Gearslutz.com - View Single Post - Anyone familiar with the Symetrix SX (208)?

**Tim Farrant** · 28th March 2005

Hey John,

I am not familiar with the Sx208, but the interference you speak of could be caused by poor earthing somewhere, ie, bad connections or broken wiring. Or the power supply might be in need of some attention. The circuit driving the leds might have lost it's power supply bypassing and is oscillating when switching the leds. This might be a LM339 quad comparator chip singing away to itself. Have you got any schematics for this unit? Have you got a scope you can hang onto the led legs and take a look?

Tim.

28th March 2005	#2
Tim Farrant Moderator Joined: Jun 2002 Location: New Zealand Posts: 2,407	Hey John, I am not familiar with the Sx208, but the interference you speak of could be caused by poor earthing somewhere, ie, bad connections or broken wiring. Or the power supply might be in need of some attention. The circuit driving the leds might have lost it's power supply bypassing and is oscillating when switching the leds. This might be a LM339 quad comparator chip singing away to itself. Have you got any schematics for this unit? Have you got a scope you can hang onto the led legs and take a look? Tim. __________________ "Come on, make my day" Dirty Harry (Clint Eastwood) Visit Buzz Audio