I've taken my Epiphone Treebird back home from my mom's place (i've keep about half my gear there since moving out because i lack room in my apartment). I wanted to test out having a series/parallel switch & see how useful it is for a thunderbird. The following findings can be translated to other epiphone thunderbirds (mainly the Classic which repoduces the gibson on a budget, the IVs, & others which have the 3 screw big black pickups), & Gibson counterpart thunderbirds of post 88 with the black cover pickups.
I cannot speak for vintage models 63-79, Vintage Pros, Active pre Pro epiphones, Elitist/custom shops with the humbucker sized pickups.
With that said, here's what i've heard: (note, my thunderbird does not sport a volume or tone control. Only a DPDT switch for the operation).
- In series mode, there's a lot of power behind the sound. Volume boost for sure in comparison with Parallel, however it does come a the cost of any clarity (this could probably be remedied having a tone control onboard - don't quote me on this).
- In parallel mode, it's what you'd expect out of a factory built thunderbird. There's a scooped tone, more airy in a sense, less volume to the series mode, but clarity overall. This would be your standard VVT wiring set up tone with everything wide open.
I mainly did this test to see how beneficial it is to have a thunderbird in Parallel (stock config) vs series (like the 76-79 birds of the day). I can find uses in both for sure, however i believe my preference lies with Parallel. To me, the sound of a thunderbird has a clank to it, there's clarity in the notes, & it sounds big in whatever space. Series is too much, & i'll get to why i think it worked for the 76-79 (& could possibly yield different results with the 63-66, Vintage Pros, Elitist/custom shops w/humbucker sized pickups).
The reason why I don't like Series on this, & don't feel it works great without having a tone control onboard (which i can't test without drilling another hole into my bass), is because of the pickup construction/magnets. Usually ceramic magnet equipped pickups (depending on how they're wound & wire components of course), but speaking strictly of Thunderbird bass ceramic magnet pickups - they're too "hot" to be in series. Where it worked on the 76-79 birds due to their pickups being side winder construction. Hence why, perhaps on the 3 model types of True vintage gibsons/vintage pros by epiphone, & humbucker sized equipped thunderbirds of epiphone custom shop/elitist, could yield different results having a series/parallel switch. I'm assuming they have more clarity to start with, so series mode would simply give them a nice volume boost, without perhaps sounding too muffled/woofy in a way.
I did have my treebird wired with an on/off switch because i wanted the simplicity of things. & i believe with that, i've been in permanent series mode. Which while the bass plays great in itself, i felt i had to compensate brightness wise because of this. However, i've only come to this conclusion about my killswitch & how it sounded, after play testing the series/parallel switching. If i find a way to have my thunderbird wired with only the on/off switch but having the parallel config tone when on, I will share it for those who are maybe seeking that open bird tone on a simple on/off switch.
Thanks for reading my Thunderbird TedTalk