Author Topic: Lower string sensitivity on upstroke  (Read 169 times)

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Offline jodama

Lower string sensitivity on upstroke
« on: February 14, 2017, 07:26:24 AM »
Hi everyone,
I'm new to the vguitar world and I'm still learning. I've run into a strange issue (at least I think it's strange).

I have a guitar with a Graph Tech piezo system, along with a GR33 and a GP10. When I'm playing the GR33, I get different output levels on downstrokes and up strokes (seems to be most pronounced on the high E string). The same thing doesn't seem to be happening on the GP-10 though, so I'm wondering if this is a set up issue or do I have a defective pickup?

Has anyone else had any similar issues? Does the GR33 have problems with piezo pickups? Any ideas are appreciated...

Thanks for reading!

It turns out the issue is also happening on the GP-10. Not sure why I didn't notice before. It's not always easy to hear while playing, but it's really clear looking at the string sensitivity display. This means there's definitely something screwy, right? This is a new guitar, so I'm hoping it's not the case. I guess I'm contacting support...

UPDATE 2 (in case anyone cares):
I just got off the phone with the tech (it's a Kiesel/Carvin SH575 BTW), and he hadn't heard of anything like this. Now I have to decide if I want to ship it in for service...

UPDATE 3 (pretty sure no one cares):
After a bunch of testing, it actually seems that this has to do with the way I pick. For whatever reason, when the pick 'vector' is pointing toward the guitar, the pickup seems to detect it as a louder note than if the 'vector' is pointing away from the guitar.

This is why the problem is mainly happening on the high E string. By the nature of its location (having no strings above it), my down-pick motion tends to go in toward the guitar, rather than parallel to the surface as it does with other strings. Since it does have stings below it, my up-picking motion is more parallel.

Anyway, I don't know if this is the nature of the beast with piezo pickups or what. It looks like this has all been part of learning how to adjust my style for the divided pickup (which I knew I would need to do).

This should be the last update (I hope). Thanks for being my rubber duck.

UPDATE 4 (I don't even care anymore):
I wanted to follow up on this because the above "solution" doesn't really make any sense (it just passes the buck from up/down to in/out). It turns out that I had the string sensitivity turned down too low on the GR33. Because of this, the slight difference in my picking velocity between up and downstroke was being magnified to a ridiculous amount whenever the difference happened to land on the internal "dividing line" between quiet and loud. Fixing the sensitivities has more or less completely erased the problem.

The same thing wasn't happening on the GP-10 because I had it set up correctly from the start (and the hardware is just better able to cope with the situation).

That's all.
« Last Edit: February 27, 2017, 06:54:14 AM by jodama »

Offline jodama

Re: Lower string sensitivity on upstroke
« Reply #1 on: May 03, 2017, 09:03:17 AM »
To continue this conversation with myself:

I recently had the guitar set up by a local luthier who has (a lot of) experience with 13 pin systems. He said that the in/out difference actually makes sense because of the way the piezo crystals can be set. I don't fully understand what he was talking about, but apparently if the manufacturing quality isn't up to snuff, the crystal can have a hard time sensing string vibrations if there isn't enough downward pressure from the bridge. Consequently, picking down toward the guitar could absolutely cause a louder note to sound than picking away from it.

According to him, that is probably what I'm experiencing with my bizarre picking situation.