Need help With Pi Filter For Power Amp!

fastcat95 · 30th October 2007, 12:40 AM

Hello To All:

I have a B&K ST140 power amp, and am exploring ideas
to improve the power supply. The supply consists of the
usual full wave rectification and a pair of 17000 uF 75VDC
filter capacitors feeding the boards. My questions:

1. Could I do better with a "Pi" supply filter to improve
the ripple rejection without sonic problems?
(capacitor/resistor/capacitor)

2. If so, how would I go about deciding the values of the
2 capacitors (in uF), and the value of the resistor?

Any help or references here would be greatly appreciated!

Thanks in advance!

fastcat95

Conrad Hoffman · 30th October 2007, 12:45 AM

IMO, the resistor will cause a voltage drop during sustained passages. Probably better to consider a choke, but I've never tried it on a solid state amp.

Cloth Ears · 30th October 2007, 01:09 AM

Try these.

30th October 2007, 12:40 AM	#1
fastcat95 diyAudio Member Join Date: Jul 2003 Location: Indiana	Need help With Pi Filter For Power Amp! Hello To All: I have a B&K ST140 power amp, and am exploring ideas to improve the power supply. The supply consists of the usual full wave rectification and a pair of 17000 uF 75VDC filter capacitors feeding the boards. My questions: 1. Could I do better with a "Pi" supply filter to improve the ripple rejection without sonic problems? (capacitor/resistor/capacitor) 2. If so, how would I go about deciding the values of the 2 capacitors (in uF), and the value of the resistor? Any help or references here would be greatly appreciated! Thanks in advance! fastcat95

30th October 2007, 01:09 AM	#3
Cloth Ears diyAudio Member Join Date: Dec 2001 Location: Melbourne, Australia	Try these. __________________ Jont. "It is impossible to build a fool proof system; because fools are so ingenious."

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Power supply filter mod	Ty_Bower	Tubes / Valves	3	21st July 2007 01:50 AM
230 V main power filter	spirou38	Power Supplies	0	18th January 2007 11:31 AM
Active power filter	xiaoao360	Power Supplies	3	17th January 2007 12:46 PM
passive notch filter, how much power do they take?	Puggie	Multi-Way	4	3rd February 2006 01:19 AM
How do I diy Hi-End filter power supply and power cord?	bmpa	Parts	6	24th April 2004 12:12 AM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

30th October 2007, 12:45 AM	#2
Conrad Hoffman diyAudio Member Join Date: Mar 2007 Location: Canandaigua, NY USA	IMO, the resistor will cause a voltage drop during sustained passages. Probably better to consider a choke, but I've never tried it on a solid state amp.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)