encoder – what is that?

i recently had a korean knockoff of a sennheiser SR 300 IEM G3 transmitter. this is used by musicians to send a wireless signal to their “in ear monitors”. the signal is sent to a receiver pack, which a set of special “headphones” is plugged into. there were no external labels, even the box was pretty generic. it said “professional wireless monitor system”. i did find it under the name TKG pro audio on alibaba. and Leicozic L300 IEM also labeled as 300G3.

it had a broken volume knob. the artist had done a benefit concert for a church that had been burned down in north mississippi (holly springs) and seemed that someone had tried to sabotage their gear in between the times they had set up and before the concert started.

but this “knob” was just a normal volume potentiometer. there were two similar knob on each side and after messing around with the good knob and comparing it to the broken one saw that they responded in a similar way. but i didn’t know what to look for to find a replacement. i knew it had 5 pins – with 2 side stabilizers. 3 pins on one side and 2 on the other.

on this particular transmitter, on page 7 of their user manual, it lists the encoder as a “jog-dial”. i pulled out the “switch” looking for some kind of marking to help identify it. even took it completely apart.

the only thing was a small stamp mark “LJV” and after a quick search, found a company by that name in korea. and may have since changed it’s name to LNP. if you are also looking into this, and can help give some better or updated information, leave a comment below.

i ran across another person looking for something similar.

the search term i was missing and needed to help solve my problem was “self-return switch”. it took me forever to see something related to rotary encoder. i found “plum”, “half-axis”, “incremental”, “magnetic”, etc. and just the basic full 360 degree rotation encoders. but nothing that would stop at 10 & 2.

after searching and searching, i finally found something that helped me to vastly narrow my search. it was a master list of EC11 type incremental rotary encoders from ALPS ALPINE. i knew i needed a D shaft, it was 6mm by 20mm. vertical with switch. that left 2 choices. the only thing left to decide was the travel of the push-on switch. ALPS ALPINE EC111012010H – available from mouser in the states. it had all the specifications that i could match. i checked with digikey – who i normally order from, but was not available.

after i got the part in and installed, i began to see if what i had just installed worked. and it did not seem to respond.

keep in mind, i did not have a manual and could not find any online. so i got on the phone with the artist to try to see how he used it. he was unsure, and so i went to the internet and found an unboxing video which gave me a hint. turns out this encoder works with the nearby USB port. it is for playing MP3’s from a USB drive. the press button is pause/play. brief clockwise is next song, counterclockwise previous song. long hold either way is volume up or down. mystery solved.

i got back on the phone with the artist and confidently told him that his repair was complete and ready to be picked up. another successful repair!

if you have a device that you need for me to look at, please contact me here and we will talk about it! thanks for joining me on this repair journey!