Just bought a trbx504 and loving it. They did the switch the right way on the 504/604. Many reviews said that it plays like a higher tier instrument. Excellent quality for the price. Passive is truly passive. Preamp is physically switched out and the output from the pickups are fed to the cable. I haven’t tried playing with the battery pulled, but the claim is that you can continue playing if the battery for the preamp dies (or is near death) by switching to passive mode.
I found switching between passive and active requires adjustments on your amp to get the equivalent sound out of it. That’s to be expected. Played around with the 3-band equalizer and it seems to do its job well (sorry not an audiophile).
Been playing a 605 for about a month now, and after putting it through my very basic pedalboard, I’ve got the active/passive tone equalized. The highs might be a tiny bit lower on passive, but not enough to affect where it sits in the mix.
That said, the instrument is a tone machine. Just recently put GHS Pressurewounds on it and the sucker sings in so many different tones.
Yeah. It’s got a great preamp and a really versatile set of tonal options. So does the BB734a with its similar preamp, to a slightly lesser extent; hard to beat a HH for versatility.
I had pressurewounds on my BB734 for about a year. They sounded fantastic and I’d highly recommend, very versatile strings. I just recently swapped them out for Elixirs (their guitar strings are my absolute favorites). I was looking for a little more focus rather than versatility and the Elixir’s are better at what they do imo. I’ll put another set of GHS on my Sire in the next few months when the stock strings need replacing.