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JBL 4645
07-24-2008, 05:42 AM
Found a fascinating video on how LP are cut in the record plants. One of the largest in the USA is United Record Pressing plant.

Tour of United Record Pressing plant
http://www.youtube.com/watch?v=43n5bVXAqzo&feature=related (http://www.youtube.com/watch?v=43n5bVXAqzo&feature=related)

SEAWOLF97
07-24-2008, 01:09 PM
thanx for the link, Ash..

this one is pretty good too..
http://www.youtube.com/watch?v=H342sImBY1s&feature=related

after getting a Denon transformer from Mac, I've ordered a Denon DL-103 MC cart and just waiting for shipment from Spain...good tunes a-commin' :D

so much good vinyl, with tunes unknown to CD only users, available at the thrifts for pennies.:applaud:

JBL 4645
07-25-2008, 05:13 AM
Tom
Oh, that was a good video on how vinyls are made. I need turntable as I have few LP that haven’t been played in years and, hold on a moment…yeah back just popped into the bedroom where the LP are stacked in a box. They still look okay and I really need to get a turntable at some point in time.

Most of the LP are film score soundtracks and I have a few of the same on CD so it would be nice to A&B a few in the future to see how warm the “vinyl” over CD.

The type of turntable I’d like is the Technics 1210MK II

SEAWOLF97
07-25-2008, 12:17 PM
Tom
Oh, that was a good video on how vinyls are made. I need turntable as I have few LP that haven’t been played in years and, hold on a moment…yeah back just popped into the bedroom where the LP are stacked in a box. They still look okay and I really need to get a turntable at some point in time.

Most of the LP are film score soundtracks and I have a few of the same on CD so it would be nice to A&B a few in the future to see how warm the “vinyl” over CD.

The type of turntable I’d like is the Technics 1210MK II


I have my system in pretty good trim....XM, MD and CD are toneally balanced just right, but then when I play LP's the BASS is thunderous. Had wondered why SO MUCH more low end when playing vinyl. Then reading an old Stereo Review someone asked the same question....DUH....the RIAA phono curve in your preamp/receiver adds bass boost also...is there a curve somewhere showing what the standard RIAA eq does ??

answered my own question
http://en.wikipedia.org/wiki/RIAA_equalization
http://www.graniteaudio.com/phono/page5.html

Hoerninger
07-25-2008, 02:28 PM
... but then when I play LP's the BASS is thunderous. Had wondered why SO MUCH more low end when playing vinyl.

It must be something different. The equalisation curve compensates for the cutting process alone.
For example I have compared ABBA Gold in vinyl and CD, nearly the same; Pink Floyd Dark Side of the Moon (SACD) slightly more powerful bass on the CD.

Low mass cartridge on a heavy arm?

BTW: What is XM?
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Peter

Rusnzha
07-25-2008, 04:37 PM
XM and Sirius = Subscription satelite radio

Hoerninger
07-29-2008, 11:11 AM
XM and Sirius = Subscription satelite radioThank you.



It must be something different ...
Was this info of any worth?
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Peter

SEAWOLF97
07-30-2008, 12:56 PM
The equalisation curve compensates for the cutting process alone.
___________
Peter

NO

see wiki article.....

"RIAA equalization is therefore a form of preemphasis (http://en.wikipedia.org/wiki/Preemphasis) on recording, and deemphasis (http://en.wikipedia.org/wiki/Deemphasis) on playback. A record is cut with the low frequencies (http://en.wikipedia.org/wiki/Frequency) reduced and the high frequencies boosted, and on playback the opposite occurs. The result is a flat frequency response, but with noise such as hiss and clicks arising from the surface of the medium itself much attenuated (http://en.wikipedia.org/wiki/Attenuation). The other main benefit of the system is that low frequencies, which would otherwise cause the cutter to make large excursions when cutting a groove, are much reduced, so grooves are smaller and more can be fitted in a given surface area, yielding longer playback times. This also has the benefit of eliminating physical stresses on the playback stylus (http://en.wikipedia.org/wiki/Stylus) which might otherwise be hard to cope with, or cause unpleasant distortion (http://en.wikipedia.org/wiki/Distortion). A potential drawback of the system is that rumble (http://en.wikipedia.org/wiki/Rumble_measurement) from the playback turntable (http://en.wikipedia.org/wiki/Phonograph)'s drive mechanism is greatly amplified, which means that players have to be carefully designed to avoid this.
RIAA equalization is not a simple low-pass filter. It carefully defines transition points in three places - 75 µs, 318 µs and 3180 µs, which correspond to 2122 Hz, 500 Hz and 50 Hz. Implementing this characteristic is not especially difficult, but more involved than a simple linear (http://en.wikipedia.org/wiki/Linear) amplifier (http://en.wikipedia.org/wiki/Amplifier). The phono input of most hi-fi (http://en.wikipedia.org/wiki/Hi-fi) amplifiers have this characteristic built in, though it is omitted in many modern designs, due to the gradual obsolescence of vinyl records. A solution in this case is to buy a special preamplifier which will adapt a magnetic cartridge (http://en.wikipedia.org/wiki/Magnetic_cartridge) to a standard line-level (http://en.wikipedia.org/wiki/Line-level) input, and implement the RIAA equalization curve separately. Some modern turntables feature built-in preamplification to the RIAA standard. Special preamplifiers are also available for the various equalization curves used on pre-1954 records."


and the granite audio link


Audio equipment in the 1950's had a separate knob for the playback curves. The user had anywhere from 3 to maybe 5 or more choices for the desired playback curve. This meant checking each album cover for the recommended curve or keeping a log nearby for quick reference. Users who stacked their records on automatic changers had to pick a single curve for the whole stack or run to the record changer at every change. Many 78 rpm acoustic recordings had no curve, so their tremendous sonic potential is absolutely ruined by any playback curve. Some record makers didn't give the recommended curve, so the user had to experiment. Others even lied about which curve they used. Imagine your stereo system is located in a busy airline terminal and everyone who passes turns the bass and treble tone controls to different extreme positions. Now imagine you are blind folded and trying to make your system sound "right". That was life before the RIAA standard. In a word, there was CHAOS!!!!

R.I.A.A. to the rescue. In 1955 the Recording Industry Association of America published a new standard equalization curve that was adopted by the entire industry of record and audio equipment makers. Eventually all equipment had only the one playback curve and the EQ knob disappeared. In 1965 the National Association of Broadcasters created the NAB Test Record which "constitutes the only test record made in the U.S.A. certified by any organization which writes and issues standards." Finally there was one curve and one standard by which to check it. The NAB Test Record has individual frequencies recorded on it at the exact correct level. By playing this disk on your stereo system and checking the system output with a decibel meter, you can see if your system is correctly decoding the RIAA Curve.

Hoerninger
07-30-2008, 01:17 PM
NO

You are right ;) I was too short with words. :banghead:
Be shure I know about the process from tape to disk and from disk to ear which I had once elaborated (http://www.audioheritage.org/vbulletin/showpost.php?p=141782&postcount=1).
But it is not yet clear what had happen with your playback.
"the RIAA phono curve in your preamp/receiver adds bass boost" is only one half of the story.
__________
Peter

SEAWOLF97
07-30-2008, 03:10 PM
"the RIAA phono curve in your preamp/receiver adds bass boost" is only one half of the story.
__________
Peter

correct. ....but the RIAA curve is adding to the EQ already set for the system.

almost looks like the blueprint for the Dolby process ??

Hoerninger
07-31-2008, 12:41 AM
... Dolby process ??
The Dolby process is much more elaborated and more difficulty to understand as there is a filter with a shifting time constant for the compression / decompression signal. And it works only perfect if you care for the playback level, it needs to be adjusted.

Preemphasis and deemphasis are used by FM transmissions and within tape recorders too .
------------------------------------------------------------------------
Back to your problem:
The compliance of the needle and the moving mass of cartridge and arm are forming a resonator. Its frequency should be below the audible spectrum, but it should not be too low as rumble frequencies would be enhanced. A recommended value is 15 Hz.

This resonance frequency will rise, when the weight or the compliance will be lowered - just like with speakers.

Some combinations of arm and cartridge do not work properly, When using a (presumably old) massy system on a new lightweight arm the resonance will rise. This can produce a bass boost.
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Peter