Power factor correction implementation?

For example Meitner Dacs. How is it achieved without external boxes
Isn't it as simple as using a power factor correction capacitor?

power factor correction in DACs? They consume very little current compared to a power amp that the benefit of doing PFC on a DAC by the manuf is probably not very beneficial to the utility company.
Or, am I missing something here??
Such devices would most likely use what is referred to as "passive" power factor correction - typically using some kind of passive network with one or more inductors and capacitors.

The most effective means for power factor correction is active power factor correction, which requires an impedance matching network (e.g., using var caps or other mechanism for matching the impedance of the load.) This solution, however, is more expensive and complex, and there is a question as to how much of an audible difference this would make in audio applications, particularly for line level components. (By contrast, in designing amplifiers for powering plasma chambers for thin film deposition, active power factor correction is a matter of necessity - a couple kW of reflected power is not the healthiest thing for your amp).

Rzado, power factor correction can be "Immense". Once you hear the dynamics and nuance revealed when power and current are in phase--you will remember it.
Refining the question. Technically, how is the true power versus apparent factor calculated and corrected for, within the player, for differences in the power source in various locations. Is there an automated tracking device,an oscilloscope comparing the waveforms and automatically calculating the the ideal capacitor size? Or?
Hi Ptss,

First, I certainly did not mean to imply that active power factor correction could not have an audible effect, just that there is not a whole lot of consensus on this point in the audio context - and I certainly tried to note that it can make a measurable difference. However, I am curious as to which components you considered that include active power factor correction that led to your view that the difference is "immense".

As to your more particular question, I am not sure what you are asking, particularly when you refer to the "player". To the extent I understand it, in active power factor correction you have a circuit that measures the impedance of the load (no need for an oscilloscope per se), and then via a conventional feedback loop adjusts the value of the matching network to match that impedance through, e.g., adjusting the capacitance of variable capacitors that are part of the impedance matching network. In very high powered applications, this can involve a rotating shaft that actually rotates the plates that comprise the variable capacitors, but in lower powered applications, there are a number of ways to accomplish the equivalent function.
In industrial use, Power Factor Correction (PFC) is achieved by programmable AC sources, very simply put a frequency generator for high power. They are used when the AC varies a lot and/or low distortion (THD) is required for example, a lab or medical devices. 
PFC units were wide spread till the 80s when clean power was universally available. Not quite sure why Meitner needs one. Anyway, different ways to skin the dirty power cat. 

In the recent years, I have done quite some read up and consequently, testing with power conditioning alternatives. Active ones such as the PS Audio P10 is pretty darn good but sounded solid state IME so I prefer the passive ones like BPT but more so Audience adeptResponse (YMMV).
A year ago I acquired one of the Elgar Ultra Precision Line Conditioners. The 6006B (10A) model can be found used on Ebay; the larger, 3006B is highly recommended by Ralph Karstens of Atmasphere and probably not a easy catch and you need to have the space to put it. In short, the 3006B consists of a double-shielded isolation transformer providing most of the output (70-95%), supplemented by a correction circuitry to achieve a near perfect sinus waveform (<0.2% THD per their brochure!). I am using this front ending the passive power conditioners, iow the adeptResponse that I have in my systems are fed from the Elgar 6006B in the basement (the fan operation is loud).  I would say a small increase in clarity and texture, maybe because I have dedicated lines.

I believe some here on the Gon use an isolation transformer between the box and wall outlet / conditioner with sonic benefits. The Elgar has one built in.
Thanks Jazz, you mentioned "until the 80's when clean power was universally available". My experience is that power 'clean enough' for high end systems,such as my Spectral/MIT reference level gear is not available in the areas I have lived in. It took very minimal experimentation for me to experience the benefits of improved AC power, in every unit used, from sources to amp. And this in spite of Spectral's attention to internal power supplies. I believe the quality of AC through the Oracle series p/c's made it easier to appreciate improvements wrought from isolators/conditioners. 
I'm not certain what, "industrial use" some might be used to, but-  when  doing the PFC, for the factories I contracted, simple capacitor banks were all that was required.   I'm certain there are variables, in design applications, but blanket statements generally prove uninformed. ie: (http://www.nhp.com.au/files/editor_upload/File/Power%20Quality/Introduction-to-Power-Factor-Correcti...)

I too am unsure as to what "industrial use" necessarily connotes, but as you appear to note, variable capacitance is the most common mechanism of achieving power factor correction.  The article you cite notes what common lower powered systems cite as the key benefit of power factor correction- i.e., improved efficiency due to reduction of any mismatch in impedance between the source and the load, thus resulting in more efficient delivery of power to the load.


I don't really agree with the statement "until the 80's when clean power was universally available" - clean power is not universally available now, much less in the 80s, and was certainly variable both then and now based on location and prevailing conditions.  If you are achieving <1% THD on you home power, you are doing pretty well - I have seen anything between 2 and 11% THD.

I also don't follow what you mean by "put a frequency generator for high power" - using a "frequency generator" is not a mechanism for achieving power factor correction - rather, you need a mechanism for matching the impedance of the source to the load, typically using variable capacitors / inductors.  Addressing what I understand to be your further comments, the "perfection" of the sinusoid waveform is not directly related to power factor correction - you can have a great looking AC waveform, but still poor power factor due to significant mismatches between source and load (subject to how the load responds to the reflected power).