Surge Protection

[One and a half]

A Topaz/Xentek/Elgar type isolation transformer is all you need for surge protection. No active reactance getting in the way with the likes of Panamax, Furman/Monster et al.

 

If serious lightning protection is needed, unplug before the storm.

 

I bought an Eaton 9135 2kVA UPS ahead of the Topaz, the sound was about the same as it always was, however during a blackout, the Eaton failed to re-start and died. Other opinions from sites I visit have the same opinion on the Eaton, not all that uninterruptible. Other brands are much the same reliability.

 

The problem is not so much the loss of voltage but when it returns as it usually bounces about, usually higher until it settles down, or a re-closer that attempts to clear trees or branches of faults, typically three shots at applying power in short succession. There needs to be a time of about 30 seconds for the voltage to settle back to normal, then operate equipment.

 

Sources aren't so bad, but if you forget to wind down the amplifiers, be prepared for a loud splat from the speakers. A sequencer is a great idea and avoids that splat.

[One and a half]

3 hours ago, hdo said:

Do they sell low wattage power surge protector? Say, 50 Watt or 100 Watt cut power surge protectors. I tried to find. But I couldn't find from local shops.

 

Devices like that create leakage currents and are detrimental to finding their way to DAC's front end where they goof up timing of clocks. Not recommended.

[One and a half]

When the formula used for line currents to ground (earth) I = V/Z the already pA results with a 0.005pf are close to measuring nothing,  a factor of 1000 is really challenging to measure inaudibility.

 

Z= (2 x pi x f x C) ^ -1

 

f 50 or 60

C capacitance in Farad

V = 230 or 120

 

pf = 10^-12 Farad 

[One and a half]

2 hours ago, jabbr said:

Why would you assume that leakage currents are at only f 50 or 60 ?

There could a problem of definition as to what leakage currents are. Leakage currents are signs of insulation failure at 50/60Hz, classically and these are monitored by legislation/statutes.

 

Nuisance currents, also known as conducted emissions are at higher frequencies than 50/60Hz, and these are not monitored, other than the effects of which are picked up by our ears. Attenuation is higher for these frequencies passing, or trying to pass through a Topaz via grounds. Differential frequencies can still get through.  Line frequencies can end up on the signal conductors, via various backdoors.

[One and a half]

Since EU/US/AU/NZ & other countries ex Japan use the TN system of earthing the neutral, we end up with the mess of leakage current (and conducted emissions at lots for Hz) being transferred to the earth via low impedance connection to the Neutral at the consumer's switchboard. The noise of course ends up on the lower side of the system. (in Grey). A far better idea is to have a high impedance between the earth and neutral IT or TT systems found in France and Japan for audio. That's another application on its own.

 

Even though the Isolation Transformer magnetically isolates the load, yes, the inter-winding capacitance here illustrated as a 0.0005 pf creates the conducted voltage on the other side of the transformer, not 'isolating' truly any more. The current to earth for 120V 60Hz is 22.6 pA. If the Isolation Transformer has a spec of say 100 pf across the windings, then the same current to ground is 4.5 uA. This level of voltage is enough to influence sensitive clock circuits. The load's linear device won't have the properties of the Topaz, so the effective current can still be maintained. So it pays to use the correct type of transformer, if there is one to find!!

 

If any switching device is mounted to the frame in the equipment, the capacitive coupling between the switching device and the frame, can be diode, transistor, IC and so on. The noise voltage of course unless filtered, ends up on the circuits which we hear and creates 'noise flavour' to SQ. 

[One and a half]

12 minutes ago, Speedskater said:

Isolation transformers have nothing to do with surge protection!

You don't read the fine print on the specs of these transformers,  as they are specifically built for surge protection. 

[One and a half]

There are graphs at headfi showing what's left after an impulse of several kV. Before UPS went cheap, the Topaz was the only device that was passive and protected computers,  like the VAX8500 or PDP750.

Common mode noise reduction is 140dB, another bonus. 

[One and a half]

1 hour ago, Ralf11 said:

Like this?

http://www.nextwarehouse.com/item/?285189_g10e

 

I can't tell if it needs to be wired in or not...

Why not visit the manufacturer's site to investigate further instead of asking the obvious, Mr. One Sentence Man.