Solving ripple....

Psychobiker · 30th April 2008, 09:33 PM

Hey,

Well, first off, am I ever relieved!

I've been fiddling, and the best ripple I've found yet is 10V RMS, that's out of a 16uF->680R->220uF PI filter...any suggestions?
I'm thinking along the lines of - I'm well under the limit and it improves as per increase of filter cap size...so I'll pop a 45u in there.

Duncanamps PSUD gives millivolt-level ripple...but it fibs methinks.

I'm using GZ34.

L

eduard · 30th April 2008, 10:44 PM

replace the 680 ohm with a choke with about the same resistance or add another cap and a choke so you will have cap choke cap res cap If it is for a preamp most of them will do because of the low current involved.

Psychobiker · 1st May 2008, 06:58 AM

I have a kinda-choke, an old toroidal transformer with 7.2H primary inductance. That said, I really ought to find a proper one.

I think I'll pop a larger initial cap in there and see what happens,

L

eduard · 1st May 2008, 08:42 AM

Hello,
I think replacing the 16 with a 45 will not do a lot . switching from resistor will change a 6db filter into a 12 db. It will not cost a great deal of money especially if you buy them i a surplus shop. A few euro did do the trick in the past. Try it greetings, Eduard

AndrewT · 1st May 2008, 09:15 AM

what voltage and current are you working with?

peranders · 1st May 2008, 09:16 AM

It seems to be very tube related

AndrewT · 1st May 2008, 09:28 AM

Hi,
Psud predicts mV of ripple and you are measuring 10V of ripple.
What common mode voltage is in with the ripple.
How much of that common mode voltage gets through to the AC measurement?
Have you got access to a scope?
Could you take your ripple measurement through a high voltage isolating cap? Make sure the turn over frequency of the cap and meter impedance is well below the mains frequency.

Psychobiker · 1st May 2008, 11:51 AM

will measure on tuesday, when I can get at a scope

Psychobiker · 1st May 2008, 02:49 PM

NONCE MOMENT #2!!!

Don't leave your input floating

. That makes 50Hz hum
Other than that we have good sounding music!!!
RE the ripple, that was on the filter cap. B+ has <10mV

underwurlde · 2nd May 2008, 03:13 PM

LOL

I think everyone here had assumed you meant 10mV of ripple when you stated 10V....

30th April 2008, 09:33 PM	#1
Psychobiker diyAudio Member Join Date: Jul 2005 Location: Montréal QC	Solving ripple.... Hey, Well, first off, am I ever relieved! I've been fiddling, and the best ripple I've found yet is 10V RMS, that's out of a 16uF->680R->220uF PI filter...any suggestions? I'm thinking along the lines of - I'm well under the limit and it improves as per increase of filter cap size...so I'll pop a 45u in there. Duncanamps PSUD gives millivolt-level ripple...but it fibs methinks. I'm using GZ34. L

1st May 2008, 09:15 AM	#5
AndrewT diyAudio Member Join Date: Jul 2004 Location: Scottish Borders	what voltage and current are you working with? __________________ regards Andrew T.

1st May 2008, 09:16 AM	#6
peranders Electrons are yellow and more is better! diyAudio Member Join Date: Apr 2002 Location: Göteborg, Sweden Blog Entries: 4	It seems to be very tube related __________________ /Per-Anders (my first name) or P-A as my friends call me

1st May 2008, 09:28 AM	#7
AndrewT diyAudio Member Join Date: Jul 2004 Location: Scottish Borders	Hi, Psud predicts mV of ripple and you are measuring 10V of ripple. What common mode voltage is in with the ripple. How much of that common mode voltage gets through to the AC measurement? Have you got access to a scope? Could you take your ripple measurement through a high voltage isolating cap? Make sure the turn over frequency of the cap and meter impedance is well below the mains frequency. __________________ regards Andrew T.

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30th April 2008, 10:44 PM	#2
eduard diyAudio Member Join Date: Sep 2002 Location: Holland	replace the 680 ohm with a choke with about the same resistance or add another cap and a choke so you will have cap choke cap res cap If it is for a preamp most of them will do because of the low current involved.

1st May 2008, 06:58 AM	#3
Psychobiker diyAudio Member Join Date: Jul 2005 Location: Montréal QC	I have a kinda-choke, an old toroidal transformer with 7.2H primary inductance. That said, I really ought to find a proper one. I think I'll pop a larger initial cap in there and see what happens, L

1st May 2008, 08:42 AM	#4
eduard diyAudio Member Join Date: Sep 2002 Location: Holland	Hello, I think replacing the 16 with a 45 will not do a lot . switching from resistor will change a 6db filter into a 12 db. It will not cost a great deal of money especially if you buy them i a surplus shop. A few euro did do the trick in the past. Try it greetings, Eduard

1st May 2008, 11:51 AM	#8
Psychobiker diyAudio Member Join Date: Jul 2005 Location: Montréal QC	will measure on tuesday, when I can get at a scope

1st May 2008, 02:49 PM	#9
Psychobiker diyAudio Member Join Date: Jul 2005 Location: Montréal QC	NONCE MOMENT #2!!! Don't leave your input floating . That makes 50Hz hum Other than that we have good sounding music!!! RE the ripple, that was on the filter cap. B+ has <10mV

2nd May 2008, 03:13 PM	#10
underwurlde diyAudio Member Join Date: Feb 2005 Location: S.England	LOL I think everyone here had assumed you meant 10mV of ripple when you stated 10V....

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