I am currently running two pretty cheap switching power supplies and have added some common mode filtering to them, I have been able to significantly reduce the amount of output noise and there great for things like battery charging, testing high voltage Zener diodes, digital work etc... but I am experimenting with low noise analog pre amp type of circuits and my currents PSUs cause the power rails to swamp the the incoming signal.
What I am looking for is a dual channels, configured in bi-polar, that can be adjusted by at least 10mV/1mA, at least 24V and 2A, low low noise like 5mVPP but lower is better, and lastly it MUST have binding posts that have standard spacing and fit banana to BNC! A tracking dual channel supply would be nice along with 1mV/1mA adjustment, but even two single channel supplies are not a deal breaker.
I've been looking at all kinds of options from new to used, I'm not that picky either way. Originally I was going to buy a Siglent SPD3303X since all my other gear is Siglent, but the banana plug spacing kills this option! I have also looked at the
Korad supplies and
this one from circuit specialists. The problem is there is no one out there showing the ripple and common mode noise that come out of these power supplies, not even the Siglent. I dont mind buying some used Keithley or Keysight supplies, but are they any less noisy or even that much better than a newer Siglent/Rigol etc?