"Classic" transistor circuits and signal phase issues?

[Lubdar]

Hey team,

I was wondering how much of an issue it is for a signal to be out of phase.
For the most part I think a lot of the circuits I've seen usually flip the signal back and forth, but usually have the output in phase with the input.

But what about the older odd number transistor circuits (e.g. LPB-1, Tonebender, rangemaster, etc)?

How much of an issue is the signal phase not matching the input if typical use is to put all pedals in a series, and not in parallel via some sort of mixer or signal splitter? I've read that this can lead to some sort of cancellation issue, but have never tried to test what that cancellation sounds like or if it is a big deal.

When pedals output signal is out of phase with the input signal, is it better to flip it?

Best,
   Bradford

[madbean]

Here are two reasons to be concerned about phase orientation:
1) In the analysis of a singularly contained effect. IOW, phase as it relates to the mixing of dry and effected signal within a circuit.
2) As it relates to running different effects in parallel.

For #1 - A good design takes care of this for you. If you are designing your own effects, it's something you need to be aware of and keep track of.
For #2 - If you are not running effects in parallel, then phase flips in a particular effect do not matter at all. If you are, there is a possibility of a potential issue but it is too generalized to give a definitive answer to.

Choose your adventure!

[Lubdar]

Thank you so much!!!

I'll keep these in mind as a try and design some circuits. In order to accommodate bass players needs for blending in the dry signal, I am planning on using op amp buffers. But if I'm using two non inverting op amps OR two inverting op amps that surround an odd numbered transistor design I wouldn't think this solves issue #1.

However if one of the op amp buffers is inverting, and the other is non inverting, I would presumably flip the signal back in phase with the dry signal. The question is which op amp to be inverted?

To my ears I don't hear much of an issue with two inverting op amps surrounding the circuit, but I will spend some time thinking it over, testing out the combinations, and report back!

heh, good adventures to choose...