broken sh-101?

[hoffy]

Hi guys,

I just purchased a roland sh-101. I am looking forward to getting it modded through this site in a short while. I assume postage will be a bitch from my side of the pond (Australia).

Anyways, Mine is already "bent" in a way; even at full volume, the triangle oscillator is *very* soft (almost imaudible). The oscillator also cuts out and crackles and sounds more like white noise than an sort of waveform. The Square/PW and sub oscillators have no problems at all, which gives me some hope.

Does this symptom sound like a broken oscillator, a problem with the mixer, or dodgy connection? Can this likely be fixed? And if it can be, I assume it can be fixed along with a tune/service and mod from here?

Thanks, Ashley.

[Circuitbenders]

Stuff like that is almost always down to dirty or dying faders on the SH101. I assume you mean the swatooth wave, as the 101 doesn't have a triangle wave as standard. You can't buy individual faders from Roland anymore and annoyingly they are a non-standard size, but you can buy a complete new set of faders from www.technologytransplant.com. A 101 does sound a lot better with a complete new set but they are a bit pricey at $69.

I have had good results before with removing the slider from the board, disassembling and cleaning it by hand and then reinstalling it. This lets you clean out all the crap that contact cleaner won't remove and bend the contacts back into place if they aren't working properly. It might not work but its cheaper than a whole new set of faders.

If the square wave still works at the source mixer then its most likely not a problem with the VCO chip, which could be a nightmare or somewhat pricey to get a replacement for as CEM chips wen't obselete a long time ago.

[hoffy]

Thanks for the quick reply...

I googled the service manual and though it was the slider too (as well as being very faint at the source mixer, the sound also "breaks up").

Assuming I visited the link and purchased a complete set of sliders (there's 19), would you be able to install them along with the modifications you offer (and a calibration and tune up) and if so, could you quote me a price? PM is fine...

Cheers, Ash.

[Gordonjcp]

Installing them is a simple but fiddly job.  You'll need a good soldering iron, lots of solder braid and good soldering technique - this shouldn't be the first thing you've worked on!  Even at US$69 it's worth replacing the bloody lot.  How much is an hour of your time worth, especially when you consider you could be wasting it fannying about with a broken synth with scratchy pots?

You can prove whether it's the fader or not by bypassing it with a bit of wire so it's always "fully on".  If you hear a nice loud sawtooth, it's the fader.

[hoffy]

Ahh right, nice tip Gordon.

I intend to have all the sliders replaced but since I've already paid a good price for the synth, and I've always wanted it expanded with modifications, I am (hopeing) to leave the job to the professionals =)

Cheers, Ash.

[Circuitbenders]

just sent you an email. Theres every possibility it might have gone into your junk mail seeing as you have a hotmail account.