Technics SP-15

I recently purchased a SP-15 from AKs BT, the seller described the SP-15 as non functioning and the only sign of life was that it would power on. The turntable arrived very well packaged and I went to work cleaning the controls that were all jammed solid, the on/off/pitch-speed lock lever, 33/45/78, pitch and start/stop. I was sucessful cleaning everything but the start/stop. Crossing my fingers I turned it on and it ran on all three speeds and I could ramp thru the pitch up and down. This didn't last long and within a minute it was going about 200 rpm. Paul/thedelihaus came to the rescue and volunteered to take a look at it. The runaway speed is a common problem with some of the SP-15s. Quite a few people have reflowed three of the solder points on the power supply board and the SP-15 would again operate at the correct speeds. I checked with Cactuscowboy who had mentioned in a past post that he had cured the runaway speed problem on his SP-15. Dave replied and pointed out exactly where the three solder points were on the power supply board and I'm grateful for his help. With the info from Cactuscowboy I was on the way to see Paul who kindly volunteered to take some time out of his busy schedule to clean and resolder the three solder points. After resoldering the SP-15 was powered up and all three speeds were at their correct rate and the pitch adjustment was working. The SP-15 spent it's prior life in a radio station and it had been wired up for a remote. Paul removed the wires from the logic board and did extensive cleaning to the start/stop button, this is where skill/luck ran out. The start/stop button wasn't working, even useing the pad under the button wouldn't start/stop as it should. Paul thought the pad might of been severly corroded and no amount of Deoxit was going to undo the damage. If anyone has a recommendation for a new pad we'd appreciate hearing from you. Also if anyone is familiar as to how the remote was wired up and if anything else was defeated that info would be helpful, I'm only guessing it might of been a Henry Eng. remote, they were the most common. Also Paul adjusted the mechanical part of the brake that was rubbing against the platter but the electrical part of the brake works in conjunction with the start/stop button relay. I didn't have a lot of time to listen today but I installed it in one of my Techics plinths with ATP12T tonearm and it sounded good. Again many thanks to Paul/thedelihaus and if anyone could share any info on a remote model SP-15 it would be appreciated. Your results may differ but I have a hunch that just about all SP-15s are very fixable if they develop the runaway speed problem. As for the IC failure that is probaly very unlikly issue that anyone will ever incounter and there are donor ICs from other Technics models that are plentyful. True the Technics parts list says NLA but I'm certain if someone was to search beyond the local convenience store that they can be located. Paul said he would add some info/photo re this SP-15 for those that might be looking to do the same repairs. Again a BIG thanks to Paul/thedelihaus in making this SP-15 save.

That is good info for all SP-15 owners to hear. I owned one and was nervous about the problems you described happening so I sold it. My bad! I am sure the new owner is enjoying it very much...

Sure is nice looking cleaned up sitting in the plinth majik. I'd guess you probably have checked this but isn't the stop start the same button the same as on the 1200/SP25's?

Scott by all appearances the start/stop button is the same. Paul/thedelihaus cleaned/altered it to finction and it contacts the pad underneath that sends the signal to start/stop. Paul feels that it is also very likely the pad suffered even worse corrosion and so far Deoxit hasn't cured it. The pad could very well be an off the shelf part used in many applications/products, it doesn't appear to be the same physical size as the SL-1200Mk2 pad, both need to be soldered to the board.

Hey Rich, who'd a thunk the engineers at Panasonic (or at least he bean counters) would have used a different part there? Maybe a 1200 pad would work in a pinch? The deli will figure something out.:thmbsp:

Congrats on your new TT. I love my SP-15, which fortunately came to me in working condition (although I recapped it anyway, to be safe). It looks like you have the wood version of the original Technics plinth - I have the black version, and am using a 10" Jelco 750 on mine, with a Benz Micro Wood cartridge.

I'm listening to Sonny Rollins on mine as I type.

Looking good! Happy to see it up and running.

My SP-15 also came out of a radio station. God only knows how many hours are on it, but the build quality is so good I'm confident mine has many years if not decades of life left in it.

Dunno if you own any 78s, but the SP-15 is one helluva great turntable for playing them as well as LPs & 45s.

Firstly...

Special thanks to Cactuscowboy/Dave with his assistance in solving this issue. If anyone is interested in a museum-quality organization of audio media, please check in with Dave and his impeccable and highly impressive organizational skills. It's pure poetry.

The speed issue is solved. The solder points were actually dull gray, and I swear I could see cracks in 2 of 3- and one of them quite severe. But I dunno- often these go unnoticed and are not obvious to the naked eye.

Secondly- as always, great to have Rich over. He makes for great company.

Thirdly- Scott/Muddywaters- you give me way too much credit, but I appreciate it. Muchas gracias.

Okay- now to the meat and potatoes...

The speed is now spot-on. The boogered remote control solder joints have been cleaned up. Next step is troubleshooting the start/stop mechanism.

While I'm adequate with mechanicals, I'm still in the learning-intermediate stage in the "black majick" of fine arts of electronic schematics. My next step is to replace the simple micro-switch here. If this does not work I will then re-flow any solder joints in the start/stop path. If this fails, well, that's a bridge to cross later on. Failure could be a solenoid or worst case scenario, a faulty IC.

In this interim period, any thoughts of a good vendor for the micro-switch? I'd love to start there. Replacing that, followed by re-flowing the traces to the key start/stop components hopefully will be our cure-all.

If not there, we'll dig deeper....

Nice to see some solutions being found. My Sp-15 has been rock solid except that the brake keeps going out of adjustment with changes of ambient temperature and in spite of being adjusted to the spec in the manual it will start to drag from time to time. Has anyone else had this issue and found a final solution to it?

The SL-1200 Mk II Start-Stop switch works on the SP-15. So, Panasonic Parts should have them. Dave is a great friend and archivist. Expert in media restoration. I wish Delihaus (Paul) and I lived close enough to each other. He is my type of audio enthusiast. Everyone here I wish I knew some. Keep us posted on this SP-15's progress. I have one on the way next month unless plans change.

This is an excellent example of Audio Karma at work. Excellent going, guys!

I must say the SP-15/25 series turntables have always attracted me, too.

Cheers,

David

The SP-15 has probably garnered a reputation of being Technics "bad boy" quite undeservedly. My guess is the precentage of SP-15s that have developed problems is quite small. When you consider that a great many saw duty working in broadcast stations 24/7/365 for years on end it is quite amazing that a large number are still going and have entered the second phase of their life in either another commercial setting or serious/well used home enviroment. Hopefully this post will dispell the notion that the SP-15 is to be avoided. If your handy and somewhat skilled doing soldering it's as simple as removing the SP-15 mat and platter, then with a phillips screwdriver remove the three screws marked with an arrow on the spindle/bearing motor unit. Unplug the spindle/beearing/motor unit from the wire harness flip it over and there's the board with the three closely spaced solder points that are more than obvious as Dave/Cactuscowboy told me. With equipment at hand shouldn't take more than 15 minutes and the SP-15 will be playing at 33/45/78 dead on. Kent we will take another look at the SL-1200Mk2 start/stop button/pad as an alternative replacement part. So far it hasn't been a big hardship without the start/stop feature along with the brake but I would like to get it 100% functional with these features working again. I'v noticed a few SP-15s and also SP-25s that were missing the start/stop button and maybe Kent has some insight if this might of been an intentional removal when remote start/stop was installed.

I will be adding pictures later today.

KentTeffeteller said:

The SL-1200 Mk II Start-Stop switch works on the SP-15. So, Panasonic Parts should have them. Dave is a great friend and archivist. Expert in media restoration. I wish Delihaus (Paul) and I lived close enough to each other. He is my type of audio enthusiast. Everyone here I wish I knew some. Keep us posted on this SP-15's progress. I have one on the way next month unless plans change.

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Kent,

The chrome switch is good- the issue may be the microswitch- the small square switch soldered on the board. It "clicks" but I dunno if there's anything wrong on the inside of it.

Fouled contacts in the "Klixon" style momentary contact push switches are common as there is no self-cleaning wipe action, spraying out sometimes works but assume water soluble fouling like soft drinks and coffee. Corrosion from liquid fouling will pretty much negate cleaning efforts.
That switch should be an off-the-shelf catalogue item used on the majority of their TTs, check Digikey and/or Mouser for a direct match.

Pio1980 said:

Fouled contacts in the "Klixon" style momentary contact push switches are common as there is no self-cleaning wipe action, spraying out sometimes works but assume water soluble fouling like soft drinks and coffee. Corrosion from liquid fouling will pretty much negate cleaning efforts.
That switch should be an off-the-shelf catalogue item used on the majority of their TTs, check Digikey and/or Mouser for a direct match.

Click to expand...

It's been a few years, but I recall totally disassembling the start-stop switch on my SP-15, cleaning it out, using some type of lube (silicone grease/WD-40/Contact Cleaner... can't remember!) and reassembling. No doubt a ham-handed DJ had spilled his Pepsi on it decades ago.

So it sounds like aside from this last issue with the switch, the unit is up and running. I sure like the look of that plinth and tonearm. Nice setup. :thmbsp: Looking forward to more photos.

Pio1980 said:

Fouled contacts in the "Klixon" style momentary contact push switches are common as there is no self-cleaning wipe action, spraying out sometimes works but assume water soluble fouling like soft drinks and coffee. Corrosion from liquid fouling will pretty much negate cleaning efforts.
That switch should be an off-the-shelf catalogue item used on the majority of their TTs, check Digikey and/or Mouser for a direct match.

Click to expand...

Pretty much what I was thinking, and was just saying to Rich on the phone. Thanks for the tip, re: Digikey. I had a feeling that would be a good source for this part. I've seen these switches on very recently manufactured items and know they are still in use.

cactuscowboy said:

It's been a few years, but I recall totally disassembling the start-stop switch on my SP-15, cleaning it out, using some type of lube (silicone grease/WD-40/Contact Cleaner... can't remember!) and reassembling. No doubt a ham-handed DJ had spilled his Pepsi on it decades ago....

Click to expand...

Indeed, the mechanical switch was full of gunk and debris. We did disassemble it and clean it, and actually polished the button shaft as well, then used lithium grease.

It's that "Klixon" style momentary contact push switch below, however, that I think is very possibly faulty. With the button removed, you can still cycle that switch, and it does nada.

I had to clean my switch assembly out as well. I think it's a weak spot of the design as it's really tight in the housing, meaning it's likely that the switch would stay stuck in the pressed position (as mine was) which is going to do who knows what to the electronics over time. (Maybe ruin the Klixon switch itself?)

I ended up trimming some of the plastic around the button so that it would move more freely.

That said, they're great units and don't deserve any bad rep they might have. They just need some tweaking in most cases.

I think the actual switch was actually Omron made if I recall. Hope she's 100% soon. Love these fine turntables, they don't deserve the bad rap they get.