High-quality preamp for recording

I'll put my two cents in...

I've owned the Avalon U5, a Reddi, and a UA 610. I'm currently down to a Phil Jones P-1. I used to track a lot but now I'm mostly doing live.
The U5 was great when I wanted accurate and had a ridiculous amount of detail in the highs (too much if you're a sloppy player). It also extends way way down if you want to retain the sub bass. I usually filter the ultra lows after tracking though.
The UA 610 is a great preamp for mics and instruments but it probably won't be as "tubey" sounding as you're thinking. It's more vintage flat (slightly darker than flat), if that makes sense.
The REDDI made everything sound larger than life but it's still flat enough for the intricate stuff. It's the one that I ended up using live for a long time.
The Phil Jones P-1 sounds broadly like the U5. Not quite as pristine but very very good. It won by being 1 rack unit and having eq and, incredibly transparent, compression.

Overall the U5 is my favorite for tracking. It always gave me a good starting point.

This link below is an Ibanez BTB7 into the U5 and into an interface.

 

DAV BG-1 or BG-1U
The BG-1U gives you one mic one D/I input.

I wanted a clean preamp with little coloration, 2 channels.
I already have a very nice vintage '52 Ampex tube preamp.

If you want just a D/I pre, you might look at the TAB Funkenwerk V-71

 

The #2 setting is pretty cool. It takes 40 years off of the tone. Well, it cuts a lot of mids and some highs for a vintage vibe. The other settings are all usable too except the last one; it's only good if you don't like your bass to have bass.

 

I love the 610, for me it puts a beautiful glow in anything that runs through it after it warms up for a bit. I have two and use both for recording one bass, one DI and one mic'd. I actually run my REDDI as the DI into the rear of the 610 for the extra saturated sound, which I personally love. If you're looking to only record bass, I'd look into the REDDI, it'll sweep the leg all day long. But if you're looking to maybe record some other instruments, especially anything mic'd (including your bass), the 610 is much more versatile and is absolutely killer for vocals and drum overheads. Plus having the DI plug in the front has come in handy for a more natural sound when recording guitars direct and using plugins on my DAW.

Sorry for no input on the other preamps, just giving some feedback for what I found to be quite nice.

 

I can't give you a comparison, but the UA610 is a great bass DI, and just gorgeous on flatwounds. I don't use it very often as a mic pre. Its sound is a little specialized, so it's not that often that I reach for that when micing.

If you're looking to mic an amp, there are a lot of alternatives. An API 512c is very punchy, and great on guitar and bass. Something in the Neve 1073 flavor also works. There are a lot of very highly rated 1073-style preamps. Dakings are great, too. You won't regret a Daking Mic Pre One, ever. I wouldn't get too hung up on preamps. Find something you can trust, and stick with it.

 

Just threw this together short draft, vocal and acoustic only.
Really happy with the sound quality for untreated room, air handler running non stop, fridge 20 feet away.
Used Logic noise gate plugin on both mics to kill background.
Recorded voice and guitar simultaneously.

SM57 with Tab Funkenwerk T-58 transformer upgrade on Larrivee P-10
AT 4050 @18" front right off shoulder capturing voice with some space.
DAV BG-1 into M-Audio Project Mix I/O line inputs 1&2.

Light compression, Space Designer Plugin small plate with 8ms pre-delay.
Less wet than preset.