Vintage Simmons Drums (UK) Users Group

My hero!

Von meinem iPhone gesendet

Am 01.09.2013 um 19:27 schrieb <philmurr@...>:

> I bought the SDS2000 that was recently on ebay UK.  Cost me around £58 and classed as not working (but may be just a loose wire :-)) - good price I thought. It arrived, very nice physical condition.  Checked the fuse - blown so replaced it.  Hopefully that was all and it will work I thought, so took the lid off and powered it up.  Nothing at all for about 10 seconds then a sharp crack and smoke :-( - quickly turned the power off again. The smoke came from a tantalum cap across one of the op-amp +/- supply, put there for decoupling, so I guess it was just its time to die, and nothing too serious. Looking at the schematics, the SDS2000 uses 5V regulated for the logic, then +/- regulated for the analogue sections, display, etc. and unregulated +/- for headphones etc. Disconnected the regulated outputs from the 3 regulators, powered the unit up again and measured the output voltages.  5V was spot on, but the +/- regulated outputs were giving 1.7V and -2V.  Not right. Stuck in replacement LM317 & 337 regulators, plus replaced a few electrolytics that had seen better days.  Also replaced the blown tantalum cap. Powered back up and sprung into life :-) I now have a near-immaculate SDS2000 (with reverb).  Everything tested out fine and it sounds lovely.  I know it's a later bit of Simmons kit and there's probably not much love for it, but it is actually a very good unit.  And it was good fun and cost less than £2 to repair.
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