Sure you can, but it's probably not worth the effort & damage risk. If the preamp doesn't alter the sound in a "destructive" way, this can be ok.
Split before cheap preampĪgain, both High-Z is crucial, so this should work. However, even that does rather "too much" for the amp route. An actual guitar preamp is not a good idea, but a mic preamp (those used for voice in studio recording) with instrument input can be a good choice indeed. I wouldn't use a preamp that deliberately alters the signal in any way except perhaps gentle tube saturation. The only "correct" configuration of two parallel inputs, as you say, is if both are High-Z to begin with. In principle, you can indeed fix this by inserting a resistor, but it needs to be really lot bigger – I'd recommend at least 200k, better 500, and with that the line-input's level gets even lower, which probably results in unacceptable SNR. And unfortunately, guitar pickups are ancient, horrible design that can't really handle such a low impedance (it takes away all the pickup's resonance and turns it into a pretty dull low pass). We can ignore the Vox' guitar input here: as the 10k line input is so much lower impedance, it dominates. The only relevant thing is the total parallel impedance you're feeding. It's no problem at all to use a Y-cable and feed the guitar to two guitar input (not a signal problem, at least – you will probably get ground-loop hum, however). Splitting in itself does not "take away" anything from the signal. I didn't think the guitar signal would be strong enough to try this Other solutions would be welcome as well, of course. due to plugging/unplugging a cable) damage the preamp? Is this even practical? Would a short circuit (e.g.
VOX TONELAB ST PATCH LIST MOD
Mod the effects unit to add a clean output, just behind the built-in preamp.Seems like it could solve both issues, since the guitar signal would be connected to two high-Z inputs, and everything else stays the way it currently is. Split the guitar signal before the dedicated preamp, and use the preamp only for recording.This seems like it is guaranteed to work, but will it negatively affect the live sound (which is the output of the effects unit run through a guitar amp)? I guess it just comes down to: How clean will a cheap preamp actually be? Insert a cheap dedicated guitar preamp between the guitar and the effects unit, and record its output signal.Should I be concerned about impedance issues? (The line input has 10 kOhms according to the manual.) If the two input impedances are very different, is this a problem, and can I fix it by just inserting a resistor? I didn't think the guitar signal would be strong enough to try this, so I haven't yet, but will. Simply split the guitar signal and run it into both inputs.
There are several obvious solutions, and I'm just trying to figure out the caveats they may have: The problem I'm facing is that I need two line-level signals for recording, and the ToneLab ST doesn't have any additional DI output. I'm trying to figure out the easiest way to record an electric guitar simultaneously to two tracks, one track getting the clean signal and the other getting a signal that has been processed through a Vox ToneLab ST effects unit.