Best bass amp ever period imho, recommended by Jim Bergantino himself amongst others bass gurus.
I use one of these with an Aguilar DB680 and the tone is to die for.
This is what Pro Audio Blowouts said about this model:
[i][b]"These legacy amps (built in Paramus NJ) are legendary tour-grade amplifiers. The HD9/CA9 delivers 2,000 watts of power (4 ohms bridged) with all the quality we've come to expect from Crest Audio.
The HD9/CA9 is a "meat and potatoes" bass amp that shines at reproducing low frequencies. With a damping factor of 700:1, this amp offers triple the damping performance of most lightweight switching amplifiers. Extreme current and voltage are what it takes to reproduce deep, chest-thumping bass, and this amp has it!
Many leading bass guitar preamp manufacturers recommend the HD9 (CA9) for a reason. It's an incredible amp for bass rigs. If you're a bass player, this amp could help you find that elusive deep, punchy sound you're looking for.
A 20-pound toroidal transformer is combined with eight large power supply caps for a total of 80,000 microfarads of capacitance. That's engineer-speak for obscene amounts of reserve power. The huge power supply stores current from the AC mains, and then releases it to reproduce power-hungry bass frequencies with an effortless, punchy response. Generous headroom, gobs of low bass, authoritative control over your subs--it's all right here.
They simply don't make amps like this any more. If you're NOT thrilled with the bass response of your sound system, it might be that you've got lightweight bass amps that aren't delivering the goods. The HD9/CA9 is heavy for a reason. Try one of these beasts (or a rack-full) in your system, and you'll never go back."[/b][/i]
GLWTS mate.