A tiny bit of latency is inherent in the pitch-shifting algorithm. I find it helps if you cannot hear the acoustic sound from the guitar (i.e. amp turned up or headphones). The lag is much more obvious when you can hear the mechanical noise from the pick attack.
In rehearsal or stage situations, it really isn't too bad.
I'm a owner of the JTV 69 since November last year and before I tested the guitar I was no friend of modeling instruments.
But I must say I'm really astonished and happy with the very little latency. I use it for sliding, Drop D, as a capo etc.
I felt he latency is in each tuning a little bit different, e g. capo 3rd fret, where in my practice I found the longest delay, but still acceptable.
Yes, and as snhirsch wrote, keep your amp loud enough and try also different models, because I felt that also the modeling of the guitar
has a little influence on the latency.
i notice this too...when playing direct in an ampli it is just a little latency (that sincerely i think it can be eliminated with a dual-core cpu and a little software optimization) but when i used it into a digital software such as TH2 it increase much more.
Trust me, pitch shifting ALWAYS will have latency, or else it will sound like complete garbage. It's impossible to pitch shift without running a bit of the signal through the algorithm so it can figure out what to do with it.
If it was real time, it would literally not work at all.
I swear they said they killed off a lot of latency though. In a video with Rob Chappers, a Line 6 rep said they have 0 latency, but I guess that's not the issue. I was skeptical myself, because like I said, pitch shifting will ALWAYS need latency.
It does NOT matter if your processor was the speed of light, a processor can't see into the future, so it needs a bit of the signal to calculate the pitch.
Remember, pitch = frequency = time, ergo it needs time to calculate.
That's a sine wave, the width represents the pitch, as it does represent time. You need time to read the wave, ergo it needs 9 MilliSeconds to see the whole pitch. The longer the latency, the cleaner the tracking, but we usually deal with a short frequency range, so we don't need the latency to be that high.
In short, Processing power will not help the latency.
Also someone mentioned that if your audio interface is having latency, that will tax even more latency onto everything.