Reddit mentions of Roland GOMIXER Audio Mixer for Smartphones,White

This was a surprise to me, too, when I got my first Volca after collecting a few Pocket Operators. They still play nicely together, but not in the same way. If you plan on getting more Volcas, a Volca Mix <https://www.korg.com/us/products/dj/volca_mix/\> may not be a bad idea (it can power three additional ones), though it is more expensive than other solutions.

Otherwise, there are a number of affordable mono mixers out there. I've seen people mention the Behringer Micromix before <https://www.amazon.com/Behringer-Micromix-MX400-Low-Noise-4-Channel/dp/B000KGYAYQ\>, but you'll need some adapters for 3.5mm to 6.35mm jacks. This will strictly be mono, however, so if you plan to add some stereo devices to the mix (pun intended), you'll hit a wall pretty quickly. Behringer has a range of other mixers, and you may want to check something out in the Xenyx range <https://www.amazon.com/Behringer-502-Premium-5-Input-British/dp/B000J5UEGQ/ref=sr_1_9?crid=120WM7ZC873VD&keywords=behringer+xenyx&qid=1555091076&s=gateway&sprefix=behringer+z%2Caps%2C160&sr=8-9\>, where even the lowest-end one (linked) will give you plenty of room to expand.

Personally, I just bought a Roland GO: Mixer <https://www.amazon.com/Roland-GO-Mixer-Smartphones-GOMIXER/dp/B01MYC4DVP/ref=sr_1_1?keywords=roland+go+mixer&qid=1555091001&s=gateway&sr=8-1\> to use between a Volca, a few PO's, and a microphone for straight-to-phone video/audio recording purposes, and I've enjoyed it. If you don't plan on recording things and just need something to mix, this will be super overkill for you.

First, what is the Recording device? Computer? Smart Phone? Other?

There are relatively simple Mixers that could be of benefit.

This particular mixer has 4 inputs and both analog and USB output -

https://www.amazon.com/Behringer-Q802USB-BEHRINGER-XENYX/dp/B008O517IC/

Here is an even more basic model -

https://www.amazon.com/gp/product/B0002BG2S6/

The Smart Phone Mixer would likely work too -

https://www.amazon.com/Roland-GO-MIXER-Smartphones-GOMIXER/dp/B01MYC4DVP/

Decent functional microphone can be bought relatively cheap -

https://www.parts-express.com/pyle-pdmic59-professional-handheld-unidirectional-dynamic-microphone-with-on-off-switch---248-4726

https://www.parts-express.com/cat/vocal-microphones/765

https://www.parts-express.com/cat/headworn-headset-microphones/757

There are components made for Podcasting, and even complete Podcasting Packages -

https://www.amazon.com/s/ref=nb_sb_noss_2?url=search-alias%3Daps&field-keywords=podcast+system

https://www.amazon.com/Behringer-PODCASTUDIO-USB-BEHRINGER/dp/B000PARIZU/

Podcast directly to your phone -

https://www.amazon.com/Movo-Executive-Microphone-Monitoring-Smartphones/dp/B019HQHXN4/
What you are trying to connect to, that is, the recording device, your budget, and whether this is audio only, or audio and video will be the deciding factors.