From lx@fht.comMon Jul 24 13:19:51 1995 Date: Mon, 24 Jul 1995 13:06:36 -0500 From: LX Rudis To: analogue heaven Subject: MS20 finally got my MS20 back from the shop. no, Korg doesn't have parts. no, some of the opamps are apparently korg specific and are no longer made. yes, korg knows of and can supply upgrades, but they are sometimes out of spec and require other parts (caps, resistors) to be replaced. That's not why i'm posting. This is: KORG MS20 WARNING: -------------------------------------------------------------------------------- REPLACE THE NYLON BOLTS HOLDING THE VOLTAGE REGULATORS TO THE HEAT SINK!!!!! -------------------------------------------------------------------------------- ms20 tale of woe and redemption: Being a cute little cheap synth, the Korg was bought by a lot of poor musicians. it's getting real popular again. it ain't built like no moog. I suggest to all Korg MS owners that they pop theirs open and look at the power supply. there are two voltage regulators which supply 15v and -15v to the board. these regulators are held to a heat sink.....WITH NYLON BOLTS. Mine had sheared due to harsh impacts suffered in the past decade and also probably due to hundreds of hours of uptime heating up and corrupting the plastic bolts. When mine died, what had happened was that the bolt on the -15 unit had sheared and there was like a hundredth of an inch twixt the regulator and the heatsink. regulator heated heated heated and finally just started letting voltage thru the system. first thing to go was the gate controller on my Kenton (thanks to Tom Carpenter at Kenton who trusted me enough to suggest a specific socketed chip for me to replace...a simple yet frustrating search yielded the chip and that was fixed) second thing to go was the opamp governing trigger behaviour on the dadsr and keyboard. Unit went to the shop where everything looked fine... Geof left the box on for a couple hours to burn in and ...hmm smells like burning chips.... by the time he tracked down the regulator problem it had fried about 6 or 8 components board side. nuff said? if you aren't skilled enough to do this yourself go to the shop. there's probably other things that were made to die inside this valuable little beastie. Meyer says he had his upgraded and replaced the 1/4" jacks with Switchcraft-probably a good idea... Happy ending: got Cord's (u)seq up and running with the korg. although technically a 1v/oct digital sequencer, it seems to recognize weeerd unquantised voltages. M and I have been having a grand time using the (u)seq as a sort of digital LFO loading it from square and ramp outs from the onboard LFO and using the (u)seq as a voltage source for the S/H....now if i could just figure how to invert the triggers from my 606 or make a variable length gate to use with korg's anamolous S/H (it's more of a sample/drift that doesn't hold unless you leave the gate high). thanks for all the help and sympathy: Geof - tech at Haight Ashbury music Cord - for the (u)seq. ...and for being Cord M - fretted along with me. another ms20 owner, supplied ms20 schematics Music Machines - for providing the scans of the ms20 schematics. much clearer than our xeroxes D.R.Pearson - yet another sympathetic ms20 owner Kurt Harland - same Scottocs - same Shof - hey shof. does your MS have a refractor tape sticker of an angry woodpecker smoking a cigar over the vca graphic on the faceplate? i just remembered that the momentary contact switch on my original one was broken off when i sold it. and a couple other ms20ists whose names i've forgotten. it's been months, you know. if it wasn't for Analogue Heaven this synth would still be dead. More thanks: M's plea for ms10 keys did not fall on deaf ears. one AHngel simply posted him a bag with about 3/4 of the keys he needed. the next day, RBC III drove up with Gus and a whole BAG of keys. then, literally when M wasn't looking he borrowed a couple of screwdrivers from me and simply replaced the keys himself. M went back into the studio and ....what's wrong with this picture..?...HEY-SOMEONE GAVE ME A NEW MS10!!! ----------------------------------------------------------------------------- Lx Rudis byte my shorts! 415.882.1730 Voice lx@fht.com Foley Hi-Tech 415.882.1733 Fax http://www.fht.com 185 Berry Street 415.882.1735 BBS ftp.fht.com San Francisco, CA 94107 http://www.fht.com ----------------------------------------------------------------------------- |||||| \\\\\\ ////// |||||||| |||||| \\\\\\ ////// |||||||| |||||| \\\\\\////// |||||||| |||||| \\\\\///// |||||||| |||||| \\\///// |||||||| |||||| ////\// |||||||| |||||| /////\\\\ |||||||| |||||| //////\\\\\ ||||||||||||||||| ////// \\\\\\ |||||||| ||||||||||||||||| ////// \\\\\\ |||||||| ||||||||||||||||| ////// \\\\\\ |||||||| -------------------------------------------------------------------------------- >lose the 24-line .sig you beanbag, .....Mike --------------------------------------------------------------------------------