The Secret Society of Lathe Trolls

Pretty close, I think. As I recall, I was shooting for 18 degrees, although I'm not sure where that number came from. Maybe an average of what I had read here about other Trolls 'leaning their heads back.'

Hey, TognaB; here's a link to a write-up on the project.
https://www.schlockwood.com/_files/ugd/aee96f_180a574b56ae4b6b8b301596b5a26719.pdf

Good find; I'd get it if I were you. 99% sure that it's an embosser, unless Soundscriber had some 'crossover' models between technologies, but I am not aware that they ever did mag-sheet recorders. Best to build electronics from scratch, rather than work with circuits optimized for voice. Somehow I ...

You're right, Mark. Ping-pong clicks and pops are far more distracting than mono ones. It's been decades since I looked for (and easily found) a mono crystal/ceramic pickup; are they still made, I wonder? I wasn't aware that stereo ones were available, but never had to look for one. I remember when ...

Now THAT is interesting! Thanks for posting. I had young kids back then but never came across this item in any toy stores. Heck, I'd have bought one... for me! A browser search doesn't bring up a lot, but there was one image file that linked to a YouTube video of this jukebox in operation: https://w...

Yes. And note that the angle to the record surface is similar to what our Trolls typically recommend. What Soundscriber has done here is the proper way, translating the lateral motion of the armature to lateral groove modulation. If instead, as practiced by most experimenters, you "lean the head bac...

Wow, good find, tape! This patent is something to digest; I hope that between the lot of us we can figure it out. It might well be worth looking at the references cited at the end of the patent also. Any departure from a spherical embossing stylus may negate the drawbacks noted by Milton Morse in th...

I'll bet that, by the time this model came out, tape was taking over in the office. Pity, it is a beautiful machine!

For an embossed track, that's really pretty darned good. Better results than I've ever had. Good work!

Very commendable results, John. I think you really nailed this 1D re-engineering project. Congratulations! I remember back to my Presto 1D days, and how top-end response could be extended from 10kHz to 15kHz simply by cutting the traditional "long shank" stylus down to "short shank" length. The long...

You're making good progress, JJW, and taking the time to do that empirical testing along the way too! "Responsible R&D," good man!

Holy moly! Three hundred bucks for that? Back in the '60s, the university I attended had a Presto 8DG that, by that time even, was never used in the 4 years I was there. At the time I was cutting commercials and station IDs at home onto 16" discs for a local TV station that hadn't yet migrated to c...

If you're using the dashpot simply to lower the cutterhead, an airpot ought to work just fine. The action of an air dashpot vs. an oil one is sort-of 180-degrees. An oil dashpot is effective against small, rapid up/down motion, an airpot sort of neglects that and is better at controlling large ampli...

Good advice from Mark! As for the DSP board, I've used those (probably from another source, but how different can they be?) and never had a noise problem. Make sure that the gain structure through your equalizer lashup is where it belongs. That chip has lots of dynamic range; what you describe sound...

Prestoflex was about 1/8 inch thick (3.2mm). Beautiful work on those armatures, you're good! That would be a quite involved YouTube video, I would think, well beyond the skill level of most of us.

Good to see continued experimentation and progress. And you may be right about over-damping; Presto relied pretty much on damping against the mass of the Prestoflex® block (which I think was pretty much just Neoprene), with it held lightly at just the one point to keep the damper assembly from unscr...

All good learning... and progress; keep at it! And I like the embossing angle you're using now, closer to vertical. Plus, I don't know the exact geometry of your stylus, but would think that the closer to vertical that it is, the smaller the area actually in contact with the surface of the blank. So...

Wow, like the 'diameter equalizers' of the pre-microgroove era. If that's for real it indicates that 'penetration' may be inversely proportional to groove velocity. If I had a Ph.D. I might be able to write an equation for that... for all the good it would do. Yeah, maybe because of stylus geometry ...

Can someone use this? Some time ago I ran across this item in an eBay listing: Snap3.jpg ...and wondered if it had applicability to our hobby. So I bought one and found that it did, indeed, provide plenty of suction. The only drawback is that it runs off 12 volts DC and pulls about 10 amps when it's...

Okay, thanks for all that; makes good sense. I'm not sure I understand how your springs provide any flex at all without the omega bend, it seems like they'd be compressing rather than flexing. But the implied increased stiffness probably accounts for the HF response extended past that 7-8kHz point y...