External Lyric modification (again)

[Tranquillitatis]

Sorry for yet another thread about modifying the Lyric, but here it is. I have a Martin OM-42 that I want to install a Lyric and a UST in, however I would like to install the preamp into a pedal rather than inside the guitar. This will allow me to reduce the amount of equipment inside the guitar body to affect the acoustic sound, and also run it on a mains-supplied 9V from a Strymon Ojai instead of a battery. I'm fairly certain I've got everything right, the method is as follows (also see included rough diagram):

1) cut the cable connecting the Lyric mic to the preamp.
2) install an LR Baggs end pin with pre-wired strapjack harness into the guitar. Resolder the Lyric mic and UST to the PSH cable.
3) install the Lyric preamp, including the battery snap and sound hole controller unit inside a standard 1590B pedal enclosure.
4) connect the PSH to the Lyric preamp back end using a TRS cable into the pedal.
5) connect a 9V power supply from Ojai to the battery snap.
6) connect the Lyric preamp output to two TS sockets on the pedal, outputting the two individual mic/UST signals to a mixer for leveling and blending to mono.
7) set volume and presence controls on the sound hole unit before closing the pedal enclosure.

I'm just a bit unsure about a few things and need three questions answered before I buy everything and get started:

1) will the quality of the Lyric mic signal suffer by moving it further from the preamp? I was planning on using a high grade shielded TRS cable between the guitar and the pedal, but does the cable pose the risk of introducing external RFI or impedance issues?
2) will I encounter any crosstalk or hum if I use a common ground on both the mic and UST?
3) will the built-in switch connection on the Lyric preamp TRRS jack be a problem in my intended setup since the power will be coming from a mains 9V supply instead of a battery? Do I need to connect it to the mic signal, the ground, or disconnect it from everything altogether?

Thanks for any help.

[Caleb_Elling]

1) will the quality of the Lyric mic signal suffer by moving it further from the preamp? I was planning on using a high grade shielded TRS cable between the guitar and the pedal, but does the cable pose the risk of introducing external RFI or impedance issues?
2) will I encounter any crosstalk or hum if I use a common ground on both the mic and UST?
3) will the built-in switch connection on the Lyric preamp TRRS jack be a problem in my intended setup since the power will be coming from a mains 9V supply instead of a battery? Do I need to connect it to the mic signal, the ground, or disconnect it from everything altogether?

Thanks for any help.

I've actually done something like this before to test Lyric mics, and it worked pretty well.

1) I didn't notice any tonal change by adding a 6'-10' instrument cable between the mic and preamp. I didn't test with a longer cable though.
2) If you are running a powred signal and a passive signal over the same cable, you will likely get some level of crosstalk depending on the cable quality and length. The Lyric signal is probably going to bleed into the UST signal more than the other way around.
3) If you are only going to use DC/wall power for the preamp, you shouldn't need to worry about battery drain. You will just have to make sure to short the switch to ground so the preamp stays on when power is available.

[Tranquillitatis]

Hey Caleb, thanks for the info. Sounds like the plan is a go, I’ll report back once I have everything set up. Cheers