Since I put the .047 mid cap in, I have been able to back off presense to about 50% with good results. I am actually happy with my clean tone at the moment but want to do whatever is necessary to get the bloom/harmonic content going better. I will implement all these suggestions in the coming days.
thanks,
whit