How to replace the encoders in the ASRx:

Note: This job is basic but takes proper time, attention to details, and a comfort level and skill of soldering. you will need a good solder pen (I use a weller) and solder sucker (about $6 for a nice aluminum one from Mouser). I'm sure doing this voids any warranty on your unit (as if THAT matters since the company has been sold and abandoned this instrument anyway). More importantly if you don't know what you're doing you could damage your ASRx .

This worked for me but I'm not responsible for your or your actions. Proceed at your own risk.

On with the fun...

Remove the ten hex screws and four philips head screws as listed in the ASRX manual. An open unit looks like this:
(This is also how you add memory, expansion cards, etc)

The board we will be working with is actually on the lid:
(note the grey connector cable on the board which attaches to the main ASRX board)

When you remove the ten silver philips head screws the lid is empty:

Replacing the encoders


I used Mouser parts 318-ENC160-24P:

Here are the full details of the part:
Supplier:  Alpha/Xicon
Category: Encoders & Attenuators
Mouser Part#: 318-ENC160-24P
Mfgr. Part#:318-ENC160-24P
Xicon/Alpha Rotary Encoders  16MM ROTARY ENCODER

I ordered two encoders 2/2003 and they cost $2.40/each. this part is FAR superior to the original encoder. It is much tighter and "clicks" firmly for each turn or spin.

You can also order a kit of a Encoder pot and new black knob from EPR Electronics:
Phone: 845-343-1237

I spoke with them and they were very nice. The set of one knob and a new encoder costs $15 so two would run you $30. I haven't tried these so I don't know what part they are using but they did tell me it is NOT the older Ensoniq part (which is good news)

For comparison in size here is a picture of the original knob, original encoder, and the new (and by far improved) mouser part on the right. Notice the tread is much higher and longer. this is why the ASRx black rubber knob  will not fit under the lid when you install this part. However, it will fit fine on top of the shaft of the encoder when you close it. No modifications necessary.


Here is the full board from the lid with both original pots on it and the attached grey cable. I left the cable on while I was working as it didn't get in the way.

The underside of the board. Note the five solder joints where the encoders attach. These are the ones you need to remove.


Side view of the original pots and the two large and three tiny solder joints on each encoder:

The board after I removed on of the encoders.
NOTE:  Do NOT try to remove the black rubber knob on the encoder while it is still on the board. Desolder the whole encoder and THEN remove that knob. It's on there pretty tight and struggling to take it off while it's still soldered on the board is both unnecessary and made cause stress or damage to the board.


The board after both original encoders were taken off

Close up of the board with no encoders. Notice the two large holes and the three tiny ones. these are the solder joints for the encoder. The Encoder itself sits on the small rectangle with the two circles on it.


Last step in soldering. Install the new encoders. The above mouser part # fits and works perfectly.


That's all there is to it!

Epilogue: After all of this I put my ASRx together again and realized that the increments I thought were 'skipping" on the encoder were still acting wonky. However, when I load a disk, edit an effect or sequence, etc everything is perfectly fine. i don't know if the ASRx (Rom 2.67) has a bug or if I just didn't notice that certain processes don't allow sequential access to the ROm sounds. Either way it may be that the old encoders were fine after all and the "problem" was my user error a bug in the OS. Either way looking on the bright side I am VERy happy I installed the new upgraded encoders anyway. they work and feel MUCH better and I'm enjoying my ASRx more than ever.

Now, go make some MUSIC!!!

Email any questions