Output capacitor

[mr_deadmaxxx]

So uhm I've built this certain analog amp simulator and my problem is the effect volume doesn't match the bypass volume. There's a slight volume drop on the output. BTW, there's an output buffer on it that looks like this:



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so if I try to have my output after the 1K resistor, there's a volume drop. But if I connect the output on the emitter of the buffer transistor(before the 2.2uF cap), the effect volume matches the bypass volume. So my question now is what caused the volume drop? I was thinking maybe the 2.2uF output capacitor since I saw on other schematics that they used 10uF on the output. Will increasing the 2.2uF to 10uF solve this issue?

thanks to anyone who can reply to this..

[CynicalMan]

What are you connecting this amp sim to? The 1k resistor would have more of an effect than the cap unless there's some wiring error. But neither of those should affect the volume much unless the next piece of equipment has a very low input impedance. Also, what happens if you just jumper the 1k resistor on the output?

[mr_deadmaxxx]

well that's what bugs me. if i remove those three (2.2uF, 100k and 1k resistor) and just connect the output to the emitter of that transistor, the effect volume is high enough to match bypass volume. while if i connect the output on the 1k resistor(original schematic with 2.2uF and 100k not removed) the volume drops.

so i was thinking, if i want high effect volume, should i just remove those three?(2.2uF, 100k and 1k resistor)

PS: this is actually the output part of the sansamp gt2 schematic.

[asatbluesboy]

Have you tried removing (or raising the value of) just the 100K?

[mr_deadmaxxx]

not yet but i think that would not affect?not sure about this though. i have seen other schematics using 100k that way.

[iccaros]

you must ac couple the output or else you will be placing DC voltage on the next stage and expecting that they have already done so, a lot of amps do not.
your 100K on your output is in parallel with your 1K and what ever the next stage has off the input. Most likely 1meg. With a relatively high impedance of the 1meg your 100K  becomes your load.   which is low, which is why you could be loosing noticeable gain.  Change that to 1 meg, then your 1meg and there 1.01 meg will be in parallel giving you 500.5K load impedance. That is a ball park, but I would agree with either remove the 100K or increase it, and I would remove the 1K, at least for testing.
A capasitor is  for all intent and purposes no resistance to AC signal with it rolling off lower frequencies starting at the knee. Which looks like to me starting a .72 hz and bellow or no real pass in human hearing range.
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