MFOS power supply not working with SLMS

adhmzaiusz · Joined: Jan 17, 2008 Posts: 59 Location: toronto

So I got 2 of these things, and finally got around to putting them together 2 days ago. I put them both together, but neither of them seem to work with my sound lab!

I got 7809s and 7909s on each, made sure the recifiers and tantalums were the proper orientation, hooked up the ground to the SL but still it only makes my sound lab hummmmmmmm.

Does anyone have any suspicions of whats going wrong here? I checked everything that I could think of.

Is the 78/909 supply too much amperage or something for just a SL?

Thanks!

RF · Posted: Wed Sep 02, 2009 9:35 pm Post subject:

How big are the electrolytic caps? How many? Did you check the orientation on them?
What 'wall wart' did you use?

If you used Ray's wall wart bi-polar supply it should work fine with the soundlab.

bruce

adhmzaiusz · Joined: Jan 17, 2008 Posts: 59 Location: toronto

The electros are 3300 uf, and there is only 2. Im using a 9v 1000mA AC adapter.

I found out that the hum is from an ungrounded plate that the power jack and output jack was mounted to. But after I removed the jack there is no sound at all now.

After I tried that I put in some batteries to try the soundlab and one of them got incredibly hot... I might have some problems...