I bought the BK7M to complement my existing keyboard kit. I liked the idea of a standalone unit that I could connect to my usual keyboard. It meant that I could gig using one keyboard and not have to invest in yet more keyboards. The range of sounds is much larger than my electronic piano so I can turned the Piano volume to zero and just use the BK7M to generate the sounds.

It also seemed to be handy for all gig situations :-

1) Solo piano gig, nice piano sounds and a jazz bass & drums backing for some more up tempo tunes.
2) Duo gig with bass player. Use the BK7m as a drum machine.
3) Duo gig with guitarist. Use some extra backing such as organ, rhythm guitar, drums and bass.
4) Dinner dance solo gig. Use the whole style backing.
5) Function band gig. Use wide range of keyboard / synth sounds without drums and bass.

I soon discovered that there were some missing essential features. Roland could have asked me for advice when they designed the unit, but obviously my rate was too high !

1) No software to create performance lists for gigs. This I have partially addressed with the BK7 Editor.

2) Simple means to quickly set up performances during gigs. The big selection wheel is hopeless if you have a 900 odd performance list and you want to switch between performances (e.g. verse, chorus)

I have sorted the second problem by creating a “Midi Mate”. This is a little box of electronics that is inserted into the middle of the MIDI cable connection my electronic piano to the BK7m unit. It is self-powered and unobtrusive. It filters out program change commands from the piano (these are generated when a voice selection button is pressed on the piano) and interprets them as button presses. This allows me to convert a set of buttons on the piano to a numeric keypad. The “Midi Mate” figures out what number has been entered and sends an appropriate MIDI message to select a performance setting corresponding to the entered number. I have also added facilities to cursor forward and backward from the current performance number.

I initially developed the box to use a separate numeric keypad but then thought it would be neater to use buttons already provided on the piano. So there are two versions. The unit is configurable and remembers the button configuration.

The first photo shows the basic unit with the two MIDI connectors. The red connector plugs into the Piano MIDI out port and the other plugs into the BK7M MIDI in port. This is instead of the usual MIDI cable. :-



The next photo shows my electronic piano with the BK7m unit and Midi Mate connected:-

piano and BK7m


The next photo shows the existing program select buttons on the piano that are to be turned into a numeric keypad :-



The final photo shows an added laminated template that creates the keypad blue tacked into position :-



So the buttons are used as follows :-

0..9 – standard numeric keys. Numbers can be 1,2 or 3 digits.

S – Send button. Type the required number and press “Send” to set the performance. The required performance is immediately selected on the BK7M unit.

-> – Forward button. This advances to the next performance setting in the performance list.

<- -Back button. This advances to the previous performance setting but not beyond the originally selected performance.

H – Home button. This selects the original performance before use of the forward and back keys.

The selection of performances is very slick using the key pad. e.g. if I am playing in a band I can set up performances for the verse, chorus and middle 8 with different instrument mixes and simply switch through the list using forward and back keys. No messing around with the big wheel.

This was developed for a Yamaha p120 electronic piano. Other keyboards may not have a suitable arrangement of program buttons in which case you would need an extra keypad.

If you are interested… These are rough estimates…  a kit of parts for £15 to solder yourself or £30 made up. Keypad is extra £8.


  • Hi
    I was interested to read about your midimate box

    I have been using a midi solutions event processor box to perform a similar function with my Roland fp4 piano and the bk7m. I use spare notes at the bottom end of the 88 note keyboard to effect instrument changes etc. I also use the bottom note of the keyboard to trigger a variation1 ending…. This gives a predictable ending within 1 measure.

    I have looked at designing my own midi processor and have achieved this using Arduino type boards, but haven’t managed to achieve the self power function from the midi cable due to the inbuilt internal resistance of the piano midi output. Can you offer any hints on how you achieved this?

    Best regards

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