A40 Amplifier..should i put choke?

[tone]

i want to put choke in the power supply..what value should i put?
i believe by doing so..the dc current will be increase..pls correct me if im wrong?pls advice...thanks.

rgds
tone

[Nelson Pass]

A pi (CLC) type filter would be appropriate. 1 to 2 mH
is a good value, and it must be a big coil with thick
wire, not a tiny coil, rated at 10 amps or so and .1 ohm or so.

It will not increase the current, but it will reduce noise on
the supply, and thus noise coming out of the amplifier.

[tone]

Hello Nelson,

i have two toroid transformers rated 300va 2x25volts 6A, can i uses this..im worried that i do not have enough current..is this good enough?.

rgds,
tone

[Duck-Twacy]

Originally posted by Nelson Pass
A pi (CLC) type filter would be appropriate. 1 to 2 mH
is a good value, and it must be a big coil with thick
wire, not a tiny coil, rated at 10 amps or so and .1 ohm or so.

It will not increase the current, but it will reduce noise on
the supply, and thus noise coming out of the amplifier.

So I guess using a 1.4 mm 3.9 mH aircore with a DC of 0.67 ohm is not a good choice (with the powersupply design of Kristijan http://web.vip.hr/pcb-design.vip/power-5.html , in my case for a aleph5).

A 2.0 mm^2 3.9 mH is still 0.4 ohm (and costs 37 euro )

Guess that means using a HQ core coil like (1.15 ohm for a 1.5 mm^2 3.9 mH) costing 12 euro.


Or maybe this torobar thing (looks funny) 0.17 ohm for a 3.3 mH )costing 19 euro)


Still some people I know say air cores are much better?? iron/ferro etc. cores get very hot or something?
Still wondering how critical the mH value is. Nelson always mentions 1-2 mH, Kristijan says 3.9 mH (which is much more expensive).

ps never understood how to interpret the "gauge" wire indication. We just use surface area of the wire in mm^2.