Question on Power Amps

[Groovin1122]

I am hoping to assemble a gig-worthy amp setup on a budget that will allow me to be versatile/flexible and loud. I don't 100% sure know if I want to sound like ampeg, Aguliar or orange heads.. No idea.

I heard about combining a power amp with a preamp like a sans amp would work instead of buying a head. Are there any particular disadvantages to doing it this way? Is the active component on my bass considered a preamp?

 

[Wasnex]

The main disadvantage is the size and weight of a rack rig.

An active bass has a built in preamp, but the signal level is generally instrument level. Power amps typically require a line level signal to reach full power. You can plug a bass into a power amp and it will make sound, the bass just won't drive the amp to full power.

If you look at the power amps specs you will see a metric called "Sensitivity." Sensitivity is the signal level required to drive the amp to full power. If you buy a preamp and power amp you need to make sure the nominal output of the preamp is at least as hot as the amp's sensitivity rating. Some pedal preamps can drive a power amp, and some are designed to only put out an instrument level output. Some will do both.

 

[Blues Bass 2]

Congrats , you have found the secret low budget way to get a kick butt bass amp head without spending over $1000 . Used Sans Amp RBI , maybe $200 . Used class D poweramp , $300 . 3 space shallow rack $150 ?

Maybe I'm wrong but I have done this many times , great way to go .

 

[Blues Bass 2]

I love the Class D heads that are small , light and kick like a mule but the pre/poweramp rig isn't a bad way to go either and you can get a lot of power for not much cash .

 

[Chad Michael]

Listen to Wasnex, +I have experienced this personally years ago (preamp didn't meet the sensitivity of the power)

However when done right

- separates give replaceability and interchangeability when the numbers line up.

Have recently used the SWR preamp and a QSC power amp at a gig, the tone and power were a force of reckon...

 

[seamonkey]

If you get your sound with a good pre-amp you can put it into your own amp, and/or FOH, and/or into a studio console or interface for recording.

 

[Downunderwonder]

The sansamp pedal 'line' out is a bit light for driving some power amps. You're looking for a big amp with 0.7v input sensitivity option if you want to cover the bases with a pedal. Peavey made some.

The rack sansamps are good to go, any amp you can find.

Only real disadvantage is the hauling of a rack instead of amp head that could fit in your gear bag.

 

[seamonkey]

One other thing to look at is power amps with DSPs
Some brands just ship with them already built in.
Other brands charge like $50 more for one.
The DSPs include features like EQ, HPF, LPF, Adjustable Limiting, Adjustable input sensitivity, adjustable crossover points, and some include presets to allow you to have several speaker configuration and easily switch between them.
DSP can add a lot to the amplifiers versatility over time.

 

[sonic 7]

I think you’re gonna end up making it more complicated than you’re intending. Simplicity to me would just be a small class d head and a good speaker. Actually my dream rig would be a powered cab and a pre amp pedal.

 

[John Swartz]

Love using rack rigs - I've tried a bunch of different pre-amps (my current pre-amp of choice is the Tech21 "GED-2112") going into a Class D (Peavey IPR2 3000) poweramp mounted in a shallow rack for a fairly lightweight system.

Congrats , you have found the secret low budget way to get a kick butt bass amp head without spending over $1000 . Used Sans Amp RBI , maybe $200 . Used class D poweramp , $300 . 3 space shallow rack $150 ?

Maybe I'm wrong but I have done this many times , great way to go .View attachment 3842384

What you got behind that grill? Looks similar to my rig in that I had a blacklight kicking around that fits into a single unit rack space, so I mounted it in my rack:

 

[TOOL460002]

This totally works, but maybe the DBX has something to do with it. Dunno, but I can plug directly into that or through pedals or whatever. Plus it's light and has wheels and a handle.