splitter blend check for errors

Frequent asked about building blocks: gain stages, buffers, clipping configurations, ...
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eatyourguitar
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Post by eatyourguitar »

I modified some schematics I found online that did not fit my needs. I wanted something with no FET's, one TL074, phase 180 switch. I was hoping someone could look at it and make suggestions.
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https://farm8.staticflickr.com/7571/157 ... 7133_o.gif

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The G
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Post by The G »

splitter-blend_corrections_1.png
1. You should take the IC1A inverter signal from the output of IC1B to preserve the high input impedance.
2. A resistor in series with inputs and outputs will provide protection from most of the usual misshaps.
3. A pair of diodes as drawn would provide more protection for the inputs.

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eatyourguitar
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Post by eatyourguitar »

I already have the stripboard layout made on the computer but it was very easy to move R30. I fixed it per your suggestion. now I have R30 connected directly to the output of IC1B. I don't understand why you think I need diodes and a resistor on the return if it is AC coupled by a 63v box cap. can you explain it?

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The G
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Post by The G »

Well, it depends on what you plan to couple it with. This paper or this article describe some benefits. These are just good-practice protection measures and I am using them just to be sure, since I cannot be sure I know every equipment that will be connected to my circuits. A malfunctioning tube amp could easily send more voltage than your capacitor can cope with, but, more easily, an op amp can go bad from short voltage spikes like described in the paper above.
Of course, you can leave out all diodes and resistors and the circuit will work just the same. Until it doesn't :mrgreen:.

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