Dissected, but far from dead:
Here lies the nerve center of an essentially brand-new Technics SL-100c:
So... Where to begin?
Browsing eBay on a recent evening, I ran across a listing to the effect of, " !!PARTS!! Technics SL-100/1500 Tonearm, Platter, Motherboard, Otherboard. "
Okay, uhhh... [clicks mouse]
As advertised, the seller was parting out a "damaged in shipping" 100c that he'd purchased "as a return." After some back-and-forth, a story emerged: Apparently someone bought this $1k+ turntable on Amazon, stripped off the stock cartridge and then returned it in the original box (minus most of the original engineered packaging). As many likely know, there's sort-of a supply chain purgatory where (literally) billions of returned items languish for long periods before being either bundled and resold or trucked off to a landfill. Never did I imagine those items to include things like brand-new turntables with ultra-accurate coreless motors that hifi mags have been raving about.
According to the seller, the unit was basically loose in the box and took a beating in transit: Dustcover destroyed, tonearm badly damaged, chassis cosmetically irredeemable, and... motor working perfectly. Unable to stop myself, I bought the motor, platter and everything you see here for a few hundred bucks.
Why tho?
Well for one thing, I've since confirmed the performance: Assembled with the motor just sitting on my desk, the RPM iphone app shows the platter running at 33.34 +0.03, w/f 0.15% (and even better at 45). That DUSTS the belt-drive deck I spent a mint on five years ago (which frankly leaves me wanting in other ways as well). More than anything, I just want to get my hands into this. I lust after classic broadcast decks, and have long wanted to join the SP-10 club (yes, I've spent a lot of time on The Incredible Thread). But for a lower price-of-entry, and given the specs above, this seems like a pretty cool alternative challenge.
And before anyone asks: Yes, I'm a bit out of my depth. I know this will cost more than I think. I don't yet have all the tools I'll need. There will be massive research and a lot of trial and error. I know there's a lot I don't know, and I'm prepared for this to take a long time.
So all that said, this thread will serve as the build log.
It's getting late, but at some point over the weekend I'll post my progress so far, my overall plan, anticipated next steps, and a few questions for the forum.
Really hoping a few of Technics Heads (and other experienced folks) will vibe with this project, follow and advise.
Cheers!
Here lies the nerve center of an essentially brand-new Technics SL-100c:
So... Where to begin?
Browsing eBay on a recent evening, I ran across a listing to the effect of, " !!PARTS!! Technics SL-100/1500 Tonearm, Platter, Motherboard, Otherboard. "
Okay, uhhh... [clicks mouse]
As advertised, the seller was parting out a "damaged in shipping" 100c that he'd purchased "as a return." After some back-and-forth, a story emerged: Apparently someone bought this $1k+ turntable on Amazon, stripped off the stock cartridge and then returned it in the original box (minus most of the original engineered packaging). As many likely know, there's sort-of a supply chain purgatory where (literally) billions of returned items languish for long periods before being either bundled and resold or trucked off to a landfill. Never did I imagine those items to include things like brand-new turntables with ultra-accurate coreless motors that hifi mags have been raving about.
According to the seller, the unit was basically loose in the box and took a beating in transit: Dustcover destroyed, tonearm badly damaged, chassis cosmetically irredeemable, and... motor working perfectly. Unable to stop myself, I bought the motor, platter and everything you see here for a few hundred bucks.
Why tho?
Well for one thing, I've since confirmed the performance: Assembled with the motor just sitting on my desk, the RPM iphone app shows the platter running at 33.34 +0.03, w/f 0.15% (and even better at 45). That DUSTS the belt-drive deck I spent a mint on five years ago (which frankly leaves me wanting in other ways as well). More than anything, I just want to get my hands into this. I lust after classic broadcast decks, and have long wanted to join the SP-10 club (yes, I've spent a lot of time on The Incredible Thread). But for a lower price-of-entry, and given the specs above, this seems like a pretty cool alternative challenge.
And before anyone asks: Yes, I'm a bit out of my depth. I know this will cost more than I think. I don't yet have all the tools I'll need. There will be massive research and a lot of trial and error. I know there's a lot I don't know, and I'm prepared for this to take a long time.
So all that said, this thread will serve as the build log.
It's getting late, but at some point over the weekend I'll post my progress so far, my overall plan, anticipated next steps, and a few questions for the forum.
Really hoping a few of Technics Heads (and other experienced folks) will vibe with this project, follow and advise.
Cheers!
Okay, some more details on this project, followed by some questions for the forum...
The plan:
Design and construct a stacked baltic birch ply plinth & mount the motor within it, as w/the familiar massive SP-10 and idler decks. Confirm speed accuracy/stability/damping/silence/etc when the platter is mounted. Find cool tonearm(s)/cart(s) to play with. Analog bliss.
Progress:
Step 1: (and big credit to the eBay seller, who took the time to understand my purpose and restructure his listing) was to find a service manual, unpack the parts, source few critical fasteners/standoffs, and simply hook everything up on my desk. Boom - motor & controls working perfectly.
Step 2: Obviously, this motor doesn't "drop-in" like the broadcast classics I mentioned. Here, the motor/bearing/spindle is a unified assembly that mounts to the stock table's chassis from underneath, via machine screws. So the first major hurdle to 're-plinthing' is coupling that macro-part to the birch ply. I'm working on a metal mounting bracket to achieve this. Note: this is my current stage in the process. So I'll go into detail in the next post.
Step 3: Design the plinth around the bracket. This order of operations makes the most sense to me; I can't/don't want to change the spacing or thread pitch of the mounting holes in the bearing's machined outer enclosure, so making the bracket to align with it is critical. Once that's done, it drives dimensions & cutouts for each sheet of ply. (Current idea: wood-screws around the bracket's periphery, mount recessed into the plinth so the spindle sits at a level that floats the platter just above the deck.)
Step 4: Big decisions regarding the power supply & control PCBs, tonearms/armboards and footers. Note: see questions/considerations below
Step 5: Cut the birch ply sheets (hoping to lean on a friend w/ a CNC), assemble, source/mount hardware, test performance, fix mistakes, make tweaks, finish, rock 'n roll.
Questions/Considerations:
1. Inboard vs outboard controls - No matter what, the final table's PSU will live in an external, well-shielded chassis. But at the moment I'm wrestling with where to put the speed control and button PCBs. I've read threads here about isolating the power trafos of older, linear supplied SL-1200s, as well as discussions about outboarding control/logic sections on the SP-10 thread. Options in this case:
A: Shielded PSU --5V DC umbilical--> shielded control chassis --motor umbilical--> plinth mounted motor
B: Shielded PSU --5V DC umbilical--> plinth mounted control PCBs + motor (using the very short, stock motor ribbon harness)
I'm thinking opt. A has advantages in build simplicity & serviceability, plus it maximizes mass and eliminates complexity in the plinth. Meanwhile opt. B has a much simpler 5V DC umbilical and eliminates the possibility of induction & interference re: motor power/speed control signals. Very interested in advice from experienced folks on this.
2. SMPS vs Linear PSU - The SMPS that came w/ this table is operating perfectly. Initial measurements w/ (the admittedly not perfect) RPM app show great performance. For a moment, let's set aside the sheer audacity of thinking that I might be able to come up with a power supply that beats the one professional EE's designed specifically for this table. I can 1000% understand obsessing about the PSU delivering B+ to your power tubes. But can someone lay out - in simple language - or better, point me to data that explains what linear power offers in this application?
If it could make a 0.1% difference in RPM or W/F, I'd do it.
Also... I might do it just to do it. Hell, I could see building the SMPS and LPS into the same chassis with an A/B switch.
3. Experts.... given all I've written here (frickin novel, I know.) What am I missing?
The plan:
Design and construct a stacked baltic birch ply plinth & mount the motor within it, as w/the familiar massive SP-10 and idler decks. Confirm speed accuracy/stability/damping/silence/etc when the platter is mounted. Find cool tonearm(s)/cart(s) to play with. Analog bliss.
Progress:
Step 1: (and big credit to the eBay seller, who took the time to understand my purpose and restructure his listing) was to find a service manual, unpack the parts, source few critical fasteners/standoffs, and simply hook everything up on my desk. Boom - motor & controls working perfectly.
Step 2: Obviously, this motor doesn't "drop-in" like the broadcast classics I mentioned. Here, the motor/bearing/spindle is a unified assembly that mounts to the stock table's chassis from underneath, via machine screws. So the first major hurdle to 're-plinthing' is coupling that macro-part to the birch ply. I'm working on a metal mounting bracket to achieve this. Note: this is my current stage in the process. So I'll go into detail in the next post.
Step 3: Design the plinth around the bracket. This order of operations makes the most sense to me; I can't/don't want to change the spacing or thread pitch of the mounting holes in the bearing's machined outer enclosure, so making the bracket to align with it is critical. Once that's done, it drives dimensions & cutouts for each sheet of ply. (Current idea: wood-screws around the bracket's periphery, mount recessed into the plinth so the spindle sits at a level that floats the platter just above the deck.)
Step 4: Big decisions regarding the power supply & control PCBs, tonearms/armboards and footers. Note: see questions/considerations below
Step 5: Cut the birch ply sheets (hoping to lean on a friend w/ a CNC), assemble, source/mount hardware, test performance, fix mistakes, make tweaks, finish, rock 'n roll.
Questions/Considerations:
1. Inboard vs outboard controls - No matter what, the final table's PSU will live in an external, well-shielded chassis. But at the moment I'm wrestling with where to put the speed control and button PCBs. I've read threads here about isolating the power trafos of older, linear supplied SL-1200s, as well as discussions about outboarding control/logic sections on the SP-10 thread. Options in this case:
A: Shielded PSU --5V DC umbilical--> shielded control chassis --motor umbilical--> plinth mounted motor
B: Shielded PSU --5V DC umbilical--> plinth mounted control PCBs + motor (using the very short, stock motor ribbon harness)
I'm thinking opt. A has advantages in build simplicity & serviceability, plus it maximizes mass and eliminates complexity in the plinth. Meanwhile opt. B has a much simpler 5V DC umbilical and eliminates the possibility of induction & interference re: motor power/speed control signals. Very interested in advice from experienced folks on this.
2. SMPS vs Linear PSU - The SMPS that came w/ this table is operating perfectly. Initial measurements w/ (the admittedly not perfect) RPM app show great performance. For a moment, let's set aside the sheer audacity of thinking that I might be able to come up with a power supply that beats the one professional EE's designed specifically for this table. I can 1000% understand obsessing about the PSU delivering B+ to your power tubes. But can someone lay out - in simple language - or better, point me to data that explains what linear power offers in this application?
If it could make a 0.1% difference in RPM or W/F, I'd do it.
Also... I might do it just to do it. Hell, I could see building the SMPS and LPS into the same chassis with an A/B switch.
3. Experts.... given all I've written here (frickin novel, I know.) What am I missing?
1. Inboard vs outboard controls
On the plinth or chassis or whatever you end up making, in a spot not too different from where it would be stock. Ergonomics are VERY important and having the on/off and speed controls somewhere inconvenient is just silly.
2. SMPS vs Linear PSU
Absolutely nothing at all.
On the plinth or chassis or whatever you end up making, in a spot not too different from where it would be stock. Ergonomics are VERY important and having the on/off and speed controls somewhere inconvenient is just silly.
2. SMPS vs Linear PSU
But can someone lay out - in simple language - or better, point me to data that explains what linear power offers in this application?
Absolutely nothing at all.
Subscribed. Do consider mass loading with lead shot. (You can get it in 5 or 10lb bags as diving weights.) I did this with a baltic birch plinth for one of my TD-124 and it considerably tamed some objectionable mid bass resonances in the plinth. (I drilled pockets in the plinth with a 1.5" forstner bit, filled with shot and capped with JB weld.)
Looking forward to hearing more as your project progresses.
Looking forward to hearing more as your project progresses.
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110% yes, do that with lead shot. Makes a huge difference with the SP-10.
Awesome, thanks so much for taking the ride with me, you guys!
I feel you on ergonomics, 6L6. Aesthetics and user experience are part of the vision (I mean...who doesn't love a satisfying toggle switch throw???) I'll get more detailed when the time comes, but in my imagination both the onboard and outboard design options have a top-facing button panel that exactly mimics the on/off, start/stop and 33/45 interface that a club DJ would recognize.
Onboard is probably cleanest, but I'm imagining the additional plinth layer cutouts, screw holes to align, stuff that may resonate, etc.
Outboard, I imagine something that lives immediately next to the plinth, like a sloping Hammond stomp box, or maybe a Bottlehead-style chassis that wouldn't look out-of-place next to a nice rotary mixer. At some point my design ambition may collide with my fab skills... but long as it doesn't degrade the sonics, I'm down to try anything in the form-factor realm.
At the moment I'm working on a post about my motor mount design, but there's much more to come! And PS, your SP-10 thread is a huge part of the inspiration for this.
I feel you on ergonomics, 6L6. Aesthetics and user experience are part of the vision (I mean...who doesn't love a satisfying toggle switch throw???) I'll get more detailed when the time comes, but in my imagination both the onboard and outboard design options have a top-facing button panel that exactly mimics the on/off, start/stop and 33/45 interface that a club DJ would recognize.
Onboard is probably cleanest, but I'm imagining the additional plinth layer cutouts, screw holes to align, stuff that may resonate, etc.
Outboard, I imagine something that lives immediately next to the plinth, like a sloping Hammond stomp box, or maybe a Bottlehead-style chassis that wouldn't look out-of-place next to a nice rotary mixer. At some point my design ambition may collide with my fab skills... but long as it doesn't degrade the sonics, I'm down to try anything in the form-factor realm.
At the moment I'm working on a post about my motor mount design, but there's much more to come! And PS, your SP-10 thread is a huge part of the inspiration for this.
@kevinkr thanks for the tip about the lead shot. I wonder if you'd be kind enough to share photos or sketches if you have them - any ideas about where lead should go and how much to use are most welcome.
I understand the basics of this stuff, e.g., you want a natural frequency outside the audible range, minimal harmonics/ringing, and that you add mass to lower Fn and take mass away to raise it. But if I'm honest... I'm new to this, Baltic Birch is pretty, and Finite Element Analysis really ain't my bag.
I read a ton of posts - mass loading vs constrained layer vs machining solid aluminum billet vs Panzerholz Uber Alles! - and personally, I'm not experienced enough to have strong feelings. That said, I do have a diploma from the school of Keep It Simple, Stupid so drilling holes, filling them with buckshot and sealing them up again is very appealing to me 🙂
I understand the basics of this stuff, e.g., you want a natural frequency outside the audible range, minimal harmonics/ringing, and that you add mass to lower Fn and take mass away to raise it. But if I'm honest... I'm new to this, Baltic Birch is pretty, and Finite Element Analysis really ain't my bag.
I read a ton of posts - mass loading vs constrained layer vs machining solid aluminum billet vs Panzerholz Uber Alles! - and personally, I'm not experienced enough to have strong feelings. That said, I do have a diploma from the school of Keep It Simple, Stupid so drilling holes, filling them with buckshot and sealing them up again is very appealing to me 🙂
What about a die-cast chassis/plinth?
If the prehistoric men could do it...
Pouring lead in a sand cast then press a wooden 'negative'.
I'd make it with three legs instead of four.
Most probably the arm is indipendent, not sitting on the chassis.
That leaves out the DJ (whatever that means) use and enters the realm of home audio.
If the prehistoric men could do it...
Pouring lead in a sand cast then press a wooden 'negative'.
I'd make it with three legs instead of four.
Most probably the arm is indipendent, not sitting on the chassis.
That leaves out the DJ (whatever that means) use and enters the realm of home audio.
What about a die-cast chassis/plinth?
I actually love this idea, and perhaps you're aware of it but I'll post a link to OMA's cast iron plinth anyway because it is dead sexy.
Oswalds Mill Audio
However in researching this adventure, I did run across a DIY example that is, well... less sexy. But still quite admirable, imo.
"Building my own turntable from scratch"
I'm still getting the hang of CAD for this project, so learning to die-cast might be a little aggressive at the moment. Also, I rent. Pretty sure the lease doesn't specifically forbid heating metals to 2800F, but.... Anyway, I like the way your mind works and I hope you'll stay tuned in any case.
As it happens, my mother is an artist who worked in bronze for a short time. She gave me her Dremel set after deciding to move on from the medium. Score!
Hmm ...aside from that, I see (and I feared...) that the arm is curved.
I advocate the external cabling, no cable going inside!
Eh eh those, together with the super self damping heavy base are revolutionary ideas...!?
A straight 8-10" tube is the new frontier.Most probably the arm is indipendent, not sitting on the chassis.
I advocate the external cabling, no cable going inside!
Eh eh those, together with the super self damping heavy base are revolutionary ideas...!?
After some travels last week and weekend, an update on the project...
Probably it will be good, given that some really smart, experienced DIY people are subscribed to this build... if I disclose where I'm starting from here. I work in an ad agency for a living. I'm on the creative side, so I get exposure to film/video sets, mess with cameras, animations, pro sound & vision, general problem solving. But I am absolutely not an engineer. I've done tube amp kits, DIYed all my cables, tweaked this and that.... but that's about it. I work with art school grads most days. That said, I'm a person who needs a project... or projects... at all times. Curiosity is key to my skill set, so I'm huge on diving into things I have no idea how to do.
All that to say... I gave myself a crash course in CAD this past week:
So... Part #1: A 200mm diameter, 6mm thick bracket to mounting the motor to the plinth I'm going to build. Not much to look at, but a pretty hefty design challenge for a total noob. The trickiest aspect was getting the measurements for the screw holes on the bottom of the bearing housing right. They're basically set up at the vertices of an equilateral triangle, but with M3 x 5mm screws, it's gotta be bang-on to .1 mm (which my $10 Amazon calipers....well, ain't). As you can see below, it took four tries to get it right.
Like I said, a lot of fuss for such a simple hunk o' metal. Any thoughts on the design are welcome. Basically, the idea is its circumference is wider than the motor, providing access to the fasteners around the periphery, and I want as much mass as practical. There are double cutouts to provide options on the final orientation of the wiring harness within the plinth, and the non-cutout section will be rotated toward the tonearm...theoretically putting more mass between it and the motor, while still accommodating vertical airflow.
As you can also see...I made a simplified model of the motor itself. It's certainly more detailed than it needs to be for this purpose - a cylindrical object with the motor's max circumference, height and screw-hole layout would've served just fine. But going the whole nine in an attempt to replicate a known object forced me to learn more CAD skills, which I suspect will serve me down the line as I tackle the plinth design.
Thoughts/Advice/Warnings appreciated!
Probably it will be good, given that some really smart, experienced DIY people are subscribed to this build... if I disclose where I'm starting from here. I work in an ad agency for a living. I'm on the creative side, so I get exposure to film/video sets, mess with cameras, animations, pro sound & vision, general problem solving. But I am absolutely not an engineer. I've done tube amp kits, DIYed all my cables, tweaked this and that.... but that's about it. I work with art school grads most days. That said, I'm a person who needs a project... or projects... at all times. Curiosity is key to my skill set, so I'm huge on diving into things I have no idea how to do.
All that to say... I gave myself a crash course in CAD this past week:
So... Part #1: A 200mm diameter, 6mm thick bracket to mounting the motor to the plinth I'm going to build. Not much to look at, but a pretty hefty design challenge for a total noob. The trickiest aspect was getting the measurements for the screw holes on the bottom of the bearing housing right. They're basically set up at the vertices of an equilateral triangle, but with M3 x 5mm screws, it's gotta be bang-on to .1 mm (which my $10 Amazon calipers....well, ain't). As you can see below, it took four tries to get it right.
Like I said, a lot of fuss for such a simple hunk o' metal. Any thoughts on the design are welcome. Basically, the idea is its circumference is wider than the motor, providing access to the fasteners around the periphery, and I want as much mass as practical. There are double cutouts to provide options on the final orientation of the wiring harness within the plinth, and the non-cutout section will be rotated toward the tonearm...theoretically putting more mass between it and the motor, while still accommodating vertical airflow.
As you can also see...I made a simplified model of the motor itself. It's certainly more detailed than it needs to be for this purpose - a cylindrical object with the motor's max circumference, height and screw-hole layout would've served just fine. But going the whole nine in an attempt to replicate a known object forced me to learn more CAD skills, which I suspect will serve me down the line as I tackle the plinth design.
Thoughts/Advice/Warnings appreciated!
ALSO... A poll for the group:
The plan is to use Send Cut Send to fabricate the mount. Assume we're going with stacked Baltic Birch plywood (mass loaded w/ lead shot) as a plinth material - and the bracket will span a recess within it, with wood screws around the periphery to fasten it to one of the plies.
What material would you choose:
A. Brass - (Purty; allegedly has a crystal structure that's better at damping transient vibration)
B. 316 Stainless - (Strong, and well... the most stainless)
C. 304 Stainless - (Cheaper than brass by three figures)
The plan is to use Send Cut Send to fabricate the mount. Assume we're going with stacked Baltic Birch plywood (mass loaded w/ lead shot) as a plinth material - and the bracket will span a recess within it, with wood screws around the periphery to fasten it to one of the plies.
What material would you choose:
A. Brass - (Purty; allegedly has a crystal structure that's better at damping transient vibration)
B. 316 Stainless - (Strong, and well... the most stainless)
C. 304 Stainless - (Cheaper than brass by three figures)
A straight 8-10" tube is the new frontier.
I advocate the external cabling, no cable going inside!
There's that concept of "known unkowns" ... i.e., stuff you know is important but don't understand at all. For me, that includes the math/physics of calculating an arm's effective mass, where to put null points along a tracking arc, how standing waves behave in extrusions of various shapes and materials...
When the time comes, I'm planning to buy an off-the-shelf arm. But I'm def going to cut a few swappable armboards... I'll save one for a DIY arm, down the road. Appreciate your confidence in me, tho!
Good call, thanks. I looked into that and to do prototypes of all the metal parts out of acrylic would be about $10/part. Worth it because it'll also reveal any kinks in the process with SendCutSend. An update for the moment though... Design of the plinth itself:
First, inspiration: In my book, Artisan Fidelity is the gold standard in this space. I dig the symmetrical look of their 2-tonearm 401 Statement deck: more wide than deep, platter positioned dead-center.
I also really like the deck in the second image, a design by Devon Turnbull, aka Ojas. Clean, expansive, minimalist. The hammertone looks great with the rest of the setup, I'll probably go for a natural finish. Also, I have to give Devon additional credit for inspiring this...he's the only other person I know to have "replinthed" a latest-generation Technics motor. If I hadn't seen his stuff before finding the SL-100c parts for sale, I doubt I'd be attempting this.
That said, I want to bring my own ideas to this, too. I want a wide plinth with a minimalist look, but I've decided to rule out a 2-arm situation so my plinth will have less surface area. I recall reading on the SP-10 thread that people think plinths start sounding good at 50lbs, so I'll probably try to calculate the height based on that. To get a sense of size, I cut the dimensions I'm thinking of out of butcher's paper and started positioning the parts:
For both aesthetic and electromagnetic reasons, I'll to try to integrate the speed control and button panel into the plinth. (Ideally the buttons will be perfectly flush w/the top surface.) Below, a first attempt to tackle the position and mounting method for the speed control PCB...hand-sketched and in CAD.
Currently the idea is to sandwich the main PCB between two stainless plates. This provides a both a structure to mount the board and a shield/enclosure for the electronics. The slot provides ventilation for the onboard regulators and the square hole vents the CPU. The round hole is the exit for the wiring harness that runs to the control buttons.
I'll be modeling the plinth in 3D CAD as time & schedule allow this week. Meanwhile, feedback is appreciated!
Cheers, all.
First, inspiration: In my book, Artisan Fidelity is the gold standard in this space. I dig the symmetrical look of their 2-tonearm 401 Statement deck: more wide than deep, platter positioned dead-center.
I also really like the deck in the second image, a design by Devon Turnbull, aka Ojas. Clean, expansive, minimalist. The hammertone looks great with the rest of the setup, I'll probably go for a natural finish. Also, I have to give Devon additional credit for inspiring this...he's the only other person I know to have "replinthed" a latest-generation Technics motor. If I hadn't seen his stuff before finding the SL-100c parts for sale, I doubt I'd be attempting this.
That said, I want to bring my own ideas to this, too. I want a wide plinth with a minimalist look, but I've decided to rule out a 2-arm situation so my plinth will have less surface area. I recall reading on the SP-10 thread that people think plinths start sounding good at 50lbs, so I'll probably try to calculate the height based on that. To get a sense of size, I cut the dimensions I'm thinking of out of butcher's paper and started positioning the parts:
For both aesthetic and electromagnetic reasons, I'll to try to integrate the speed control and button panel into the plinth. (Ideally the buttons will be perfectly flush w/the top surface.) Below, a first attempt to tackle the position and mounting method for the speed control PCB...hand-sketched and in CAD.
Currently the idea is to sandwich the main PCB between two stainless plates. This provides a both a structure to mount the board and a shield/enclosure for the electronics. The slot provides ventilation for the onboard regulators and the square hole vents the CPU. The round hole is the exit for the wiring harness that runs to the control buttons.
I'll be modeling the plinth in 3D CAD as time & schedule allow this week. Meanwhile, feedback is appreciated!
Cheers, all.
Everything is looking great!
I’d suggest making the plinth a more reasonable size, turntables are already large, bigger is nifty, for sure, and the larger plinths can look amazing, but as the size increases the difficulty greatly increases in finding places to put it.
As for weight, lead is your friend.
I’d suggest making the plinth a more reasonable size, turntables are already large, bigger is nifty, for sure, and the larger plinths can look amazing, but as the size increases the difficulty greatly increases in finding places to put it.
As for weight, lead is your friend.
Got on a roll this/last evening & worked out a first pass at the plinth.
I did end up with something (slightly) more reasonable than what I laid out on the butcher sheet; about 27.5" x 17". Yeah, still a monolith.
It'll make a statement, but the dimensions work just fine with the credenza-style rack that houses my setup. And I haven't settled on an arm, but for visual scale reference (and fun) I measured for and scaled an image of a Schick 12.5. The counterweight will overhang the back edge unless mounted with the rest at a slight angle.
More design details forthcoming. I'd really love for experienced plinth builders to chime in!
I did end up with something (slightly) more reasonable than what I laid out on the butcher sheet; about 27.5" x 17". Yeah, still a monolith.
It'll make a statement, but the dimensions work just fine with the credenza-style rack that houses my setup. And I haven't settled on an arm, but for visual scale reference (and fun) I measured for and scaled an image of a Schick 12.5. The counterweight will overhang the back edge unless mounted with the rest at a slight angle.
More design details forthcoming. I'd really love for experienced plinth builders to chime in!
CALLING ALL PLINTH BUILDERS!
Especially if you work with CNC...thoughts & advice much appreciated.
I've never done any of this before. Images of the full design are above (post #19). Below are details...
If they look messed up to you, please lemme know!
PS: I'm hoping to collab with a friend who has a CNC. Not an audio guy. A boatbuilder. Who does very nice woodwork. (However, he's out-of-state, so shipping may get prohibitive. Open to options and suggestions for suppliers and shops. I live in SoCal.)
Anyway... Cutouts for tonearm and control buttons are coming to a future post. Presently, my focus is good measurements to accommodate the motor & platter, plus adequate accounting for wiring and ventilation. Here's each layer (all are top view):
1.
2.
3.
4.
#1: Complex cuts all the way thru, leaving underside recesses open for easy service. The space top left is for the speed control PCB, which will mount between two .030" plates of 304 stainless for general protection (hoping also to experiment w/grounding to reject EMF). There's a wide opening for the 11-pin harness to the motor PCB and a narrow, half-channel for power. That cable comes off the board as a 4-pin ribbon but I'll terminate to XLR and an umbilical to the PSU.
#2: Rubber meets road. The cut-thru matches sheet #1 to further make room for airflow, wiring, and heads of the bolts that mate Technics' bearing to my DIY mount. That mounting bracket (see post 13) will meet the face of the plinth via wood screws. The trick is recessing that face to a depth that floats the platter just above the deck. Definitely will mock this up something cheaper than birch. Maybe foamcore?
Not much to #3. Except to mention the design assumes 4 layers of 1" ply. If that needs to change, it's just a matter of adjusting the # of layers and thickness of the extrusions in CAD.
#4: One Technics design detail I love is how the platter is recessed so its chamfered edge is flush with the plinth. How many migraines will I get trying to nail this?
OKAY, Stupid Question Time:
First, any red flags in these designs? Certainly more complicated things have been done in the Garrard/Lenco world, but I don't know what I don't know.
Second, measurement tolerances. I'm guessing baltic birch isn't actually available in both imperial and metric, and that listings for 1" vs 25mm are the same products. Is that an accurate assumption and if so, is 0.4 to 0.5mm a good margin for error?
Also, how accurate is your average pro-sumer CNC machine, anyway?
If you read this far... THANK YOU!
Especially if you work with CNC...thoughts & advice much appreciated.
I've never done any of this before. Images of the full design are above (post #19). Below are details...
If they look messed up to you, please lemme know!
PS: I'm hoping to collab with a friend who has a CNC. Not an audio guy. A boatbuilder. Who does very nice woodwork. (However, he's out-of-state, so shipping may get prohibitive. Open to options and suggestions for suppliers and shops. I live in SoCal.)
Anyway... Cutouts for tonearm and control buttons are coming to a future post. Presently, my focus is good measurements to accommodate the motor & platter, plus adequate accounting for wiring and ventilation. Here's each layer (all are top view):
1.
3.
#1: Complex cuts all the way thru, leaving underside recesses open for easy service. The space top left is for the speed control PCB, which will mount between two .030" plates of 304 stainless for general protection (hoping also to experiment w/grounding to reject EMF). There's a wide opening for the 11-pin harness to the motor PCB and a narrow, half-channel for power. That cable comes off the board as a 4-pin ribbon but I'll terminate to XLR and an umbilical to the PSU.
#2: Rubber meets road. The cut-thru matches sheet #1 to further make room for airflow, wiring, and heads of the bolts that mate Technics' bearing to my DIY mount. That mounting bracket (see post 13) will meet the face of the plinth via wood screws. The trick is recessing that face to a depth that floats the platter just above the deck. Definitely will mock this up something cheaper than birch. Maybe foamcore?
Not much to #3. Except to mention the design assumes 4 layers of 1" ply. If that needs to change, it's just a matter of adjusting the # of layers and thickness of the extrusions in CAD.
#4: One Technics design detail I love is how the platter is recessed so its chamfered edge is flush with the plinth. How many migraines will I get trying to nail this?
OKAY, Stupid Question Time:
First, any red flags in these designs? Certainly more complicated things have been done in the Garrard/Lenco world, but I don't know what I don't know.
Second, measurement tolerances. I'm guessing baltic birch isn't actually available in both imperial and metric, and that listings for 1" vs 25mm are the same products. Is that an accurate assumption and if so, is 0.4 to 0.5mm a good margin for error?
Also, how accurate is your average pro-sumer CNC machine, anyway?
If you read this far... THANK YOU!
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