This is my review on the DOREMIDI High Speed USB Host Box, model UMH-21. Now DOREMIDI makes a number of MIDI boxes that kind of LOOK similar, but have different uses from one to the next, so if you’re shopping for one of these online, make sure you’re looking at the correct one.

What this model does is convert a USB MIDI signal into a traditional 5 pin MIDI signal, so this allows you to connect devices that only have USB MIDI out ports:


to other devices that have 5 pin MIDI ports:

5 pin MIDI cable
5 pin MIDI cable

so that they can communicate with each other. Also note that there is a version of this box that is NOT high speed – that one is model UMH-10, but the UMH-10 is only compatible with USB 1.0 and 1.1; the UMH-21 has up to USB 2.0 compatibility and only costs a few dollars more, so if you’re in the market for one of these I’d highly recommend the high speed one so you have less chance of any compatibility. . . or any lag issues.

My Use Case

Connecting A USB MIDI Keyboard To My Yamaha CK88

Ok so as I mentioned, the UMH-21 will allow you to connect a device that only has a USB MIDI out to a device that has a 5 pin MIDI port; there are TONS of use cases for this that DON’T involve keyboards, but the reason I went out and got one of these devices is for MY specific use case:

To be able to connect a keyboard that only has a USB MIDI out to the 5 pin MIDI in on my new Yamaha CK88 stage piano, so that I can use that external keyboard as a MIDI controller and trigger the awesome sounds on my CK88!

Connect USB MIDI Only Keyboard To My Yamaha CK88

This opens up all sorts of cool functionality:

  • having a lighter key action available for organ or synth sounds (or if you have a CK61 that doesn’t have a fully weighted keybed you could connect a fully weighted MIDI controller for some of those piano songs if you wanted)
  • to have a small keyboard to use for left hand bass without having to lose an octave or two on my CK by doing that with a split
  • to allow 2 people play keyboard at once, just using the sounds on my CK.

I actually did a video that demonstrates how to do ALL of those things with the CK61 or CK88 already which I will link to in the description below, so you can check that out if you’re interested.  But in that video, I used an external MIDI controller that DID have a 5 pin MIDI out, so I only needed a MIDI cable; I didn’t need the DOREMIDI host box.  But as I mentioned in that video, most keyboards & digital pianos, and also, most of the less expensive and physically smaller MIDI controllers nowadays tend to only have USB MIDI out ports, and no 5 pin MIDI ports.  And since I have a lot of keyboards JUST like that, I thought I’d pick up one of these boxes so that I’d have the option of connecting them to my CK.

How Do You Connect Everything?

The connections are super simple:

  • connect the power at the back to an outlet or USB power bank
  • connect the external USB only keyboard to the USB HOST port on the front
  • connect the 5 pin MIDI OUT on the front to the MIDI IN on the back of the CK61/CK88

Other Use Cases

Now if you have a more complex use case in mind for the DOREMIDI host box, you CAN apparently connect up to four USB MIDI devices to the box by using a USB hub, and you can also connect another MIDI device to the 5 PIN midi IN port on the host box.  Now I haven’t tested any of that, I just wanted to see how well this box would work for using a keyboard with just a USB MIDI out as a controller for my CK, and . . . it works REALLY REALLY well. 

My Long Term Plan

My long term plan for this is try and find a MIDI controller or keyboard that has a key action that will work better than the CK’s fully weighted GHS keybed for organ songs, in particular Hammond organ which I’m super interested in and starting to play more and more of.   So, an ideal choice for that would be a midi controller with a full sized, semi-weighted key action (and there’s LOTS of those – I tried an M-Audio Oxygen Pro 49 out and it has a nice key action); but ideally it would also have WATERFALL keys which is great for organ slides – these look at first like piano keys, but they don’t have a lip on the front edge like piano keys do, and the front corners of the keys are slightly rounded which makes them much more comfortable for those slides. 

So you’ll find keys like that on actual Hammond organs, or some other organ centric keyboards like the Nord Electro, but so far, I’ve had no luck finding a MIDI controller with waterfall keys.  I have seen a number of organ players on YouTube create 2 or even 3 tiered organ setups that use MIDI sound banks, and they often do use M-Audio MIDI controllers, so I may be on to something there. 


For my use case, which is connecting a USB MIDI only keyboard to your CK series stage piano?


I should clarify that I only tested this box for this specific scenario, but it seems to work really well, so I would assume it should be fine for whatever use case you throw at it.


I looked at my local music store for alternatives to the DOREMIDI USB Host and they didn’t know of any such product, and I looked online and to be honest I didn’t find anything else that does the same thing; and it really isn’t expensive, so if it will solve your needs, I would recommend just picking one up.

Check Prices On Amazon

I have included links below to Amazon so that you can check current pricing – please note that as an Amazon Associate I earn from qualifying purchases


5 Pin MIDI Cable

Some YouTube Videos:

Video version of this review:


Connecting Another Keyboard To Your CK Series Stage Piano

If you have any questions about my experience with the Yamaha CK88 please feel free to contact me!

Piano Training I Recommend

I’ve taken a number of online piano courses; the ones I’m listing here are my favorites and I can highly recommend any of these if you are looking for some online training to get started on learning piano, or to take your current skills to the next level.


This is a fantastic option if you are mostly interested in rock music (and if you’re interested in Hammond organ!) This course was created and is taught by Marine Lacoste, who is not only a fantastic instructor & pianist, but she is also a very accomplished hammond organ player – she performs regularly with her own band, as well as playing keys regularly for multiple recording artists on tour. I started this course in 2023 when I joined a band, and it is helping me greatly in taking my playing to a new level!

If you sign up for Online Rock Lessons yearly subscription, use code PIANOTONE at checkout to let Marine know I referred you, and she will give you a free 20 minute orientation call!

Piano Man Approach

The Piano Man Approach:

This course is an amazing option for learning piano from beginner up to being able to perform; it teaches multiple genres of music and focuses on how to be a “one person band” on the piano. This course is taught by pro pianist Steve Lungrin – Steve has been teaching and performing his whole adult life and is a fantastic instructor and performer.

I took this course from 2020 to 2021 and it elevated my playing from a very basic level to being able to play songs in multiple genres.

Beginner Blues Piano & Improv

Bird’s Piano Academy (Beginner Blues):

If you like the blues, and (or) want to ramp up your improv/soloing abilities on the piano, this is a GREAT course. It’s taught by Arthur Bird, who has a number of courses available on blues, jazz, as well as just getting started on piano. I found his beginner blues & improv course in 2022 when I “hit a wall” in my soloing abilities, and it really helped my improv and soloing in a big way.



If you’re looking for the least expensive way to get started on piano, Pianoforall is a great option. It’s a unique course created by Robin Hall that uses downloadable eBooks with embedded videos and audio instead of a website.