Power Conditioners: Why different inputs?

[Dialectic]

What about Furman? Anyone has an experience with them?

Furman makes regular MOV surge protectors that seems to be slightly more robust (in terms of build quality and surge protection) than what one would get from Tripp Lite or APC. I have been told by people in areas with a lot of surges that their Furman surge protectors have tended to work slightly better than other MOV surge protectors.

They do not protect against lightning strikes, and because they use MOVs, the protection is sacrificial.

I have a couple of Furman units. One has been trouble-free for 12+ years. In the other (a PST-6), the "Protected" light stopped working after about seven months, which supposedly means it can no longer protect against surges.

Because we live in an area with a lot of surges caused by the power company, I have switched to using three series-mode Zero Surge units on all my expensive stuff. All three of those have been genuinely trouble-free.

 

[Frank Dernie]

I have this Dynavox X7000 power conditioner and it has 6 inputs. Four of them are filtered the manual says, two are unfiltered. The analogue devices need to go in the unfiltered, the digital devices (cd player, dac etc) need to go in the filtered. Can anyone explain why this is? I thought it would have been best if everything is filtered? Filtered = cleaner so especially for the amp, but this is not the case?

It's also the case with the Vincent PF-1 Power Conditioner and probably more? Only Vincent calls it the analogue and digital inputs. The manual can be read here: https://www.vincent-tac.de/fileadmin/pdf/BDA/Powerfilter/BDA_PF-2_DE_EN_FR.pdf

Mine has 3 different types of output.
One pair for power amps with filtering but no power restriction, one set for low level analogue like my preamp and phono stage and a set for digital. They have different sort of filtering for low level analogue and digital.
Having written that the manufacturer subsequently added filters to the actual components in later models so the device is now obsolete.
Most modern electronics will be sensibly filtered to avoid anything nasty getting in from the mains, incompetent/bad engineering if not IMO.

 

[Speedskater]

I have been told by people in areas with a lot of surges that their Furman surge protectors have tended to work slightly better than other MOV surge protectors.

One wonders how 'people' arrive at that conclusion?

 

[Dialectic]

One wonders how 'people' arrive at that conclusion?

Their homes are hit by surges, and the stuff connected to Furman units survives. The stuff connected to other MOV surge protectors does not.

The rudimentary test data that is on the internet is consistent with the anecdotes:

https://www.nytimes.com/wirecutter/reviews/best-surge-protector/
(Ignore the "recommended" units, and look at which unit protected against surges the best.)

Despite the anecdotes and measurements suggesting that they work better than other disposable MOV surge protectors, I don't like Furman surge protectors. The quality control apparently is poor (my PST-6 experience is very common), and I know from installing electrical outlets in my own house that Furman uses inexplicably crappy outlets in its surge protectors.

 

[JohnYang1997]

Noise in AC power line does literally nothing. It will be lost in transformer and any power supply filtering.