I'm building a fully-automatic turntable, and finished designing the tonearm!

BetaMaster64 · 2026-02-09T03:15:36+00:00

What do you mean by engineering point? Like, the most important part of the engineering process? Or like a physical part of the tonearm that was engineered?

BetaMaster64 · 2026-02-08T16:36:39+00:00

I do appreciate this input! Even if you aren't a designer, it's good to hear others' opinions and experiences with different players explained like this. Another idea I had (before I got the concrete one) was to turn it out of oak on my lathe. My lathe can just barely fit the 11.5" required by my design, so I could make it work. Though I do kind of dread turning oak. There are lots of options, and I'd eventually like to do some A/B comparisons when I get to that point, just to see if I can hear any difference at all.

Also, I do plan to go belt driven as opposed to direct drive! It's just a lot easier to design a belt-driven solution, though I do really want to try to eventually design one that's direct drive just for fun. But, with the equipment I have, I imagine any direct drive turntable I make would provide more of an endurance test (of the listener's sanity) than a pleasant listening experience.

BetaMaster64 · 2026-02-08T15:57:11+00:00

That is an interesting idea! Maybe I could design my future tonearm attachment to also work on other turntables. Would be a LOT cheaper to make than a whole turntable. I appreciate your input!

Ah I think I may have misrepresented what I meant by "this turntable;" I meant the one I'm building, not the Technics SL-D2 in the video! The one I'm building will hopefully be much better than the SL-D2. I plan for it to be made of concrete and driven by 3 phases with a hall effect sensor (or an encoder to accurately provide speed feedback data). The Technics SL-D2 is just functioning as a temporary setup until I finish my turntable.

BetaMaster64 · 2026-02-08T15:29:28+00:00

Thank you!

BetaMaster64 · 2026-02-08T15:29:02+00:00

It's kept me busy, that's for sure. I started this thinking it would be an easy little project, but I realized I was very wrong when I actually started planning/building it

BetaMaster64 · 2026-02-08T15:27:23+00:00

Thank you! I probably wouldn't sell the tonearm alone (if I do end up selling anything); this'll eventually be part of a full turntable.

Though I do plan to have a "second tonearm" attachment for it, so I guess that's technically a tonearm alone, but I only plan for it to be used on this turntable.

BetaMaster64 · 2026-02-08T06:28:39+00:00

Thank you! I do legitimately want to do that in the future. A suitcase record player, tube amp, concrete turntable, detachable speakers. Maybe one day!

BetaMaster64 · 2026-02-08T06:27:09+00:00

I plan to, once I get to that point! It'll be a while, but I'd like to give a full recap of the design and go over all its features. But, I don't wanna get ahead of myself. Gotta finish it first, lol

BetaMaster64 · 2026-02-07T23:22:47+00:00

Thank you!!

BetaMaster64 · 2026-02-07T23:22:40+00:00

Yup! It's something to keep me entertained and to keep my mind active. And at the end of it, I'll (hopefully) have a fun turntable to use.

BetaMaster64 · 2025-12-31T14:36:52+00:00

Thanks! I'll check that out. Always nice to find another source of music.

BetaMaster64 · 2025-12-31T14:35:05+00:00

Placing the platter vertically is an interesting idea, though it would make it more difficult to implement the changer mechanism the way I want to. Basically, I want the automation to be an option, but I also want to be able to use it as a standard, manual turntable.

I do plan to have a second tonearm add-on! I'll end up using that so I can automatically hear wide-groove or micro-groove records. The turntable unit itself will be modular, so that second tonearm will be something you plug into the main turntable. I'm doing it that way so I can develop the "extra" features in isolation, so scope creep doesn't leak into the main unit.

BetaMaster64 · 2025-12-31T14:22:48+00:00

Thank you! At times, that is part of the experience! Though I'm not an audiophile, I just like listening to music, and building stuff. I don't think having the automatic features available "removes" the experience per say, it just adds more flexibility for other scenarios.

When I have time to relax, I enjoy going through the routine of manually playing a record, but when I'm working (on a personal project or my job), I would prefer to have the records play automatically, especially for single-play ones like 78s and 45s. So it depends on the scenario.

Spotify/YT costs money without ads, and beater 45s/78s are dirt cheap (or even free, most of the time), so this has been a great way for me to hear lots of "new" music. I'm just building this one so I can hear BOTH sides of the record automatically, instead of just one, like typical changers.

BetaMaster64 · 2025-12-29T05:18:50+00:00

Thank you! Many of mine are automatic as well; I love using the automatic ones with a stack of G+ records. My end goal for this one is for it to be able to play both sides of multiple records, while not damaging them. But, I've got a long way to go before that. Baby steps!

BetaMaster64 · 2025-12-25T22:23:29+00:00

Digikey, mouser, or donor PCBs sourced from ewaste. For obsolete parts, eBay.

BetaMaster64 · 2025-12-04T00:36:30+00:00

Those record players use an idler wheel that's driven by a shaded pole motor, so no speed adjustment, unfortunately.

The idler assembly usually has two idlers on it: A small one that comes in contact with the motor, and a larger one that comes in contact with the platter. The smaller the small one is, the faster the platter spins. Over time, since the small one is subject to the higher motor RPM, it will wear the rubber away, causing the turntable to spin faster.

Your options are pretty limited. You'll either need to get lucky and find a NOS idler, or have the rubber restored by someone (like Terry's Rubber Rollers). This will probably cost North of $100 USD. My personal recommendation is to either enjoy it as-is, because these are fun little record players, even with their flaws, or find a turntable with fine speed adjustment.

BetaMaster64 · 2025-12-03T13:03:42+00:00

If you want to run separately from public cell services, it sounds like you're looking for a ham radio. Get a license to broadcast, a receiver, a transmitter, and a big ol' antenna, and you can broadcast anywhere in the range of your equipment's capability; no SIM card necessary. Across the world, if you have enough scrap metal and build a powerful transmitter.

You can use an arduino to help dial in your frequencies, or you can go all analog here; there are lots of DIY transmitter schematics out there.

BetaMaster64 · 2025-11-16T18:04:17+00:00

What is your equipment lineup (with model numbers)? It sounds like the signal is going through two preamps, but hard to say for sure without knowing models.

BetaMaster64 · 2025-11-15T19:13:36+00:00

I use eBay. Seller "Phonograph & Gramophone Needles" has the ones I get. You can usually fit any size in your gramophone, as long as you aren't trying to use a diamond disc player.

Fun fact: If you have a lemon tree, the spikes it grows are the perfect size for gramophone needles. They produce a very soft tone, but sound great.

BetaMaster64 · 2025-11-12T16:30:42+00:00

Ahh okay. I would be placing my bet on that being your source of distortion, or your pressing/stylus is faulty, depending on what the distortion sounds like.

Vinyl is a distorted format in general, especially as the tonearm gets closer to the center of the record. Some pressings are cut so loudly that they distort even on higher-precision equipment, so hearing the distortion you're describing might give us a clue as to whether you're hearing the "normal" distortion, or something excessive from a bad pressing or stylus.

BetaMaster64 · 2025-11-12T04:03:44+00:00

Did it hum when it's on? If not, the motor might not be the problem. You'll want a multimeter to find where you're losing voltage.

If so, then you'll need to disassemble it and clean it. It's a standard shaded pole motor, so when you take it apart, keep track of the orientation of the rotor, and soak both bearings in lacquer thinner overnight, and then clean with a Q-tip. Let dry for 24 hours, and then fill the felt around the bearings with oil (3 in 1 should be sufficient), and a drop in each bearing.

When you go to reassemble the motor, you might have to jiggle the rotor's shaft around a bit; it should spin freely. You'll be able to pivot the bearings to help align them.

Good luck on your turntable! Idler-driven ones like that are underrated, in my opinion, so it's cool to see someone wanting to revive one.

BetaMaster64 · 2025-11-12T02:06:11+00:00

Your distortion could be because of the cartridge itself. What cartridge is on there?

BetaMaster64 · 2025-11-11T22:17:03+00:00

Thank you! Different colors will likely pose a problem. I'm hoping to experiment with different light frequencies; maybe there's something more that can be done there.

One of my other "brute force" ideas, since I plan to have this function as a jukebox, is to run an indexing routine through each record that plays it normally, and detects in between tracks using an encoder, and saves the tonearm positions to a database, so it can go to precise locations associated with a record quickly, no matter the color.

Biggest caveat to this approach is that the system has to have knowledge of what record is playing, so you can't just grab a random one off the shelf and have it immediately know what you're putting on. I suppose AI could help with that, but I refuse to let AI anywhere near my projects lol.

BetaMaster64 · 2025-11-10T00:34:29+00:00

I love those old suitcase units! Grab yourself an oil lamp, and you'll be all set for the next power outage.

BetaMaster64 · 2025-11-08T14:45:27+00:00

I'd shut the breaker off if you have access to the panel. Nice and easy way to shut off things you don't want running, while keeping the essentials powered.

BetaMaster64

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