Hiraga 24V power supply -

[ConceptD]

Hiraga 24V power supply - capacitor choice

Hi,

I'm a complete noob when it comes to DIY audio building, but I have to start somewhere.
The project I want to take on, is building a Hiraga class A 20W amplifier. Mayby not the most obvious/wise choice for a first project, but as I already have one (original transistors) it will give me a point of reference to judge the result.

Many thanks to all members who contributed to e.g. the existing Hiraga 20W thread. It provided schematics, helped me select suitable transistors ,gave some guidance for the transformer, etc.
I would like to start out building a 24V power supply and am tempted to include a choke (CLC). Specific transformer type undecided for now but probably EI or R-core.

My question mainly concerns the condensators for the power supply.
The guidelines I found (here and elsewhere) tell me to distinguish between the first set (directly after rectifyer) and the second set (after choke);
* second set should have very low ESR, the first just low
* but to improve lifetime of second set; select long life/high temperature condensators for first set
* second set would be 3x more capacitance
* better to split up the second set in a series of smaller capacitors

The problem is I get totally lost when I try to translate that into specific capacitors (F-values, brands, series). Too many variables for me to wrap my head around.

So:
would someone be willing to give me some advice? Ideally I'm looking for a (simple) design/combination of components that has been tested and proven, but will gladly settle for clear advice on just the capacitors. I'm starting the project without any parts in stock.

Thanks,
Carlo

 

[vishalk]

Hi Carlo

Welcome to the forum and to building a Hiraga amplifier, like you i chose this amplifier as my first build, and i am still building it!

So i can hopefully help you from my own experiences.

Are you able to source R core transformers? I had a difficult time getting hold of them, and to have them made was costly. EI you can get very easily and less expensive to make.

Have you decided how much capacitance you want? Do you want to go large or small? 0.4 to 1F? Or are you going to build an original design?

Have you decided what chokes you will use? Fairly important as you will need to get the right transformer voltage to get your 24V.

As for capacitors just check mouser you will have to budget for your transformers and capacitors as they are costly.


Check my threads out maybe some information on there will help you.


Good luck!

 

[ConceptD]

Hi Vish,

Thanks for the reply.

For the transformer: I will probably resort to an EI for initial setup and testing. My understanding was that 18V output should deliver about 24V, but that was before considering the voltage drop of the choke. Testing will tell I guess. R-core is on the wishlist, indeed depending whether or not I can find some that do not cost an arm and a leg.

The total capacitance is undecided right now and relates to my initial question. Checking your own thread (as you suggested) however I stumbled across a valuable suggestion by Edouard which has put me on the right track. I might end up with about 2x 0.4F

For chokes I also found some suitable suggestions on the forum which I definitely need to research a bit more (due to lack of knowledge/experience).

Still in the process of gathering all the information I need to draft a shopping list. Your questions did push me to consider some elements more deeply, for which I thank you.

Carlo