Learn more about how a preamp and power amplifier boost your sound in different ways.
Have you ever used separates for preamp and power amplifier? If so, what was the setup?
- Yes, episode is over ?
- Line6 Bass POD Pro → Mackie power amp
- Studio: Avalon U5 → board
Where do I find preamps?
- Most instrument amplifiers have one
- Preamp section where your instrument plugs in
- Power amp comes after the FX, EQ, any comp/limiting, etc.
- Dedicated preamps — rack or desktop
- You can get preamp stomp boxes
- Some DIs can function as a preamp
- Dave — SansAmp
- Multi-effects pedals usually can function as preamps too
- Can’t power speakers with just a preamp
- But you can run the preamp into an active speaker and it will work, because an active speaker has its own power amp!
- Just not passive speakers
What makes it different from a power amp?
- A preamp is just an amplifier to get the very weak instrument signal to a signal that’s strong enough to be fiddled with.
- But not strong enough to drive speakers, which takes quite a lot of power.
- Helps the signal resist noise as you apply processing to it (like EQ, compression, etc.)
What happens if I’m using a pedal that works as a preamp, and running that into my amp head’s preamp section (instrument input)?
- You may be effectively boosting the signal twice
- Often the resulting sound will be clipping or at least distorted before it hits EQ, FX loop, or anything else, or the preamp
- However, some amps have a preamp “gain” control separate from the power amp volume
- You may be able to compensate here, just like you compensate for a louder active bass vs. a passive one
- This can be touchy — if you preamp elsewhere, better to come into the FX return as an already line-level (somewhat amplified) signal.
Why preamps make better recordings than plugging your instrument straight into an interface (usually)
- Because the preamp boosts the signal, you can lower the gain on the interface
- This means less intrinsic noise from both your bass and the interface itself
- Some interfaces offer an instrument level that sets a built-in preamp at the right level
Are there benefits of having separate preamp/power amp?
- Mix and match convenience
- Preamp you can carry to recordings
- If one piece goes, the whole unit isn’t useless