Maida's regulator

[mark_titano]

I'd like to try the Maida's reg using an Mje340+Lm317. What I want to know is which is the best way to use it if I need to feed two channels with only one regulator.

So after the reg is best to:

-put two RC filters to provide a bit of channel separation
-put only a cap bypass (I usually put 100nF across every section but I’m asking if 100uF for channel in place could be a problem for the reg or not)
-nothing more than the local100nF because, due to the low impedance of the reg, channel separation is not a problem

Thank you

Mark

[SY]

It depends on the nature of the stages you're feeding. For example, if they're running class A strictly, then the loss of dynamic regulation from post-filtering with an RC is not fatal. But I would question the need for that.

In my power amp, I use a Maida reg for the driver stage. Both channels draw from the same point. If there's any crosstalk issue from that, I can neither hear nor measure it.

[Brian Beck]

Having used all kinds of variations of the Maida regulator through the years, I can say that your last option is probably the best. At low to middle frequencies, the regulator will exhibit low impedance which will minimize channel interaction. At higher frequencies the regulator’s performance drops off as impedance rises, emulating a series inductor. I’ve used large electrolytics in the output with no problems, but I’ve come to believe that just a small or medium sized polypropylene cap near the load is sufficient. In your case, make that at least one poly cap near each channel. Morgan Jones has a good discussion of this regulator in his book "Valve Amplifiers" where he goes into details such as adding small series resistors to the shunt caps to dampen ringing, among other considerations (your wiring may have enough resistance to accomplish this). Probably worth reading if you haven't already.

[yagas]

In terms of sound the best combination for me is to put after the Maida regulator an RC filter 22R or 47R with 47uf cap.(each channel). The RC filter should be as close as possible to the load.


Mic