What's the difference? True bypass completely bypasses the circuit, while buffered bypass buffers the signal when bypassed. This may sound like true bypass is better, but that isn't always the case.
First, the type of bypass applies only when the effect is bypassed. When the effect is active, the signal is buffered — regardless of the type of bypass. So, if your effect will be active all the time (as a reverb might be), the type of bypass doesn't matter.
Second, we generally recommend that the first and last effects in a signal chain be buffered-bypass or "always on" effects. This ensures two things:
- a constant input impedance presented to the send (effect send or instrument), ensuring consistent tone when bypassing effects, and
- an uninterrupted output driver to the return (effect return or amplifier input), minimizing any true-bypass switch pops due to slight differences between local ground references.
The effects between these two may be true bypass, if so desired. The more pedals you have, the more you may want them to be true bypass to minimize any accumulated noise. However, if you only have a few effects, then it's less critical that they be true bypass.