Home Tube DIY Asylum

Do It Yourself (DIY) paradise for tube and SET project builders.

Re: Choosing the right amount of PS filtering

Hello Mr. 34
IMHO you PS has way too much capacitance.
50 uF > 10 henry > 50 uF should be more than enough and will sound much better.
BTW a simple technique to find out the righ amount of capacitance is to measure AC mV at the speaker terminals with a shorted RCA plug inserted into the amp input. Also, listen for hum with your ear close to the loudspeakers.
Make a note of the total hum level (in AC mV), then decrease capacitance by half. If there is no increase in audible hum, keep decreasing the capacitance until you can hear a slight increase in hum, then go back one step.
The smaller the caps, the faster and less distorted your amp will sound, until you reach the critical point where the hum becomes unbearable.
In summary, it is a balancing act.
Also, if you can go as low as 50 uF, you can try ASC PP in Oil or Unilytics caps, which sound way superior to electrolytics.
Keep in mind that you will probably need a higher capacitance for the input and driver tubes, which usually run on a lower voltage (therefore require more filtration).
I hope this helps.



This post is made possible by the generous support of people like you and our sponsors:
  K&K Audio / Lundahl Transformers   [ K&K Audio / Lundahl Transformers Forum ]


Follow Ups Full Thread
Follow Ups


You can not post to an archived thread.