Re: [ARSCLIST] RIAA phono EQ and Neumann time constant

[Scott Phillips <scottp@xxxxxxxxxxxxxxxxxxx>]

I have worked in studios for, oh, 30+ odd years one way or another. I
saw MANY times +/- 2db in response from tape itself more times than I
care to think about. (in a single tape batch). Unless you worked or
owned a facility that aligned for every single session, every single
day, the taped results were 'variable', to say the least. (I was in such
a place, BTW) I remember dealing with Phil 'R' one day when he brought
some tapes down to Criteria cr. 1980 from NYC. I found that the 'head
height' of the tapes he brought from his last studio were wrong,
indicating a physical alignment problem on the machine that made them in
N.Y., or perhaps a slitting issue. (not in this case though)  I ask him
if he wanted me to alter our head alignment (as in this session only) to
agree with the recordings he had brought. We would willing have done
this, it wasn't a dig, the only thing that mattered was the music. He
was FURIOUS with the NY studio when I 'developed' his tape with spray
developer and showed it to him. The difference was not just level, it
was azimuth, variable tape path, and noise issues, which he got without
further explanations. A very bright person.

Yes, there are a Huge number of variables in tape or any recording
system. That said, I fall on the side of finding every single variable
you CAN control, and doing so. I am more than a bit aware that tapes
without 'tones' were more than poor practice, they leave everything to
chance. The variables are endless. Richard (IMHO !!) is well qualified
to do well with these. I guess the point of this rant is that we should
ALWAYS minimize the variables we can in any transfer, then never forget
that we ARE likely the ones that a future generation will use to judge
the music of the (recent ?) past. I saw too many times an engineer (or
me !) could indeed tell and judge a 1 db (or less) difference in R/P of
a reproduction, in a completely blind test. Heaven knows, I was prepared
to discount this sort of thing, but it was just too consistently  proved
to me.

Mind you, yes, those with the $1000 speaker cables make me laugh... They
just didn't get the chain that the recordings were made and monitored
through were not like theirs, the 'difference' they heard was just that,
a difference, and did NOT make 'their' playback more accurate than
someone else's. It just made it different. When is the mix that 'they'
made back then through their monitor and mixing chain less the image of
what they mixed and aimed for ??

Scott Phillips



-----Original Message-----
From: Association for Recorded Sound Discussion List
[mailto:ARSCLIST@xxxxxxx] On Behalf Of Richard L. Hess
Sent: Sunday, April 01, 2007 2:17 PM
To: ARSCLIST@xxxxxxxxxxxxxxxx
Subject: Re: [ARSCLIST] RIAA phono EQ and Neumann time constant

At 03:25 PM 2007-04-01, Eric Jacobs wrote:
>Having a good understanding of the minimum error in the disc cutting 
>system (ie. just how flat a frequency response could be achieved, and 
>how accurate are the test discs used to calibrate the cutting systems) 
>will help make specifying minimum RIAA accuracy for reproduction less 
>arbitrary.  If disc cutting systems were accurate to 0.1 dB of RIAA 
>from 20 to 20 kHz when properly set up, then I think the Neumann 
>constant is worth looking into more deeply.  If disc cutting systems 
>were accurate to 1 dB of RIAA, then the Neumann time constant is a far 
>smaller consideration.
>
>I do believe it is a slippery slope to say that just because there are 
>many other elements in the reproduction chain that introduce far bigger

>errors, we should ignore the potential influence of the Neumann time 
>constant - especially if the Neumann time constant could be easily 
>compensated for.

Hello, Eric,

I believe that we will be very lucky to be holding +/- 1dB from 20 to 20
kHz with the tape component--in fact, holding +/- 1 dB from 50 to
15 kHz across the board would have been quite excellent. In just ten
tapes from a major broadcaster known for their quality, I saw one tape
way outside +/- 1 dB at 15 kHz and each session varied within the range
while tapes from the same session were very close. These were 15 in/s
tapes.

While that begs the issue of direct-to-disc recordings, I would suggest
that the vast majority of recordings made from perhaps 1950 until the
end of the LP era were made via tape.

Yes, it's a slippery slope and that's why I suggested that you
contribute an article about this to my blog where we can document all of
these little gotchas. It doesn't have to be long, but I will set up a
separate topic as I plan to add more tape ones in the future -- or if
you write it on your own website, I'll make a note of it and link to it.

And oh, the chemistry issues. Tapes, like the plumbing in "The Money
Pit", are not getting better with age.

Cheers,

Richard


Richard L. Hess                   email: richard@xxxxxxxxxxxxxxx
Aurora, Ontario, Canada       (905) 713 6733     1-877-TAPE-FIX
Detailed contact information:
http://www.richardhess.com/tape/contact.htm
Quality tape transfers -- even from hard-to-play tapes.