Main Encoder Defective?

So I’ve been using my yellow magic nonstop but have been having problems with the main encoder.
It jumps to the next function before it fully clicks and as I turn it more and more the problem worsens until it doesn’t jump to the next function or skips/ stutters
maybe 3-4 functions ahead or none at all. After this cycle of about 20 or so clicks its starts over again. Does this sound defective to you?

I much prefer the encoder that came with the 4 Pole Mission as it had a really solid click.

Is it this one from the 4PM bom?:

Unfortunately I can’t find it in the usa @ mouser. What are my options?


The one that comes with the standard kits is actually custom-made and I don’t have any in stock. A batch is currently under manufacturing for the next batch of Shruthi-1 kits (and this time I got the length of the shaft just right!). I probably used it for the two 4PM runs. The part that came with this kit is PEC12-4225F-S0024 from Bourns. Do you want me to order and ship a replacement for you?

If you want to ship me the replacement that would be great. I was going to say you could buy from mouser here and ship to me to save money but it seems they are out of it:( You can pm me if you don’t have my address handy.

Also, I’ve never removed a component like this, is it better to use a solder sucker than wick to avoid burning the board and having the pads come up?

You’re really lucky I’ve got one! Please send me a private message with your address.

I’ll let other members comment on the replacement procedure, I’ve never done it.

Lucky me:)

PM sent

with parts like this where the legs clamp the board it’s best you fill it first with solder, then suck it out with a good sucker.
bra(i)d is better for ic legs etc.
the pins shouldn’t be hard to get loose but the big legs go easily if you heat the whole thing up while grabbing the leg with a plier and bend it to the middle. (cut the whole thing off the body first if possible)
then wiggle till you got it out, just no force.

I must admit, the encoder on my YME Shruthi doesn’t feel great, but it seems to work ok, so no real complaints here.
It feels very different to the encoders on all my other Shruthi’s though (including 4PM) , which have a nice positive click to them. The YME encoder feels looser and a bit vague.

As for replacing… To add to Roschs post… There is little point trying to extract the old one whole. Cut the legs off, remove the encoder, then you should find it fairly easy to desolder and extract the legs 1 by 1, using braid and/or a sucker to clear the holes, ready for the new one to go in.

Yeah, the YME encoder feels smooth at first, but can be a bit fiddly to set careful +/- 1 changes. Does it have more clicks per rotation ?

It has 24 click, the “original” has 20; so this is not a big factor.

I’ll stay away from this part in the future. I find it quite strange that people consistently prefer the parts from my obscure chinese source compared to Bourns/Alps :slight_smile:

i always used the reichelt encoder in the past, which is great. this one feels different, but i can’t really say, i need to solder the LCD first and house it.

I’ve had some Bourns encoders (with leds) that I have been completely unimpressed with. I would love a source of non-detented encoders like those Akai uses on the MPK series keyboards, they have a nice feel to them, very solid and smooth.

You can remove the detent from mechanical encoders. You have to open them up and flatten the spike that causes the “click”.

Some products use optical encoders as they tend to last longer. But they also suffer from getting full of crud which you have to remove by spraying cleaner into them.

Olivier, as I mentioned, I thought it only worthy of a mention, rather than complaint. So long as it works and doesn’t wobble, im good with it. The ‘feel’ of it is perhaps as much down to personal preference and what you are already used to as anything else.
Unless mine happens to fail (no sign of that currently) then im content enough to leave it where it is.

While im here… Im not that familiar with Bourns parts. But i’ve got through heaps of Alps parts over the years, and problems have been rare to non existent. Quality parts in my experience!
Is the YME encoder Alps though?

The part that came with the YME kits comes from Bourns - that’s the Mouser reference I have given above (bought from Mouser indeed). Bourns is supposed to be a well-respected company for trimmers/encoders - and I expected the quality to be better than the “standard” part, which I get from a “no name” chinese source which is mostly serving the “consumer audio” market (though I’m still pleasantly surprised by the absence of quality problems I get from their parts). This is not the first time this happens indeed - there had been some similar problems on a few assembled MIDIpal units, but I gave Bourns the benefit of the doubt - I discussed this with the company manufacturing the MIDIpals and they thought a bad batch was the only explanation - though we haven’t completely ruled out the theory that it might be due to excessive heat during soldering. I’ve also checked my debouncing/decoding code - I have logic analyzer traces that show that a faulty part generates mismatches pulses that cannot indeed be detected in software.

well i can’t complain. it works as i’d expect it to.

about bourns: when i once bought some 24mm pots from musikding i couldn’t get all the values from alpha. but they carried those from bourns (more expensive). so i thought i’d do a good thing using these but they turned out to have complete different feel to the alpha pots. the alpha have a nice resistance to the turn, while the bourns felt like i just need to cough and they’d turn fully clockwise.

FWIW I used a Bourns from Mouser on my Ambika and a Shruthi digital board-I have noticed both of them will very occasionally jump two steps per click-didn’t notice that with the parts I got with my 4PM or late-2011 SMR4 kits, or Farnell/Alps encoders. I can confirm it’s not likely to be soldering heat-on both boards I tack-soldered the signal pins and didn’t solder the body tabs as I didn’t like the rotational feel to start and wanted to leave options open for an easy swap to Alps equivalents…

@rosch: Conductive plastic pots tend to have less turn resistance than carbon track-lot of modular builders used to pay a premium for Spectrol 248s for this reason until prices got silly.

For 9mm pot feel I would rate Panasonic with threaded bushing (very solid)>Alps collared (standard mutable)>Alps uncollared (slightly more sideways play than the collared)>Alpha>Bourns (very wobbly)

I prefer to order Panasonics from Digi-Key for my self-sourced Shruthii, the Ambika etc over the Alps. However, I normally stick with Alps for the encoder as they can be had both here and there. Unfortunately there’s no EVU-F 100k log to be had at Digi-Key, or Mouser for that matter. Gotta browse around to see if anyone carries those…

Had similar problems like kingrhythm with my 3rd Shruthi. I’ve used STEC12E08 from Reichelt so far without problems except during my last build. Not sure if it was a dead on arrival or if I heated it up to much during soldering the big legs.

Replacing the thing was an ugly procedure. I cutted the legs, except for the left big one next to the LCD (not enough room to use a cutter). After that I bent the encoder body multiple time to break the last leg. I heated the tin with the iron from one side and used a pair of tweezers to remove the cutted legs from the other side. After that I tried to clean the holes with a soldersucker and a small drill. The last thing is key because you need to insert the new encoder. I killed one brand new encoder (broken leg) while giving to much pressure. But finally I could manage to replace that thing within an half hour and my 3rd Shruthi works fine! :slight_smile: