[sdiy] Opionions on Switchmode PSUs for analog synths?

[Neil Harper]

On 10/30/19 5:48 PM, Ben Stuyts wrote:
> Hi Neil,
>
> Depends if you can tolerate the noise. I’ve used quite a few products
> from Mean Well, and although their price if very good, their noise and
> EMC performance is terrible.
>
> There is orders of magnitude in difference in noise between these kinds
> of DC/DC converters and a good low-drop-out analog regulator. I’m
> currently looking at a LT3088 LDO (3-pin, needs one ext resistor to set
> output voltage) at
> https://www.analog.com/en/products/lt3088.html#product-overview. It has
> 27 uV RMS noise. The Mean Well has 3 orders of magnitude more. So if you
> have the budget, go for some SMPS to generate pos and neg and followed
> with some analog regulators. Maybe even put a point-of-load regulator on
> each board.
>
> BTW, do you have to use a wallwart? Regular transformers are plentiful.
>
> On the other hand, there were similar awful DC/DC converters in Buchla
> 200e boats and nobody complained…

hey ben, thanks for the reply..
that LT3088 looks really interesting.. 800mA, but in a very tiny package
like that.. what's going on? My LM317/LM337 stuff gets very hot even
with a modest current draw. Are these doing something fancier inside
than just the 'convert excess voltage to heat' that i'm used to
regulators doing?

the general consensus does seem to be follow up a SMPS with very good
linear regulators.. thank you.

as for not using a transformer, i don't want to deal with mains-level
voltage.


--
/// Neil Harper
/// Every Wave is New Until it Breaks