ej_whyte
Well-known member
I recently picked Self's Small Signal and have been plowing through it, really good stuff I am quite interested in the Baxandall active vol circuit that is described in chapter 9, but have couple of questions.
What resistors are used in calculating the cut-off of the 1st blocking cap? (C1 on schemo). I can't work out whether it is just that left-hand end of RV1 or if R3 should be added in series, not sure how the cap in between the pot and R3 would affect.
Also, why is it that the last cap, C4, has its polarity reversed from what you normally see for a coupling cap? Whilst on the subject actually, I would also like to clear something up: polarised electrolytics introduce distortion when the voltage goes opposite-to-polarity, and therefore add distortion to every negative half of a cycle?
Finally, is it at all feasible to substitute the inverting op-amp stage with a tube stage? I guess it would be advisable to put the C4 blocking cap before the global feedback to RV1.
Cheers
What resistors are used in calculating the cut-off of the 1st blocking cap? (C1 on schemo). I can't work out whether it is just that left-hand end of RV1 or if R3 should be added in series, not sure how the cap in between the pot and R3 would affect.
Also, why is it that the last cap, C4, has its polarity reversed from what you normally see for a coupling cap? Whilst on the subject actually, I would also like to clear something up: polarised electrolytics introduce distortion when the voltage goes opposite-to-polarity, and therefore add distortion to every negative half of a cycle?
Finally, is it at all feasible to substitute the inverting op-amp stage with a tube stage? I guess it would be advisable to put the C4 blocking cap before the global feedback to RV1.
Cheers