Roland SH-101 Bender/Powerswitch repair

#1

In the last couple of weeks I bought parts from Syntaur to rebuild the Bender unit and replace the Power switch in my SH-101
I fitted the new 6pin switch as instructed to replace the original 8pin version and the synth powers up and is now pitch stable.
After soldering in the new bender pot (part#4952) and mod switch (part#3569) assembling the bender plate/spring and lever, I set up the centre pitch and checked the voltage of the Mod offset was 0+/-V. However, the pitch will now only bend around +/- 2tones at maximum setting. The old pot (while a bit scratchy) offered more than +/- 12tones.
The MGS-1 handgrip bender performs as before in an upwards direction approx’ 12tones.

So, is this the wrong Pot value I’ve been sent or could it be related to the new 6pin power switch creating a problem?
On the old 8pin switch pin1,2,3,4 were soldered into the board while pin 5+6 from the edge of the board not soldered in. 7+8 were soldered in.
The new 6pin switch had instruction to solder in furtherst from the edge pins 1,2,5,6.
What did the pins on the old 8pin switch do that are now not connected?
Thanks.

#2

The switch is definitely not the problem - it sounds like you have installed that correctly.

I am concerned about the bender pot though, because we have another customer who is reporting the same problem. What is perplexing is that we have sold a good number of these pots without any issues, but if two of you are having the same trouble with the same part, I need to look into this further. It sounds like the taper is wrong on the pot, and it could be that some incorrect pots were mixed in at the manufacturers…?

I am going to so some research on this end, and will post back soon on this. I’m sorry you are having this trouble!

#3

Thank you for your quick response and for looking into this for me.
I look forward to hearing from you.

Regards PKH

#4

Have you had any success looking into this problem with the bender pot’?
I’d like to get the job finished with the correct part please.
Thanks.

#5

I’m sorry for the delay on this. We finally were able to test these pots, and did find that the taper is incorrect; we have let the manufacturer know about this, and are waiting to hear what can be done to resolve this. In the worst case scenario, we will refund your payment - but we are hoping that these can be replaced fairly quickly with the correct part.

Contact us any time (sales@syntaur.com) if you’d like to initiate a refund, and I will post back here as soon as I know if we can get good replacements for these. I’m very sorry for this trouble!

#6

Thanks Sam,
I’m prepared to wait for the correct part for now, so hope it won’t be too long.
Regards
Paul.