diytube.com

I have a simple question guys, after been reading for a while about power supply design for tube amplifiers I figure that must of the time for home use as "high fidelity" they use larger caps but for guitar power supply they use smaller size because of the sound they prefer to hear, I spend a couple of weeks designing this power supply I mean weeks because every time I read from other sources new ideas and recommendation keep updating the schematic, here is the question I know that the first capacitor should no larger than 100uF because of the stress of the transformer having larger numbers like 680uF or 1000uF caps, will act as a short in my opinion I might be wrong , so how larger the second cap can be? I was thinking that 680uF should be fine because I will use a choke but I'm not sure how large the choke can be too, I will leave the details here of how I want the mono block audio amplifier "not for guitar" home use only

the power supply is an Edcor part number XPWR247

660V (330 - 0 - 330) 325 mA / 6.3V @4A / 6.3 @4A / 5V @4A / 5V @4A

the configuration will be in Ultra Linear

from a Williamson schematic

the caps are placed in series to have enough room for voltage that is why I have a larger number caps in series "cut in half their value"

other question, I already simulate on PSU Designer II but I'm sure if I'm doing it correctly how large the choke can be for this application ?



KT88 x 2
6SN7 x 3
diode rectification 1N5408


Regards
Juan

The second, third, etc. caps can be any size you want or can afford. However - with power supply capacitance, there comes a point of diminishing returns and a greater risk of a voltage doubling effect. In the link below is a formula for calculating the minimum power supply filter capacitance, based on the amp's B+ and estimated output audio wattage. The minimum result should be sufficient.

http://tubes.nekhbet.com/power.shtml#fil

You can go higher than 100uF on the first cap. Look at Patrick's Turner's supplies. He generally goes with 2 470uF caps (in series) for the first cap off the rectifier.

http://www.turneraudio.com.au/poweramps.html

Also you can use Duncan's PSD II to look monitor inrush current to make sure you don't blow anything:
http://www.duncanamps.com/psud2/

Be sure to enter the DCR of your PT secondary and the resistance between the 1st and 2nd stage. And don't forget the bleeders with those big caps.

Shannon

In home amps with a choke in the PS I've had issues with ringing when the second caps are large, specifically the cap after the choke, so YMMV. This is the amp I had issues with, you'll notice a 470uf before and after the choke.
http://electra-print.com/docs/6bx7pp0001.pdf