Cutting A Record… On A CD

Vinyl records are an amazingly simple technology, but surprisingly we haven’t seen many builds to capitalize on the ease of recording music onto a vinyl disk. [Seringson] made his own vinyl polycarbonate cutter to record his own records at home. The impressive thing is he did this with parts just lying around.

Just like the professional and obsolete record cutters of yore, [Seringson]’s build uses two speaker drivers mounted at a 45° angle to reproduce a stereo audio track. Each of these drivers reproduce the left and right audio track by carving them into the polycarbonate of a CD with an extremely sharp needle. From the video, the audio quality of [Seringson]’s record cutter is pretty good – more than enough to recreate the sound of a 1940’s 78 RPM record, but not quite up to the task of reproducing something produced and mastered recently.

We’re extremely impressed that [Seringson] was able to a record cutter out of scraps he had lying around. Now we’ll wait patiently until a combination record/CD is released.

Tip ‘o the billycock to [Gervais] for sending this one in.


28 thoughts on “Cutting A Record… On A CD

  1. My friend Mike has been doing this for years, granted he uses refurbished antique record lathes instead of a home-made machine.

    He runs a little boutique record label if you want to some of his work. All of his lathe cut records are a work of art, in addition to the musical works of arts he cuts.

  2. If you glue two CDs together, cut the top one as a record and burn the bottom one as a CD and you would have a Record/CD combo (although I wouldn’t play it in MY CD player. :) )

    1. Start with double sided DVD (the ones you have to flip over to continue) and you would be good to go. I would wonder however how would track recorded on “vinyl” side would disturb balance at 56x speeds…

    2. CD’s play from the inside->out. The etched portion plays from the outside->in. It could be possible to burn/etch a half-and-half CD.

      I also wonder just how much the etching impedes the laser. It might be possible for the etched section to overlap areas storing data — that is just dreaming, though. Talk about dual-layer. :D

    3. CD:s have the data recorded in the top of the disc, just below the artwork so they can’t be carved on the top side. DVD:s on the other hand have the data in the middle of the disc so it would be possible to carve the top side of a DVD without destroying the data.

    4. A dvd would probably work better. Single layer DVDs often have 2 layers of plastic, with the reflective aluminum coating between the two, so you could safely etch the top of the disc and burn the bottom.

  3. This is great! I’ve been brainstorming on this for about a year, but couldn’t find anything sharp enough to actually cut the CD. This is just excellent. Nice hack!

  4. <blockquote cite="Brian Benchoff" … impressed that [Seringson] was able to a record cutter …
    I think you accidentally a word.

    I usually don’t bother pointing these out, but seriously: proof reading is not rocket science.

    As for the hack – this is freaking awesome.

  5. Not to take away from this, it’s pretty neat, but now I am started on a train of though what you could do with those old recordplayer needles and amps, you have very sensitive fine sensors basically and there must be some non-musical use for that too. Something original.

  6. 45 degrees?! I think 90 degrees is the proper angle. That way each track is at a right angle to the other and should (in theory) be ignored by the other.
    I wonder if a dremel type tool with a pointed diamond cutter could be used to cut the groove. It may not having a small enough point.

    1. how would that equate to pushing the needle down? The 45 degrees is so they each translate in to movement of the needle up and down. If the needle were mounted at 90 degrees the side to side motion of the needle would have it scratching into other tracks making it useless.

  7. I still don’t get how a stereo stylus can truly play stereo sound – it seems that there must be significant inherent cross-talk between tracks. If the stylus moves significantly right in the groove, then it can no longer respond to input from the left side as well. Obviously, it works, I just don’t get it from a basic physical perspective. Is it because the track walls are at a 45 degree angle? Then, as the stylus moved rightward, it would also move down the wall of the right track (as the grove widened) and so maintain contact with the left wall, just deeper in the groove.


    1. im no expert but theres an easy way to find out the amount of “seperation” *_without_* reading any manuals…

      ever heard of a “difference recording” ???

      hint: its used to partaily remove the vocals, provided that…(google/wiki)

      do a difference recording of the same song from the two different devices and compare…

      EX: original CD > difference-recorded MP3
      original OLD RECORD > difference-recorded MP3
      (same song)

      1. i suspect FM STEREO isnt perfect either…
        remember its NOT really a stereo transmission, that takes two seperate tuners for two stations (L&R)

        FM-STEREO is actually a mono track with a high-frequency CARRIER signal that carries indication of PAN-left-right, and (i think) suspect to weak signals and interference, hence the mono/stereo switch on the botton/back of older radios

        there was actually equipment in the 80’s that had a mono and a stereo-carrier connections, so two plugs but worth three connections(no need to use left as mono) but you needed to put a stereo-carrier decoding chip into all 2-channel amplifieres and it quickly died out.

      2. That’s not technically true. The FM stero sums and subtracts the two channels to get one channel that contains both signals, and another channel that contains the difference signal. The difference signal is not the same as panning, but is actually used to separate the original left and right channels out of the sum of the two. It is not panning the signal left-right.

        Just as 2+6=8 and 2-6=4 we can calculate that the mono signal amplitude at that specific time is 8 and the ratio between the left and right channel amplitudes is 1:4 which allows us to play either the mono signal or separate it back into stereo.

    2. Actually, it’s simple PWM (pulse width modulation), with a mechanical filter in the form of the needle’s mass.

      A wildly incorrect representation of this is putting a paper playing card into the spokes of a moving bicycle wheel – at different speeds, you get different frequencies. If you were to stick a card into the spokes from both sides, you’d have stereo.

      Of course, from an audio standpoint, that isn’t very interesting to listen to, but… you get the idea. Spokes suck for use with PWM audio, but for a few hundred years they were the first real portable digital audio encoding method, with one spoke per note. You may have seen a mechanical music box – that’s where it all started.

      (I’m skipping the original paper punch technology line to keep this short, as well as the lines on smoked glass or film tech. It’s fascinating.)

      However, spokes break, so cutting grooves into the material was the way to go. To get two channels, you needed either two grooves, two records, or different profiles on each side of a single groove. As always, the cheapest way won out.

      The original 90 degree cut was replaced with two 45 degree (off center) cutters and allowed both channels to be applied at once.

      Older mono players could synthesize the two channels into one; newer cartridges had two peizo elements to pull out two channels. There is a long history of filter design intended to alter or improve the sound that came out of this mess.

      As for FM, the L+R channel is broadcast as baseband audio, with a second channel of L-R that mono receivers can’t pick up. The individual L and R channels can be extracted from these two (L+R) (L-R) signals with reasonable separation.

      Games with this allow digital information to be superimposed on top of the mess, as well as the older SCA sub-carrier (such as books for the blind) services.

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