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View Full Version : Sb3 together with Tripath Amp on same SMPS => noise



topa
2007-05-09, 09:22
HI!

I have a little "41Hz.com" micro amplifier much like the T-amp for use with my Squeezebox SB3 and now wanted to elegantly combine two power supplies into one by using a Skynet 8080 SMPS.

Theoretically an ideal solution as the Skynet regulates (needs a current) on the 5V rail which is the required voltage for the SB3, and I can use the 12v rail to feed my little amp. (Skynet is rated 5v/10A and 12v/6A)

The result however is not so good, there is quite some noise when running both simultaniously. Interestingly, the noise is reduced when I dimm the display of the SB3. A second constant back ground noise cannot be altered though. Noises don't change with distance between units, I gather the SB3 spills out some form of noise back into the SMPS via the power cable?

I want to stress that all parts work just fine when not running together. SMPS with only one of the two (SB3 or Amp) also.
And finally, using individual powersupplies, the SB3 and Amp work fine together too.

Maybe it helps you to know that the same SMPS powering an SB3 and a (12v) NOS DAC instead of the Amp works excellently. And by the way sounds much better than the DAC's original wall-wart.

Regards,
Tobi.