No contradiction- the 2 Ohm value is simply not correct. Its likely closer to 0.05 Ohms or the like.
Ralph Karsten's Theory on Voltage and Power Paradigms in Layman's Terms
- Thread starter PeterA
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It is correct - they have measured it and so have I. I'll ask them to offer some explanations.
The issue with the website seems to be solved.
@Atmasphere If you read over the link I mentioned, it clearly states that it is a « quasi constant power steering »:
« The PowerDAC-SX offers quasi constant power steering (OUTPUT POWER IS KEPT MORE OR LESS CONSTANT). Because the output power is kept constant, overload conditions cannot occur. PowerDAC-SX can therefore drive any load from dead short to open circuit without issues. At speaker resonance the output power is kept constant so it won’t boost resonance like a tube amp would. This way the bass is kept perfectly under control.
The PowerDAC-SX has no analogue circuits / components and NO local and NO global feedback loops that could get disrupted. The speaker dynamo voltage therefore CANNOT disrupt the PowerDAC-SX, the result is VERY low distortion and NO coloration regardless of volume setting. »
The solution has its advantages (and all people I know who have actually used it agree on its sonic merits) but also two important restrictions:
- the concept can only work with a digital input, so this means that analog sources have to be converted first. This may not appeal to vinyl lovers, though very few have experience with ADCs (and even fewer with this new “amplifier”)
- maximum output power is limited, so speakers with high sensitivity are required to reach high listening volumes. I’m personally fine with 90db speakers in my living room, but I never blast music, and on a few recordings with high dynamite range the very low volume segments can be an issue. Choice of speaker is key.
As engineers like you are well aware of, the general concepts are one thing, but the devil is in the details, and their current design is already being refined…
@Atmasphere If you read over the link I mentioned, it clearly states that it is a « quasi constant power steering »:
« The PowerDAC-SX offers quasi constant power steering (OUTPUT POWER IS KEPT MORE OR LESS CONSTANT). Because the output power is kept constant, overload conditions cannot occur. PowerDAC-SX can therefore drive any load from dead short to open circuit without issues. At speaker resonance the output power is kept constant so it won’t boost resonance like a tube amp would. This way the bass is kept perfectly under control.
The PowerDAC-SX has no analogue circuits / components and NO local and NO global feedback loops that could get disrupted. The speaker dynamo voltage therefore CANNOT disrupt the PowerDAC-SX, the result is VERY low distortion and NO coloration regardless of volume setting. »
The solution has its advantages (and all people I know who have actually used it agree on its sonic merits) but also two important restrictions:
- the concept can only work with a digital input, so this means that analog sources have to be converted first. This may not appeal to vinyl lovers, though very few have experience with ADCs (and even fewer with this new “amplifier”)
- maximum output power is limited, so speakers with high sensitivity are required to reach high listening volumes. I’m personally fine with 90db speakers in my living room, but I never blast music, and on a few recordings with high dynamite range the very low volume segments can be an issue. Choice of speaker is key.
As engineers like you are well aware of, the general concepts are one thing, but the devil is in the details, and their current design is already being refined…
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All related questions are already answered in this blog on our website:
https://ecdesigns.nl/2024/07/11/no-pre-amplifiers-in-the-signal-path-at-all/
In short:
PowerDAC-SX output impedance equals exactly 2.125 OHms and is pure resistive.
It offers quasi-constant power steering as explained in the blog mentioned above.
Best Regards,
John Brown.
ECdesigns.
So its not 'constant voltage' as I previously had quoted incorrectly ('output voltage stays CONSTANT' was taken from the blog post but apparently out of context).
So this is an example of power paradigm technology. Since it has a higher output impedance, the choice of speaker to be used with it must be done with care (just as with a zero feedback tube amplifier) to prevent tonal anomalies.
I think that amplifier may be a better example of a total BS paradigm technology with respect to the marketing and blogs?
That’s a very disrespectful comment to make. No wonder many people stay away from online forums…
If there are specific points made that you challenge, say so.
I clicked on the link… In here:
There are lots of words, but it seems like a lot of double talk to me.
Maybe I need to look harder at it.
In other words you make zero effort to understand what is explained but feel the need to make a public comment that it is “BS”.
I don’t know, but any educated is welcome. So far, your comments are completly useless and by continuing to post here you are just wasting everyone’s time.
I would be curious to find out more about the point made by Atmasphere regarding potential tonal anomalies, which I have not experienced, afaik, but I have always used it with crossoverless or first-order crossover speakers (so perhaps confirming the point made by RCanelas).
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You can try helping, or you can report it.
I appreciate that the fellow is trying to run a business, but…:
- it takes in Toslink
- has no amplification
- and powers a speaker.
It looks like a power supply with a switching bank behind it.
It cannot be low output impedance or it would supply too much current and be too loud.
So the output impedance would likely rise and fall with the signal falling and rising.
It is either voltage paradigm, a current paradigm, or something else.
And yeah I should C) something else.
The switching bank, from my understanding, is the digital signal bits controlling different value resistors. So you can view it as an « attenuator » instead of an amplifier.
You can read the product manual as well for some more explanations:
They already confirmed that it was a constant current paradigm. If you don’t understand how that is possible, you will find their email address on their website, or you can PM them.
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Or like an R2R DAC without a power supply that is big enough to drive a speaker.
They have the chart on page 6 that shows the output power in watts for 2, 4 and 8 ohms.
The output impedance seems a bit high, so how does it sound?
The power is a bit limited, so I am guessing this is for horn systems and the like with higher than average sensitivity/efficiency?
It is an R2R DAC. A DAC does not drive speakers directly, so the comparison stops there.
See my previous comments.
Sorry - I meant with a power supply bug enough to power speakers.
A handful of resistors is not dissimilar to an R2R.
Crossoverless ('using 'full range' drivers) might imply power paradigm tech. First order crossovers do not.
It amplifies for sure, since taking a small signal and making it bigger is amplification. Put another way, you can't drive a speaker directly with a digital signal, and if I'm not mistaken its possible to change the volume. The system might not be done the way amplification is done in a conventional sense but it is amplification nevertheless.
I am not a technician, but this is my understanding:
The digital signal itself is not amplified.
The digital signal is split into parallel signals corresponding each to a given bit of the digital signal (to minimize the impact of bit errors, the most significant bit is actually split into multiple bits - hence the term “fractal” DAC they coined).
Each bit”s signal controls a gate allowing the power supply to go through (or not) a specific resistor value.
The resulting current that has passed through each gate and resistor is summed and directly powers the speaker drivers.
All the gates are opened/closed using a clock whose frequency is determined based on the incoming digital signal. The clock signal embedded in the Toslink signal is not used/reclocked. The clock signal is completely independant from the Toslink signal.
It is all pretty ingenious!
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Yes- from my perspective, the engineering is better than the marketing. Can you change the volume? If yes, then amplification is occurring.
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