DC filtering question

[bluebunny]

And the 10Ks are indeed 10Ks?

[nonoxxx]

yes indeed

[nonoxxx]

The only mods on this circtuit, is the range of gain (twice as much at max , and a little lower at min) and the  switch for bass roll of.
Also , a Burr Brown for the opamp

[nonoxxx]

Thanks a lot for all your  replies,

Guy's, I am always  pleasantly surprised by your kindness and your knowlege .

Someone now a effective way to know the current draw of a circuit ? (Edit :  I find how on youtube lol)

[amz-fx]

Someone now a effective way to know the current draw of a circuit ? (Edit :  I find how on youtube lol)

I did just that in my previous reply in this thread.

You know that you have a 100 ohm resistor and the voltage drop across it is 0.2 volts, so V= I * R, or I = V/R and we have 0.2/100 which is 0.002 A (2 ma.)

You could also do it directly with a multimeter, which is probably what you say on Youtube. 

Best regards, Jack

[nonoxxx]

I had understand the calculation, but it was to know the current through the circuit before putting the resistor.

Thanks you very much

[duck_arse]

which burr brown? try a TL072, measure the current, and compare the difference, if any.

[PRR]

> If you look at the last chart on this datasheet: http://eecs.oregonstate.edu/education/docs/datasheets/XC-600178.pdf

Gotta be a typo on that particular data. The 1uFd cap is working about 10X better than it should. Maybe it was a 10uFd cap? Maybe the data plotter got cross-eyed?

As recently(?) as the 1950s, a big electrolytic cap would go inducty at the top of the audio band. Nevertheless they were often ample for bypassing radio-guts working at 0.45MHz-1.5MHz. (But just-barely-- in cold, or as caps aged, RF/IF whistles set in.)

So we old guys were always told: for good work, use a small RF-capable cap with your big bass/buzz cap.

I think by the 1970s, evolution of electrolytics made this more a non-issue. Even accepting that the cited datasheet may be off by factor of 10, about any e-cap will hold less than 1 Ohm out to 10MHz, at any temperature you would play in.

(You _do_ have to small cap bypass *fast* opamps like LM318 and even '5532. You think they do audio, but they do MHz pretty good.)

But in the 1980s some audio-philes went nuts throwing 0.1uFd caps like holy-water. Which it is and isn't. A Muff doesn't need it. Even a TS, with '558 chips, shouldn't need it.