Power Conditioner


Hi everyone, 
I need help here with any suggestion, wich of these 2 Power Conditioner is the best and why? 
-Furman Elite 20PFI
-Furman Elite 15DMI
Do i need both? 
Thank you. 
128x128martin_leger
I have Furman Elite 20PFI and like it very much.  I bought it used for about $650.  It has very tight non-sacrificial over/under voltage protection and I believe that it filters HF noise well.  My previous amp had plain unregulated power supply and did not suffer any loss of dynamics when plugged into it (high current bank).  I have whole house spike protection, but Furman already turned off circuit breaker few times.  When it happened I noticed bulbs got brighter for a moment.  Now with double protection I feel very safe.  Whole house protection is a must since everything these days is electronic, including appliances and even light bulbs, but Furman gives me extra protection for expensive gear.
The 20PFI has a big toroidal transformer inside to help with blocking A/C noise.  It also has the Power Factor Technology "current reservoir".  This is a big capacitor inside the power conditioner which gives faster immediate current to your devices which the A/C line would not normally provide.  The 20PFI is very expensive, but these two items really provide a lot more.

The 15PFI also has the "current reservoir" capacitor, but lacks the toroidal transformer.  It's less expensive, but still better than the "DMI".
What about the utility to have both conditioner? 
Also, the swap of the fuses will void the warranty on the equipment? 

Be warned, power conditioners tend to rob some of the dynamics & limit current in amps.
The ones that don't, usually have massively large transformers & cost much more than the Furman.
Unless it has a lot of capacitance, which these do. Simply putting a great big cap on your AC will improve dynamics and bass like you won't believe. The problem is it needs to be carefully designed, or else filling all that will draw so much current it blows breakers - which already happened to kijanki see his comments above. 
How big of a capacitor across the AC line Millercarbon?  Since you say careful design can you tell us what that value is?
Trying to figure out if you know absolutely nothing about capacitors, or know a little but just aren't thinking, or are another one of these guys trying to take a jab at me. Read my post, read kijanki, think about it.
Well I don’t think I am pretty certain you have no idea what size the capacitor needs to be. That capacitor in the Furman is fairly useless other than for higher frequency EMI which it will help. It’s voltage tracks AC voltage and is only above the reflected voltage of the power supply capacitors for a short period of time.

That capacitor is going to be at most about 200uF. That’s a physically large cap. Probably its more like 100uf. Peak AC voltage on 120V is 168. Let’s say we have a DC rail on a linear supply of 40v. At best, that 200uF is like 168^2 / 40^2 = 3500uF added to the amp DC rail. Most good amps have far more than that. Because the current transfer is only for short period where reflected AC on the cap is above DC the effective adder in uF is effectively maybe 1/2 that and practically much less.

But hey, why don’t you tell us how it works.

Now if your amp has a switching power supply, then yes this will help, not in power delivery but reduced EMI especially if that power supply already has active power factor correction.
Based on what i got from all the posts, this is what i've done :
From the panel, i got a dedicated line with Romex NMB Cable 6/3 wire. Then i bought a SYNERGISTIC Research Blue HC 1.5M Power Cable from the wall to the Furman ELITE-15 PF I, than i bought some decent quality 10 awg power cable for all my equipement plug at the Furman Power Conditioner. Do i miss something?
That's a great solution. Especially the 6/3 and Synergistic PC. The "decent quality 10awg power cable" you can always upgrade those later.