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Re: [ARSCLIST] 78 & LP tests



I thought centering varied on every single pressing. Am I wrong? I've watched the old videos and read how pressing was done and it seems that they cut the hole after pressing the biscuit. Am I totally wrong on that?
Phillip


Steven Smolian wrote:
Many 78 tests were made from masters rather than stampers. The compounds used for tests were initailly quieter but usually oxidised badly. Some suviving tests were used for the wear test- being played 50 times, and are noisy as a consequence.

However, they have much more presence. The two additional plates that gave us the stamper also took out some of the immediacy.

I wonder if this might not have been the case with some LPs as well.

Incidentally, aother reason for making test pressings was to check centering.

Steve Smolian

----- Original Message ----- From: "Tom Fine" <tflists@xxxxxxxxxxxxxxxxxxx>
To: <ARSCLIST@xxxxxxxxxxxx>
Sent: Tuesday, July 03, 2007 5:47 AM
Subject: Re: [ARSCLIST] LP pressing question



Well, I can say how test pressings were used at Mercury Living Presence, cannot speak for others because I never heard the details first-hand but I bet most other classical shops operated the same way.

Test pressings were a tool to make sure the master was correctly plated and production parts were not carrying defects. Plus, since RCA pressed the MLP records (superior plant, superior vinyl compounds, Mercury plants never got up to snuff until Philips took them over), this was a way to make sure the plant was doing exactly what they said they would do.

Test pressings were distributed to the producer, the engineer and the mastering guys. Everyone was encouraged to at least spot-check and the producer listened to every test pressing all the way through, comparing with notes made during the mastering session.

Now, the fact is that production LPs don't sound as good as the test pressings, which is why I asked my original question -- what makes the production LPs generally noisier and less punchy? I'm assuming that the plants pulled out the "maker's mark compound" biscuits for the test pressing and that production itself wore down the stampers and mothers, and perhaps the simple act of being quickly sleeved effects production vinyl.

Back in ye olde days, a test LP would arrive as a white-label affair, identifiable only by the cutting marks, in a rice-paper-like sleeve in a paper envelope. There was a separate test press for each side of a production LP. The general way things worked at Mercury, a clerical person would pencil in the catalog number on the white label and distribute copies, including one for the files. When the QC listening was done, it was done with a stop-watch so that times could be known for problem, which were noted. Visual inspection was also done and vinyl "zits" or clearly-visible groove problems were measured from edge and noted. The rejection rate was somewhere south of 10% most of the time.

The same care was taken with mono, because mono out-sold stereo even with classical music until the mid-60's when retailers stopped carrying both formats (see John Eargle's JAES article).
-------------------------------
Stereo/Mono Disc Compatibility: A Survey of the Problems
Volume 17 Number 3 pp. 276-281; June 1969


The record industry is now phasing out the mono disc, and the subject of compatibility has once again been raise as it was with the introduction of the stereo disc ten years ago. Then, the problem centered largely around stylus-groove relationships and considerations of trackability; this time the problem is mainly concerned with the way a pair of stereo channels combine to yield a suitable mono channel.
Author: Eargle, J. M.
E-lib Location: (CD aes3) /jrnl6877/1969/6797.pdf
-------------------------------
available at www.aes.org


-- Tom Fine

----- Original Message ----- From: "phillip holmes" <insuranceman@xxxxxxxxxx>
To: <ARSCLIST@xxxxxxxxxxxxxxxx>
Sent: Tuesday, July 03, 2007 1:24 AM
Subject: Re: [ARSCLIST] LP pressing question



I've been told by collectors and people that were in the business, that test pressings were pressed in very low numbers, IE, 100-200 copies for the musicians, A&R people, producer, big wigs, and the like. Every test pressing I've seen had a plain white label with just the bare basics typed or handwritten, and I only have 2 major label test pressings and 3-4 "audiophile" test pressings. The jacket had a pasted on (typed or handwritten) note with just the basics--tracks and artist stuff. If anyone wants a picture, I'll send one. But it's impossible to confuse a white label promo with a test pressing. Obviously, the idea of the test pressing is to give fair warning about what's going to be on the record. It supposedly gave the musicians the opportunity to sign off on the final product, but this really was a micromanagement tool for the front office types. I can imagine some imbecile in management spitting his coffee all over the board room table while listening to Black Sabbath for the first time. "Fairies wear boots? What the hell is this crap? Who signed these bozos? I need to fire the A&R department".
Phillip





Roger

Tom Fine <tflists@xxxxxxxxxxxxxxxxxxx> wrote: Why do most test pressings that I've heard sound better than a bought-in-store version of the LP? Did the plants do something special for the test pressing or use a "brewer's choice" biscuit compound or is it more a random chance of having a further-down-the-production-run copy in a store and thus worn stampers? Where I've been able to compare a master laquer to a test pressing to a bought-in-store version of the same cut/matrix/whatever, the test pressing usually sounds pretty darn close to the first cut but the production disk sounds inferior, usually lower s/n ratio and noisier surface. This was less true in the one case I've been able to compare all 3 for a modern LP reissue and I assume it's because a modern reissue that appears at retail will be pressed with more care on better vinyl and fewer copies will be made per stamper, but I might be wrong on that.

In some older examples, late 50's and early 60's, the retail version vinyl seems to definitely be a different compound from the test pressing, which more resembles modern, "softer" quieter-playing compounds.

-- Tom Fine


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