Windows 7 sp1

[Miska]

Surge protection is pretty much useless in my opinion - it may protect your system once, perhaps even twice, but after that you have to replace the dang thing- it's just a power strip.

 

It's rather cheap to replace as needed, compared to fixing broken electronics.

 

Cheap accessories like this work quite well based on what I've been using:

http://www.apc.com/products/resource/include/techspec_index.cfm?base_sku=PF8VNT3%2DGR

For this, they have more detailed filtering specs too.

 

And for UPS these kind of things have been working well for computers:

http://www.apc.com/products/resource/include/techspec_index.cfm?base_sku=BR900GI&total_watts=200

Here the filtering is defined just as "Full time multi-pole noise filtering : 5% IEEE surge let-through : zero clamping response time : meets UL 1449"

 

[Miska]

Not merely useless (as I pointed out previously, the protection circuits are most often too slow to stop the most damaging surges, such as those caused by lightning) but actively harmful to the sound - it is the job of surge protection, after all, to stop steep transients.

 

What would be the mechanism for harming the sound? The PSU in my analog electronics contain enough capacitance to keep the device playing music for ~10 seconds after flipping the power switch. The time constants on those protection devices are much shorter. (thus the audio equipment is always running out of it's internal charge and not directly from the mains)

 

 

[Paul R]

... and you don't know it.

 

This exact model

 

(http://www.apc.com/products/resource/include/techspec_index.cfm?base_sku=BR1300G&total_watts=200)

 

not only got fried in a recent power event at my house, but also let the equipment on the filtered end (including a Mac Mini) get fried too.

 

What's really sad is I knew better - my computer gear - the stuff I make money money with - is on dual conversion UPS systems and nothing at all was damaged.

 

Yes, APC is covering the damage (sort of) but, I would far rather have not had any equipment damaged at all, even if the battery backup unit was destroyed.

 

 

-Paul

 

 

 

[Miska]

It's not cheap if it is blown... ... and you don't know it.

 

I have one or two that have discontinued their work contract, by the "protection" LED going off. So far the devices have been working as advertised.

 

But if possible, online-UPS should be better. But when using online-UPS with audio equipment extra care should be taken to check that the waveform it generates is actually clean. There are lot of bad inverter designs where the generated waveform is really really far from a pure sinewave. Spectrum analysis helps. For computers anyway running off a switching PSU it doesn't matter that much.

 

 

[Jud]

Miska writes:

 

What would be the mechanism for harming the sound?

 

What would be the mechanism for not allowing a surge in current through to your electronics?

 

And what would be the means of getting the protection circuit to distinguish between a surge "asked for" by the amp to follow a steep transient, versus an "unrequested" one sent by the power company?

 

(This is assuming the circuit works in the first place. As Paul's story anecdotally confirms, the cheaper consumer level gear for the most part is less real electronic protection than a small insurance policy included in the sales price. Simple actuarial tables tell the company how much they need to add to the price to more than cover payouts.)

 

[Jud]

Miska writes:

 

But when using online-UPS with audio equipment extra care should be taken to check that the waveform it generates is actually clean. There are lot of bad inverter designs where the generated waveform is really really far from a pure sinewave. Spectrum analysis helps. For computers anyway running off a switching PSU it doesn't matter that much.

 

I'd be very curious to know how the equipment I linked to earlier in the thread would compare sonically and in measurements to what you currently run.

 

OTOH, I don't expect you to fork over nearly $300 to satisfy my curiosity, even if the company does have a try-and-return policy. :-)

 

BTW, I'm interested in giving HQPlayer a good listen, but wasn't able to get sound from it when I last tried. I'll make another attempt soon, perhaps this weekend (maybe the 100ms delay setting you mention on the web site will help).

 

[Miska]

And what would be the means of getting the protection circuit to distinguish between a surge "asked for" by the amp to follow a steep transient, versus an "unrequested" one sent by the power company?

 

Mains here is 230V 50Hz, anything exceeding that boundary is clearly unwanted. This is fed through transformer, rectifier, filtered with capacitors and regulated to create smooth DC voltage. Any variation in that smooth flat DC power is unwanted.

 

Now the audio circuitry works on the audio signal and assumes that the DC power rails remain absolutely perfect, without any variation regardless what kind of signal is fed to the input. Circuit itself should be also insensitive to possible DC power rail variations (PSRR), because any noise it lets through creates noise modulation.

 

Thus, in my devices, in my normal listening conditions, the DC power rail remains within the specified boundaries for ten seconds after the AC power feed has been cut, that defines the robustness of that DC power.

 

Some strong surges or RF noise on AC power feed could cause variations on the absolute quietness of the DC power rails. For my own electronics due to internal filtering, practically lightning is the only thing that could interfere. But with less filtered PSUs (like typical power amplifier stages) strong transients from mains could get through the transformer, rectifiers and filtering capacitors to the DC rails causing interference (noise modulation or other).

 

Standard base line (FCC, CE) in any equipment is that it is supposed to reject incoming interference coming from AC mains, and not cause any interference back to the AC mains. And same for any other connections it may have.