Matching the sensitivity of two amps for bi-amping

You're just going to spend a lot of time and money on something you probably won't be happy with, for 2 reasons. First is that you'll hear the 2 different amps quite clearly. It will sound like 2 different systems patched together. Second, is you are almost certainty going to have to use an external active xover.

The only practical way to biamp is to use 2 stereo amps or 1 4 channel amp, and do it vertically.

I agree with Zd. Even if you get the gain to match at a certain level, both amps won't increase at the exact same rate.
If you want to see if bi-amping helps, you could use both of your amps on one speaker and see if you get more detail or punch? Then, you may end up buying 2 more Audio Notes :-)

I too agree with ZD. I would add, with respect to the passive biamp configuration you are proposing, that in most cases it would not be correct to match the sensitivities of the two amps. What should be matched is their gain, the relation between voltage out and voltage in.

Sensitivity is the input voltage required to drive the amp to some power level, usually its maximum rated power. Since the max power ratings of the two amps would probably be different, if sensitivities were matched the same input voltage would result in different output voltages from them, and hence different output powers for a given load impedance.

Power amp gains are often unspecified, but are commonly indicated in measurements provided in reviews, such as those in Stereophile. Also, gain can be approximately calculated from the sensitivity and max power capability specs of an amp, as I described here.

Finally, I see that your present amp is rated at 8 watts. A point to be aware of is that if you were to passively biamp that amp with a much more powerful solid state amp, that is somehow properly gain matched, you would not be able to utilize most of the power capability of the solid state amp without driving the lower powered amp into clipping.

Regards,
-- Al

Nikmilkov hi,

All you need to do is purchase a solid state amp that has higher sensitivity than your AN amps that also has input level controls.

Set the level controls so your bass sounds balanced in your system with the AN amps, an then your CJ preamp volume will be the master volume for both amps.

Cheers George