Economy Plywood Turntable

Intro: Economy Plywood Turntable

Make it Move. This was my actual challenge. This is a serendipitous project borne out of stumbling across a super cheap & probably super "crappy" turntable mechanism. Less than 20€ for a turntable. Wow.

You need one of these to complete the project, or you may need to tear apart a salvage turntable.

So, I wanted to make, both turntable and standalone record player. This project would be a lot simpler, without the addition of an onboard amp and speakers.

The Caveats - Look at my list of parts!! - This ended up costing a lot more than I thought. Most components were only available in Multi Packs... so the reality is, THE NEXT ONE will be super economical. I now have a huge box of spare parts, maybe for another project!

This instructable is really "food for thought" and not a precise how-to. It is to help people brain storm how to revive a broken turntable, make a new turntable, adapt a turntable etc,

So after I bought this dreaded turntable mechanism, (Semoic 28cm Metal Turntable) I faced the challenge...how do I make it move.

No power supply, no outputs, no inputs... just a strange 6 pin connector.

STEP 1: The Plan - How to Make It Move!

Once I figured out the dreaded 6 Pin Connector, on the dreaded base.

R (Right Channel Output)

L (Left Channel Output)

G (Ground For Output)

C (Some kind of control)

G (Ground For 12V DC In)

V (Power for 12 V DC in)

I the needed to figure out what on earth I could use to connect to it. After a lot of googling I figure out that it was a 6 pin JST male connection. So all I needed was a single 6 pin JST female connector, which I got in a gigantic box full of various JST connectors.

I drew a 1:1 mockup / circuit diagram, to help figure this out in my head.

Basically:

Connecting the channels Out to the corresponding pins on a mini amp.

Connecting the 12V DC to both the AMP and the Motor

Adding inline switches on the 12V DC live wire.

Adding Speakers to the outputs on the AMP.

Adding a loose output connection for a REAL AMP!!!

I wont go into too much detail on this, the fun is in the working out. It is extremely tedious to terminate the JST connections, and 100% requires a crimper. I have included the crimper I purchased in the Tools list at the start.

Honestly, for something that looked extremely complicated, when its broken down into it's constituent components, it's just a few very simple connections, and logical leaps that anyone familiar with a home stereo would make.

STEP 2: The Fun Stuff

After Marking out the shape of the sandwiched plywood enclosure I do the following.

1. Screw the 3 boards together, in inconspicuous locations, so the outer cut of all three boards is the exact same.

2. Cut the outer cuts. I used a band saw, ajig saw would do here. there is plenty of tidy up sanding required in any case. You want super clean cuts on ply, so if using a jigsaw, i would suggest putting masking tape, on the cutting line, or even sandwiching the whole assembly between 2 sacrificial plywood boards, to ensure a super clean cut and no frayed edges on the top and bottom.

3. Cut the inner cuts, using the turntable mechanism as a template.

4. The Glue up - Find as many clamps as you can, and as much wood glue as you can and go nuts.

STEP 3: The Red Herring

For some reason, I thought, "wouldnt it be nice if the platter was made from plywood also"

Off I went to cut out a perfect circle platter, and a perfect circle pulley wheel, to sit beneath the platter.

Its worth noting the process :

1. See my circle cutter base that I made for my router. Scrap plywood, screwed into router base.

2. A number of incremental passes with a straight cutter bit.

3. Leave say 4mm. Cut the remainder out roughly on a bandsaw.

4. Use a flush trim bit for the reamining piece. Leaving you, a PERFECT CIRCLE, with a PERFECT CENTERPOINT.

It certainly looked good, but untimately was a load of ABSOLUTE NONSENSE, that even if it had have worked with the motor provided, ended up adding far too much height to the central spindle. It alsowould have required a hollowing out of the "pulley" to allow the "arm-return" feature to click in.

Im afraid it was back to the plastic platter. However, the failures are an important part of the process to document.

STEP 4: Pulling It All Together

In order to truly complete the wiring beyond test circuits, holes must be drilled in the plywood plinth, to accommodate switches, input, output, and volume control. I took care in the setout of these parts, as the devil is in the detail.

At some point before this, obviously play a record, and satisfy yourself that your circuit works.

Some Notes:

Switches

Note, the stainless steel rocker type switches work well with the semi industrial plywood aesthetic. I toyed between keeping the "on / off" signage, and ultimately removed it.

Volume Control

Note, from photographs, how i cheekily extended the volume control knob, using a bolt off cut, and hacksaw, to splice an extension onto the existing control.

The Platter

I purchased a cork turntable mat, which i trimmed perfectly to size, using the plastic platter as a template.

STEP 5: Finishing Touches & Epilogue

One coat of Matt Varnish - and the job was complete.

Epilogue

The in built speakers and amp, are tinny, and really, novelty only. I naively thought that, they would be better, however running through my Technics Amp, this turntable sounds absolutely fine, to my untrained ears.

I have a new heavy weight pressing of Nirvana Unplugged in NewYork, amongst my vinyl collection which was begging to be played, after my vintage Beogram decided to only play through one channel. I'm very happy to lovingly play my small vinyl collection again.

This is NOT a project for an audiophile, rather a project for a curious tinkerer, perhaps one with the odd record, lying around, looking for one last spin.

The seductive quality of the "20 Euro" Turntable...ultimately cost maybe €60 - No doubt it is on par with similar cost new devices, however, it certainly looks good in my living room!

Comments

[MyenK]

can you please advise for C (Some kind of control) pin, what is the purpose of this pin?

on the picture, what amplifier you used? can you please give the aliexpress link of your used amplifier?

Thanks,
Kamol

[Rob Salmon]

Hi Kamol, to be honest I have no idea what the C pin does... maybe an on/off functionality... for this project, I ignored it!..
Link to amp below... to be honest, I dont know how succesful this was, connecting directly to speakers (see Andy Tech Dudes comments below) It works, but sounds very tinny- It does however work perfectly, when the outputs are connected to an actual amp (but this defeats the purpose!!) - Hope this helps!
https://www.amazon.co.uk/Amplifier-TPA3116D2-Subwo...

[lachie0702]

Hi Rob,
Great project and such a nice outcome. You have inspired us to do a similar project. However, could you be so kind in helping with the "dreaded 6 Pin Connector, on the dreaded base" and advising where the pins for ground, + 12V etc. are on the connector to save my sanity?

[Rob Salmon]

Hey, See attached photo, which should explain it - the key or legend, is actually printed on the circuit board . Hope this helps and best of luck!!!

[MyenK]

can you please advise for C (Some kind of control) pin, what is the purpose of this pin?

on the picture, what amplifier you used? can you please give the aliexpress link of your used amplifier?

Thanks,
Kamol

[lachie0702]

Hi Rob,
Thanks for the connector pin-outs. Such good units but whey know instructions or diagrams. My next challenge will be the mounting.
Cheers. Chris & Lachlie

[zemavietnam]

good i have

[Moorec]

Rob, the deck looks amazing and tbh €75 is nothing when you think this is your personalised record deck.
Quiet a few years ago saw one that was made by a artisan type HiFi come and it sold for around the £600.00 mark.
i have an old Akai record deck sitting in a box and when you get it out it wants land rights it’s so big. Good project I think.
best wishes Chris Moore

[Rob Salmon]

Chris, thanks alot for your encouraging words!

[burzurk]

How much did ALL parts cost?

[Rob Salmon]

Hi, I'd say 75€total... but almost everything came in multipacks, so If i was making another, it would be closer to 40€..... Alas, I wont be making another :) - but lots of spare parts for new projects!

[Gastonone]

Nice!
But..
The platter is often as heavy as possible for various reasons. I am not very much into this matter, but the reasons I think of are suppression of 'rumble', which is low frequency noise, leaking from the motor mechanism through the platter into the needle, element and so on.
The other reason they are made as heavy as possible is to get the plattter spinning as regular as possible. the more regular it spins, the better the sound.
Have fun!

[r.a.knack]

Nice! I'd like to build one but I can't seem to find that particular TT mechanism, at last not that source easily to the US (the link you posted seems to be a dead end, I'm aftraid...)

[Rob Salmon]

If you google "AAAE Top-28Cm Metal Turntable 33/45/78Rpm" you should get "AliExpress" links to this device. But... You're probably better off searching through junk sales for a turntable that you can take apart and revive! To be honest, I'd say this device is at best, something you'd find in super cheap USB record players!

[andytechdude]

Nicely done. Cost aside it is always good to see anything resurrected these days instead of going to land fill. Plywood layers are always a classy finish.
A note on the electrical output from a vinyl playing turn table should anyone wish to add their own amplification for the fully self contained unit.
The output from the bit that converts the groove "vibrations" on the record into an electrical signal representing the sound (stylus and cartridge) have a particular frequency curve that is not flat like those from say a CD player. If the turntable signal is simply amplified the sound will appear "odd" lacking bass and a lot of top end. This curve is known as the RIAA equalization.
(https://en.wikipedia.org/wiki/RIAA_equalization)
The really small turntable signal (about 10mV) needs to be corrected and amplified to normalize the sound and give the level a boost to a signal equivalent to that provided from a CD player or tape deck (about 300mV) before being fed into the power amplifier. This per-amplifier is built into amplifiers with a phono, (turntable input). Another slight complication is that the cartridges that were generally available came in a few different flavors. Depending on the type (moving coil / moving magnet / ceramic) the output signal voltage varied by quite a bit so the better amplifiers provide a couple of different settings to correct for the output type. The correction electronics can be a bit involved but there are cheap kits (US$19) available on the net that do the job.
Long live vinyl, or as the grand kids say really.....really big CD's

[Rob Salmon]

Wow Thanks - Very informative ! My sound is very good going directly to phono connection of 70's amp. The sound from my inbuilt amp is incredibly tinny, which I had put down to the laptop speakers (which didnt really sit right, as I dont get that kind of sound from a laptop!)
- my kids "just about "call vinyl "DVD's" - The eldest is 6. The next batch of kids, may not be aware of any "circular thingys"

[boffincentral]

If anybody is interested in making their own turntable from this and does not have a platter; I would recommend MDF over plywood for the platter. Yeah, it's horrible stuff to work with when cutting because of the dust it kicks up; so you are going to need dust collection but, you are much more likely to end up with a balanced disk.

Some of the new makers of lower cost turntables use MDF for the same reason.

[WWHverring]

Very interesting! I'm more in the category of "I wonder if I could repair my turntable" rather than actually building one. But for that end this is informative too, so thank you!

[jessyratfink]

Beautiful work!