Proper output impedance for driving a poweramp

michaelc · #1 03-28-2010, 10:28 AM

I've been looking for a preamp pedal to drive a power amp, but I know the output impedance needs to be correct to fully drive a poweramp correctly. What would be the proper range of output impedance? Any suggestions on pedals that would be good for this application? I was leaning towards the tri-logic my self, but that pedal has 10 ohms output where as the Tone Hammer has a 100 ohms output impedance.

jnewmark · #2 03-28-2010, 10:56 AM

Why are you putting this in the classifieds?

::::BASSIST:::: · #3 03-28-2010, 11:04 AM

Quote:

Originally Posted by michaelc

I've been looking for a preamp pedal to drive a power amp, but I know the output impedance needs to be correct to fully drive a poweramp correctly. What would be the proper range of output impedance? Any suggestions on pedals that would be good for this application? I was leaning towards the tri-logic my self, but that pedal has 10 ohms output where as the Tone Hammer has a 100 ohms output impedance.

Yeah, wrong posting section, but the answer is to get a VT Bass. Very high output and sounds excellent with lots of tones to choose from. Add an EQ pedal and you're good to go.

seanm · #4 03-28-2010, 01:33 PM

Depends on the power amp. Some can be powered by a pedal preamp, some can't.

Look at the input impedance spec for the amp. A perfect match is best but unlikely. In practical terms you want 10x less than the input impedance. For example, the Stewart Audio World 1.2 has an unbalanced input of 10k. So exactly 10k would be perfect. But anything < 1k will work great. So both the 10 and 100 ohm output impedance would work well.

Also look at the input sensitivity, this is more likely where you will run into problems. Behringer, and I believe QSC?, amps need a lot of input voltage. More than you can get from a 9V pedal.