Strong low-pass filter

pw · 2013-02-14T15:14:30+00:00

I want to make a low-pass filter (-0.1 dB/20kHz, -150dB/22050Hz) for digital audio 44.1...192kHz (from S/PDIF). What use for this ? DSP processor OR FPGA OR something other? What is the easiest way to do this? Thanks in advance Pawel

Feb 14, 2013 46 Replies

Rate this thread:

Jan Panteltje 13 years ago

On a sunny day (Fri, 15 Feb 2013 09:42:05 GMT) it happened Jan Panteltje wrote in :

PS, I see you did CRT rejuvenation.

formatting link

I have done close to a hundred BW and color I think, I used a simple 1 phase rectifier diode and electrolytic on the 240 V, and a 15 W or so (fridge type) lightbulb in series with that HV, at normal heater current. Connect until light bulb burns steady, for each gun in a color CRT I have never done it to a scope CRT. Never had a one that did not want to rejuvenate.

Vote

David Eather 13 years ago

You don't need anything like that level of filtering. Since the aliasing only occurs with the presence of the real signal being -40 db down is enough to make it inaudible in almost any setting and most of the time you could get away with just -20 db.

Vote

John Miles, KE5FX 13 years ago

Yes, since posting that page I've learned that everyone has their own recipe for zapping CRTs, and most of them work pretty well. It seems that LCD retrofits are going to be the best option, though, at least after the prices come down a bit more. My old faithful 8566B has an LCD now...

-- john, KE5FX

Vote

rickman 13 years ago

I had to check to make sure this post was in sci.electronics.design! Someone discussed a topic and was courteous, friendly and agreeable! It must have been a glitch in my newsreader and this message is from some other group!!!

Rick

Vote

Uwe Hercksen 13 years ago

Dave Platt schrieb:

Hello,

but 150 dB will damage the hering in a very short time. More than 134 dB will cause pain and 120 dB are enough for damages in a short time.

Bye

Vote

Michael A. Terrell 13 years ago

Is that another red hering joke?

Vote

boB 13 years ago

maybe his herring has been impaired ?

Vote

Join the Discussion

Have something to add? Share your thoughts — no account required.

Didn't find your answer?

Ask the community — no account required