power supply sizing recomendations please

[ericpeters]

I want to build 2 monoblock power amps and i tipically want as much power as possible but also a high current amplifier because i will driving full range ribbon speakers with them.
I was thinking in continious power range of 200 watt/8ohm, 400 watt/4 ohm and 800 watt at

Because I lack the knowledge and experience to be able to build a complete amplifier from scratch i've decided to use the LC audio zappulse 2.2 se modules.
I currently run these modules in a temporary setup with a 50VAC / 500VA transformer and a PS with 12*4700uF capacitors (for 2 modules!) This is defenitely not sufficient for my speakers!

At first I wanted to install (in each monoblock) a 2*50V / 1000VA transformer and 2 pcs 47000uF capcitors, but if I use a 45VAC transformer I can use 4 pcs cheaper capacitors (63V) for the same price.
I'm also lookin at choosing 8 pcs 22000uF per mono amp but this would cost more at less capcity.

Any suggestions what would be the better choice?


BTW i want to build the PS as suggested on this page:
http://www.zero-distortion.com/techno/powersupply/powersi_05.htm
so I've also done the calculations on the next 2 pages of this site

thanks

Eric

 

[lucpes]

You'd want slightly lower rails than 63V if you were to use 63V caps (the mains current can vary, under no load the voltage would increase a tad bit if the trafo is specced under load).

I'd go with a 1000VA/40VAC with good regulation which ain't a problem at this size (or 42VAC -for the sake of it- if you can custom order)/with one bridge/94.000uf/63V per rail/monoblock, for ribbons you don't need lots of power in the 8ohm zone, but large current capability in the 1-2-4 ohm region.

 

[jan.didden]

My friend has just done that for his 1-2 ohms ribbons. Two LC modules fed by 1000VA xformers and 33.000uF reservoirs. Look here: http://www.gydotron.com/ . He's thrilled. You can contact him, he'll love to share his experiences.

Jan Didden

 

[ericpeters]

Jan,

Small world, I'm actually visiting Guido this afternoon.

 

[ericpeters]

Guido's a lot bigger capacity in his amps and a lot lower voltage.

The soundquality in the treble region is considerably better, only one track of a record showed that immediately.
I'm not sure if this is because I run the modules at the limit voltage or just because of a too small ps (I expected that the bass would the biggest difference if the supply is too small)


I will probably make something similar like him with 42 volts transformers.

 

[K-amps]

With a 1000VA and 42vac secondaries, the DC rails will be about +/-58v dc. I built one amplifier with the above with 30,000uF per channel.

I could not get more than 165w into 8 ohms at clipping...

Not sure you will get the 200w @8E you are looking for but then would you need it?

Cheers! 😉

 

[ericpeters]

Hi I updated the transformer to 1000VA 42VAC and the amp improved dramatically, treble, bass and soundstage.

I now will look for very good 63V capacitors to finish the project.

I'm thinking of BHC ALS30 or BHC Splitfoil (more expensive)

any other suggestions?