Large capacitor across mains: any sonic advantage for line conditioning?

[Pano]

That's an unsualy good analogy. Thanks.

 

[simon7000]

The cap is not a frequency dependent voltage divider. It is half a frequency dependent voltage divider. The other half is the mains impedance.

Noise source impedance plus mains impedance in parallel with load impedance, all at noise frequency.

 

[ygg-it]

Thanks for all inputs.

I decided to include 4.7 uF before and after the isolation transformers in my power line conditioner.

I don't see any issue yet and I like a little bit the resulting sound effect in my audio chain.

 

[ApolloZhang]

Headphone systems could be potentially more sensitive to those shunt caps. I used about 3uF between live and neutral, the background's lot darker, overall less aggressive. But I would avoid inductive filtering like coils with magnetic core. They usually make harsh sounds.


Also I remember that some expensive power conditioners, perhaps from shunyata Research, used like 20uF of film caps across L N.

 

[DF96]

Speaking of sound quality and line conditioning, I have found that a 2.5k R across line and neutral to lower the noise floor, when located near the device, is a ham radio trick I picked up.

That sounds more like an old wive's tale than a ham radio trick.

 

[ApolloZhang]

That sounds more like an old wive's tale than a ham radio trick.

The resistor could just damped the series resonance between the transformer's primary inductance and what-so-ever in his mains setup.


See this Link: Mains DC and Transformers ,figure 7.

 

[ygg-it]

So the thermal part is spread out over the inductance/cabling, makes sense now.
Please forgive my ignorance as to thinking that would have been isolated to the cap in question...
Speaking of sound quality and line conditioning, I have found that a 2.5k R across line and neutral to lower the noise floor, when located near the device, is a ham radio trick I picked up.
That could be a 7w incandescent bulb. Am guessing that there is a damping effect, haven’t got out the scope to try and make a visual.
Most of the line conditioning i have tried is like the cleaner-wax you get for your car, polishes a little bit but won’t take out any deep scratches.

Interesting... I have to experiment it !!

I suppose I have to put 10K ohm as I have 220 V to get your 5W dummy load.

 

[DF96]

The resistor could just damped the series resonance between the transformer's primary inductance and what-so-ever in his mains setup.

Does he have a DC blocker? If not, there is no series resonance to damp.

 

[phase]

No dc blocking or anything in series.
Both cases are smaller, 30va.

Don’t care much if you choose to try it or not really, but if it works for you, then thank some ham operator in the Midwest....

 

[Bigun]

For some Ham frequencies is it possible that the power line is inductive?

 

[DF96]

Ham operators are as prone to believing and propagating nonsense as audio people, although most ham nonsense is related to antennas and transmission lines.

 

[phase]

I think I have what would be a resonant circuit with different values, as there are X capacitors inside my DACs.
You figure out what the opposite of a resonant circuit is, maybe?

 

[danielwritesbac]

Large caps are well used for driving speakers. Be mindful! When we use parts on purpose, they'll work much better. Did you want that? Ask your tech. As a tech, I have to report that we have suffered some iodicy, appreciated some cussouts, and this matter is like an everyday thing. So, ask your tech.
Honestly, ask them. It'll be such fun for them and they won't admit it.

 

[phase]

I work with a bunch of PhDs, EEs, Physicists, and the like, will have to get some perspective when there’s time. The techs will give you a textbook answer usually, with the primary effect noted, likely in the context of a product or system that is familiar to them.
We are all pretty busy with multiple projects though, and honestly, nearly all of them are more interesting than this, and I don’t really care that much myself to quantify it, if that isn’t obvious by now...

 

[DF96]

PhDs, EEs, Physicists, [Hams]

I can tick four of those boxes.

 

[danielwritesbac]

In a split rail supply, those caps are in series; so, to meet the needs of a reasonably high performance speaker (an output cap would have to do at least 6600u for one 8 ohm speaker), then we have a volume. That is 6600u if single rail, for an ordinary speaker. On your supply, you'd need four times that, as in four of 6600u for a split rail supply. That matter is quite simple!
I'll admit that it is also inconvenient, as in bulky.
It would be great to replace that bulk with clever circuits; however, I find the baseline of immense value. We do need something to face off; and it goes better when that's really hard to do.

 

[trobbins]

The concept of shunting your mains supply at your 'sensitive' hifi equipment connection point is that all manner of spike and transient currents generated throughout the house, or even external, will preferentially circulate along the mains cable path to your equipment. Your equipment is then likely to need more noise filtering than you first envisaged!

 

[Speedskater]

Hello,
...................................
Second, if you were to put this across the line voltage, need to add a bleeder resistor such that the cap gets discharged when the power is off. Otherwise it could be setting there with voltage across it and shock you badly.
................................

The only way that could happen is if you disconnect the load downstream, when you disconnect the power upstream.

 

[mchambin]

With a cap large enough it will be as good, if not better, as an UPS.