Right. A synchro tone, used to synchronize tape recorder to cameras in the movies industry.We used it for decades in the film industry. Nagra recorders would often have a 60Hz control tone.
It was used two ways. On Nagra III, (mono) a 50/60Hz tone were recorded at 90° from the audio signal on the tape by an additional head.
On Nagra IVS (Stereo) it was a signal, recorded in FM in the little central space on the head between the two audio tracks.
The perforated 16 or 35mm magnetic tape recording machine, used to recopy the 1/4" original magnetic tape and used later on editing machines was often using synchronous motor on the AC. And the speed of the Nagra was servo-ed to lock the phase of this tone with the AC one during this copy process.
This had survived long time after SMPTE signals were available in the audio industry to synchronize multi tracks between them in the music industry.
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We used it for decades in the film industry. Nagra recorders would often have a 60Hz control tone.
I was thinking transfer of LP's, both of the big guys in this business sell products that claim fixing warp and rotational wow for transferring music that is only archived as master disks or cylinders. From what I have seen there is even some 10th harmonic of the .55Hz present on LP's. Some of the wax cylinders probably pre-date 60Hz mains.
In communications with Jamie H, he has said almost anything can be used for recovery if it was initially stable. So, they have used mains, bias freq, servo pwm leakage or anything else that can be identified. They may also heterodyne down the bias freq to something that will "fit" into the recovery bandwidth. An Ampex ATR100 has a bias freq of 432khz, now what will we record that with? (it also has a servo leakage of 28.8khz that is consistently recoverable)
Using mains as the recovery signal will give you quite a bit of speed correction on old recordings with varying speed, but no scrape noise or other hf correction. Now whats the bandwidth of information on a 60hz carrier?? Hence the desire to use such things as bias, which is commonly in the 100-200khz area for many professional recorders.
Alan
Using mains as the recovery signal will give you quite a bit of speed correction on old recordings with varying speed, but no scrape noise or other hf correction. Now whats the bandwidth of information on a 60hz carrier?? Hence the desire to use such things as bias, which is commonly in the 100-200khz area for many professional recorders.
Alan
Marc Orbert-Thorn has been using CEDAR and research into historical pitch for a long time.
http://charm.cchcdn.net/redist/pdf/s3ObertThornnotes.pdf
http://charm.cchcdn.net/redist/pdf/s3ObertThornnotes.pdf
ok dumb question. How do you play only one groove wall?
Laser?
billshurv,
Is that even physically possible? It would seem you would have to be able to bias the stylus to only touch one side, I don't see how you could do that?
Is that even physically possible? It would seem you would have to be able to bias the stylus to only touch one side, I don't see how you could do that?
exactly. I've read about this before, but on less salubrious fora than this. I always figured it was people getting confused and assuming L measured one wall and R the other!
But curiosity is piqued now!
But curiosity is piqued now!
A fuller version of the obert-thorn presentation http://charm.cchcdn.net/redist/pdf/s3ObertThorn.pdf
I can almost hear the gasps of horror from some on his setup!
I have to say I rather like the Dutton releases, but he clearly thinks they are over processed! Must listen to that nimbus prima voce CD I have again (accoustic player with calrec mic shoved into the horn).
I can almost hear the gasps of horror from some on his setup!
I have to say I rather like the Dutton releases, but he clearly thinks they are over processed! Must listen to that nimbus prima voce CD I have again (accoustic player with calrec mic shoved into the horn).
Untitled Document suggests no lasers in use at least for his day job!
Mark was first brought to my attention by a totally non-tech music loving friend simply for the quality of the end product.
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reading the article he wrote suggests a real love for what he does, which always bodes well. I do wish there was more published on how Michael Dutton does his stuff.
You may have guessed I have a thing for historical re-issues 🙂 I also am an avid supported of Naxos for the sheer volume of weird stuff they release cheaply!
You may have guessed I have a thing for historical re-issues 🙂 I also am an avid supported of Naxos for the sheer volume of weird stuff they release cheaply!
I'm starting with PPM source , amplifying with PPM silicon.
Then I end up with the mess that my physical drivers (loudspeaker) make of this
perfection.What am I missing ?
Subjectively , I'm listening to 200W aggressive rock now , the amplification
is absolutely stellar. What could the guru add to this ?
Could he give me a source that would make my -200w more stellar ?
PS - I'm PC- DAC - 200W amp - straight shot !!)
OS
You said it yourself, I think. You've picked most all of the low and high hanging electronic fruit.
Speakers and room, my friend. Ransack Diyaudio for Earl Geddes and Tom Danley speaker design thought. Also their sites, Gedlee.com and DanleySoundlabs.com. Pay lots of attention to what Geddes says about diffraction and psychoacoustics.
IF you're fixated on source, ask Richard Marsh or Damian (1audio) what's optimal (as opposed to perfection).
But I think you'd get a bigger bang working on speakers fit for the electronics you've designed.
You said it yourself, I think. You've picked most all of the low and high hanging electronic fruit.
Speakers and room, my friend. Ransack Diyaudio for Earl Geddes and Tom Danley speaker design thought. Also their sites, Gedlee.com and DanleySoundlabs.com. Pay lots of attention to what Geddes says about diffraction and psychoacoustics.
IF you're fixated on source, ask Richard Marsh or Damian (1audio) what's optimal (as opposed to perfection).
But I think you'd get a bigger bang working on speakers fit for the electronics you've designed.
I made my statement because I had a taste of what my 200W sounds
like on some good Canadian loudspeaker (Paradigm S6's).
I must say there is a lot more "lore/Voodoo" in the speaker design
threads. Many subjective preferences.
OS
I made my statement because I had a taste of what my 200W sounds
like on some good Canadian loudspeaker (Paradigm S6's).
I suspect, cuz I can't find any decent polar response measurements, that the S6's are barely decent even though they perhaps sound better than most bought-in-in-a-store gear in their price range. But that's probably OK as I seem to remember you were/are using pretty ragged speakers.
But even the 'Econowave' speakers folk here are making at 10th the price of the S6's probably would come out well in comparative measurements and subjective impression if the builders deal with diffraction.
Yeah, that's why I pointed you at Geddes and Danley because their work is science based.I must say there is a lot more "lore/Voodoo" in the speaker design
threads. Many subjective preferences.
OS
Did-you missed the Le Cleac’h thread ?Yeah, that's why I pointed you at Geddes and Danley because their work is science based.
http://www.diyaudio.com/forums/multi-way/140190-jean-michel-lecleach-horns-new-post.html
And don't you think "science based" is just half of the way ?
Once again, Hifi or audio recording/reproduction is a "make believe" game. Science is a tool to save time, ensure a component in your system satisfy minimal requirements. And they are all far from perfection. Only your subjective judgement will ensure a tune you are listening-to will be "believable" or not...for your ears. And this is all the beauty of our hobby ;-)
Loudspeaker development is more knowledge based than science based, although the latter comes into play.
erm does that statement actually make any sense given the std definitions of science?
I think he's talking about the kind of knowledge that a craftsman has, more intuitive.
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