Half Speed Mastering

[SUNBEARS]

Hey Trolls. About to dive into doing some Half speed mastering. Any wisdom you guys can offer? I do all of my RIAA encoding in the box, does anything need to change or do I just go for it? Thanks much!

Cheers,
J

[markrob]

Hi,

Is your plan to pre-process the file with the RIAA first and then downsample.

Also, watch your levels. Remember that at normal speed, 5cm/sec 1Khz is only 2.5 cm/sec at 500 hz when you slow it down 50%. So you should be able to back off on the level a bit (or shoot for a hotter cut than your head would normally allow).

[tragwag]

Just want to echo what mark said about the hotter cut, with the mono heads when I slow down audio for playback at 45 RPM, I can cut much louder and usually end up skipping on playback due to overmodulation. (at least on the cheap playback deck)
so I would say start conservative with the level, you'll be relearning how the system responds basically.

[SUNBEARS]

Thanks for the help guys!

Been trying to get my hands on the halfspeed module for my Vinyl Recorder. Eager to get started. Thanks for the notes guys.

Cheers,
J

[phdutton]

I would echo whats been said, very easy to overcut at half speed, so give it a lot of room.

[symatic]

Thanks for the help guys!

Been trying to get my hands on the halfspeed module for my Vinyl Recorder. Eager to get started. Thanks for the notes guys.

Cheers,
J

KABUSA now offers 16RPM mods for technics.

Souri also does a mod, but it involves a heavier platter to avoid the cogging effect you get by running the deck too slow.

KAB's approach changes the circuit board out so you can get better control over the motor and maintain accuracy and torq.

I haven't tried KAB's mod yet.... but i will

https://www.kabusa.com/frameset.htm?/m1200.htm

[tragwag]

Wow, only $175 for a half speed mod on your 1200?
sounds like a deal to me.

Also curious, what's made you look into this?
Just the option of getting the "HIFI" crowd interested?

best,
-TB

[diamone]

Ever try mastering at 33 for 45 playback?
Intended for deep groove DMM because of the necessity for long sides (i.e at Teldec) it never really got off the ground because CDs were taking over - but extensive research says the 3/4 speed heads had a lot better sound.

[symatic]

Wow, only $175 for a half speed mod on your 1200?
sounds like a deal to me.

Also curious, what's made you look into this?
Just the option of getting the "HIFI" crowd interested?

best,
-TB

Im a scratch dj - and I prefer to scratch using ultapitch turntables. we have special ultrapitch scratch sample records that are cut at 33.33 with sped up sounds, so when played back on a deck at -50% (16 rpm) you get the correct pitch but you have twice the amount of time/space to play with.... i can explain more if that doesnt make sense but I dont wanna bore anyone

but basically the technics is still a really nice turntable to scratch with. it has a certain feel and so on, so I always wanted a ultrapitch one.

I noticed a UK hifi guy had invented an external pitch control, some really advanced stuff, but it's pretty pricey - although it WAS designed for library archivers etc (would probably be ideal for VinylRecorder users too), but I know I couldnt afford it for what i wanted to do with it, and no turntablist would wanna spend over £2000 on a mod!

heres the guys high end mod:

https://www.youtube.com/watch?v=jN_SercyeCU

he even stops the platter and shows the torque is still high.

so i knew it was possible, and that the motor was capable of doing this speed without juddering, and i looked into what was going on (with my VERY limited electronics knowledge) and asked around people who might make a similar thing.

so thats how i ended up speaking to Souri but he explained his mod was about making the platter heavier on the technics to compensate for the judder which occurs when the motor is sent a lower voltage. It seems the mod i posted above is some sort of waveform synthesizer that creates a very accurate lock to replace the Quartz lock on the technics, which works (i think) by having a quartz crystal used as a reference point for the electronics to have a sense of 'time' and they can all syncronize turning magnets on and off in time with each other so the motor moves around....

I know other people have had good results by changing the crystal in a technics for one with a different value, but below 20% ish you get this juddering effect.

So I asked KAB about it and he suggested remaking the board in the deck, and he seems to have cracked it!

[opcode66]

A vinyl mastering engineer can time stretch your program material either direction and cut to disc at a standard speed. When played back pitched up or down it would be at the original speed. That sounds like what you are looking for. I can cut high quality one-off records like that for you.

[diamone]

A vinyl mastering engineer can time stretch your program material either direction and cut to disc at a standard speed.

If I'm not mistaken, I think he wants the same as me - to be able to cut real-time without all the digital artifacting involved by digitally compressing or stretching the original material and cutting it at 33.

SUNBEARS - if that is indeed your intent - like the guy in the VinylEngine post referenced below - I have been trying to get somebody to do just exactly that - and on DMM to boot - for years.

To the commercial mastering and pressing houses, it's the same ``headache'' as the all-analog audiophile guys that master live from original quarter-inch and half-inch mono, 2-track, 3-track and 4-track work parts to SuperSonic 45 RPM masters intended for single-sided 180-gram audiophile LPs.

These stretch one LP out over 4 discs that retail for $200 a title - the equivalent of prerecorded 2-track stereo reel-to-reel tapes of the early 50's when a deck cost more than a small car and one tape might be a week's salary for the average working man.

Like these guys - in my opinion - digital ANYTHING is not acceptable. I dunno about you, but I am loath to engage with people who think accommodating my needs is a ``headache'' and ``not worth the bother''.

Those kinds of projects all have their own dedicated avant-garde mastering houses as well as pressing plants who do nothing but small runs, oddball mastering and other similar noncommercial projects. They also charge 2-10 times the money for the privilege of being out of the mainstream - hence the $108.95 a disc consumer cost for e.g. Serato timecode vinyl.

See this post: http://www.lathetrolls.com/viewtopic.php?f=11&t=5654
and this one: http://www.lathetrolls.com/viewtopic.php?f=15&t=4096

Several other guys have also attempted similar projects - see thread here: http://www.vinylengine.com/turntable_forum/viewtopic.php?f=96&t=26571&p=647437#p647437.

Everybody keeps telling us the same thing. Digitally shift your file and we'll cut it on a normal lathe at a normal speed just like a talking book (8 RPM playback but mastered at 33). Not interested.

Like I said - as a niche-market project - me and all the rest of the guys doing oddball mastering like this all found out that you simply can't have anything to do with any kind of commercial mastering house with a bottom line to maintain - that would have to cut into its' main business by taking a lathe that may be cutting 16 or even 24 hours a day five, six or even seven days out of the week - out of service to implement the necessary modifications to the rack or cutting head or input stream or any one of a dozen other things - do your project as a test - wait for final approval - do the final mastering - and then put it all back the way it was so they could go back to their normal everyday 24-7 mastering of normal commercially viable projects.

They simply don't have the interest, and many don't have the time or expertise.

It's the same reason you are having difficulty getting pressing houses to do such short runs - especially when normal AUDITION AND DEMO runs are at least in the hundreds of copies - nevermind COMMERCIAL mastering which expects runs in the thousands or tens of thousands as a MINIMUM.

And like I said about the oddball mastering - commercial pressing plants are under the same business restrictions as commercial mastering houses. Meaning - besides having to find an avant-garde mastering house who doesn't have to worry near as much about a bottom line - the same would apply to needing to find out where an avant-garde pressing plant would be in order to be able to press such a short run compared to a commercial pressing plant.

I'm reminded of the difference between say a commercial-cinema projectionist who neither knows nor cares about the COMMON aspect rations (flat = 1.85:1 and scope/anamorphic = 2.35:1) because they are all pre-encoded on the film to flip a lens turret in or out of the projection chain - where all the projectionist has to do is press START and then two hours later press START again - nevermind the SPECIALTY rations we had to learn if we were going to work in foreign film or art-house cinemas (Academy sound film - 1927 and on = 1.33:1, Academy silent film - before 1927 - 1.375:1, European `flat' = 1.66:1, 4 track magnetic from the 50's = 2.55:1 etc etc etc) - where everything was all done by hand.

Which is why I have been trying to raise funds through the nonprofit on which I'm a board member to find, purchase and install a DMM lathe with the necessary abilities already built in - and to find a couple of nice semi-automatic (Hamilton? 24-inch throat?) presses to be able to do everything myself in my own basement. ]

The only thing I don't have to worry about is the platers - since the seventeen-and-a-half or even 22-inch blanks will fit in normal electroplating tanks - and a local drycleaners which has closed still has the necessary cyanide site license to be able to operate it.

Meaning you'll need a noncommercial operation to master for you and a noncommercial operation to do your pressing. You may be able to get away with using a commercial plater though - but if you get attitude about such a small project - remember the commercial platers are used to dozens and even hundreds or thousands of masters and have the same need to maintain their business as any other commercial venture.

I'd even check with the close-to-retirement age chief mastering engineers at the Library of Congress or the American Printing House for the Blind - both of which still have 16 RPM LACQUER lathes - albeit sitting dormant since Y2K - and see if they'll put their mastering suites back together for you, me, the guy from France on VinylEngine, the guy from Germany on AudioKarma or any one of a handful of other guys doing different versions of the same thing.

[SUNBEARS]

Hi,

Is your plan to pre-process the file with the RIAA first and then downsample.

Also, watch your levels. Remember that at normal speed, 5cm/sec 1Khz is only 2.5 cm/sec at 500 hz when you slow it down 50%. So you should be able to back off on the level a bit (or shoot for a hotter cut than your head would normally allow).

I hadn't considered this.. Is this something I need to do?? Preprocess and then do the time stretch?? Thanks! Can I not do time stretch use a different.. or changed riaa?? or do I use the standard riaa for halfspeed. Thanks guys, got my halfspeed mod on the way.

Cheers,
J

[diamone]

Digital speed reduction - and down to 50%? Ugh. Artifact City. And digital downrezzing? Equally bad. You'd be better off bumping to 15 or even 30 IPS quarter-inch (or even the new JRF Magnetics 2-track half-inch) analog - adjusting your NAB curve (or recording at 30 since there's no curve to adjust), playing back at half-speed - running THAT through your re-adjusted RIAA prior to recording digitally at 192/32 - and then cut from THAT file if you can't cut from tape.

Or if THAT's not an option - there's a few rack-mount systems around that will just spit out the digital bits at half-speed - then you don't have to downsample OR do the time stretch and you can tweak your RIAA at the cutting stage just like MFSL guys do.

[SUNBEARS]

Digital speed reduction - and down to 50%? Ugh. Artifact City. And digital downrezzing? Equally bad. You'd be better off bumping to 15 or even 30 IPS quarter-inch (or even the new JRF Magnetics 2-track half-inch) analog - adjusting your NAB curve (or recording at 30 since there's no curve to adjust), playing back at half-speed - running THAT through your re-adjusted RIAA prior to recording digitally at 192/32 - and then cut from THAT file if you can't cut from tape.

Or if THAT's not an option - there's a few rack-mount systems around that will just spit out the digital bits at half-speed - then you don't have to downsample OR do the time stretch and you can tweak your RIAA at the cutting stage just like MFSL guys do.

So you're sayin' there is a pre-adjusted RIAA EQ? That's really my question. Anyone have any specifics on what the change might be? Thanks ya'll!

Cheers,
J

[SUNBEARS]

I'm assuming every frequency point of the RIAA would have to be cut in half. Correct me if I'm wrong. Thanks!

Cheers,
J

[diamone]

It's either Sooooooo Expensive to get one of the rack-mount processers or Soooooo Time Consuming to build it yourself with only marginal results that it's better to take the file you have now to any one of a handful of Half-Speed-Mastering houses that are still left (Nautilus, MFSL, CBS Halfspeed etc) and just tell them to use their already-built RIAA and other half-speed processors and cut at 16 RPM.

Toronto has one, L.A. has one, N.Y. has one. London has one. They're around.
You just FTP them the file or put it on an LTO or whatever and they take it from there.

https://www.gearslutz.com/board/mastering-forum/753547-vinyl-mastering-45prm-33rpm.html

And different versions of the same thing on all the other audio engineering forums (Steve Hoffman, Audiokarma Home Recording, Tapeheads, VinylEngine etc etc etc)

[phdutton]

Digital speed changing for half speed cutting is easy, and artefact free. Just play the file at half the sample rate. More often than not I cut half speed from a 96k file, so I just play that at 48k, playback problems solved.

[diamone]

and then how do you adjust the RIAA curve?

[phdutton]

Lathe has been modified to have the RIAA switchable from full to half speed.

[grooveguy]

Okay, guys, ready for a bit of humor?

Back in the late 1970s or early 1980s, my company was doing some business in Europe with the aid of the late Steve Temmer of Gotham Audio. Gotham was the US distributor for Neumann; mostly pushing microphones, but he sold the occasional cutting system as well. Steve was iconic in the sound recording field, having worked in Germany with performers like Edith Piaf as far back as the end of WW-II (or maybe before!).

Steve had a card-indexed collection of Limericks, mostly off-color, but I think that was the extent of his sense of humor. He was a no-nonsense kind of guy who, true to his Teutonic heritage, took everything at face value.

At that time in audio history there were two "performance improvements" for disc recording: Half-Speed Mastering and Direct-to-Disc. (Direct Metal Mastering came a bit later.) My Sales Manager at the time jokingly suggested that the two technologies ought to be merged: Half-Speed Direct-to-Disc. I thought that idea was a scream and suggested that he and I propose it to Steve Temmer with straight faces. There was an AES show coming up where we'd be in New York, and the occasion and venue seemed ideal.

So one evening in the bar at the Waldorf Astoria Hotel, we 'crashed' the table where Steve was entertaining some visiting dignitaries and, in all seriousness, proposed our idea. That is, the orchestra and vocalist would play and sing one octave below the score and at half the rate. This would be recorded directly to the Neumann lathe with the turntable rotating at 16-2/3 r.p.m. We insisted that the results would be spectacular. (And we managed to keep straight faces and sound serious, too!)

Well, Steve listened to us and said, "You are joking, of course, yes?", to which we replied that we were quite in earnest about the matter and would be trying it soon on the West Coast. Needless to say we were called 'idiots,' told that the idea would never work, and even the visiting dignitaries at the table looked at us as though we were nuts. A month or so later we sent Steve a 15ips dub of a classical recording session, which we assured him had been recorded with our revolutionary technique.

The topic was never even mentioned again, as though it never happened. A true example of "I won't dignify that comment with a response" if I ever saw one.