Woo, that's quite the write-up! Thanks for taking the time to edumocate your questioning followers out here on the interwebs.
So far, your experience has me really liking the sound of that little PJB. I'm looking forward to hearing what you think when you plug in other basses. Considering my Jazz is a go-to instrument for me, I'm keen to hear your experience with your Jazz. Small, portable and sweet are a great start.
I took my GK MB150E upstairs to the office, and played 4 of my basses through it yesterday. Mostly, I'm trying to establish what my existing neutral setting is. I have all my EQ set flat, volume (input) is about 10:00, and output is 9:00, so this is barely even on. After a few minutes of noodling, I asked how loud it was in the house and was told it was acceptable for non-concentrating time.
I'm impressed how much better the little cab sounds in a room with real wood floors and plaster (1928 era) walls compared to the basement. My short-scale P-copy with flatwounds had a smooth jazzy (music style, not bass) tone that would sound great in an acoustic or laid-back group. It copped a tone between a double and a Jazz, and really was sweet and pleasing to my ears. I think it made me play better.
Next up was my Squier Affinity Jazz with Fender flats and tuned DGCF. Much clearer and more defined, with a sweet growl through the neck pickup or both, and a pleasant burpy bridge-only tone. It was very clearly a different bass, which my wife commented on when she came back up to see what I was doing.
Then my corrupted TUNE Bassmaniac with swapped-out passive P/J pups from Epic Custom and light gauge DR Black Beauties. I'm still not sure how much I like the tone from this bass after the conversion. It's less authoritative than the passive Jazz with stock pups. But it sounded completely itself - and I have to wonder if the smaller strings are part of why it does not seem as metal as I expected. Once again, dialing in different knobs for blending and tone-changing did not cause a harsh or muddy tone from the GK. This bass also sounded like itself - or at least how it sounds now.
Then the big Yeller dog came out. My Schecter Riot-8 with all of it's barking active electronics and chiming (even though slightly out of tune) 8 strings. This bass always sounds w i d e and full, and it was certainly being shown to best effect by the single 12". I dialed in bass, I dialed in treble. I ran only neck, I ran only bridge, I blended them in the middle. An 8 is a limited-use bass, but for songs which have room to let it bloom, it sounded great. So much better than in the dank and cold basement where the sound just goes to die.
So in review, the GK MB150E is a useful and transparent partner. I knew it sounded good, but I really have not focused on it in months. It does not give any room to hide, so my technique flaws were in the same light as when I pulled off a really tasteful piece. Taking it out helped to re-calibrate my ears for other amps.
I
like this amp, I just want something smaller and lighter for more portability.
The bar is set. Who will clear it?