Will a tube preamp give me what I want?

1) Maybe, Bose has a special EQ for their systems.

2) Bass into preamp from the preamp to the effects return of the BL600 (bypass the BL600 preamp).

 

you're not gonna get much of a bass tone through that. They aren't really designed for electric instruments. The only time I've heard them work as advertised is in coffee shop type settings. Id run acoustic guitar, vox, maybe even keys through it. I wouldn't run bass through it if I could help it. The tone might be there, but the oomph wouldn't be.

 

You would get the tone from the preamp pedal bypassing your BL600 a nice pedal to consider is the Tube Works Blue tube it uses a real preamp tube I would suggest a nice vintage Tung Sol or RCA Black Plate

 

Yes, you could run the preamp directly into the Bose system and it would do OK. Here is the real question(s).

Are we talking about a single system with one sub?
Bar band or small private/coffee house stuff?
How loud are you guys?

If this is a bar band that plays pretty loud you may as well just keep bringing your amp and line into the system just to help spread a little bass around. Even two of those subs won't fill a room with bass at any kind of loud volume.

 

If you want the tone of the BL600 why are you wanting a tube pre?

 

If the preamp into the Bose won't do it, hookup as I noted above and that will make the BL600 into just a power amp and cab. The "voice" of the BL600 will be pretty much bypassed.

 

A tube preamp can mean different things. Some "tube" preamps are just chip based solid state preamps with a tube jammed in there, badly. OTOH a fully tubed preamp with not a single transistor will be more "authentic", but will likely be much brighter and harsher than what you think a tube amp sounds like. Especially when you take a direct line out and plug straight into the bose system. You would probably want to use some kind of speaker emulation box to round off the edges if that was the route you took.
You would probably get a closer approximation of "tube sound" with a Tech 21 RBI or their Ampeg(R) emulation box. VT bass? Something like that. Even though it isn't a tube amp, it will sound closer to one coming out of a Bose system than any of the Ampeg or Mesa preamps.

 

Like SS pre-amps, "tube pre-amps" all have their different voices—and those voices can differ greatly. Some sound very clean (almost clinical—a lot like a tone some people reductively associate with solid state preamps). Some tube pres sound warm to the point of mushiness. Others are in the middle. Some of those might be close to the sound you're after, some won't.

In your shoes, I'd definitely not buy a preamp without trying out a bunch of them first—unless your budget is generous enough to support a season of buying and selling preamps until you find one that suits you and the rest of your rig.

 

My band's PA is 3 Bose L1's, with a total of 6 subs. Everything but the drums (keys, 4 vox, 2 mic'd guitar, 1 DI'd bass) go to the board and from there to the Bose. For my bass, it sounded horrible if I just went direct in (YMMV if you have a dedicated L1 and can play with the EQ pre-sets), so I go thru my pedal board with includes a BDDI and compressor, and from there lines out to the board and on to the L1s. I use my amp for stage monitoring.

In your case, could you go bass > tube pre > GK Backline 600 > post eq XLR out to board/Bose?

 

+1, that's the way I'd go.

The Tech21 SansAmp tube emulators are solid state but remarkably tube-like. They are also much less expensive than quality tube preamps, especially boutique all-tube designs.

There are a wide range to choose from, ranging from pedals to rack units. The most popular is the Bass Driver DI, known as SABDDI or BDDI for short. It's been a staple in recording studios, even the highest quality ones, for decades. The RBI is essentially a rack-mount version of the BDDI.

There are many options, but IMHO the SansAmps easily give you the most tube bang for the buck.