How important is the pre-amp?

Streaming sounded like the best way to go, as I was getting my system going.  I was trying to watch spending.  My preamp was failing.  So I connected the streamer to DAC then direct to the amp.  How creative, I thought.  Well, I didn't realize the digital volume was cutting bits.  So with 100 dB speakers, I thought an active preamp would make my volume control run on the lower third.  I currently have a tube buffer.  Greatly improved vs the direct connection.  The preamp is a Tubes4HiFi SP12.  A solder joint and I can make it active.  I think it has 5dB gain.  I have not tried this version yet.  Would this cause problems?  I have a Pass XA25 with horn speakers(Crites).

The preamp IS the heart and soul of a system - it’s the driver in the car. The driver puts the car in gear, controls the steering and direction, and controls the throttle making the engine do what it needs to do to run the car. This is all the functions of a preamp in a sound system.
It drives the system! It has to accept and manage a wide array of sources; Turntable, CD and/or BluRay player, Streamer, Cable/Satellite Box, etc., allowing you to select between all of those sources, and has to control what the amplifier does with your speakers. It’s gain, balance, treble/bass, dynamics, it controls all of those things between the sources and the amp.
Without a good preamp, it would be a lot like putting a kid who just got their driver’s license behind the wheel of a race car. If you can’t manage the sources well, that’s like not knowing what gear to be in. If you can’t control what the amp is doing, it’s like not controlling the throttle, which you’re likely to blow the engine and burn the tires along with not being able to handle the steering. That’s much like not getting a good image between your speakers because you can’t control the balance and not being able to fully handle what the amp is doing to the speakers where it can sound distorted or likely blow your speakers. I hope that’s not confusing and gives you the direction you need?
Good luck in your quest!

I have a DAC and amp with balanced capability and the DAC has volume control.  My tube pre only has single ended connections. Sometimes I run the DAC strait to the AMP via balanced. I always recognize the music a little more analytical with the balanced connections. Then I switch back and put the pre in. I always seem to settle in on having the pre in the mix for longer periods before switching back to the DAC directly connected to the amp.   I am in agreement that Balanced is not always better than single ended. It's like wine , it depends on your taste.

Essential for getting the most out of the source. Don't fall for the story of using a DAC output alone. It is lifeless and unrealistic on every DAC I've tried this with. I know, digital is digital, blah blah, but something goes wrong without a quality preamp in the chain.