Okay folks, as the OP of this thread...which honestly has moved far beyond where I thought it would ever go thanks to all of your collective knowledge....I'm tossing in another review and some sound samples.
GK PLEX REVIEW & COMPARISION
As mentioned above I picked up a used GK Plex. I've long wanted to test this preamp but when one popped up for a good price I either missed it or had my cash tied up with something else. Testing this stuff is expensive. I don't get things provided to me to test like some of the YouTubers and such. It all comes out of my pocket.
So...back to the Plex. First off, for the TLDR people...it's good. Really good...with a few caveats.
First off, they are retailing for $400...which is just dumb. The Pod Go can be bought for $450 and it is FAR, FAR, FAR, FAR, FAR superior to anything in that price range and most things costing more than double that price. The tonal options of the Pod Go are such that I don't think you'd ever be about to use them all. But we're not here to talk about the Pod Go (although there will be a comparison clip of it as it's my current gold standard). If you can grab a Plex used for cheap...do it. It's a great do it all preamp in a small package that's built like a tank.
First thing I had to do was update the Plex to the current firmware. It was super easy. Just plug it in with a USB cable while holding one of the switches and it shows up as a hard disk on your computer. Delete the existing firmware file, drop in the new one, and you're done.
Once updated, I messed around with all the various amp sims and settled on the RB800 which seemed to have the most robust bottom end and a warm tone. More so than the tube amp emulation it has, which I thought was odd. I've never played through a GK rig, so I can't say if the emulation is accurate. But the RB800 one sounds good and it does have that real amp "feel" if that makes any sense. There is a coloration for sure.
I ended up using the "bump" function for the bass and adding +6db then turning the bass knob just past noon. I'm a fan of big full low end. The rest of the EQ knobs stayed flat. Rolling off the treble knob did give a nice tone too, but for the purposes of this test it was flat.
The compressor on the Plex is...um...well...it's okay. If you just want a little fattening in your tone it works fine. I fiddled with it a bit to get it to my liking. I don't really like to hear the compression. I just want it to level things out and fatten things up. It does that. The drive is fair. I'm not a big distortion fan, so none of them really wow me, but the Plex OD did maintain the low end well and it wasn't unpleasant as long as you used the "1" or "2" setting. Beyond that it it sounded like death metal wanna be.
I didn't try it as an interface because I run a PreSonus StudioLive mixer that serves as my interface. So I can't comment on the pedal as an interface to your DAW.
At first, I thought the pedal was crazy noisy, but I took some time to adjust the input gain to the proper level and it got fairly quiet. There is an audible hiss that comes from it if you listen really hard and nothing else is coming out of the speakers. But then you hear it go away....the Plex has a noise gate and it works pretty well.
SOUND COMPARISON
I took some time to compare the Plex with the Pod Go and my trust old analog board anchored by a Shaw Tube Injection. The two digital rigs obviously had the upper hand with compression and more comprehensive EQs. But the Tube Injection held it's own and there is a warmth and smoothness to the all analog tube tone.
My plan is to use the Plex at band rehearsals instead of putting the wear and tear on my Pod Go. It's small and will easily fit in the pocket of my Mono bag. Because it has a tuner, comp, EQ, drive, and DI....it's all I need for rehearsals. Speaking of the tuner....HELLO GK...PAY ATTENTION HERE....you have to double tap the compressor switch to engage the tuner. Too fast...it doesn't work. Too slow...it doesn't work. It's maddening!! Why not just have a hold to tune like everyone else? Why double tap to get out of the tuner? If you're tuning, and you're done...just a tap on any switch should take you out of the tuner (um...just like the Pod Go...Yamaha/Line 6 has their act together!).
Without further adoo....here's the samples.
Signal chain is:
Moonshine Custom Guitars bass with Nordstrand ZenBlades in 60's Jazz position, passive mode --> TC Electronic Ditto Looper --> JHS buffered splitter --> to respective preamp --> PreSonus StudioLive AR8c Mixer --> GarageBand (no plug-ins or EQ)
The Tube Injection did have one handicap. The Becos compressor on that board developed a short in the switch and is currently back in Romania getting some TLC from it's creator. So the Shaw is uncompressed.
The Pod Go and the Tube Injection both have high pass filters on them. The Pod Go is, of course, digital and set at 30hz. The Tube Injection has a sfx microThumpinator in front of it. These let you push the low end without a bunch of sub sonic mud...which is fabulous. The Plex doesn't have any HPF functions.
GK Plex:
Line 6 Pod Go:
Shaw Tube Injection:
Let me know what you think. But keep in mind cost of these units:
GK Plex: $399
Pod Go: $449
Tube Injection: $949
If the Plex was $250 - $300 it would be an amazing deal. The Tube Injection is expensive, but consider that what you are hearing is just old school analog tube tone. There is no amp sim, no cab sim, no compression, no 10 band parametric EQ, etc. So it's pretty dang impressive for what it is. A very high quality hand made preamp.