Click to view our Accessibility Statement or contact us with accessibility-related questions
Showing 1 of 108 conversations about:
A community member
Apr 12, 2018
bookmark_border
What is the output power?
The specs say 2 Volts. However, that is not a power specification, it is a voltage spec.
Power is defined as volts x amps. Volts x amps = watts.
Basic ohms law. Without the current spec (amps), there is no way to solve for watts when given volts.
As such, the power output is entirely unknown.
In my experience, when a manufacturer tries to obfuscate and/or capitalize on the ignorance of the general public, there is usually something to hide.
Probably not much power at all coming from this unit, though it would be nice to know for sure.
Apr 12, 2018
jaydunndiddit
3262
Apr 13, 2018
bookmark_border
140mW @ 32 Ohm/THD 0.01%.
The full spec sheet is on their website. If anything, you're buying this more for the DAC than the amp.
Apr 13, 2018
CapnCook
43
May 15, 2018
bookmark_border
2 V (prob rms) is likely the rca out. I doubt they were trying to obfuscate...at least not by that specification.
May 15, 2018
A community member
May 16, 2018
bookmark_border
CapnCook2Vrms is NOT a power output specification.
It is a voltage specification.
According to this little something called Ohm's Law, Power is voltage times current.
Without a current spec in addition to a voltage spec there is no way to know the power output of a device.
To help illustrate the concept, a device with 2VRMS output may have less power output than another device with 1 vrms output.
If the device w 1 V rails can push 4 amps of current, it can output 4W of power. If the device with 2 V supply rails can push 1A of current, its power output limit is 2W and thus it is capable of only half the power output of the amp with the 2V rails.
By giving only a voltage spec, then by definition they were obfuscating the power output rating.
Whether this was intentional and what the reasons were is unknown.
They probably figured many people wouldn't know the difference between voltage and power.
Thanks for unwittingly helping to prove part of my point.
May 16, 2018
CapnCook
43
May 16, 2018
bookmark_border
My point was it was probably (or likely as I stated in my OP) for the rca and not the headphone. Thanks for unwittingly showing that anonymity brings out the worst in people.
May 16, 2018
A community member
May 17, 2018
bookmark_border
CapnCooka) if it was in reference to the line out, then my point is still valid. Headphone output power is not given.
b) nothing unwitting about anything I wrote.
May 17, 2018
CapnCook
43
May 17, 2018
bookmark_border
Have a great day.
May 17, 2018
MigratingCoconut
8
Jun 2, 2018
bookmark_border
Current is given by voltage divided by the total impedance/resistance of the circuit, so the maximum power output will depend on what you connect it to. For an example: an 8ohm load with 2V across it will yield 1/2 a Watt of power, which will translate into a volume that's dependent on the sensitivity of your headphones. If there is a current limit to this device, it's probably there for protection against short-circuits, so having a load there probably won't trip it. So it won't change a thing.
Jun 2, 2018
A community member
Jun 2, 2018
bookmark_border
MigratingCoconutCurrent limiting in amplifier design is not limited to protection against shorts. It is often a function of the capabilities of chosen output devices, and current is often limited based upon this as opposed to solely dependent on the load. Not to mention current limiting for thermal management and battery life. Sensitivity/efficiency and the subsequent SPL produced by the headphones is not relevant to the discussion, which was about output power. While there is an element of truth to your example (8 Ohm load, 2V rails), however it is only an accurate example into a dummy load. Impedance is a function of frequency. NOMINAL impedance is an average across the frequency range. The ACTUAL impedance will vary across the frequency spectrum. The amount of variance depends in part on the type of driver (planar and especially electrostatic will have wider swings, with the latter often being less than an ohm at the top of the frequency spectrum). Yes, the current delivered is dependent IN PART upon the load, but that does not mitigate the fact that a voltage spec does not tell you the output power, it is only indicative of the voltage rails available before clipping. The point is that some manufacturers specify a voltage rating instead of a power rating to obfuscate the fact that the power output of their product may be relatively low compared to others, even if the rails are substantial. That was the point of my comment, and nothing you wrote mitigates that point. -B.S. E.E. Florida Institute of Technology; B.S. Audio Engineering, Full Sail University.
Jun 2, 2018
MigratingCoconut
8
Jun 9, 2018
bookmark_border
If artificial current limiting factors are not relevant, why would you need anything more than the impedance and the voltage? Most decent headset have a fairly flat frequency response, with few peaks/lows that are fairly subtle, and that would mean that for a certain output voltage you will get power that varies across the range of frequencies, but that power will also translate into volume in a way that results in that same flat frequency response. Basically, all you care about is the voltage across the headset, their nominal impedance as well as an average Watt/decibel function and you get your volume. Did you mean, then, that the voltage spec specified is not the voltage you'll see across you headphones, or that there is some relevant artificial current limit put in place(for one of the reasons you specified) that would limit the output power?
Jun 9, 2018
A community member
Jun 10, 2018
bookmark_border
MigratingCoconutSir, I suggest you read and comprehend posts before replying to them.
1) I said " Current limiting in amplifier design is not limited to protection against shorts ." I did not say current limiting factors are "not relevant." In fact, I said the opposite. I said (paraphrased) that there were several relevant current limiting factors beyond protection against shorts.
2) "Flat" frequency response is a relative and subjective term, especially if tolerance is not specified; i.e. +/- some number of dB. However, if you look at the peaks and valleys in the frequency response plots of the vast majority of headphones (or speakers, or any other electromechanical audio output transducer for that matter), and you consider that flat, then I postulate you wouldn't know a nice tittie if one motorboated you upside the head. Regardless, frequency response is irrelevant to my point and is not correlated to impedance. And, I would say that speakers and headphones have the widest FR variances of any component in an audio system. I would also say that this doesn't much matter to a large extent and many other factors have a greater impact on perceived fidelity.
3) Again, POWER by definition is voltage times amperage. One does not know the POWER output of an amplifier if only the VOLTAGE is specified. VOLTAGE only tells you the available rails before clipping. It is only part of the story. IMPEDANCE (not frequency response) is the AC approximate equivalent of resistance, and VARIES WITH FREQUENCY. The NOMINAL impedance of a speaker or headphone driver is an AVERAGE across the audible spectrum. At any given frequency, it will vary. Depending on the driver type, the actual impedance at any given frequency may vary significantly from the NOMINAL or average rating given. For example, my Martin Logan electrostatic speakers have a NOMINAL impedance of 8 ohms. But, this varies widely across the spectrum and at the upper frequencies the impedance is as low as 1/2 ohm. This is part of the reason why power testing into a dummy load such as an 8 ohm power resistor does not always translate well to an actual load. It is true that if there were no limiting factors upon current in an amplifier design, then one could derive the output power from the voltage rails and the impedance of the load, at least at a given frequency. But amplifiers often have many design constraints that limit the output current and thus prevent a given voltage from delivering the maximum theoretical amount of current into a given load. These can be power supply limitations, output device limitations, thermal protection, battery management, etc.
Unfortunately, I don't have the time to teach an engineering course here, so if you have further questions I suggest enrolling in a basic electronics course at your local community college.
Jun 10, 2018
MigratingCoconut
8
Jun 10, 2018
bookmark_border
Would the current limiting factors of the amifying circuit really matter that much with a headset? Considering most heasets I've seen have a nominal impedence of 50 Ohm or more, you should expect a current of 0.02A on average. Are the current limits you can expect from an amplifying circuit really that small, and does impedence vary so much that the current will ever get to a significantly higher level?
Jun 10, 2018
View Full Discussion
Related Products