DR103 preamp - what does the CF do?

[bea]

I notices that the tubes of the Mywatt can be reached by removing the front panel. Nice. So i inserted an ECC81 - an old, used Telefunken which served as the PI of one of my old Dynacords for decades. As i am still not able to move the amp around i can test it only in my living room.

... IME the 12AT7/ECC81 works better in this position, but for a 50 or 100 it doesn't make much difference until clipping, at which time all bets are off and it's up to what sounds best to you. ...

Without a real A/B comparison of two otherwise identical amplifiers the difference is, of course, hard to tell. Nevertheless, with the ECC81 PI the Mywatt seems a bit smoother, maybe even less scooped than before. But i must honestly confess that i do not think it will be really audible in a band context.

(yesterday i had the crazy (?) idea to use the free ECC83 system as an active 50 Hz highpass filter for speaker protection...)