too much ripple

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I have built my regulated power using the LM337 and 317 and made the changes as suggested but still get about 1mv of ripple at the ouput. This also appears at the preamp supply pins even with onboard suppression and its appearing at the output as a low hum. The ripple occurs about evey 8ms. Is this the best that I am likely to get from these regulators. The ripple at the reg input is about 38mv pk-pk Has anyone had anything better from these.

Steevo
 
ripple

1mv seems to have an effect on my preamp, the low level ripple is audible through my power amp when I cobbect it to my preamp. I thought the Ne5532 opamps PSRR would have taken care of 1mv but it doesnt seem to have. When I turn of the transformer the ripple and therefore the noise dissapear. Apparently because of the high gain inside the feedback loop they are very sensitive to noise.

Steevo
 
Re: ripple

steevo said:
1mv seems to have an effect on my preamp, the low level ripple is audible through my power amp when I cobbect it to my preamp. I thought the Ne5532 opamps PSRR would have taken care of 1mv but it doesnt seem to have. When I turn of the transformer the ripple and therefore the noise dissapear. Apparently because of the high gain inside the feedback loop they are very sensitive to noise.

Steevo

Are you sure you don't have some kind of earth loop? Opamps are very good at rejecting supply noise
 
power supply ripple

I have reconnected the ov from my power supply board instead of going straight to my preamp board have connected it to the phono sockets signal earth. here I have all the phono socket signals earths connected daisy chanied together at the back of the preamp. I then have screened cable from the phono inputs to a selector switch, from the selector switch to the volume pot, from the pot to the preamp input, then from the preamp ouput to the phono output socket.This seems to have elimited almost all of the noise. There is still some noise but to hear it I have to take the the grill of the speakers and push my ear into the bass cone to hear it so its almost gone Its just a bout micorscopic to the ear. Has anyone got a better way of connecting the ov to preamp to avoid earth loops, is this the correct way.

Steevo
 
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