* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Panning for Fun - the GEO Home Page
Oscilloscope types wikipedia , lookup
Cellular repeater wikipedia , lookup
Power dividers and directional couplers wikipedia , lookup
Phase-locked loop wikipedia , lookup
Wien bridge oscillator wikipedia , lookup
Oscilloscope wikipedia , lookup
Index of electronics articles wikipedia , lookup
Radio transmitter design wikipedia , lookup
Dynamic range compression wikipedia , lookup
Regenerative circuit wikipedia , lookup
Power electronics wikipedia , lookup
Voltage regulator wikipedia , lookup
Resistive opto-isolator wikipedia , lookup
Two-port network wikipedia , lookup
Integrating ADC wikipedia , lookup
Flip-flop (electronics) wikipedia , lookup
Wilson current mirror wikipedia , lookup
Oscilloscope history wikipedia , lookup
Current mirror wikipedia , lookup
Zobel network wikipedia , lookup
Transistor–transistor logic wikipedia , lookup
Valve audio amplifier technical specification wikipedia , lookup
Negative-feedback amplifier wikipedia , lookup
Analog-to-digital converter wikipedia , lookup
Switched-mode power supply wikipedia , lookup
Valve RF amplifier wikipedia , lookup
Schmitt trigger wikipedia , lookup
Operational amplifier wikipedia , lookup
Panning for fun A1 When pot is all the way toward B, then voltage at A1 is A R R A1 = A X 0.707R R+(0.707R||R) =Ax (0.707Rx R) (0.707) R+(0.707R) 1+(0.707) R+ R B (0.707R||R) R (0.707Rx R) =Ax 1+ R+(0.707R) = A x 0.29289 (0.707) 1+(0.707) B1 is of course zero - it’s shorted to ground B1 When pot is all the way toward A, then voltage at B1 is likewise B x 0.29289 When pot is in the middle, then voltage at A1 is (0.35355Rx R) A1 = A X (0.35355R||R) R+(0.35355R||R) (0.35355) 1+(0.35355) R+(0.35355R) =Ax R+ =Ax (0353557Rx R) 1+ R+(0.35355R) (0.35355 = A x 0.2071 1+(0.35355) And the voltage at B1 is B x 0.2071 as well. Since the middle of the pot is grounded, A and A1 do not interact with B and B1. A R - R Out + 0.707R R B A - R R Out1 + 0.707R R R R - If we take note that the inverting input of an opamp is at a virtual ground, we can connect both of the output R’s that were grounded and get the same result, but the opamp mixes the signals, and at the same time, can supply some gain. If we make the gain setting resistor in the feedback loop be just enough to make either A or B have no loss when the pot is turned all the way to one side, then we have a constant power cross fader. The value of resistor to do this is one divided by the loss or 3.41 times R. Convenient values of resistors are R=15K, 0.707R = 10K, and the feedback resistor is 51K. Out2 + If we want to pan one signal to two differnent places, we can do it by using two opamps, each with a gain of 3.41, but connect them to the two different sides. Now A is panned from one output to the other, in a constant power manner. + - R A R + Rf R R A 0.707R R - Out1 R R Rf 3.41R 0.707R R - R Out1 R R 2.41R Out2 + We can do the same thing without inverting the signal if we take the signal at A1 and B1 to two separate opamps, and correct the gain of the opamp. Now we need another resistor from the inverting input to ground, and Rf needs to be 2.41R. If R=15K, 0.707R=10K and 2.41R = 36K. Out2 + We can even get one output inverted, the other not - just use the right opamp circuit on the side you want true/inverted. Notice that we could use two signal sources, too. It doesn’t matter what the signal is. The circuit pans the input(s) with constant power. Copyright 2003 R.G. Keen. All rights reserved. No permission for local copies or display from web sites other than http://www.geofex.com. To Effect Input From Effect Output Pan in and Pan Out 51K 15K 100K 1M +9 1M 0.22 to 1uF - + Output + + 10K 100K Input 15K 0.22 to 1uF Vb - 1M + 0.22 to 1uF + 15K LED Vb +9 4.7K 15K Here’s a panning application - an effect blender. The input signal is inverted by the first opamp and drives the panner circuit but also goes out to an effect-loop out jack. The return from the effect loop goes into the other side of the panner circuit. The “bypass” switch does not bypass. What it does is in one position, it grounds the effect side of the panner circuit, and opens the wiper lug to ground. This is the same as forcing the pot to be rotated all that way to the effect return side, so the effect-only side of the panner has signal through it as though the pot were turned to full signal. In the blend position, the switch grounds the lug of the panner pot and the other section of the switch turns on an indicator LED. To Effect Input From Effect Output The input impedance is not particularly high, only 100K. This is because the input opamp inverts the signal to keep the final output in true phase with the input. If this is not a high enough impedance, an emitter follower input buffer can be added. -- or you could use the high impedance version shown below. The input stage has been reworked to have an input impedance of about 1M, ignoring the 2.2M at the input cap. This version will give no treble loss with a raw guitar input. 22pF 100K cw 51K 100K 15K 1K Input 100K 2.2M Vb + + 10K 0.1uF 1M - 0.22 to 1uF + 1M +9 Vb 15K 1M Output + 0.22 to 1uF Vb 1M + 0.22 to 1uF 15K LED +9 4.7K 15K Copyright 2003-20063 R.G. Keen. All rights reserved. No permission for local copies or display from web sites other than http://www.geofex.com. Pan between outputs 51K 100K 15K 100K 15K - + + + Vb Output 0.22 to 1uF Vb 1M 100K 10K +9 51K 0.1uF Input +9 +9 + 15K 10K 1M 15K - Vb + Output 10K + 510K 10K + + 22uF 22uF 0.22 to 1uF Vb 1M Another panning application - panning one source to two outputs. You might use this to pan one guitar between two effects chains. You may be able to pan between two amps; but remember, that application is fraught with hum problems, and this circuit will not make the hum issues better or worse. I have only shown generic opamp pinouts. You will have to match the pins on your actual opamps with the functions shown, like the non-inverting input (+), the inverting input (-) and outputs. You will also have to select opamps. I would use two dual opamps like the TL072 or LM833. But a single quad opamp like the TL074 will work too. See the trick with the bias voltage? I did a normal bias voltage for the opamp inputs, but separated the “ground” connection ot the panning pot. This ensures that the signal from the panning pot does not pollute the bias voltage and cause oscillation problems. Copyright 2003-20063 R.G. Keen. All rights reserved. No permission for local copies or display from web sites other than http://www.geofex.com.