Search found 263 matches

by ricardo
Sun Apr 16, 2017 4:30 pm
Forum: Build
Topic: Phono Transfer System Construction Information
Replies: 126
Views: 99477

Good digital RIAA EQs ... accurate and Minimum Phase

Wayne, I think you posted somewhere a short list of the digital RIAA EQs which you'd found good ... accurate and Minimum Phase ... and the ones which weren't.

Could you please help a beach bum with the info ;)

I've searched the 2 huge phono preamp threads and this one without success
by ricardo
Fri Jan 20, 2017 4:27 pm
Forum: Document
Topic: Neumann SE66
Replies: 41
Views: 25780

Neumann SE66

Gold wrote:Basically every Neumann lathe document ever produced. I don't want everything floating around the web. Gotta keep the punters thinking it's magic.
You mean it isn't??? :o
by ricardo
Sun Jan 08, 2017 10:18 pm
Forum: Pro Audio Design
Topic: A Second Order Elliptic Equalizer for Vinyl Mastering
Replies: 52
Views: 54073

Re: A Second Order Elliptic Equalizer for Vinyl Mastering

I wanted to provide another set of visuals to illustrate the self-defeating nature of hyper-compression when the crushed version of the master is used for vinyl. Compression and limiting is a good thing. In a preemphasized environment hyper-compression is simply self-defeating. But but BUT ... 3dB ...
by ricardo
Fri Jan 06, 2017 8:55 pm
Forum: Pro Audio Design
Topic: A Second Order Elliptic Equalizer for Vinyl Mastering
Replies: 52
Views: 54073

Re: A Second Order Elliptic Equalizer for Vinyl Mastering

I think ANY non trivial EQ will 'unwrap' the 'hidden peaks' in a severely compressed/clipped signal. The limiting case is MLS as used to test speakers. A long pseudo random sequence .. which is a 2 level digital signal is LP filtered and the result is near Gaussian Random White Noise. Loadsa funky m...
by ricardo
Sat Oct 29, 2016 4:56 pm
Forum: Pro Audio Design
Topic: A Second Order Elliptic Equalizer for Vinyl Mastering
Replies: 52
Views: 54073

Re: A Second Order Elliptic Equalizer for Vinyl Mastering

Since the description of the effectiveness is somewhat subjective I could add an objective take on the effectiveness of reducing vertical modulation with each method. I would also toss my subjective opinion in. These are of course my 2 considerations. One objective and the other subjective. In the ...
by ricardo
Fri Oct 28, 2016 4:06 pm
Forum: Pro Audio Design
Topic: A Second Order Elliptic Equalizer for Vinyl Mastering
Replies: 52
Views: 54073

Re: A Second Order Elliptic Equalizer for Vinyl Mastering

I think there are 2 considerations when using MS filtering. Firstly is getting rid of subsonic crap .. especially for the vertical (S) signal. For this, at least 2nd order is required and peaking is bad. The other consideration is crosstalk which will be poorer due to unavoidable phase etc issues. T...
by ricardo
Wed Oct 26, 2016 12:29 am
Forum: Pro Audio Design
Topic: A Second Order Elliptic Equalizer for Vinyl Mastering
Replies: 52
Views: 54073

Re: A Second Order Elliptic Equalizer for Vinyl Mastering

... derived loudspeaker crossovers where one active filter is subtracted from unity to generate the other output. The real filter can have multiple pole response, while the derived output is only -6dB/oct. There's 2 considerations. Firstly, in theory, you can have both outputs 'symmetrical' (eg hav...
by ricardo
Fri Oct 14, 2016 3:52 pm
Forum: Pro Audio Design
Topic: An Improved Dual Class-A Output: The "DCAO2"
Replies: 40
Views: 44949

Re: An Improved Dual Class-A Output: The "DCAO2"

mediatechnology wrote:The new LME49720s I recently bought are improved over the previous lots.
You mean no 1/f noise? :o
by ricardo
Fri Sep 16, 2016 4:48 pm
Forum: Document
Topic: TI Parts Going End of Life
Replies: 20
Views: 25621

Re: TI Parts Going End of Life

Looks like TI had a change of heart and moved the LM4562, LME49710 and LME49720 back into production on an 8 inch line. .... Lets hope they got the burst noise problem under control. I wonder if the original NS made parts had the burst noise. In da old days, it was very dependent on the exact proce...
by ricardo
Mon Sep 05, 2016 4:14 am
Forum: Pro Audio Design
Topic: A Universal Sallen-Key Filter Board
Replies: 35
Views: 30737

Re: A Universal Sallen-Key Filter Board

I've done loadsa S&K filters in commercial designs and have never had problems with stop band stuff ... but I don't do DAC reconstruction filters or anti-aliasing active filters. My main grouse with S&K filters is they are more sensitive to component tolerances than practically any other filter topo...