BehringerMicroAMP HA400 4-channel Headphone Amplifier (HA400d1)

No sound drop out, no cracks or pops, easy to use just plug and play!

I got one of these to allow my wife or I to listen at whatever volume we want while keeping the TV speakers muted so the other person can sleep. It works just as I wanted and expected it to.The only problem is that it uses 1/4" TRS jacks for the input and outputs. This is fine if you're using it with standard recording studio/musician's connectors and cables, and of course, that's the market this amp was designed for. I think the manufacturer would sell a TON of these if they made a version with RCA jacks for the input and 1/8" TRS jacks for the headphone outputs. That would match what most consumers will have coming from their TV these days and what they'll find on their headphones/earbuds.So the issue becomes finding 1/8" Female TRS to 1/4" Male TRS adapters that aren't total junk. I tried a few different ones found here, and had extremely poor results from most of them. Most didn't make a secure positive mechanical or electrical connection. It's hard to imagine how they can even sell most of them! But again, this is NOT the fault of this little amplifier, it's just something to be aware of.I finally ordered some adapters from Parts Express (a seller who does sell here on Amazon), but I had to get them directly from that supplier since they didn't seem to have them available here on Amazon. I hope I can say that on here without it being censored or causing friction.Those adapters work perfectly. They fit tight and make solid electrical contact.With that problem taken care of, the unit does just what I need it to do, and the sound quality is plenty good for TV viewing. I'm not going to say that it's an audiophile-grade headphone amp, but it's really not bad at all.Having independent volume controls for up to four people is nice so everyone can use a setting that suits them. As I said, the main use for me is so either my wife or I can watch TV without disturbing the other person if they're sleeping or talking on the phone, etc. We just keep a couple pairs of headphones and this amp at our usual watching position, and it's very handy.I've seen complaints on here about buzzing or receiving AM radio broadcasts. I suspect that in all of these cases, the true culprits are either poor electrical contact when using crummy adapters or cables OR they've managed to allow the metal case of this unit to come into contact with something that's grounded (but not well) to another piece of their equipment, thus creating a "ground loop". Ideally, you will keep this unit's case electrically isolated from anything that might create a ground loop back to your audio source. With this amplifier and your headphones "floating" electrically from everything else, you will not likely get hum or buzz.And with good, solid electrical connections (avoiding poor adapters, etc), you will likely avoid any reception of strong AM radio signals in the area.All of this would be true of any amplifier.The sound quality is perfectly fine for an amp of this price range. It drives various headphones to levels far above anything I've needed. It seems to have fine frequency response and reasonably low distortion. The volume controls move smoothly and create no static. And I've been using it for a few years and had zero reliability issues.So I give the amplifier five stars for doing what it is supposed to do quite well.

I have a computer where I have two headphones and a sound system attached, and I was wearing out my jacks switching between them. I though of just bringin in a mini-mixer from my setups, but it would take lots of precious desk space. I saw this thing, and knew it was the schnizzle the moment I saw it. It arrived today and after getting my setup in place, I am happy to report that it is pretty good for the price. It seems to have a negative effect on the bass, but just doing a little EQ from the software to boost the bass turned this into a 5 star device. The knobs are typical Behringer quality (read: high quality) and the cables lie nicely out the back. I bought some 3.5mm to 1/4" stereo jacks since all my stuff is 3.5mm but a nice 5 pack cleanly fixed this since you need 5 to fill all the slots.This unit is perfectly sized and looks sharp. The all metal case makes it look like it is ready to hit the road, and hit it hard while still looking good. The unit has a good weight, and the amplification is modest, with perhaps a little distortion after 3/4 throttle, like most mixers. For my Bose sound, I cranked my laptop to max and the speakers to half volume, and at 1/2 throttle it is very loud. I typically run it at 1.5/10 to 3/10. At 0/10 with the speakers at max, there is a little tiny bit of a hum which is there when disconnected from the amp, so this little mixer is very, very quiet.If you are like me and have two or more audio setups on your computer that you are constantly changing between or if you just want a knob to turn up or down, you need to get this unit along with the appropriate converters and you will not ever regret it.

I returned my Pyle Pro PHA40 micro amp that was shooting sparks at me and decided to get this instead. I am very pleased. This little amp has some kick. You will need a 3.5mm female to 1/4 male adapter if you use standard 3.5mm headphones, but that's only a $5 purchase at your local guitar center. Also, you should know I have a pair of Koss Pro 4AA headphones that have a 250ohm impedance. This amp was MORE THAN ENOUGH to power my hi-fidelity cans. I cannot speak of how it would handle 600ohm headphones but it does 250 just fine. The volume goes way up. I was literally pained when I turned the volume all the way up. I do not recommend turning up to 11 just yet. You don't want to go deaf in the first week. So a nice bonus here is the fact you can have 4 separate headphones plugged in at 1 time with 4 separate volume controls for each pair. There is however only one input source available to you. Also, my major issue was that at maximum volume this amp does tend to distort a little. That however was using some pretty low quality audio (YouTube) and I have not yet tested with FLAC files. I can say that at normal human listening levels it sounds clear and loud. One more critique is that it has no on or off switch. Its a minor issue but it would be nice to just leave it plugged in all the time and flip it on and off at will. As its manufactured now the only on and off switch is disconnecting it from the included power supply. I definitely recommend this little amp if you just need that extra punch in your ears or if you need something to drive some higher quality cans. It was well worth the $25 bucks I paid and is really the cheapest amp option out there on the market.