King of the Automatics - Technics SL-1600 MK2 Restoration

Back in the early to mid-eighties Technics began revising their core consumer turntable lineup, creating the MK2 series of SL turntables. These were, and often still are, regarded some of the highest quality and most feature rich turntables ever built. While the lineup has largely been overshadowed the monumental success of the MK2 SL-1200, there's one model that's held in nearly as high of regard: the MK2 SL-1600. Here's how I got along with one.

The MK2 SL-1600 succeeds the MK1 and they share the same core principal features; a direct drive motor, a suspended chassis, and a fully automatic mechanism. That's where all the similarities effectively end though, as the SL-1600 MK2 shares nothing else in common with it's predecessor. Honestly, that becomes apparent the second you look at this thing. With it's prominent front mounted control panel and slew of LEDs, you immediately know that this turntable is a completely different animal than the MK1.

What this basically is: it's a fully-automatic SL-1200 MK2. It sports the same style VTA adjustable tonearm and quartz locked direct drive motor as the 1200 MK2, and even the pop-up target light and pitch adjuster - now a small wheel on the front control panel with a KITT-like array of LEDs instead of a full-blown slider. This is a world-renowned DJ deck in the guise of a fancy 1980s home turntable.

This 1600 MK2 was in pretty spectacular condition considering it's age, but it had two major problems. The suspended chassis wasn't working and more importantly, the turntable itself was totally dead. The LEDs on the control panel would light up and respond to inputs, but the turntable wouldn't rotate and the tonearm wouldn't cue or move automatically. Usually, the most common things to go wrong in these decks is a bad tonearm belt or cracked drive gear, but neither of those things should affect the turntable being able to operate manually. The faults here are certainly electrical.

Starting off, I decided to try and figure out why the suspension was effectively non-existent. Looking at the bottom of the turntable, I really couldn't tell what the issue was since all the feet and springs looked intact. So I flipped it upright and pulled the platter off, thinking the issue might be internal.

I was instead greeted with a big fat warning label and three blue tinted screws along with the handful needed to pull the top cover off. The label says to remove the blue screws before use because they're meant to keep the plinth secured during shipping.

"Ah!" I thought. "That's the problem! Whatever nincompoop owned this thing prior never even bothered to pull those screws before using the turntable. Simple fix." And why wouldn't I think that? All I'd have to do is undo those screws and problem solved, right?

Wrong.

As soon as I pulled those screws out, front suspension propped up but the rear remained totally collapsed. I was befuddled. Obviously something crucial was missing, but even after looking the turntable over again, I still couldn't tell what it was. I ended up turning to the internet, and sure enough I wasn't the only one who went through this confusion.

Turns out there are supposed to be two red screws in the back of the turntable that link the suspended base to the plinth, and mine were missing. This differs from the MK1 where the feet screws were what joined the two halves together. On the MK2, only the front feet serve that same purpose. The rear feet just screw directly into the plinth and bypass the suspension pieces completely. I replaced the screws with some rough equivalents from the hardware store that I still had to cut down to size. The originals appeared to be metric sheet metal threads of sorts, so while my imperial replacements weren't quite the correct fit, they were snug enough when tightened down.

With the suspension sorted, it was now time to dive into the internals of the MK2. Pop the top cover off and you're greeted with a mind-bending slew of PCBs. If the MK1 was engineered like a Volkswagen Beetle, this thing is a Bentley Continental. Having just come off repairing the insanity that was the Sharp VZ-3000 though, this thing was a breath of fresh air. A fresh round of electrolytic capacitors seemed like a good place to start in addressing this thing's electrical woes.

This is just so stupid.

I'll still take this time to gripe about some of the more idiotic design choices Technics made with regards to the SL-1600 MK2's construction. Technics once again opted to separate the power supply and control PCBs from the motor and tonearm by mounting them to the plinth instead of the base - except there' now three large control PCBs partially buried under the plinth instead of the single easily accessible one of the MK1.

And then there's these two stupid wires that send AC power to the motor board. These two wires need to be disconnected from the motor board in order to fully separate the two halves of the turntable. But instead of just using a connector - in spite of all the dead space around the PCB, Technics opted to just tightly wrap the wires around two posts. And if the stripped ends of those wires break, you might encounter them just being soldered to the posts like mine are. Just fucking shoot me.

This all makes diagnosing the turntable's problems quite the pain in the ass. You have to effectively disassemble the entire top half of the turntable, just to be able to see all the PCBs when you reconnect everything for testing. But, considering where Technics wanted to go with this turntable, none of this is too surprising really. This is overengineered excess at it's finest. Sensibility be damned. 

The actual recap job is pretty straightforward otherwise. There's 29 electrolytic capacitors across the entire turntable, all of which cost me about $16 to replace from Digikey.

I also decided to take a look at the tonearm while I had everything apart. Unlike the MK1, the MK2's tonearm is driven entirely by a separate motor and everything from cueing to start/stop detection is controlled by infrared sensors and microswitches. What's interesting about this, is that even though the MK2 has a cueing lever, it doesn't actually actuate an oil damped piston like on the MK1. It's basically a glorified switch, and a kind of redundant one at that when you have button on the front panel that does the exact same thing. 

I don't know what Technics was hoping to accomplish with this. You can't raise or lower the tonearm with the lever if the power is cut and if the tonearm belt or gears are shot, then the entire thing is fucked until they're replaced. Maybe they were trying to eliminate the need for damping fluid, but it's hard to tell when any one of those components tends to go bad on a device this age anyways. It really just feels like a solution to a problem nobody had.

On the bright side, my belt was intact (possibly already replaced), as were the nylon tonearm gears. I strictly focused on re-lubing the VTA adjustment, which involved taking much of the tonearm mechanism apart - no simple task given that it's buried under a B-2 stealth bomber's worth of wiring and sensors. I had to desolder the tonearm wires since they passed the bulk of the parts, and I didn't want to risk them getting snagged.

You also really want to make sure all this stuff - especially the weirdly shaped cam plate (not pictured) that runs between the array of IR sensors, all goes back on exactly as it was before it was removed. The cam plate determines where the tonearm drops and lifts on a record and if it's not centered exactly as it was before removal, it can drag on other parts of the tonearm mechanism. There isn't any physical feature that helps you center this piece and there's a weird amount of slop in it's placement, so you have to carefully eyeball it and ensure it's not rotating off center before fully tightening everything down.

One of these things does not belong.

While I was removing the tonearm I ran into another odd discovery. One of the nylon standoffs for the tonearm was completely missing and in it's place, was one of the missing red screws from the rear suspension just threaded directly into the tonearm base from the underside of the turntable. I couldn't imagine how that standoff went missing, but it needed to be replaced.

Technics SL-1600MK2 Tonearm Standoff by YALE70

Near-impossible to source parts like this is where the 3D printer comes into play. I modeled a replacement off one of the existing standoffs in Inventor, then printed it in PETG. Two hardware store screws later, and problem solved. No more jank.

With all the internal work done, I threw on some new brackets for a shiny new Reloop dust cover and set to work dialing in the start/stop system - probably the biggest pain in the ass of this entire rebuild. Remember that cam plate I mentioned earlier? It features three adjustable plates that shift the position of the start and stop points. The only problem is that it's very sensitive and stiff, and you have to adjust it using a flathead screwdriver through a quarter-inch wide peep hole on the tonearm base. It takes absolutely forever, even with guidance from the manual. But once it's set, it's staying that way.

Where did all that work get us, though? Turntable nirvana.

Well, pretty damn close to it anyway. I'm not overly fond of the electronic cueing, or how the IR based record size sensor flat-out doesn't work with transparent vinyl, but this thing is whisper quiet and it holds speed like glue thanks to quartz lock. The VTA adjustment is also a very welcome addition, especially for those more fickle cartridge/styli combos like the VM95ML. I put it use immediately when I threw my own slipmat on top of the factory one to trick the size sensor into always dropping the needle for 12" records, transparent or not. 

The pitch adjuster and target light feel a bit like vestigial leftovers from the 1600 MK2's disc jockeying bones, but it's cool that Technics opted to include them even though it doesn't really need either. And of course, there's the looks. This thing looks sharp as hell being roughly four decades old and you don't see anything nearly this cutting edge looking on the market nowadays. I'm kind of surprised Technics hasn't done a refresh of this beast. We're on generation seven of the SL-1200 now and vinyl is more popular than it has been in decades. How about a SL-1600 MK3? Go nuts.

I guess the more pressing question is if the MK2 1600 is better than the MK1. Honestly, I feel like it's kind of a toss-up. One is pure simplicity and other is over-the-top extravagance. Unless you have an absolute need for quartz lock or VTA adjustment, it's still really hard to go wrong with the MK1. It's simpler to work on and less fussy in operation while still performing nearly just as well. That's not me discrediting the MK2 though. It's a damn good turntable and apart from my little complaints with it's operation, I suspect it's going to be a hard one to beat.