discrete voltage regulators from different manufactures, are they all equal?

[KevinLee]

Hello,

There has been a lot of discussion lately regarding replacing regular TO-220 voltage regulators with a more discrete drop in design.

Manufactures that offer these discrete regulators are:

-Dexa UWB regulator, www.partsconnexion.com

-Tent Labs shunt regulator, www.tentlabs.com

-Burson Audio Super Regulator, www.bursonaudio.com

-Sercal SPower regs, www.audioupgrades.co.uk

I am not sure of what to look for when comparing these modules, or trying to figure out which one might be the best part.

I will be using the regs in a CD player to supply the opamps, clock and dac.

If someone has the time to have a quick look at these choices (there may even be others) and give me any insight into their design or any positive or negative attributes, it would be greatly appreciated.

Thanks

Kevin

[KevinLee]

Anyone?

How about someone with an opinion on the Linear Technologies LT1085 series?

Thanks

Kevin

[Gopher]

Most will be variants of the Jung/Didden regulator. Pretty much similar performance I'd imagine.

From what I hear the ALW regulator may be the best of the bunch, but don't lose sleep about minor differences.a All of them are more than good enough for the highest performance audio circuits.

[Robert F]

The Tent regulators are shunt types whereas the others do not appear to be. I have not tried them but I do like the sound of shunt regulators vs series regulators myself.

Rob.

[ticknpop]

I have Borbely's shunt regulators, Walt Jung's updated supper regulator, and 1085's .

The LT 1085 circuits can be made better ( lower noise and better regulation) by using it with the LM 329 as descibed on page 7 of the LT 1033 data sheet and appying it with appropriate component reversal to the LT 1085. Even all tricked out the LT 1085 isn't as good as the discreet shunts and super regulators, but is one of the best 3 terminal
solutions.

Also use a 1N4148 in series with 22 ohms for input short circuit protection ( if used ) - not a 1N4001 - this reduces RFI feed through as 1N4148 has lower capacitance.

[ticknpop]

If you have the voltage headroom using 2 LT 1085 regulators in series improves line rejection and overall performance - using a choke or CLC or CRC arrangement in the raw supply along with soft recovery diodes also helps. The CRC or CLC raw supply helps because the 3 terminal packaged regulators have poor HF rejection compared to the best discretes. Use 1 k for the reference resistor ( not 120 or 240 ohms) and 100uf for the adjustement bypass cap - it improves the LT ( and LM ) regulators performance as shown by Walt Jung in the mid 90's