See my article "Phase Equalization and its Importance in the Reproduction of Disc Records" in the Spring 2010 issue of the ARSC Journal. I am quite certain that there are many more digital EQ programs available now that meet the requirements of mimicking the phase response of analog filters, than there were at the time I wrote that article. The Virtual Phono Preamp in DC 8 through 10 is one of them. 

But, I do not agree that digital EQ is necessarily more accurate. With properly designed analog EQ it's easy to get RIAA accuracy +/-0.1 dB from 20 Hz to 20 kHz, which I achieve in with the RIAA settings on my own archival phono preamp. I've designed several other RIAA phono preamps that are within +/-0.05 dB. These levels of accuracy can be achieved with any playback curve, and I doubt that a digital EQ program can do better. There may be other reasons for choosing digital phono EQ, but I don't think that superior accuracy is one of them. 



Gary Galo
Audio Engineer Emeritus
The Crane School of Music
SUNY at Potsdam, NY 13676

"Great art presupposes the alert mind of the educated listener."
Arnold Schoenberg

"A true artist doesn't want to be admired, he wants to be believed."
Igor Markevitch

-----Original Message-----
From: Association for Recorded Sound Discussion List [mailto:[log in to unmask]] On Behalf Of Paul Stamler
Sent: Tuesday, January 23, 2018 1:56 PM
To: [log in to unmask]
Subject: Re: [ARSCLIST] Multiple conversions

On 1/23/2018 5:28 AM, Ted Kendall wrote:
> Not all digital EQ exhibits the same phase characteristics as the 
> equivalent analogue network, and this is important when applyng RIAA 
> playback EQ, for example.

Some experiments I did a few years ago suggest that the parametric EQ and the "scientific filters" in Audition do mimic the phase characteristics of minimum-phase analog EQs. a quick test suggested that the EQs in DC-EIGHT (and presumably DC-NINE) do too. Those are only two programs, of course, but they offer the possibility of phase-correct digital de-emphasis.


> On 23/01/2018 11:09, Lou Judson wrote:
>> I don�t know in the ARSC community, but in generalaudio 
>> engineering, digital EQ can be more accurate and efficient than 
>> analog, and can be done in faster than real time. Why would you want 
>> to do that, I�m curious.
>> Mastering engineers do some work in analog domain, but not just 
>> simple EQ.
>> <L>
>> Lou Judson
>> Intuitive Audio
>> 415-883-2689
>> On Jan 22, 2018, at 9:07 PM, Steve Smolian <[log in to unmask]> wrote:
>>> Using 96/24 throughout, what is present thinking about converting 
>>> from a digital file to analog, equalizing, and reconverting, using 2 
>>> computers and 2 converters?
>>> Steven Smolian
> ---
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