The main pcb in the Count to 5 is tagged “xyz rev XXX’ where XXX is a lower case letter between ‘h’ and ‘m’ inclusive. The easiest way to know the revision is to actually remove the backplate and look at the text on the pcb. The information on this page is to help people understand what difference the revision makes.
rev ‘h’ and ‘i’
The very first units sold were rev ‘h’ and there are not too many of these. Functionally it is the same as rev ‘i’ but some small layout changes were made to make production “easier”. Rev ‘h’ and ‘i’ are characterized by the fact that they have a M and E switch, but no Q switch. They also have a slightly smaller font size which tends to give them a distinct look. They were painted “Ford Light Blue”made by Eastwood, which with the white knobs creates a very smurf like aesthetic. The audio a/d/a conversion is only 12 bit and so the sound of rev ‘h’ and ‘i’ is a bit harsher than the more modern versions. These revisions were sold from late 2014 until early/mid 2015. The last firmware supported by these boards is 0.931 (outdated and does not have all the latest features).
rev ‘j’
This revision resembles more the modern version in that is has 3 toggle switches (includes Q which was not on previous versions). However it is also only 12 bit audio. All rev ‘j’ were also painted “Ford Light Blue”. These revisions were sold from mid 2015 until late 2015. The last firmware supported by these boards is 0.931 (outdated and does not have all the latest features).
rev ‘k’ and ‘l’
The overwhelming majority of count to 5s in existence are rev ‘k’ or ‘l’. Electronically they are the same circuit, with rev ‘l’ having a few components moved on the board. These revisions improved on rev ‘j’ by using a 24-bit resolution audio CODEC. They were sold from late 2015 until mid 2021. Earlier units continued to use the “Ford Light Blue” but at some point the shade of blue was darkened to “Playboy Blue” from prismatic powders. Even later the shade of blue was lightened again to “RAL 5012”. While not an exact match to the original blue, it is much more similar. In 2020 some green units were made to give a (late) nod to the 5th anniversary of the device. Some of the green ones had simple shapes engraved into them instead of the usual text and shipped with the “nightly” firmware variant. These revisions are still supported by the latest firmware and will be supported by future firmware.
rev ‘m’
Due to the CODEC used on rev ‘k’ and ‘l’ becoming unavailable a new board revision was made using a different but similar quality device. This is virtually the only difference from the previous version. Due to this similarity this revision is still supported by the latest firmware (“Classic” 0.97 and “Nightly” 0.92) and will be supported by future firmware. In their short time being available they have been painted Green, White and RAL 5012 Blue.