[mvalpreda]

ProSub 800 has high level inputs and outputs. So I can do this:

Computer --> mini-X a-100 --> powered outputs --> ProSub 800 high level input
ProSub high level output --> SM45
 
ProSub 800 has a high pass filter on the powered outputs. That helps!
 
So long Klipsch.

 

[cel4145]

Yes. Optical out will let you use the DAC in a receiver that has optical inputs.

Small receivers? Difficult if impossible to find. Units like that Teach AH101 are pretty rare. Even the Marantz slimlines have the same foot print as your average AVR. If you can bear the size of a full-size receiver, your options and choices open up greatly. For example, here's a brand new ONKYO TX-NR414 for $199 (promo code EMCXVWS49). Doesn't cost much to buy one then.

I can use the volume control on my keyboard with my USB DAC. Not certain about optical output.

 

[mvalpreda]

I don't think the AVR route will be the way to go for me. Is the Topping TP-30 a nice DAC/amp combo? Maybe something like that with a bit more power?

 

[weez82]

That Toppings looks good and amazon has it for under $100. And it has plenty of power for the 45's

 

[cel4145]

If you buy the Topping, you will have to get a subwoofer that has speaker level inputs and outputs, so that you can hook everything up like this Topping->subwoofer->speakers.

 

[mvalpreda]

The ProSub 800 has high input in/out. I think I am going to go with the Topping. For $100 I think that will be a good starting point.
 
Is there anything along those lines with a bit more power output?

 

[mvalpreda]

Sometimes it is fun to look on the links for what other people are buying on Amazon. This looks pretty slick.
http://www.amazon.com/Teac-AH01-S-Stereo-Amplifier-Converter/dp/B00647G78M/ref=pd_sim_sbs_e_44

 

[cel4145]

The ProSub 800 has high input in/out. I think I am going to go with the Topping. For $100 I think that will be a good starting point.

Be aware, though, that the ProSub 800 is not a very good value unless you are getting it about half off MSRP. And Def Tech posts very misleading specs for their low frequency roll off on their subs. For instance, the ProSub 800 is 28db down at 24hz from it's peak at 62hz (see sidebar). If you ask in this thread over at the AVS subwoofer forum where a bunch of home audio sub enthusiasts hang out, they could help you pick something out that is better and probably save you money: Budget subwoofers discussions, opinions and questions thread.

 

[mvalpreda]

$285 on eBay for the ProSub 800.
 
Posted on that thread for a recommendation. Thanks.