Also, I've seen some AB1 basses that have the three knobs and some that have the knobs plus what appears to be a switch near the bridge pickup. What's the switch for? What other differences are there between the two aside from the switch?

Earlier AB-Is have both pickups wired in parallel. Those ABs have a special circuit called BluEQube that could be turned on/off with that switch. I'm not sure what it was supposed to be doing, but it's some EQ. Later ABs have the bridge pickup wired in series while the neck pup is wired in parallel - and it's a great thing. It made the BluEQube somewhat redundant and it was removed. No current models feature a BluEQube as far as I know. Personally, I like both my pups in series mode individually. Combustions have the bridge pup in series stock, neck in parallel. In case you don't know, pickups in series have more low mids and stronger output, while parallel pups are somewhat mid-scooped. So a series bridge pickup produces a nice mid-oriented sound that nicely complements the neck pickup, while producing equal output because there's less string movement near the bridge. Series/parallel modes don't change whether pickups are humbucking. I can't help you with listing the differences between the two models, but I understand they're quite different beasts, i.e. owning them both might not be redundant. Oh, and welcome to the forum!

Also, AB1 is passive whilst Combustion is active, if that's a consideration.

Thats not the one for sale in Oregon, is it?

I'd go for the ABI. Both basses are not in the same class. - The ABI with FD-3 pickups are very hot, louder than most, if not all, of my active basses - The ABI will be lighter - The ABI has a slimmer neck and balances better (although, the Combustion balances well too) - The ABI, in my opinion, has a clearer and a more cutting sound - The ABI is more responsive (you'll need some good muting technique to keep the sympathetic ring down) It probably sounds like I don't like the Combustion, which I do, but for the $200 difference, I would go for the Afterburner hands down, especially at that price.

Thanks to everyone for the feedback. Sounds like AB1 is where I need to focus since I am partial to passive basses, and the AB1 also seems to be a little higher on the food chain.

[quote="Bocete":ls92jk0d]Earlier AB-Is have both pickups wired in parallel. Those ABs have a special circuit called BluEQube that could be turned on/off with that switch. I'm not sure what it was supposed to be doing, but it's some EQ. [/quote:ls92jk0d] It was/is a mid-cut switch. Mark

[quote="DaveC":f3a4rsxr]Thanks to everyone for the feedback. Sounds like AB1 is where I need to focus since I am partial to passive basses, and the AB1 also seems to be a little higher on the food chain. [/quote:f3a4rsxr] Get the Afterburner. You won't regret it. Mark

[quote="guitarded":3j7mcvj2][quote="Bocete":3j7mcvj2]Earlier AB-Is have both pickups wired in parallel. Those ABs have a special circuit called BluEQube that could be turned on/off with that switch. I'm not sure what it was supposed to be doing, but it's some EQ. [/quote:3j7mcvj2] It was/is a mid-cut switch. Mark[/quote:3j7mcvj2] That's what I thought, but I wasn't sure because, well, how did the series bridge pickup make a mid-cut switch obsolete? That pickup change only brought more mids to the overall sound.

[quote="Bocete":2wbloml6][quote="guitarded":2wbloml6][quote="Bocete":2wbloml6]Earlier AB-Is have both pickups wired in parallel. Those ABs have a special circuit called BluEQube that could be turned on/off with that switch. I'm not sure what it was supposed to be doing, but it's some EQ. [/quote:2wbloml6] It was/is a mid-cut switch. Mark[/quote:2wbloml6] That's what I thought, but I wasn't sure because, well, how did the series bridge pickup make a mid-cut switch obsolete? That pickup change only brought more mids to the overall sound.[/quote:2wbloml6] The parallel combination of the neck parallel/bridge series sounded very similar to the parallel combination of neck in parallel/bridge parallel/bluEQube. Some players loved the bluEQube, a lot didn't understand it. In the end, the series bridge added cost at our end that would have meant raising the price or cutting the bluEQube. The original philosophy of the Afterburner was keep it simple but effective and keep the cost down. So we cut the bluEQube.

Thanks