nickyboy6100:   I wonder how they'd work with my desktop computer.

Very interesting document. Thanks for posting it.

Ok, this is what I get in trying to educate ...a wasted afternoon responding to nonsense. This reminds me why I didn't go into teaching.   So why don't you explain what measuring the voltage difference between the neutral at the load, and the ground at the panel through 50 ft of Romex 14 carrying 15 amps has to do with generating a ground loop? That will be interesting ... Let me save you time - it has NOTHING to do creating a ground loop and that has nothing to do with the noise and ground loop discussion. Let me educate you more - That zero potential must be measured at the neutral and ground AT THE SAME POINT WHERE THE DEVICE CONNECTS TO THE POWER not the voltage difference of the neutral at the device and the ground 50 ft away! What are you thinking?   With the neutral and ground bonded together at the panel, the voltage difference will be zero between the two at the same point equal distances from the bond point. Let me guess your next response - "but the voltage difference at the same point will still be different by 0.001 volt... See I'm right" Yea sport you are right...   I know I know, you have to find some way to save face...so knock yourself out, but I I have better things to do.   Oh BTW why don't you post your vast education and experience credentials that generate such great electrical engineering wisdom.   Otherwise have a great day!

Ha! @babadono, "upgrade" is clearly the wrong word, my apologies! La Scalas need NO upgrades! I do love their signature sound. @CWOReilly, they do still sound so, so good, so I'll wait on the "modifications" for now. Thanks for all the info!

Mike Jackson. If you want better than LSI’s, find a pair of MWM’s. They are better. Just much bigger. 

Very cool that you are at least considering keeping them Klipsch LaScalas have their own signature sound that I love. You either love it or hate it. Still have my pair I bought brand new in '77. As others have stated the crossovers MAY need new capacitors. There is a Klipsch authorized vendor for replacements that supposedly preserve the "Klipsch" sound. What upgrades are available? Now that there is a huge can of worms. Even the word upgrade is not allowed around here. They are modifications not upgrades. Many from here have migrated to AudioKarma. 

I'm sure by now the OP has long nodded off and tuned out of this discussion.   But back to the OP's original question of the power conditioner being worth it, I read a little about the Furman units on their website. They do not provide any technical details on what exactly their system is and does, and that in itself is telling. The most I can glean from their information is that these units provide some level of filtering and perhaps voltage regulation. They are concerned about RFI and EMI but how do they correct for it? No explanation. They offer units that do power factor correction, which is a power delivery efficiency issue, not an audio quality issue (fewer amps are needed to drive the load with power factor correction).   I could get into another long technical discussion, but I'll try to avoid it. In a few words this sort of "power conditioning" is not worth the price tag and will not correct many of the real-world problems present in home power systems. Period.   If you want RFI and EMI protection, install twisted pair power wires in metal clad shielding or conduit is the accepted method. And keep the wires away from motors, transformers, and strong magnets.   The filtering is almost certainly filters for high frequency sources (such as digital sources), but ignores the most common noise on power lines which are 60 Hz and lower. These are corrected with isolation and shielding. And you also must not connect digital sources (your CD, DVD, streamer players etc.) on the load side of the power conditioner.   As I discussed previously, if you need voltage regulation, you got bigger problems than your audio system. Do you share power with an industrial plant?   Another high dollar, snake oil product IMHO. There are more cost and performance effective solutions.

I mainly eat salmon and not much of other types of fish. That was the last one too

"Must be zero" but it will never be...this is common misconception. Neutral is bonded to ground at service entrance. And if no current is flowing in ground then at that point it is at the same potential. Now 50 feet down a piece of 14ga romex wire that has 15 amps flowing through it... no way is it at the same potential.

im ready to pay extra :) Im definetaly need more tweeters. But how?