ZK-1002/ ZK-1002L/ ZK-1002T/ ZK-502L/ ZK-502C/ ZK-502T/ ZK-TB21 manual *Manual For Mono/Subwoofer Amplifier: NOTE:Due to different TV types, some TVs default Dolby or DTS sound output, Q4 DOES NOT Support Dolby and DTS sound, please select RAW/PCM Sound; otherwise, you will hear a lot of noise or no sound output.) Another great feature of this particular headphone amp is that it’s super easy to use. Simply rotate the knob to adjust the volume. You can press and hold the same knob to power the machine on or off. Giving the knob a short press allows you to switch between the setting menus for you to adjust features to suit your needs. This also allows you to switch between input and output ports. A unique feature of this amp is that it comes with a gain switch. This allows you to easily adjust the level of gain between low, medium, and high, depending on how much power you want to drive to your headphones. This will be a handy feature to have on your headphone amp if you want to better adjust the sound to your preferences.

You may also want to consider how many output sections the headphone amp has. Depending on what you need to use your new headphone amp for, you may need to have output to several different sets of headphones or even speakers as well. A headphone amp that allows you to control the output to these different channels will be a handy feature to have. Sound control I want to thank Fosi audio for the sample of the K5 pro, as always this is my opinion on it and I've not been paid or influenced by anything other than the music. Please change the power supply adaptation and retest; why? Because of the aging of the power supply, there may be an abnormal power supply resulting in white noise. We recommend using the PC-USB port/5V power adapter to power it. Rounding off our list of the best headphone amps is the LOXJIE P20. This headphone amp makes use of military grade vacuum tubes which give it a warmer sound overall.In my opinion this is more than enough for most headphones, as demonstrated by it easily ‘correcting’ the notorious SA3000. The LOXJIE P20 headphone amp is the perfect choice for those of you who prefer an old school style amp. This particular headphone amp features military grade 6N3 electronic tubes as well as carefully tuned circuits. These vacuum tubes give the amplifier a warmer sound than some more modern headphone amps, making them the perfect addition for those who want a different sound quality from their device. And finally, due to the small size of the unit, some might find that it is impossible to turn the control knobs without raising the unit off it’s resting surface. It’s worth bearing in mind that this may be dependent on the price of your chosen model. Some of the cheaper models don’t offer this level of sound control. However, you shouldn’t shell out for the most expensive model you find. If you want this greater level of sound control over your music, you should take a look at the Fosi Audio Q4. Balanced audio

edit: I know for a fact it's the poor dac chip or implementation in the Q4, I used the pre outs on it into a few amps and it was just...... well it wasn't good at all. The amp might be fine but the dac is terrible. As to why this is actually happening only in Spotify I'm uncertain and would have to take wild guesses. I would HIGHLY recommend trying to get the budget for a Schiit Fulla or Fiio K3, that or just run onboard audio, it's far superior. I do not own any products with optical or coaxial output, so that part will not be part of this review. A handy feature of this headphone amp is that it offers 4 output sections. These are capable of working independently from each other for high quality audio. You won’t have to worry about someone else’s headphones impacting your sound quality if you’re using the headphone amp with a friend and you need to adjust your settings. The levels can be independently controlled via the level controls.Prepare Q4, AC adapter, Micro-USB cable, Coaxial device (TV, for example), Coaxial cable (no include). This only happens in Spotify, all other audio on my PC is working and there isn't any static / hissing sound. However, I don’t recommend using the tone controls to their extremes. I noticed that maximum bass volume will introduce mild distortion.

No special software, app, or driver to install, a true plug-and-play digital audio adapter. with bass and treble control, can be used as a preamp or volume controller for your PC/MAC/Computer. Mini Compact D/A converter, stream bit-perfect 24bit/192KHz HD with low jitter, with output, protect the circuit, safe for your expensive audio system. Full metallic shell to ensure high quality.Note:The Micro-USB cable cannot be fully inserted into the device power port; please do not force it. Subsequent revisions have been made.