interesting phenomena in the cutting room


We've (my friend Bob and myself) been working on an LP cutting lathe for some years. Its been a while refurbishing the lathe itself, finding parts and solving problems/puzzles, rebuilding the electronics, etc.

The lathe itself is a Scully, the cutterhead a Westerex 3D and the electronics the 1700 series built for the cutterhead by Westerex.

About 6 weeks ago we finally hit upon the magic combination of stylus temperature, vacuum, depth of cut, etc. It works beautifully! So we have been playing with parameters, including different amplifiers. The stock amplifiers were built about 1972 and are solid state.

Now those of you that know me know that I am all about tubes. But the stock amps worked quite well! As we gained familiarity with the system, we found out why: the Westerex cutting system is a high efficiency cutterhead- it does not take a lot of power to make the head work. It can easily cut grooves that no cartridge could ever keep up with, and do so without breaking a sweat. So the amps, which can make 125 watts, are loafing through the most difficult passages.

I had a Dyna ST-70 that I had rebuilt so for fun we swapped that amplifier in and it did quite well. Our next step is to use a set of our M-60s, as the cutterhead is an easy load relative to most loudspeakers.

What is interesting about this is that we can make cuts that literally demonstrate the audible differences between amplifiers, something that can be demonstrated on any playback system.

Its also apparent that the cutting process is relatively unlimited as a media compared to any other recording system. The dynamic range is well beyond that of analog tape or any digital system- like I said, it can cut grooves with such range that no cartridge could possibly keep up, yet is dead silent (if the lacquer is OK, that is). The real limitation in LP recording is the playback apparatus, not the cutters.

There is a fun little forum website for more information called 'Secrets of the Lathe Trolls'. Here's a post on that side made by my friend Bob (Bob has run a recording studio for some 20 years and was a roommate of mine in college):

http://lathetrolls.phpbbweb.com/viewtopic.php?p=19435&mforum=lathetrolls#19435
128x128atmasphere
With out importance level in that process and with out know almost nothing about I list some limitations on that normal process ( not " audiophile " but normal. ):

- quality level of microphone.
- microphones place during recording.
- use of limiters, equalizers, reververation or other electronics artefacts.
- quality level of monitoring system.
- bias of the recording engineers or recording producer to some kind of sounds.
- edition work.
-dubbing.
-mastering and platting.
-quality level of all the electronics surrounded the recordings: microphone amps, cables, connectors, amps and preamps, overall recording consoles, etc, etc.
-quality of pressing.
-and many other " characteristics " where you can put some light to ignorants as me trying to learn.
Of the things listed most have nothing to do with the LP except the mastering, plating and the resulting quality of the pressings. IME the quality of mastering means a lot more about the pressing quality than the work of the actual plant.

We did one job where the customer was doing the pressing at United, which is not known for pressing quality. I knew some people that got a project done there and the finished LP seemed kind of .... compressed. But in our case when we got the finished pressings back they sounded fine. We didn't add any compression to the recording- usually with LP there's no point to it.
Dear Atmasphere:  "  Of the things listed most have nothing to do with the LP except the mastering, plating and the resulting quality of the pressings. "  

WOW!, I'm totally an ignorant because my thought is ( ? ) that different icrophones have different quality level performance and that it's not the same to make the recording of the 1812 with only three micros than with 8 or 25.

Please let me know, because according with your statement I'm totally wrong, if the audio signal that goes throught the micros, cables/connectors of those micros and micro amps is the audio signal used throught all recording process that at each single link of that process the original audio signal was and is modified/degraded  or it's that at each single link on the recording process only is used the audio signal coming from the micros in original status?  and how is that the quality level on the open reel tape deck used for the " masters " has nothing to do with the LPs?
So from where came the audio signal that we are listening during LP's playback?

Yes, could be that I'm stupid but I don't get it your answer to my question.

Can you help me?, appreciated and than's in advance.

Regards and enjoy the music,
R
Dear Atmasphere: You was whom started the thread and as I posted I'm just one more ignorant ( down there ) about the overall recording process and that's why I ask to the expert that in this case is you but you don't gave any explanation about and only said: "  the things listed most have nothing to do with the LP except the mastering, plating and the resulting quality of the pressings. "

IMHO I think that an explanation is in order to why the other " subjects/recording characteristics " have nothing to do with the LP because I can read in several LP's " histories " how the recording was made where talks on many those recording links that you say " have nothing to do with LP ". Examples:

- in the Rega recording of Cristine Collister LP Roy Gandy ( that I think is not an ignorant as me. ) write in the " historty " of this recording: " After trying many new and vintage microphonesCristine choose the amazing Pearl C22.... to avoid the increase of sibilance.... we built a new mixing console......all the voices and instruments were recorded directly  into the tape machine ( Studer A80 ) via a Rega designed mic preamp.....to mix the final 8-tracks onto two-track 1/4 inch Rega designed  a purpose built fully discrete 8-channel mixer based on the Rega pre-amplifier. Monitoring on various Rega speakers... "

- Sheffield was and is famous because their D2D great recording where they by-pass ( between other things ) the tape recorder used nonmally in all LP recordings and where exist always a degradation of the original audio signal.
Sheffield made other non D2D very good recordings: " live to two-tracK ".

- Music Labs has its own K2 recording technology.

- The Super Analogue Disc were famous recordings because they explain and by pass more than 4 normal recording process links.

- VTL not only builded his mics mixer/amp but build in purpose the microphone that was used during the VTL recordings.

-Three Blind Mice ( Misty ) made this recording ( and others. ) using 3 mics on the piano, 3 mics in the bass and 8 mics in the drums ( almost all different mics ). So, 14 mics for three instruments.

- other label recordings use only 3 mics and other labels 20-40 as deutchs gramaphone.

- on those recording LP examples the producers and enginners were different and all those LP sampels sounds way different with different quality level.

Why all those recording labels took so many care and choices and even build own electronics to make better recordings where we can hear the differences?  if almost all what I listed " have nothing to do with the LP " from where comes the differences on each recording?

Could you make a wide explanation that put some light in what I posted here and elsewhere in this your thread?

Regards and enjoy the music,
R.


Dear friends: Like you I'm a guest in this Atmasphere thread. Because he decided to stay " dead silence " against my posts where I ask for a wide explanation I have to ask to a today expert recording engineer trying to learn and understand not only what for me was a no-sense answer from Atmasphere but if what I posting here was totally wrong and this is what he email me:


""""  Mics and preamps, as well as microphone placement is one of the most important parts of the recording processes. You can never correct for this, if done wrong. You can always remix and remaster.....as well as recut. So, IMO, anyone who says otherwise has not consider just how important this is...... """"""

by coincidence in my non-expert list I posted that.

Not only for the answer of this recording engineer but for what I posted in my first post this thread (    " The real limitation in LP recording is the playback apparatus, not the cutters. "

That I remember in this forum I never read a post where some one saids that cutters were the problem with the LP recordings/playback. )
was only part of the Atmasphere's agenda to promote what he do because at the end he is a seller. Nothing wrong with that, this is a free world.

Regards and enjoy the music,
R.


Perhaps Ralph understands that all the points you raise about the recording processes are common to both digital and analogue and have nothing to do with the 'cutting' processes of the LP....?