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on December 2, 2015
I read a lot of the reviews of this little amp before buying a couple to try out for myself.

What struck me about the reviews was that there were a lot of people who gave the unit five stars and were completely satisfied with what you get for the very low price. But then there were quite a few one-star reviews where people said that the amplifier didn't actually amplify the signal at all.

There were also various reviews in between those extremes, and complaints that the 1/4" TRS jacks were unreliable or mis-sized such that you couldn't get reliable contact or even had to have the plug inserted partway into the jack to get proper stereo.

Further, this amp was, naturally, compared to the very similar Behringer HA400 also sold here on Amazon:

 Behringer HA400 4-Channel Stereo Headphone Amplifier

Many reviewers were perfectly happy with the Behringer, but found the Pyle to be substandard or completely useless for their application.

I already had one of the Behringer HA400s and have been using it for several years. But I needed another similar amp and figured I'd give the Pyle a try despite the higher percentage of negative reviews. (The Behringer also has some negative reviews, but they're easier to dismiss for reasons I'll get into further on).

Many of the complaints common to both the Behringer and this Pyle are about poor contact with the 1/4" TRS jacks that both of these units have. My experience with the Behringer has been that because I am using it with headphones and an input cable that use 1/8" TRS plugs, I had to purchase adapters to make the transition between the two sized connectors.

I tried two different brands/makes of adapters and found both of them to be completely worthless. They were intermittent at best, sized incorrectly on both the 1/4" outsides and their 1/8" insides. It was extremely frustrating to say the least! You'd have to hold the headphones' plug at some angle and pull it out slightly to get it to make contact. Or in some cases there was no way to achieve contact. It was shocking that such adapters would even be sold, for any price, no matter how low.

I finally ordered some adapters from Parts Express (another seller here on Amazon), but I had to go directly to them because these adapters were not an item that they sold here (at least at that time). The ones I got there have been flawless. They fit the amplifier perfectly and they fit the headphones and my input cable perfectly as well. And they make good, solid, reliable contact with zero fiddling.

Since I got those "good" adapters, I have had zero problems with the Behringer amplifier. And it's done its job very well.

I think my application is a lot like many people here have described. I have a cable running from our home entertainment system back to the couch where we usually sit when watching TV or listening to something, and the little headphone amp is there, in a console in the couch, and we have several sets of headphones plugged into it so everyone can set their own listening level. Mostly, my wife and I use this setup when we're watching or listening alone and don't want to disturb the other person when they're sleeping, reading, listening to something else on their tablet, etc.

And most people doing this will find that their headphones and whatever they're feeding the amp with will NOT have a 1/4" TRS plug on it. So they'll need adapters. So I attribute many of the bad reviews of both of these amplifiers to the adapters that many of these people are probably using. I know I had burning heck with this issue, but I knew that it was the fault of the adapters because I also had some "real" 1/4" TRS connectors that mated perfectly with the amp itself.

Of course, it is possible that people are getting amplifiers with poor 1/4" jacks. So I can't dismiss all of the bad reviews entirely as it really being bad adapters, but, after my bad experience with several different adapters, I suspect that's the problem with many of them.

So now we move on to the poor reviews of this amp that claim that the amplifier doesn't actually amplify the signal. And you get clipping before the headphones are putting out a loud enough level.

I have disassembled and traced the circuitry for both the Behringer HA400 and this Pyle PHA40, and drawn up schematics of what's inside.

I was sort of surprised to find that the circuits are virtually identical! Someone reverse engineered someone else's OR this is a "cookbook" design found in one of the semiconductor manufacturer's datasheets for the OP amp that both unit use (the ubiquitous 4580 dual op amp).

The ONLY difference between the two is that one unit uses a 22pF compensation cap from the output to the inverting input of each amp section while the other unit uses 20pF caps. That is purely a matter of that value being more readily available, I'm sure. It would have an almost unmeasurable effect on the performance - the difference is probably less than the tolerance of the parts, actually.

Seriously. The circuits are the same. The same OP Amps, the same, exact topology, and the same values of each and every component.

BUT... And this is what I discovered in my Pyle unit that makes me think I've found the reason for the "this amp has no gain" type reviews.

In both the Behringer and the Pyle, a 47 Ohm resistor is placed between the output pin of the amplifier and the connection to the headphones. This introduces some isolation to protect the amplifier and help assure stability with a variety of loads. These little Op Amps don't really have enough output current capability to properly drive low impedance headphones. They wouldn't be my choice for a headphone amplifier output stage. But they're inexpensive, and this setup does work, even if it's not really the ideal way of doing things.

And a lot of other things aren't ideal about this design. But remember that you're getting a four output headphone amplifier with enclosure and wall cube for between $16 and $25 depending on the one you choose. You'd be hard-pressed to buy the enclosure, connectors, pots, and other components, let alone the PCB for that money. So we've got to keep in mind what we're dealing with here.

Anyhow, the circuit boards in both units have the component values silkscreened onto them. In the Behringer, the actual values are shown. In the Pyle, the "codes" for the values are shown (this probably makes it easier for anyone assembling the unit to get things right even if they aren't trained to know what those codes found on the components actually mean).

In the Behringer amp of mine, these output isolation resistors are, indeed, 47 ohms. But in my Pyle unit, even though the PC board is silkscreened with "470" (which, being the code for the value actually means 47 times ten to the 0 power - or 47 Ohms), the components actually installed are all marked "471" which means 47 times ten to the 1st power or 470 Ohms. And, indeed, when measured with an Ohmmeter, they are actually 470 Ohm resistors.

Now, unless someone changed their mind about the design after they laid out the PC board and put "470" on the silkscreen, this is an error. I've got output isolation resistors that are ten times the design value!

Now, ideally, any amplifier driving a speaker will have as low of an output impedance as possible in order to have good "damping factor". Damping factor is really the ratio of amplifier output impedance to speaker impedance. And what this tells you is how well the amplifier will be able to control the motion of the speaker cone. The higher the damping factor, the better. We want the amplifier to be able to impress its "will" upon the speaker. The lower the amplifier's output impedance, the more accurately it can control the voltage appearing at the speaker terminals and thus, the current through the speaker voice coil, and therefore, the motion of the speaker.

When the amplifier output impedance is high with respect to the speaker impedance, the speaker is more free to move on the basis of its inertia. A speaker is a device that converts current through a coil into movement. And the speaker cone and coil assembly always has some mass. Further, to move air, it must create force with which to push or pull on that air. None of this can be done accurately if the amplifier's output impedance is high.

The 47 Ohm resistance is bad enough. But having 470 Ohms in that position is ten times worse.

Further, as you might imagine, with ten times the output impedance, the amplifier will be very hard pressed to deliver much voltage to the speaker if that speaker has a low impedance. The combination of this output resistor and the speaker impedance (speaker in the headphones) creates a voltage divider.

Let's say we've got a set of headphones with an impedance of 8 Ohms (yes, they exist). The voltage delivered to that 8 Ohm speaker will be 0.0167 times what the amplifier IC is actually trying to put out! So right off the bat, you've only got about 1/60th of the signal level! Of course, even the 47 Ohm (correct) resistor will be creating a divider that is cutting you down to about 1/7th of the voltage that the amplifier IC is trying to put out.

Now, if we've got a set of headphones with a higher impedance (as is often the case), then this voltage division will be proportionally less. So people who use this amp with higher impedance headphones may not notice any problem. The unit delivers enough voltage to the headphones to operate them well enough.

Of course, another variable is the efficiency of the headphones. Some may not require much power to deliver quite high sound pressure levels to your ears. While others may be very inefficient and require a lot more power to deliver that same sound pressure level. So the impedance along with the efficiency of the headphones someone uses with one of these amplifiers will play a large part in how they perceive both of these amplifiers. But especially if they get one of these Pyles, and it has the 470 Ohm resistors installed.

I've got a pair of Sennheiser HD201 headphones that I use for TV watching. These are not high-end phones. They're just what I use to watch TV. I've tried them on both the Pyle and the Behringer, and I got adequate volume level out of them on the Pyle. I'm sure I had to turn it up a bit further, but it was acceptable. These headphones are rated at 24 Ohms, with a sensitivity rating of 108dB SPL. Headphones are rated for sensitivity (efficiency) as the sound pressure level achieved with 1 milliwatt of power delivered to them.

Now this gets a bit complex because the impedance of the headphone speaker will enter into the equation to determine the power delivered to that speaker for any given voltage applied across the coil. And this all interacts with the output impedance of the amplifier to determine how loud any given headset will play with one of these amps.

But the simple version is this: If you have high sensitivity and high impedance in your headphones, you won't be bothered by the 470 Ohm resistors. The lower the sensitivity and impedance, the more likely you are to find the 470 Ohm output impedance of this amplifier to be a problem.

Also, I don't know if someone changed the design of this Pyle amp and didn't change the silkscreen legend on the PC boards, OR if the one I (and perhaps many others) got was actually manufactured incorrectly, and it's really supposed to have the 47 Ohm resistors in that position, the way my Behringer does and the way the PC board legend indicates my Pyle SHOULD have. Beats me, but it seems like a manufacturing error.

There are other complexities to all of this as well.

In both of these amplifiers (remember, I said the circuits are identical) they use a 100 uF capacitor to block the DC path from the common (sleeve, negative) terminal on each headphone jack from system ground. This cap is, therefore, common to both of the stereo channels. It saves them four capacitors per amplifier over the more traditional capacitor coupling method of using one capacitor on the output of each amplifier channel. But it also introduces some crosstalk at low frequencies between the two stereo channels. Whether you can hear this or not is questionable, however, because we tend NOT to get much location information from low frequencies anyhow, and that is, for example, why you can get away with a single subwoofer in a system. You really don't care where those low frequencies are coming from because you can't really tell anyhow. So this is a sneaky, yet clever way to save some money.

But the real point is kind of strange. Because you've got a 100uF cap in the signal path, you've introduced a high-pass filter into the system. But the amount of filtering will depend on, you guessed it, the impedance of the headphones to some extent.

And somewhat ironically, using the 470 Ohm output resistor actually lessens the effect of this low pass filtering. The amps that have these "undesirable" 470 Ohm resistors may actually deliver better low bass than the ones with the 47 Ohm resistor because the effect of the capacitive reactance of this small cap will be less of the total signal loss in the systems with the higher value output resistors.

But, of course, on the flip side, you've got far worse damping factor, so the bass may be more prominent yet less "well controlled".

Anyhow, there's a lot to all of this, and the things I take away from all of this are:

These are NOT audiophile amplifiers. But they're not intended to be. They're meant to do a job and do it for cheap.

The complaints of no or little gain with these Pyles may very well be due to a manufacturing error where they've put 470 Ohm (marked 471) resistors in the output circuits of some or all of the Pyles. Or the manufacturer may have done this on purpose, but that seems like a bad idea. But in either case, this may well be why we don't see those same complaints of "no gain" in the reviews for the Behringer units.

These amps are incredibly inexpensive. And I've gotten great use from the Behringer unit of mine. Now that I know that the circuits are identical, but my Pyle has what appears to me to be the wrong value of output isolation resistors, I may well solder in what I believe to be the correct 47 Ohm resistors in my two Pyles so they'll actually be identical to the Behringer which I've enjoyed for several years.

Doing this will obviously void any manufacturer warranty, but really, on a $16 device, do I care? Plus, I know the design works and is reliable with the 47 Ohm resistors in place because my Behringer has worked flawlessly for me over these several years that I've had it. And I leave it on 24/7. So the complaints about these units not having a power switch seem a bit silly to me. The wall wart is likely going to waste more energy due to losses in the cheap transformer even if you DID switch power off at the amplifier anyhow. So either way, if you're trying to save the earth by switching one of these units off, you've got to unplug the wall cube anyhow. I'm too lazy for that. Besides, the "waste" heat all goes into my house anyhow, and its COLD outside right now. So it's not wasted at all. :)

I know all of this discussion is going to bring out the desire among us audio nuts to modify these amps to make them sound better. And I fully understand that urge. But I'm not sure I'll do much of anything to mine other than put in the "correct" value resistors in the outputs. If I was going to build a good headphone amp, I wouldn't start with this design, or case, or power supply... So I kind of think this is one of those instances where ignorance is bliss. And leaving well enough alone might make more sense.

Then again, I also fully understand the urge to do just a bit of "tweaking" of things to eek out a bit better sound.

The photos I've attached show the bottom of the PC board out of the Pyle. One is the overall shot, and the other a close-in crop showing one set of these "incorrect" resistors with the 470 legend silkscreened onto the board but with the 471 resistors installed.

Again, the silkscreen for all of the other components on the Pyle PCB show the "code" for the component value. So even though the board says "470" and has a 470 Ohm resistor installed, this still appears to be an error.
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on September 6, 2013
I bought this headphone amp to split the signal from my audio interface to multiple headphones, and to plug my headphones into my TV. It works perfectly for both applications. Just take the headphone-out from any device (computer, receiver, interface, etc.) and plug it in into the input on the Pyle-Pro with a stereo 1/4 inch cable (or 3.5mm to 1/4 inch adapter). The signal is then split into 4 outputs where you can adjust the volume independently for each. Simple as that.

For devices without a headphone jack (such as my TV) an RCA to 1/4 inch adapter can be used to send audio to the Pyle-Pro.

Some things I like about the Pyle-Pro are:
1) It's small. Really small. Smaller than my LG cell phone. For those worried about it moving or slipping, a little bit of velcro, or even blue sticky, tack should solve that.
2) The sound. This thing sounds great (maybe not Audiophile-great, but it's quiet and accurate), and it gets LOUD. So loud that I haven't turned the volume to max for fear of going deaf. Even using a pair of Grado Alessandro MS-1s, which are hard to drive, I find it painfully loud at about 3/4 volume.
3)The price. For less than $20 shipped I couldn't ask for anything more. This thing provides a lot of power, splits it 4 ways, and has a small footprint. Definitely worth the money.

What I don't like:
1) No on/off switch. It's nothing to nitpick over, but you have to unplug it to power it down. For me it's fine, but for some it may be an inconvenience.
2) The LED. The red light when it powers on is a little bright. Not obnoxious, but a little bright.

All in all this is a wonderful purchase. I wouldn't hesitate to buy another one.
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on November 8, 2016
I had a Rolls 4-output headphone amp for over 10 years that finally started shorting out on me. Knowing it was time to find a replacement, I opted to do a little research and find a headphone amp that was cheap. I really don't have any needs beyond 4 TRS-1/4" outputs.

I certainly was interested in this PHA40 headphone amp since the price was a steal. And I'm familiar with the Pyle brand, having purchased their hardware in the past. But the real question was: Is an $18 headphone amp really going to cut it?

The first issue I had in researching this Pyle headphone amp was the rather odd reviews left by some other customers. Clearly they aren't using 1/4" equipped headphones or even in some cases, an audio source that uses a 1/4" output. There's lots of talk of buying 1/8" -> 1/4" adapters in other reviews, which is a little strange (but certainly doable). So those don't directly reflect the more typical use case of running a headphone-out from a mixer or amplifier to this headphone amp and splitting it up to 4 pairs of headphones.

After reading the customer review written by "J-sigmo", pointing out the similarities in the board used in both the Pyle and Berhinger headphone amps, it was almost a no-brainer to go with the Pyle. So I ordered it.

This headphone amp works flawlessly. There is absolutely zero line noise produced by the unit and each headphone output gets a significant boost in volume when cranking the volume knobs.

What else do you need? This is a no-brainer purchase if you're in need of a headphone amp.
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on January 20, 2015
I believe several of the negative reviews should be taken with a grain of salt. Likely some of the users are simply not connecting things properly (e.g. several comments about only the left channel working suggest plugs not fully inserted, likely the 3.5mm plug is not completely inserted into the 6.3mm adapter, as many of the adapters require significant force to make the correct connection). I do sympathize with users who have legitimate problems with non-functioning units, as the price is so low as to make shipping costs for repair or replacement hardly worth the bother. But then, we should be happy that the price is so low!

This is a low-power unit, not intended for speakers, and not really great with low-impedance (e.g. 8-ohm) headphones. Even with 32-ohm and higher headphones, you will likely be disappointed if you want to really crank up the volume to eardrum-splitting levels, particularly with several headsets. The user guide states that the output impedance is 80 ohms, but in fact it's at least 470 ohms, because there is a 470 ohm resistor in line with each output connector (I made oscilloscope measurements, and opened the mixer to visually confirm the resistance) That will seriously limit the current to the headphones (but that's necessary, because the very tiny integrated circuits could otherwise overheat), and for inefficient headphones with very low impedance, will likely give somewhat muddy bass and noticeable distortion at even moderate sound levels.

BUT - what do you think you are getting for less than 20 bucks? This is a very capable device, producing quality sound at moderate levels with appropriate headphones. Mine is well-constructed, no issues at all. I can barely detect a miniscule amount of noise when there is no input and the volume is cranked all the way up, and with 100 ohm headphones the volume level is very satisfactory and the sound is very clean. If I were an audio professional, I might look for something with better capabilities, but I would be paying a lot more for that, and I have no need for it. Five stars.
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on November 21, 2013
I have to start off this review by addressing several of the one-star reviews that this device as woefully underpowered for their use. Most of them have apparently tried to connect this device to speakers, which it will not be able to drive at all.

This is a **headphone** amplifier and when used as such it will be more than loud enough. If you need a speaker (or PA) system, look at other products. This is only for people wanting to boost and/or split their headphone output.

Now, I agree with one-star reviews if you have a channel (it tends to be channel #1) that only provides static when used with headphones and there are a couple of those reviews out there. Luckily, all four channels on my device work flawlessly. If I lose a channel, this review (and the star rating I give it) will be adjusted accordingly. That being said, I'd still give this about four stars with a channel not working because I don't need four channels... I only need two. Anyway, on with the review.

BOTTOM LINE - A great little device that amplifies stereo input for headphones (AND) allows you to split the output into four seperate stereo channels, each with it's own volume control.

NOTE: This plays very nicely with the Hosa MHE325 Female TRS 1/8-Inch to Male TRS 1/4-Inch Headphone Adaper Cable (25 ft, ~$10) which allows you to position the box where you need it (i.e. near the TV) and gives you extra cord to reach across a room. You'll want one of these cables per channel (unless you want to use a splitter at the end)

Pro's
- Powerful & Compact
- Single-Channel Input to (up to) 4 channel (HEADPHONE level) output
- Individual volume controls for each channel
- Price
- Solid construction
- NOT battery powered

Con's
- Bright Red LED
- Always On

Review: I purchased this, like a lot of other reviewers to amplify sound from our television's audio out port to headphones.

We were using a long cable with a series of adapters and a splitter so we could have two sets of headphones and listen to the television quietly after the kiddos were in bed. Since our TV output is RCA, we needed to convert that to a 1/8" (female) stereo plug and then add in a splitter. Since the audio on the TV was a "line-out" port, we had no control over the volume and it was just barely loud enough to hear anything.

I eventually got frustrated with not hearing half of the conversations on our favorite programs and began to look for a full receiver that had a headphone output on the front that I could use. I really didn't cherish having to drop a couple of hundred dollars on a speaker system I'd hardly use.

I stumbled across this item by chance and decided at the low price point I'd give it a shot. I was very pleasantly surprised with the outcome. The box is very small and well constructed. It's very powerful (only needed the channel turned up less than a quarter of the way to hear it very loud and clear through our headphones).

My only real complaint is the little red LED on the front of the box is so bright, it distracts when the lights in the room are out and we are watching TV. I used a small piece of black electrical tape to cover it up and it's much better. Another minor gripe is the fact that there is no on-off switch so it's always on... but since my DVR is always on, this is a minor concern. We also plugged ours into our surge protector (which is highly recommended when working with sound equipment).

All in all, this is a wonderful little device that will definitely work nicely as a headphone amplifier and channel splitter. If you are need of something like this... Pyle has you covered.

If you are looking for something to power speakers, don't buy this. Look for a good PA system instead.
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on September 30, 2016
I work on a small office with a bank of three cubicles. We recently started a tradition in our division of playing music on Fridays.

We use the Pyle-Pro PHA40 to split the output of my iPod, iPad or iPhone into three individual signals that run to speakers on our desks. The amplifier ensures that we don't lose signal strength like we would if we just used splitters. We also each have independent control of our volume on both our desk speakers and the amplifier itself.

I've also tested this with what it was actually designed for: headphones. The sound is very clear when listening to songs played from my iPod. You can definitely tell a positive difference between the amplified output and the standard output from the iPod. This unit is pretty bare-bones, but it has anything you need to faithfully split your signal.
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on January 14, 2016
This would be a very nice headphone amplifier except for one problem. Each of the 4x2 channels is basically a current amplifier with an input impedance of 90 kOhm and a maximum voltage gain of 6 at a source resistance of 240 Ohm. So with a load of 100 Ohm the voltage gain is 1.5; and with actual light-weight headphones (Panasonic) having 33 Ohm dc resistance, a maximum voltage gain of 0.75 was measured. These numbers are constant over the whole audio range.
The problem is that the output audio signal rides on a constant dc voltage of 7.5V behind a source resistance of 480 Ohm. With the headphones, the actual dc output voltage measured 0.46V. The resulting dc current of 14 mA will bias the headphone, pushing the diaphragm out of its center position, which can restrict the dynamic range and cause distortions. A 30 µF capacitor in each output channel would prevent this problem, but capacitors with connectors are not readily available.
I gave the device 2 stars under the assumption that the user can build himself such an adapter. Of course, if more than one headphone channel is actually needed, this would hardly be worthwhile.
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on September 2, 2014
This is an out of the box / initial impressions review. I will update this at a later date to reflect long term function and quality.

I purchased this headphone amp to split headphone signal among 4 headphone jacks for my home podcasting / recording studio setup. I am working on a bit of a budget here so the PylePro jumped to the top of the list quickly, reviews were sketchy, but at the price I figured it was worth a gamble.

Packaging. This is what you initially see, and I was NOT impressed. The photos on Amazon of the item itself were accurate, but not the packaging. There was no label over the clamshell portion that housed the transformer, which leads me to believe that my unit might be a used return. I have concerns with that.

Product. It's a tiny metal box shaped vaguely like a seriously downsized Atari 2600 game console. The housing IS all metal which is nice from a durability standpoint. The input and outputs are all on the back of the device, and appear to be sol
The individual volume adjuster knobs appear solid as well, and operate smoothly, all in all the device has a general feel of quality construction. But look and feel is only part of it...

Use: My initial plug in and test brought me great concern. My rig is a Behringer XENYX 1202FX mixer, Hosa 10' stereo 1/4 to 1/4 jumper, the Pyle Pro Rig, and then headphones, 2 pairs Behringer HPS3000, 1 pair Behringer HPM1000, and 1 pair AKG K44s. My first run was playback of an Audacity voice over recording I had made, the "Level1" sounded absolutely terrible, distorted, staticky, just miserable. I tested the other 3 ports and found no problems. Went back to port 1 and unplugged, then plugged back in and tested. Problem gone!

I manipulated the jack by jiggling the cable to see if it was a loose connection and no undue noise. I honestly have no clue what happened...

After the initial garbage sound got cleared, I was able to test each port and found that volume levels could be turned up beyond where I want to listen to them, and there was no induction of any unwanted noise into the whole thing.

I am giving my initial impression a somewhat hesitating 4 stars. The packaging and initial noise issue give me pause, however as it is working now, I have no real reason to doubt its function, and it at least appears to be well made. Time will tell, and considering I have had the jumper to connect the box to my mixer for less than an hour, I haven't had enough time yet.

IF this thing lasts, it will be a great addition to my recording studio rig, and for the minor pittance paid for it, I would count it as one of my best audio buys in years.

****Update after using it for a week****

I have found audio through the first channel distorted and full of static. I got to thinking about it, and realized my phones out level on the mixer was turned all the way up. I turned the knob down to about 50%, just a hair under actually, and got crystal clear audio on all 4 channels. The documentation didn't say anything about this, but if I had to guess, I would think my mixer was overdriving the input on this little amp.

I moved power for this, and my mixer which like this does not have a power switch, over to a regular cheap surge supressor / power strip. All told, I think we are good to go with the configuration now. I simply flip the switch on the power strip and the mixer and headphone amp come right on. Like I said, with the input power moderated instead of wide open, I am getting crystal clear audio from this little device. I suspect that possibly reviewers that complained about the first port dying on their unit may have been overdriving it. This REALLY should be mentioned in the documentation for the amp.

****Update after using it for several months****

The headphone amp itself is inducing a weird buzzing noise, like the mic is bad, but it does the same thing whether I use a condenser or dynamic mic, a line in from an instrument, or other inputs from my mixer. I always seem to have the same problem on the first headphone jack. No problems on the others, no problems phones or monitors out of my mixer... This thing simply put is NOT holding up at all well.

Will be looking to replace it with something better.
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on August 11, 2013
I bought this amp to power and clean up the sound on my work computer that was producing nothing but static for my Sony MBR500X headphones. Does an excellent job and gets a lot of compliments when people visit my desk. Worth more than its price.
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on February 10, 2016
I like this. Apple has inconveniently placed the headphone jack of the iMac in the back of the unit, along with all other jacks. It's simply too difficult to switch between speakers and headphones. So, this amp is now plugged into the iMac, and the sound distributed to headphones and speakers, with the separate volume control for each. It works, and is probably a better audio setup to have even if you have a well-placed headphone jack. This eliminates dangling cables for the headphones or speakers, and you don't have to keep switching the plugs (which might eventually wear the jack out, and then you would need a repair or even a new motherboard).

The amp weighs little, and moving the headphones will move it around a bit on the desk. So I'm probably going to apply some museum putty to the bottom of it to affix it securely.

I do wonder about leaving it on all the time. It's plugged into a power strip, which I rarely turn off, as I just leave my systems running in standby most of the time. I wish it had a power switch. One can, however, simply unplug the power cord on the unit itself.
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