[Navyblue]

About line filters like these: Farnell Export

1. Would I find these in commercial audio products such as CDP?
2. Are these what I would find in low end "power conditioners"? How about those costing big bucks?
3. When using these for audio equipment, would these reduce noise coming from the mains?
4. If the above is true, would I benefit from connecting multiple units in series?
5. Would the inside of these units look like these? Jon_Risch's Web Site

Thanks for reading.

 

[Navyblue]

The answer of question five is in the datasheet (why didn't I thought of that?) which is a yes.

I'd replace it with another question:

6. Would these adversely affect sound quality by limiting current flow and resulting in lower dynamic?

 

[FallenAngel]

1) Yes
2) Yes
3) Yes
4) Don't think so
5) Yes, there is usually a diagram on the unit
6) No, they are rated for much higher current than your equipment can possibly pull (most are at least a few amps).

 

[Navyblue]

So I guess if audio products have built in mains conditioing, commercial mains conditioner would not do much unless it is a more powerful variety or having attenuation properties that complements the built in mains filter?

I have been hearing a high pitch whirring sound from my CDP when my PC is on. It is somewhat softer when my PC is off, but it's still there nonetheless.

Of course being cheap I always felt that those mains conditioner costing thousands are a rip off considering the technology employed, so I'm looking at what I can do in the DIY realm that can rival the best that these products could offer.

 

[FallenAngel]

That's because most "mains conditioners" are complete ripoffs. Just replace the IEC with one of these babies and you're good to go.

http://www.mouser.com/catalog/635/1088.pdf

 

[tangent]

Quote:

Originally Posted by Navyblue /img/forum/go_quote.gif Would I find these in commercial audio products such as CDP?

They're most popular in digital equipment, where they can be necessary to make the device pass RFI conformance tests. (FCC, TUV, CE...) You rarely see them in analog gear because they're just nice to have, not required. $10 in parts becomes $50 in price difference at the register, so it's hard to justify such a thing when not absolutely required.

Quote:

Are these what I would find in low end "power conditioners"?

Pretty much, yes.

Quote:

How about those costing big bucks?

Bigger power conditioners usually just use higher value parts -- more farads, more henries -- to get greater attenuation. They add other niceties, like voltmeters, fuses, spiffy cabling and plugs... Whether all of this is actually beneficial is debatable.

There's two other classes of high-end power conditioners besides the passive ones we're talking about here: balanced power and power regeneration. Totally different deals.

Quote:

When using these for audio equipment, would these reduce noise coming from the mains?

Yes, particularly the higher frequencies; like, your CD player has poor RFI filtering, so you put filtering elsewhere to catch what escapes onto the AC line.

AC line filters do nothing for ground loops and AC line hum, however.

Quote:

would I benefit from connecting multiple units in series?

I'm not sure if you're asking if the effect is audible, or merely electrically doubled. The answers are maybe and yes. Two cascaded passive high- or low-pass filters have an additive effect. Many higher-end AC line filters have a doubled filtering section for this reason. Whether it results in an audible improvement is not something you can predict easily.

 

[Navyblue]

So I guess in most cases a high pass filter would suffice?

I see that there are some of these parts that cost more than the others and claim better attenuation. In some case, price difference is more than 10x;

Earlier on I mentioned connecting in series. partly I was thinking if it would have an effect using these for audio components that already comes with these things, and if I would benefit (at least in theory) by having multiple cheaper units as opposed to one single expensive unit. But I guess multiple different model would make more sense than multiple of the same model.

Forgive me for being so annal, I really wish to do it exactly right the first time.

 

[tangent]

Quote:

Originally Posted by Navyblue /img/forum/go_quote.gif So I guess in most cases a high pass filter would suffice?

Low pass, you mean. And, that's what these filters are: they attenuate high-frequency noise, allowing 50/60 Hz AC go through unimpeded.

Quote:

I see that there are some of these parts that cost more than the others and claim better attenuation.

Undoubtedly true if you're looking at datasheets and not marketing slicks. (Yes, the difference between the two can be narrow at times...but you can't lie outright on a datasheet.

)

Quote:

In some case, price difference is more than 10x;

You may also be seeing a difference in current-handling ability. Thicker wires means greater cost, more mass to be shipped around, bigger box to put it in...

 

[pinkfloyd4ever]

4 words baby: sealed lead acid battery

what are you powering?