Just bought an SP10 Mk2 P/L from 'thebay'. Its been stored for the past 8 years, and a small amount of corrosion on the deck surface is consistant with the description. It will be sent off for powder coating when all the electronic modifications are completed.
I think I got lucky, it's probably one of the last Mk2 units, dated on the bottom 'Nov 81'. I'm in the process of modifying the control pcb to allow the stop/start button to work properly.
I used to work with 7400 series logic many years in the past, but if anyone's got the info to hand I would appreciate not having to exercise my remaining grey cells too much.
I may build a proper linear psu, but I'm currently using two switchmode supplies; a 5V 2.5A and a 32V 2.0A, which seems to work perfectly; is there any reason these should not continue to be used?
I've read through this whole thread, and it's full of useful info, but if anyone's got any specific advice regarding my P/L machine I would appreciate it.
Thanks
I think I got lucky, it's probably one of the last Mk2 units, dated on the bottom 'Nov 81'. I'm in the process of modifying the control pcb to allow the stop/start button to work properly.
I used to work with 7400 series logic many years in the past, but if anyone's got the info to hand I would appreciate not having to exercise my remaining grey cells too much.
I may build a proper linear psu, but I'm currently using two switchmode supplies; a 5V 2.5A and a 32V 2.0A, which seems to work perfectly; is there any reason these should not continue to be used?
I've read through this whole thread, and it's full of useful info, but if anyone's got any specific advice regarding my P/L machine I would appreciate it.
Thanks
(Newbie alert!)
I just acquired an SP-10 MK2A that had many years of service at a radio station. It had been in storage for several years after that.
I applied three drops of SFWO 010 and installed it into a test plinth - basically just a couple pieces of butcher block oak with some isolation pods sandwiched between.
Looks like I've got some wow/flutter problems. I'm seeing some very slight movement on the strobe at all speeds, but I've got an audible rapid speed fluctuation problem that may or may not be the same. It presents almost like vibrato, with very rapid (but small) small pitch variation, especially noticeable with guitar & piano, as you'd expect.
If I put my ear a few inches from the motor while it's running, there's a "just" audible rapid mechanical noise, that changes in frequency with the platter speed.
My electronics skills are very basic. I can use a multimeter and have novice soldering skills.
I'm pretty certain the PS and motor units are using the original electrolytics.
Any suggestions where I should start troubleshooting?
I just acquired an SP-10 MK2A that had many years of service at a radio station. It had been in storage for several years after that.
I applied three drops of SFWO 010 and installed it into a test plinth - basically just a couple pieces of butcher block oak with some isolation pods sandwiched between.
Looks like I've got some wow/flutter problems. I'm seeing some very slight movement on the strobe at all speeds, but I've got an audible rapid speed fluctuation problem that may or may not be the same. It presents almost like vibrato, with very rapid (but small) small pitch variation, especially noticeable with guitar & piano, as you'd expect.
If I put my ear a few inches from the motor while it's running, there's a "just" audible rapid mechanical noise, that changes in frequency with the platter speed.
My electronics skills are very basic. I can use a multimeter and have novice soldering skills.
I'm pretty certain the PS and motor units are using the original electrolytics.
Any suggestions where I should start troubleshooting?
Luckily I have a scope (or two ) and many many years of diagnosing and fixing electronics so recalibrating and modifying my SP10 Mk2 P/L to work properly didn't hold any great fears, especially after looking through the schematics and finding that Technics was 'kind enough' to use industry standard components.
Unfortunately a combination of lack of experience and tools, combined with Technics' later version (Mk2A) which uses fewer, but bespoke, integrated circuits make it a near impossible job to carry out for the 'newbie'. I would suggest you try to find a (preferably local) specialist to checkout, replace caps where necessary, and recalibrate your excellent turntable.
If you let us know where you live someone here may be able to point you in the right direction.
Good Luck
Unfortunately a combination of lack of experience and tools, combined with Technics' later version (Mk2A) which uses fewer, but bespoke, integrated circuits make it a near impossible job to carry out for the 'newbie'. I would suggest you try to find a (preferably local) specialist to checkout, replace caps where necessary, and recalibrate your excellent turntable.
If you let us know where you live someone here may be able to point you in the right direction.
Good Luck
After looking over the Service manual and schematics you would need both a signal generator and an oscilloscope in addition to the DVM you already have in order to calibrate the turntable properly.
I don't know whether it would be possible to repair (if necessary) and set up the adjustments with a different motor in which case only the board would have to be shipped to a specialist, or if the whole unit would need to travel; I suspect the latter.
Though not too close to you it might be worth contacting About – The Turntable Shop North Vancouver ( in Vancouver, BC) for professional advice, they have an excellent reputation and I'm confident would give honest advice.
Good Luck
I don't know whether it would be possible to repair (if necessary) and set up the adjustments with a different motor in which case only the board would have to be shipped to a specialist, or if the whole unit would need to travel; I suspect the latter.
Though not too close to you it might be worth contacting About – The Turntable Shop North Vancouver ( in Vancouver, BC) for professional advice, they have an excellent reputation and I'm confident would give honest advice.
Good Luck
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Sorry, my bad; no ac signal generator needed, but you do need a 40mV dc supply as part of the setup.
I've been having a few more thoughts regarding the feasibility of at least recalibrating the TT, this might be done using a low cost PC oscilloscope add-on. These are available on 'thebay' for as little as $50 and should be easily capable of doing the job.
There are a couple of caveats however,
1. If there is an underlying fault with the TT, beyond tired electrolytic capacitors which can be easily replaced, then you really do need an experienced technician to sort things out.
2. You must be extremely careful when using 'scope probes on/near ICs not to allow any short circuits to occur, mostly these cause no continuing harm, but in some cases it is possible to destroy the chip in no time at all.
I've been having a few more thoughts regarding the feasibility of at least recalibrating the TT, this might be done using a low cost PC oscilloscope add-on. These are available on 'thebay' for as little as $50 and should be easily capable of doing the job.
There are a couple of caveats however,
1. If there is an underlying fault with the TT, beyond tired electrolytic capacitors which can be easily replaced, then you really do need an experienced technician to sort things out.
2. You must be extremely careful when using 'scope probes on/near ICs not to allow any short circuits to occur, mostly these cause no continuing harm, but in some cases it is possible to destroy the chip in no time at all.
Help needed: Looking for SP-10 brake solenoid spring
I'm rebuilding and SP-10 mk2, and have gathered all the parts and now have the table running, but I'm missing the spring from the brake mechanism. If anyone has a parted-out SP-10, or has removed the brake from their unit, and has one of the springs they would sell, please contact me.
Photo of the part attached.
Thanks in advance.
Mike
PS No luck at local hardware stores - all appropriately sized springs were too strong.
I'm rebuilding and SP-10 mk2, and have gathered all the parts and now have the table running, but I'm missing the spring from the brake mechanism. If anyone has a parted-out SP-10, or has removed the brake from their unit, and has one of the springs they would sell, please contact me.
Photo of the part attached.
Thanks in advance.
Mike
PS No luck at local hardware stores - all appropriately sized springs were too strong.
Attachments
Jeff-
Thanks. They don't seem to have any that match exactly what I need, but I've ordered a few in hopes that I can cut them shorter to fit the shaft. The spring I sourced from a local hardware store didn't fit well but more importantly was much too stiff - the solenoid wasn't strong enough to compress it.
I'll post back with a part number if any of these work.
Mike
Thanks. They don't seem to have any that match exactly what I need, but I've ordered a few in hopes that I can cut them shorter to fit the shaft. The spring I sourced from a local hardware store didn't fit well but more importantly was much too stiff - the solenoid wasn't strong enough to compress it.
I'll post back with a part number if any of these work.
Mike
If you search "solenoid" on eBay you'll find things like this: Solenoid electric solenoid type push / pull 10 mm DC 12 V 2.1 kg force R1F8 | eBay
New SP-10 project with custom base completed
I've just completed building a refurbished SP-10 from the spare parts I had on hand. Thanks to all those whose suggestions and ideas I used. Build details here:
Technics SP-10 Mk2 Custom Build - mpbarneysources
Mike
I've just completed building a refurbished SP-10 from the spare parts I had on hand. Thanks to all those whose suggestions and ideas I used. Build details here:
Technics SP-10 Mk2 Custom Build - mpbarneysources
Mike
An externally hosted image should be here but it was not working when we last tested it.
I just bought a SP10 mk2 recently after reading so much about this incredible machine.
It is a working set that came with the original power supply.
However, while in 33 and 45 rpm mode, the platter turns smoothly. But under 78 rpm mode, i can feel the whole turntable chatter/vibrates....
Next problem is while stopping, the platter will reverse its direction about 1/4 of a turn in all 3 different speed mode. I tried having to remove the brake band mechanically, but to no avail...the platter still reverses 1/4 turn while stopping.
I tried stopping the patter by my finger at the same time i hit the stop button, i then can feel that the motor forcefully try to rotates backward, so it may be a logic control that is sending the wrong or overly corrected reverse "braking" signal or command to the motor.
I have since recap all capacitors in both power supply and the TT unit itself, this problem of reversing 1/4 turns still exist....
Can anyone who have this problem share your experiences here ?
Btw, i do not have a oscilloscope yet to tune the PLL timing as stated. I did adjust the VR101/33rpm at different setting, the platter still looks LOCKED on as shown by the strobo window.
Thanks.
It is a working set that came with the original power supply.
However, while in 33 and 45 rpm mode, the platter turns smoothly. But under 78 rpm mode, i can feel the whole turntable chatter/vibrates....
Next problem is while stopping, the platter will reverse its direction about 1/4 of a turn in all 3 different speed mode. I tried having to remove the brake band mechanically, but to no avail...the platter still reverses 1/4 turn while stopping.
I tried stopping the patter by my finger at the same time i hit the stop button, i then can feel that the motor forcefully try to rotates backward, so it may be a logic control that is sending the wrong or overly corrected reverse "braking" signal or command to the motor.
I have since recap all capacitors in both power supply and the TT unit itself, this problem of reversing 1/4 turns still exist....
Can anyone who have this problem share your experiences here ?
Btw, i do not have a oscilloscope yet to tune the PLL timing as stated. I did adjust the VR101/33rpm at different setting, the platter still looks LOCKED on as shown by the strobo window.
Thanks.
