Search found 3705 matches

by JR.
Thu Mar 19, 2015 4:13 pm
Forum: Pro Audio Design
Topic: Limiters with FETs
Replies: 16
Views: 40965

Re: Limiters with FETs

Are we talking instantaneous overload protection or audiophile-quality limiting during capture committed to flash or disc? A diode clipper can be made to soft-clip as it approaches the clipping point and it will be less audible than the op amp, A/D or more often than not the limiter doing it for yo...
by JR.
Thu Mar 19, 2015 3:11 pm
Forum: Pro Audio Design
Topic: Limiters with FETs
Replies: 16
Views: 40965

Re: Limiters with FETs

A diode clipper is NOT gentle on the waveform... unless you think a fuzz tone guitar effect is gentle. There are far more than three versions of FET (variable impedance) shunt limiters. (I've done more than three myself over the years). Probably the lowest distortion I've seen was one that Cordell u...
by JR.
Thu Mar 19, 2015 9:35 am
Forum: Pro Audio Design
Topic: modified GFCI
Replies: 92
Views: 163020

Re: modified GFCI

The tester I have is fooled by a 3 prong AC cable that goes nowhere; I don't know why it thinks ground is present. Perhaps the tester is faulty... ? A cheap tester will connect a lamp between line and ground so that ground needs to sink a few mA to light the lamp...If an open floating ground still ...
by JR.
Tue Mar 17, 2015 9:12 am
Forum: Pro Audio Design
Topic: modified GFCI
Replies: 92
Views: 163020

Re: modified GFCI

I've probably already said it: the simple testers are easily fooled for even ground connection. Plug a 3 prong cable into an ungrounded outlet. Plug the tester into the other socket of same outlet; it will tell you ground is present because of the other ground pin presence, NOT because ground is ac...
by JR.
Mon Mar 16, 2015 12:41 pm
Forum: Pro Audio Design
Topic: modified GFCI
Replies: 92
Views: 163020

Re: modified GFCI

I continue to work on my "hard to fool" outlet checker. The problem is simple outlet checkers can be fooled since the voltage is AC there is no easy way to determine wiring polarity without an external reference. As mentioned a neon lamp or high impedance VOM will work using the human body...
by JR.
Mon Mar 09, 2015 7:48 pm
Forum: Pro Audio Design
Topic: Voltage follower for high-pass
Replies: 11
Views: 31685

Re: Voltage follower for high-pass

never mind...

JR
by JR.
Mon Mar 09, 2015 4:37 pm
Forum: Pro Audio Design
Topic: Voltage follower for high-pass
Replies: 11
Views: 31685

Re: Voltage follower for high-pass

Maybe Walt will chime in with his concerns. In general if you are going to add an op amp for a HPF you might as well make it 3 pole (-18dB/oct. You can put one underdamped active two pole in series with one real pole to make a 3 pole with less loss at the cut-off frequency. Butterworth alignment is ...
by JR.
Mon Mar 09, 2015 10:51 am
Forum: Pro Audio Design
Topic: Limiters with optocouplers
Replies: 48
Views: 125144

Re: Limiters with optocouplers

That part is after my time so I never checked it out myself (I used my share of cheap gain cells like NE 570 family). Looks like it will be better than clipping but just barely... The below limiting path is not very pure, but you can decide if it is clean enough for your needs. I am partial to limit...
by JR.
Sun Mar 08, 2015 2:06 pm
Forum: Pro Audio Design
Topic: Limiters with optocouplers
Replies: 48
Views: 125144

Re: Limiters with optocouplers

If you are proud of your woofers and amps, here's a track to listen to. And don't crank it up until you are confident you system can keep up. :oops: http://www.danleysoundlabs.com/danley/wp-content/uploads/2015/02/Finale4.zip He only claims 70 dB dynamic range but I trust him that it's a solid 70......
by JR.
Sat Mar 07, 2015 11:51 am
Forum: Pro Audio Design
Topic: Limiters with optocouplers
Replies: 48
Views: 125144

Re: Limiters with optocouplers

I do not understand the modern revival of vinyl. No it isn't better than digital. Thread veer alert: I have a hunch that vinyl masters aren't clipped to death like CD and iTunes releases of the same material and therefore actually sound better despite the medium's limitations. I'd like to test that...