Little Bear MC5 Mini Portable Stereo 4 Channel Audio Mixer Passive Live Studio Console Recording Low Noise (No Power Needed)

This is an excellent little mixer, I'm very happy with it. There is the big caveat mentioned in other reviews - the audio level output (a.k.a. volume) is quite low. This is a passive mixer, it does not and cannot boost the signal of your sound sources. If you are plugging this into speakers with their own power source (such as a battery powered speaker), you should be able to boost the signal enough for it to be usable. Likewise for plugging into an audio interface to record into a DAW. However, if you are plugging into passive speakers (such as the studio headphones in my photo), the volume will be very low. Everything is still audible, and at what I might consider to be a 'practice' volume, but you will be disappointed if you are trying to rock the house. There are two solutions to this - either the resistor mod explained in other comments, or you can add an amp to the output to boost the signal (typically this is called a 'headphone amp' and they can be expensive).With that out of the way, I love everything else about this mixer! The knobs feel good, with firm and smooth action, they aren't scratchy at all, and I've had no issue with using them to live mix my instruments. Audio quality sounds great to me. The mixer sits solidly enough on a table, and the included rubber feet help. Plenty of space between the 3.5mm ports to accommodate fatter plugs. The usable range of the knobs isn't huge, generally 12'o'clock to 5'o'clock (50% - 100%), at least for my various battery powered synths. That's plenty for my needs.If you plan to carry this around in a backpack or gig bag, I would recommend that you either build a small enclosure for it or at least wrap some tape around the sides to keep dust out. Or carry it in the small cardboard box it comes in. Dust and other stuff could mess with the circuitry and degrade the audio quality over time. In my project this will live inside a larger metal box, so I'm not worried about it. I also like that the bottom panel can be easily removed, so you could mount this onto a pedal board, synth face plate, or something else. I plan to use Velcro at first, then maybe something more permanent later.If you are searching for a mini-mixer that won't break the bank, this is it. Don't expect this little passive mixer to move mountains, you'll love it.

My use case is probably different from many others. I am into retro-computing and listening to mods on my Amiga while drawing. However, due to the full stereo separation of the Amiga's audio channels listening on headphones was very intense. Ms. MadLemon on YouTube made a device to be able to adjust the mix the L/R channels to soften the experience. I thought, there must be a way to do this without building something. (Not that I couldn't build it I just don't want to at this point.) My first approach was to use PulseEffects on my PC with the Amiga connected to the line in. I made a loopback device with 1ms delay so the Amiga would play through mixed with the PC audio and then adjusted settings in PulseEffects until I got the desired result. This works great except for when I plug in another device that has audio capabilities - then everything "auto-magically" switches to the new device on Linux Mint. After some searching I for a very basic audio mixer I hit on the Little Bear MC5... and I thought and thought about it for a couple of months due to the negative reviews. Finally, I pulled the trigger and got it the other day. I made a short 3.5mm L/R crossover cable to reverse the channels. I plugged the Amiga directly into input 1 and then split and reversed signals into input 2. With input 1 at 100% and input 2 at 75% I get just the right blending of the left and right audio. Better still, my PC goes into input 3 now and I have another one open for one more device on the desk if I am testing. PulseEffects and the loopback aren't needed anymore so I am pretty happy!Pros:Small - Doesn't eat up desk space.Modestly priced.Passive - no extra USB or power cables.Good weight and solid build.I don't detect any added noise through my powered speakers or headphones even when crank the volume on the speakers. (Bose Companion 2 series III speakers also drive the headphones.)Cons:None that I can see.Other thoughts:Now that I have it I would like a version that has a small integrated amp. (Or an add on amp with extended case screws in the same form factor as the MC5 that you can attach to the MC5 and keep it all one package.)I knew this was passive and would not boost the audio. That is NOT the issue. The issue is that I forgot that PulseEffects was boosting the gain from the Amiga's input and the PC's normal sound. This drives the blinking lights on my Sony SEQ-430. Without that amplification the spectrum analyzer can only move on the strongest sounds. Not a huge deal but now it has me thinking about a headphone amp to put inline.

Solidly built, nice pots and knobs. Seems to have some noise or distortion of the sound at high levels but acceptable for my application of putting audio from two PCs and accessories to one set of speakers.

It works as advertised, all the channels work just fine and its easy to use. While I personally like the almost DIY look to it, it definitely doesn't feel like the most durable thing. The ports aren't loose, but cables do come unplugged easily.As it is a passive mixer, expect volume to be lower when through the mixer as opposed to direct. There doesn't seem to be much variance in volume from one channel when mixed at various levels with others thankfully.The main drawback is the poor filtering, a lot of noise is introduced via the mixer, so you will get constant, albeit mild, buzzing. Its easy to drone out if there's any audio output but is very distracting during silence.