View Full Version : DIY PSU & Regulator
This DIY project is based on the ideas and schematics that Jim (6L6) put forward in his thread:
http://theartofsound.net/forum/showthread.php?26620-SL-1200-DC-Power-Supply-DIY
For clarity I‘ve brought all the elements of my build together into one place and added further instructions for anyone wanting to try and build this version.
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STOP!
Before you put yourself or others in danger, think very carefully about whether you are qualified to carry out any of this work.
Art of Sound Electrical Safety Advice
The Art of Sound is an open forum for music lovers and a place where all members can share their views on music and the equipment used for its reproduction.
The forum also caters for those who are interested in the DIY aspect of everything related to the audio replay chain, and therefore there will always be a healthy number of DIY articles and discussions in threads across the forum. Given the number of these, it is not possible to monitor or moderate all technical aspects of posts made by members.
The Art of Sound would therefore like to remind all who read such articles that while we encourage discussions on all audio related DIY we cannot and will not accept liability for the information given on any DIY related matters contained in any thread or posts herein.
We strongly advise extreme caution when considering any modification or building projects described, especially those concerning any mains voltage related upgrades, earth modifications and/or any other high voltage related modifications or building projects.
Unless you are suitably qualified or otherwise capable of carrying out such modifications/suggestions, then we strongly advise you consult qualified personnel.
We would also like to remind all our members and readers that some or all of the modifications found within the threads and posts of the forum may not be legal in certain countries and therefore advice on the legalities or otherwise should be sought before carrying out such modifications.
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We are basically taking the stock Technics Transformer and housing it in an external enclosure, thereby removing any noise and/or vibration it generates from the turntable. The external PSU is further enhanced by the addition of some fairly large smoothing capacitors. The rectifier is also removed from the turntable PCB and one incorporated into the external PSU, so only DC voltage is supplied to the turntable.
The stock on-board regulator is replaced by a better quality item based around an LM317, its small PCB is mounted in the same location as the original.
These simple and low cost improvements significantly upgrade the decks performance.
They make what is already a good deck noticeably better.
I produced PCB’s for my build as shown below, anyone interested in purchasing a pair can contact me through email, details of which can be found on my website as per the footer. Please bear in mind, I produced these for my own use, the PCB’s are not production standard, but are of a good prototyping quality, as can be seen in the picture. The rest of this build is based around these PCB’s.
http://www.jkwynn.co.uk/Pics/PSU_REG_Boards.jpg
PSU
The first task is to remove the transformer and its PCB from the deck and mount the transformer in a suitable external enclosure, its small board isn’t needed. Jim and others have covered mounting in an external box before so I won’t repeat it.
The transformers come in different forms:
Illustrated below on the left is the North American type. The two blue wires are the AC supply to the transformer primary coil and the two yellow wires are the output from the secondary coil which will be attached to the new PSU PCB.
On the right we have a typical European Transformer. For 240V mains supply the Blue and Brown wires are connected to the supply, the Yellow wires are the output to connect to the PSU board. Note that these transformers have twin secondary’s and for this supply voltage, they should be joined in series by connecting the Black and White wires, to produce the correct output.
http://www.jkwynn.co.uk/Pics/Techie_Transformers.jpg
Pictures courtesy of 6L6 and Frankyc2003
With both Transformers, when connected to the correct supply voltage, the output across the Yellow leads should be around 32Vac, check this before connecting it to anything else.
Now let’s look at producing the PSU board.
If you open the PDF file linked below, page 1 shows the schematic and parts list, page 2 shows the component layout and some assembly tips.
http://www.jkwynn.co.uk/Pics/PSU_Build.pdf
What you end up with should look like this:
http://www.jkwynn.co.uk/Project_Images/Tech/Tech_038.jpg
The completed board stands 48mm tall including the pillars and can now be connected to the transformer and mounted in its case, I used a case from Maplins.co.uk order code BZ75S like so:
http://www.jkwynn.co.uk/Pics/Inside_PSU.jpg
Check the output from the board is around 42Vdc.
Regulator
Moving on to the regulator construction, you will first have to remove the stock regulator and it’s leads connected to “J1/J2/J3” positions on the main board.
The schematic for the new regulator and its parts list are on page 1 of the PDF file linked below and the component layout and building tips are on page 2.
http://www.jkwynn.co.uk/Pics/Reg_Build.pdf
The unloaded voltage from the Regulator can and should be checked prior to connecting to the deck. Connect the positive lead from the PSU to the Reg input and the negative from the PSU to the Reg ground. Measure across the Reg output and its ground, which should show around 20.5 to 20.7Vdc. When testing in this way, without a heat sink on the regulator, connect to the power for no more than around 20 seconds to avoid overheating.
To recap on the voltage checks throughout the build, you should make these measurements:
1). Check the output from the transformer is around 32Vac before connecting to the PSU board.
2). Check the output from the PSU board is around 42Vdc before connecting to the regulator board.
3). Check the unloaded output from the regulator is around 20.6Vdc as shown below before fitting to the deck.
http://www.jkwynn.co.uk/Project_Images/Tech/Tech_039.jpg
The PSU can now be connected to the main TT PCB as shown below, note that the stock rectifier and pair of capacitors will have to be removed from this location first.
http://www.jkwynn.co.uk/Pics/Stock_Reg.jpg
Picture courtesy of 6L6
http://www.jkwynn.co.uk/Pics/TT_Connection.jpg
Picture courtesy of 6L6
The lead used here for the connection is screened, note the wire joining the screen to the main grounding point.
I don’t have the strobe pillar and it’s on off switch on my deck, if you wanted you could run the DC power coming in to the deck, through this switch before it goes to the main board.
I just use an on/off switch on my external PSU case to do the same job.
The regulator leads can now be soldered to the main board as per the PDF instructions and the small PCB mounted into its location with the aid of the spacer as below. A spot of heat sink thermal compound between the spacer and mounting boss is a good idea to improve heat transfer.
http://www.jkwynn.co.uk/Pics/Reg_fixings.jpg
Remember – Do not power up the deck with the platter removed, it should always be in place, because if you accidently hit start without it, you will fry the motor circuit.
Well that’s all there is to it, and time for a big thank you to Jim (6L6) for coming up with the idea of this combination of upgrades and for his advice throughout my build, I am extremely happy with the outcome and performance.
Hopefully, by offering the PCB’s and instructions, I have made the execution of the project a little more straight forward and professional looking for any competent DIY’er that wants to build it. ;)
Wakefield Turntables
21-10-2013, 15:53
Fantastic!
Wonderful!
Nice to see it all on one place. :) :) :)
Thanks Guys
For anyone else wanting the PCB's this is a direct link to my website page:
http://www.jkwynn.co.uk/1200_PSU_Reg/1200_PSU_Reg.html
RobbieGong
25-10-2013, 20:53
I'm always in awe of you guys who can actually suss this electrical stuf out, build and improve your gear - :thumbsup:
DarrenHW
10-11-2013, 17:09
Hopefully, by offering the PCB’s and instructions, I have made the execution of the project a little more straight forward and professional looking for any competent DIY’er that wants to build it. ;)
Thanks for making this very informative guide available, looks to my novice eye's like a first class job, I've just emailed you to order your PCB's.
Based on feed back to date here are a few pointers.
Farnell seem to be out of the 100 Ohm resistors for the Regulator.
I used Maplins part M100R these are 0.6W 1% Metal films at £0.36 each, buy a few and measure to get the closest match, remember 6L6 originaly used 240 Ohm and it worked fine, 100 Ohm is theoreticaly better and should make the LM317 more linear.
For the Regulator Alu spacer try a local iron monger, any thing you can crop a 4mm thick piece out of, angle strip etc. Or try one of the on line suppliers, I use clickmetal.co.uk as they will supply small pieces, they have 4mm sheet you can buy a piece 300x20mm or flat strip at 3/4"x3/16" its a bit thicker but you can buy a 200mm length for a little less money than the sheet.
For the Regulator longer screws I used No4 x 1/2" self tappers like these: http://www.ebay.co.uk/itm/Stainless-Steel-screws-size-4x1-2-2-9-x-13mm-pozi-p-hd-/200937973938?pt=UK_CarsParts_Vehicles_BoatEquipmen t_Accessories_SM&hash=item2ec8d628b2
:)
Just wanted to say thanks to Qwin an 6L6 for their work on this, I wouldn't have attempted it without the excellent PCB's as it made it so much easier and neater.
To anyone thinking of doing it... go for it!
http://i42.tinypic.com/t8u1p0.jpg
http://i43.tinypic.com/2mo1fgz.jpg
For the Regulator Alu spacer try a local iron monger, any thing you can crop a 4mm thick piece out of, angle strip etc. Or try one of the on line suppliers, I use clickmetal.co.uk as they will supply small pieces, they have 4mm sheet you can buy a piece 300x20mm or flat strip at 3/4"x3/16" its a bit thicker but you can buy a 200mm length for a little less money than the sheet.
There is company on ebay (forward metals) selling 25mm width strips, min length 100mm but provide a free cutting service, cost me £4.23 incl. postage. I have the spare 65mm length off-cut that I can send to anyone who needs it, it just needs cutting down to 35mm, easy enough.
Anthony -- looks great!
Have you hooked it all up? What do you think of it?
Anthony -- looks great!
Have you hooked it all up? What do you think of it?
Apologies for delay, yep all hooked up but didn't manage a extended listening session until yesterday. I'm not good with words so all I will say is that it is a noticeable improvement and sounds good to my ears, then factor in that it didn't cost much (I could never afford a commercial offering) and I enjoy tinkering it gets a big thumbs up from me!
Thanks again.
Thanks for the comments!
Yes, it's a very good and obvious improvement to the deck. I am sure that anyone interested in trying it will be extremely pleased with the results.
:D :D :D
DarrenHW
02-12-2013, 16:46
First and foremost many thanks to Frankyc2003, 6L6 and Qwin, for their work and publication on this. A special thank you to Ken (Qwin) who has held my hand throughout this project and without whom I would not have had the confidence to take this on. To anyone looking to do this with little experience, I would highly recommend buying these PCB’s from him, they’re extremely well made and in conjunction with his guides and parts lists make for an easy to follow paint buy numbers modification. You can contact him via his website (http://www.jkwynn.co.uk/) which to anyone looking into modifying an SL 1200 is well worth a visit, his projects are inspired and his site is a wealth of information.
My PSU turned out a little different, instead of using the recommended Double Pole Switch I used a Single Pole Switch and soldered the cables to set the voltage to 240v. It was getting late and this made the most amount of sense to me at the time, if anyone can see a flaw in this please let me know!
http://i1324.photobucket.com/albums/u606/drtwas/PSU_zps7fc41d40.jpg (http://s1324.photobucket.com/user/drtwas/media/PSU_zps7fc41d40.jpg.html)
When I initially spoke to Ken, I expressed my reservations that I was not expecting to reveal huge sonic improvements as the SL1200 is the first piece of “serious” hi-fi equipment I have bought and playback is via a home cinema receiver and a pair of 40 year old Technics speakers! In order to objectively review the changes I spent the evening before doing this listening to the following to try and imprint the way they sounded in my memory. What follows is my attempt at a written review of the changes / improvements in the playback.
Peter Gabriel / Kate Bush – Don’t Give Up 12” Single 45 RPM.
From the moment the stylus touched down on the record it was obvious just how much quieter it is! Before hearing this I had no idea there was so much back ground noise bleeding through to the stylus, I had expected the blacks to be blacker but this is far beyond my expectations. There are improvements in the vocal, most notably Peter Gabriel, his voice sounds more natural and with so much more detail, Kate Bush’s breathy vocals on this track are also made clearer and have far clearer enunciation. There are little details and back ground vocals that i have never heard before creeping through everywhere and maybe I’m imagining things, but I’m sure the sound stage is deeper!?!
Tracy Chapman – Fast Car 12” Single 45 RPM.
Again I’m greeted by more of the same, a massive decrease in background noise, and a huge increase in the level of detail. What really stands out is the increased detail and reality of this more “acoustic” recording, all the instruments sound more real, they seem to have more echo / reverb / dimension etc... I’m no “muso” so I’m really struggling to articulate the phenomenal difference there is but everything is so much more real, I can hear fingers sliding up and down guitar strings, the bass is crisper, Tracy Chapman’s voice has so much more depth and the timing’s so much tighter. A big and very obvious improvement, I think I need a little lie down!
Kate Bush – Never For Ever 33 1/3 RPM – Side 2, Track 5 - Army Dreamers / Track 6 - Breathing.
As soon as Army Dreamers starts the improvement in speed stability is clearly obvious, I had been very impressed by the speed stability of the 1200, but the new regulator has put the unmodded 1200 to shame. Again I’m blown away by the detail, Breathing is so immersive, the little fragments of distortion that used to flutter around the vocal are gone, stereo separation is so much more defined as well as being deeper and wider, I really, really like this mod!
Pink Floyd – The Wall - 33 1/3 RPM – 1st Pressing.
Holy Moly! I was not ready for that! Earlier I thought the sound stage had increased now I know it has, it’s deeper, it’s wider and the effects seem to fade out to a distance far beyond the physical dimensions of the room! There is more detail coming from the playground, the teacher is even more terrifying, taking, laughing etc in the background is so much clearer and more defined, stereo imaging is lifted to another level, the helicopter comes close to some of the best DTS HD BD’s I’ve heard through 5.1, very impressive for a 34 year old record and a pair of 1970’s stereo speakers!
This project cost about £60.00 and took about 15 hours all in, money and time very well spent in my opinion. Ken’s PCB’s and guide are both excellent and easy to follow, if you are considering this I would definitely recommend this path. If I were to change anything (and I probably will), I would drop the Maplin ABS enclosure and use a steel enclosure, I don’t think there’s anything wrong in using the ABS enclosure (so long as it’s far enough away from the T/T) but I found it the most awkward part of the project. Bluebell (http://www.bluebellaudio.com/) do a number of steel enclosures which cost about £12.00 for an enclosure the right size and finished in black powder coat, you will however need to be able to drill relatively large holes (16mm was the largest I used) and cut the steel to fit the IEC.
Thanks again to everyone involved and a special thanks to Ken for his guidance.
Frankyc2003
02-12-2013, 17:19
:)
yes you are right, PVC is not a very material to work with, but it's cheap and easy to manipulate when you haven't got loads of tools.
Your project looks great! Much tidier than mine!
So glad to see people doing their own DIY projects. It is SO rewarding!
Enjoy!
Great that you can hear the benefits Darren.
These mods really do perform way better than they should for the modest cost, the bang per buck ratio is sky high.
Enjoy! :D
DarrenHW
03-12-2013, 10:57
:)
Your project looks great! Much tidier than mine!
Enjoy!
Thanks Francois, but you were the pioneer here, for me it was simply monkey see monkey do, far easier (especially with the aid of PCB's) to route everything once I'd seen a couple of examples, after taking the photo drilled the vent holes and applied some hot glue "cable management" just to keep everything out of the way.
DarrenHW
03-12-2013, 11:35
Great that you can hear the benefits Darren.
These mods really do perform way better than they should for the modest cost, the bang per buck ratio is sky high.
Enjoy! :D
Amen to that! I'm really pleased with the sonic improvements, morale was running a little low at the end of the project, it had taken a lot longer that I'd anticipated and after pretty much sacrificing my weekend, I kept telling myself it would be worth it on the grounds of good practice! However, literally the instant the stylus touched down morale was through the roof the differences are that obvious. As for value for money, I completely agree. Prior to this the only mod I'd performed was to replace the stock feet with Sorbathane, which offered a welcome improvement in detail and really tightened up the bass at a cost of just under £25.00 delivered I was more than happy. The PSU weighs in at just over twice the price of the feet, is it twice the improvement? Hell yes, then some! Since completing the PSU I have bought a brand new stock tonearm and rewired it with Cardas 33AWG from bayonet to RCA (actually directly into the phono stage, why not take out as many physical breaks you can?) the total cost for that was about £80.00, amazing value for money for the performance increase, everything sounds so much more lifelike, listening to it for the first time was like listening to a different (and far more accomplished) T/T! So for very modest expense (although that is still half of what I was originally planning to spend on Project Debut Carbon, how easily boundaries can change!) I have heard dramatic improvements in SQ.
Next I shall be turning my attention to the bearing, how's your latest bearing project coming on?
Darren - The modified techie bearing is fully sorted and works great.
My new platter/bearing combination, which is really just adapting the parts off another deck to work with the Techie motor/pcb is still under development. The parts have to be centred very acurately as the clearances between magnet and coils etc is very small. I've just dropped off a drawing with a local model maker, he is going to turn a brass addaptor for me, this will centre the magnet and position the detection hub. I have made a chip board lash up to accept the parts as a proving ground before getting into making a new concrete plinth. Will post all this in a seperate thread soon. ;)
I’m greeted by more of the same, a massive decrease in background noise, and a huge increase in the level of detail. What really stands out is the increased detail and reality of this more “acoustic” recording, all the instruments sound more real, they seem to have more echo / reverb / dimension etc... I’m no “muso” so I’m really struggling to articulate the phenomenal difference there is but everything is so much more real, I can hear fingers sliding up and down guitar strings, the bass is crisper, Tracy Chapman’s voice has so much more depth and the timing’s so much tighter. A big and very obvious improvement, I think I need a little lie down!
That's the best single articulation written of what this mod does; there is the obvious and very direct - objective - reduction on background noise, but the subjective increase in "real" and "musical" is just fantastic.
Thanks for taking the time and courage to modify your table, and I am very pleased that you are happy the improvements.
Are you switching the live or neutral? It looks like the neutral. I'd fit a double pole and switch both. As you have it now it's potentially dangerous.
Agree, if your switching just one lead make it the positive. But its much better to switch both and completely isolate the device from the mains.
Agree, if your switching just one lead make it the positive.
Is that what you guys call "live" in AC?
You need to switch the live, not the neutral.
Its AC there is no positive, the live wire is the one that can kill you ;)
DarrenHW
04-12-2013, 09:11
Are you switching the live or neutral? It looks like the neutral. I'd fit a double pole and switch both. As you have it now it's potentially dangerous.
Agree, if your switching just one lead make it the positive. But its much better to switch both and completely isolate the device from the mains.
Is that what you guys call "live" in AC?
You need to switch the live, not the neutral.
Yes, you're right I am switching on the neutral!:o Thanks for spotting that Neal and thanks for putting in in context for me Ken, wasn't sure what the issue was until you wrote "completely isolate the device from the mains" then the penny dropped. I shall pick up a DP Switch today, Ken had already told me to pick one up (and is clearly stated in all the write ups) and I thought I had, right until the time when I had to install it, by then it was about 21:30 and I just wanted to get it finished! A mistake made by choosing form over function, when presented with all the options at Maplin I got lost in choosing the one I liked the look of most!:doh:
A BIG Thank You to all of you for looking out for me.:youtheman::youtheman::youtheman:
Darren.
Good one. The last thing we want is an AoS member (or anybody for that matter) toasting themselves on mains voltage! Its not pretty :) Mains voltage is lethal and anybody reading this thread and thinking of 'having-a-go' at building the PSU should put safety first and if in any doubt either don't do it or seek out somebody who knows how to.
"put safety first"
+1 :thumbsup:
DarrenHW
04-12-2013, 09:50
That's the best single articulation written of what this mod does; there is the obvious and very direct - objective - reduction on background noise, but the subjective increase in "real" and "musical" is just fantastic.
Thanks for taking the time and courage to modify your table, and I am very pleased that you are happy the improvements.
Hi Jim!
Thank You for publishing your work on this in the first place (and also your write up on your tonearm rewire which I referenced before / whilst doing mine). Without the work you, Francois and Ken have put into this I wouldn't have had a chance of doing it (as the previous posts will attest!). I can't even pretend I understand how this mod works on an technical level, but my ears like it very much! I do however think you've summed it up better in one word than any of the others I used, "Musical". There is a huge increase in musciality which (as stated above) I wasn't expecting and can therefore say without any doubt that this is in no way psychosomatic, but a very real, dramatic and oh so welcome (not to mention budget friendly) improvement to the stock SL 1200.
I'm going to stop there as I fear this is becoming a little too sycophantic, but I am honestly very grateful to you and all involved on AoS for not only doing this but in sharing it with everyone else.
Darren.
DarrenHW
04-12-2013, 10:15
Good one. The last thing we want is an AoS member (or anybody for that matter) toasting themselves on mains voltage! Its not pretty :) Mains voltage is lethal and anybody reading this thread and thinking of 'having-a-go' at building the PSU should put safety first and if in any doubt either don't do it or seek out somebody who knows how to.
Agreed! Jim commended me for my "courage" in doing this, but there's definitely a fine line between bravery and stupidity and in hindsight it would appear I'm on the wrong side of the line! Now I feel bad about posting this in the first place, my intention was to encourage others like me who are new to this to take the plunge, but fear I may have just done the opposite. I honestly had doubts concerning my ability to do this as my knowledge of all things electrical is pretty non-existent but I'm determined, stubborn and stupid (my ego wants me to type "fearless" not "stupid" but all evidence would point to the contrary!).
Hopefully my previous post will act as a guide on what "not" to do, highlight the need to fully read and understand the instructions and make sure you have the correct components before embarking!
"A little knowledge is a dangerous thing!"
Now I feel bad about posting this in the first place, my intention was to encourage others like me who are new to this to take the plunge, but fear I may have just done the opposite.
Goodness gracious no.
You made a very common and very simple mistake. One I have seen done by people with much, much more experience than you. I have certainly done it as well.
It's easy to sort out -- do so, and make a photo with the correction so people can see it, think about it, and (hopefully) learn from it.
If you do that, Robert will be, in fact, your Mother's brother and the collective knowledge of this forum will be increased by a little bit. :) :) :)
DarrenHW
04-12-2013, 14:16
A quick trip to Maplin and hopefully all is good?
http://i1324.photobucket.com/albums/u606/drtwas/PSU2_zpseeea231b.jpg (http://s1324.photobucket.com/user/drtwas/media/PSU2_zpseeea231b.jpg.html)
All voltages read correct on the multimeter, T/T operates as it should and it still sounds great.
My actions should in no way be seen as a negative reflection of this modification or any of the contributors, but literally my inability to read, understand and follow the very clear instructions. It should be seen as a very positive reflection of the AoS community who are inventive, educated, helpful and where appropriate may just save you from burning your house down!
No Turn Tables were harmed during this project. :)
Wow - that was fast!
Looks good! Now it's time to spin your whole collection and hear things you haven't before. :D :D :D
Cheers!
DarrenHW
04-12-2013, 15:55
Looks good! Now it's time to spin your whole collection and hear things you haven't before. :D :D :D
Well that's a huge relief! I've just had a pretty epic listening session this weekend, indeed hearing many things I've never heard before ad with so much more clarity. Just happy nothing "untoward" took place during what was cracking on for 12 hours of solid playback! I can rest easy now, but it's forced my hand into rehousing into a steel enclosure as after installing a new switch I now have holes where they shouldn't be!
Thanks for the kind words earlier, I do feel like a complete twerp (that's the family friendly word!) for turning what was a very simple procedure into something potentially leathal.
Darren.
belloire
04-12-2013, 16:00
a pal has built this psu mod for me (i'm useless.....), i'll post some pics when i get a chance.
makes a nice difference though, kinda feels more 'solid' in a realistic way if that makes sense.
top job :)
DarrenHW
04-12-2013, 16:48
a pal has built this psu mod for me (i'm useless.....), i'll post some pics when i get a chance.
makes a nice difference though, kinda feels more 'solid' in a realistic way if that makes sense.
top job :)
I could do with a pal like yours!:lol: Certainly agree with it feeling more "solid" especially is respect of bass response. Have you done the regulator mod as well?
Darren.
belloire
04-12-2013, 19:08
Yeah, the whole thing, he's out a couple of fuses in it, and an on/off switch.
It's in a cheap plastic case that sits inside a wooden sleeve to match the plinth my techy is in
Bump.
Couple of folks contacted me as they couldn't find this thread so I've given it a lift up the order.
Shipped three pairs of boards to a guy in Norway which means I only have one pair left now from the batch I made.
If anyone is interested get these now as it may be a while before I can make some more. ;)
http://www.jkwynn.co.uk/1200_PSU_Reg/1200_PSU_Reg.html
Thats the last pair of boards gone - to the States.
If there is enough interest I will make another batch? :)
Edit: Ok the interest is there, give it a couple of weeks, I will make some more.
Is there any practical reason why this rectified output voltagle is so high (41V)? I know this is stock transformer so voltage is what it is. But if using any other transformer, transformer output voltage 18-20V (rectified 25-28V) should be sufficient, cause most modern regulators has 3V or less dropout voltage. Is there any other reason for having such high voltage beside re-using stock transformer?
Bacek - you are absolutely correct - the stock transformer has a comparatively high voltage compared to the regulated output. If you wanted to use another transformer and modern regulator, you certainly could use one with a lower voltage secondary.
I secured a pair of Qwin's excellent PCBs before Christmas 2013 and these are now assembled and performing very well. The following attachments show the finished mods. Sound wise the turntable is much more transparent and features a better defined and wider sound stage. I am now hearing detail I never knew existed on many favourite albums.
I just need to finish the casework on the power supply enclosure by making a front panel to match my amp and preamp.
DarrenHW
23-01-2014, 08:12
Hi Basil,
Nice job! A couple of questions; why have you kept the original PCB / what case have you used to house the PS? I'd recommend replacing your feet too, not as drastic an improvement as the PS but audible non the less, I have simple sorbothane hemispheres which for ~ £20.00 and 10 minutes installation offer excellent value for money and there are of course the highly rated Isonoe's :eyebrows:.
Hi Basil
Glad you are enjoying the improvements these mods bring. ;)
Question - Why are you using the original PCB in your case?
It's not needed, you can connect the Transformer direct as shown at the first post on this thread, but space is not a problem in your case, so if it works for you......
I am working on another small batch of PCB's, applied the tinning to the tracks yesterday and will be adding the solder mask this morning, for anyone interested they should be ready by the beginning of next week (27th Jan), two pairs are allready spoken for.
Edit: You beat me to the question on the PCB,s Darren - I also use the Sorbothane feet you mention.
DarrenHW
23-01-2014, 10:30
I am working on another small batch of PCB's, applied the tinning to the tracks yesterday and will be adding the solder mask this morning, for anyone interested they should be ready by the beginning of next week (27th Jan), two pairs are allready spoken for.
Good to see more of these rolling out :thumbsup:. IMHO the best value mod I have performed on my Techie, just acquired a KAB Fluid Damper (from a fellow AOS member for a very reasonable price :)) and the improvements are very similar, tighter bass, quieter back ground, improved sound staging and detail, but nowhere near the same league as the improvements yielded by the outboard PS. So, as you're now in the second production run you and Jim should come up with a name for this mod, I've resorted to calling it the "6L6 Super SL DC PSU with Qwin PCB's", my cheesy suggestion to get the ball rolling "JK SRDC" (Jim and Ken Super Regulated DC) :sofa:.
Thank you for your feedback. The original PCB was retained purely for the protection fuses and because there is plenty of room. I must admit on reflection it doesn't compliment the overall appearance internally, so I will look at changing later.
Regarding the enclosure, this was purchased from World Audio Designs (WAD) many years ago during a management change, I originally used it to house a DIY cloned Armageddon power supply for my Linn - now no longer used. The enclosure will eventually match my WAD preamp and power amp, once I have made and fitted a new front panel.
Attached is a photo featuring my Technics SL1200, c/w WAD amps and PSU enclosure.
The advice on the Isonoe's has been duly noted, I will certainly look at changing the feet in the near future.
IMHO the best value mod I have performed on my Techie... tighter bass, quieter back ground, improved sound staging and detail, but nowhere near the same league as the improvements yielded by the outboard PS.
Thanks for the kind words. :) So far we have a 100% pleased rate (honestly, chuffed to bits, if truth be told...) of those who have done the modification.
I've resorted to calling it the "6L6 Super SL DC PSU with Qwin PCB's", my cheesy suggestion to get the ball rolling "JK SRDC" (Jim and Ken Super Regulated DC)
Yes, a new name might be handy... But I like what you are calling it!
Hi Basil
Glad you are enjoying the improvements these mods bring. ;)
Question - Why are you using the original PCB in your case?
It's not needed, you can connect the Transformer direct as shown at the first post on this thread, but space is not a problem in your case, so if it works for you......
I am working on another small batch of PCB's, applied the tinning to the tracks yesterday and will be adding the solder mask this morning, for anyone interested they should be ready by the beginning of next week (27th Jan), two pairs are allready spoken for.
Edit: You beat me to the question on the PCB,s Darren - I also use the Sorbothane feet you mention.
Ken,
Please count me in for a PCB from the next batch (if I'm not one of the two people you mentioned)
Thanks,
Alex
The latest batch of PCB's is ready. :)
I only made 8 pairs this time and Two sets have shipped allready, so get em while you can.
Currently working on mine. Haven´t gotten all the parts yet that i need but pics will come.
Anyway´s. If people are looking for the 4mm spacer. I have a bunch. I´m in the aluminium business and we have a punching machine. I have like 20 here to give away and can make more within 24 hours.
I can gladly send all 20 of them to Qwin so he can ship them together with the boards for those who order them. They are pretty light weight since they are alu. So shipping shouldn´t be much higher. If anyone needs one right now i can send right away. Hit me a PM.
https://dl.dropboxusercontent.com/u/70345924/Spacers.jpg
Hi Sindre,
You have PM... my build is about to start!.
Best regards,
Alex
A question - what type of connector are people using for an umbilical cable connector?. I was thinking of a 3 pole XLR type socket and plug, but that seems like overkill. I might just hardwire it with a gland through the case, but wanted to look at what options there are.
Best regards,
Alex
I thought it was a pair of capacitors with the rectifier, But seems like just this big unit. Anyone seen or have this?
In my opinion, doesn´t change a thing i guess. Remove it connect the umbilical?
https://dl.dropboxusercontent.com/u/70345924/2014-02-04%2021.47.02.jpg
A question - what type of connector are people using for an umbilical cable connector?. I was thinking of a 3 pole XLR type socket and plug, but that seems like overkill. I might just hardwire it with a gland through the case, but wanted to look at what options there are.
Best regards,
Alex
Something like this works well http://www.maplin.co.uk/p/maplin-3-way-audio-locking-connector-line-socket-fk23a sometimes referred to as a microphone connector, I seem to remember my old CB having these style connectors for the mic. Farnell have them as well, you can get 2 way, 3 way, 4 way etc...
A picture might help. I haven't started the conversion, but the bridge rectifier and caps will need to be located and removed...
Regards,
Alex
Sindre - what model TT do you have?
Alex - I used those Microphone connectors from Maplins that are linked, they are sometimes refered to as Mini XLR connectors.
Regular 1210 MK2.
After the serial number, seems to be made in 1996.
Sindre - According to the MkII service manual, what you have in your picture is an early model with the early rectifier.
In the MkII service manual Suplement for later models the rectifier was changed and the caps C5 and C6 were added. This change is identified in the serial numbers 7th character from the left, if it is "D" it is this later modified version.
So you need to remove your rectifier and connect your DC to the outer two positions which should be marked +/- make sure you connect these the right way round.
Sindre - According to the MkII service manual, what you have in your picture is an early model with the early rectifier.
In the MkII service manual Suplement for later models the rectifier was changed and the caps C5 and C6 were added. This change is identified in the serial numbers 7th character from the left, if it is "D" it is this later modified version.
So you need to remove your rectifier and connect your DC to the outer two positions which should be marked +/- make sure you connect these the right way round.
I've got to say that this thread and the other associated PSU/regulator threads are full of top quality info. Well done to Ken and the other contributors for pulling this together into such a well thought out and easy to execute DIY project, and for making some key components available to others to try this for themselves. I could have done it on a breadboard, but sooo much nicer lookingl/easier with Ken's PCBs.
Thanks also to Sindre for supplying a couple of aluminium spacers - I got them in the post this morning.
I have got all of my bits (apart from the case), so I'm going to be spending the evening with my soldering iron and reading specs. I'll let you all know how I get on!. There are some components I ordered from Farnell that had a minimum order quantity of twice or more what was required, so I'll post a list of spares/left-overs that someone can use when they do their build (micas, resistors, caps etc).
Best regards,
Alex
Take your time, double check everything, and enjoy the process.
The results will be gobsmacking - you will not believe how much a difference it makes, and all good.
Jim, thanks for the advice - I will be careful to check everything and test carefully step by step. It's a while since I last wielded a soldering iron, but my joints are sound, if not as tidy as they would once have been!.
Some progress - boards stuffed and soldered. Am planning to go and find a case from Maplin, extract the transformer and do preliminary wiring and testing.
Regards,
Alex
http://farm4.staticflickr.com/3830/12372145425_4fc9155826_c.jpg (http://www.flickr.com/photos/14548229@N07/12372145425/) SL1210 DIY PSU board (http://www.flickr.com/photos/14548229@N07/12372145425/) by alexmastersuk (http://www.flickr.com/people/14548229@N07/), on Flickr
http://farm6.staticflickr.com/5520/12372146765_a85d01812f_c.jpg (http://www.flickr.com/photos/14548229@N07/12372146765/)
SL1210 DIY PSU board (http://www.flickr.com/photos/14548229@N07/12372146765/) by alexmastersuk (http://www.flickr.com/people/14548229@N07/), on Flickr
http://farm8.staticflickr.com/7425/12372311673_c0aa58d454_c.jpg (http://www.flickr.com/photos/14548229@N07/12372311673/) SL1210 DIY DC regulator (http://www.flickr.com/photos/14548229@N07/12372311673/) by alexmastersuk (http://www.flickr.com/people/14548229@N07/), on Flickr
I found a nice two-pole, fused, switched IEC inlet from Schurter - less internal wiring. When I get the deck apart, I will have a look at whether it is feasible to retain the standard on/off switch as the PSU won't be located somewhere it is easy to get to. Has anyone looked at this? I haven't seen a discussion relating to this on the other threads
http://farm8.staticflickr.com/7311/12372307983_df8515af72_c.jpg (http://www.flickr.com/photos/14548229@N07/12372307983/)
Schurter IEC (http://www.flickr.com/photos/14548229@N07/12372307983/) by alexmastersuk (http://www.flickr.com/people/14548229@N07/), on Flickr
Looking good Alex.
I really like the way this project has gone, folks supplying knowledge and abilities in a shared effort for the good of all.
This is a cracking mod and the kind of thing I joined the forum to learn about.
Keep the feedback and build pictures comming ;)
Alex - The stock on/off switch can be used but it's best avoided.
If you have to use it because of access isues to your external box, then you don't really want to switch your nice clean DC supply coming ino the deck from your PSU. Also switching the output from the PSU would not diconnect the transformer from the mains when the deck is switched off so unless you unplug it or switch off at the wall socket, it would be perminently live.
It would be better to run the mains supply into the deck, through the switch and back to your external PSU box. Its not ideal as there is more back and forth cables, but at least you are not messing with the DC going to the board and the transformer is isolated when the deck switch is at off.
This is why it is easiest just to switch the mains supply to the transformer by putting one on it's case, no AC in the deck at all then.
Don't worry about the stock micro switch being up to the job, it is switching mains voltage in normal use so you can use it in this way if you must.
Alex - do you have a power strip or mains conditioner that has some switched outlets? Use that for the power on/off. You can use the stock switch on the 'table for AC switching, but you will have extra wire and the like, I don't really suggest it. Keep the mains off the table, it really helps.
Your build is looking great, please keep the photos coming. :D :D :D
Ken/Jim,
Thanks for that. I know the main A/C switch on the deck normally switche the transformer and therefore the whole deck. I guess I am more concerned with preserving the active electronics in the deck than in our PSU - I assumed that this would be ok being powered more or less indefinately especially if the DC load was open circuit. I wasn't anticipating any problems with the DC being introduced by switching the PSU feed in front of the reg, but that said, I haven't looked at how the switch is connected yet so this may be messy/involve track cutting etc. I wansn't thinking of looping the AC through the deck to switch the transformer as I agree that a part of the benefit is removing any AC-related fields from the deck.
Had a very frustrating visit to Maplins - after braving the wind and rain to get there, I spend ages finding all of the bits and pieces in the catalogue to find that they had none of them in stock!. They were apologetic and processed the order for home delivery, but I was hoping to get started today on final assembly and testing. I will get my scope out and get some traces from the PSU and regulator when I get it put together.
Best regards,
Alex
Just a reminder, you cannot start the motor without the platter attached - damage to the circuitry will ensue.
More obstacles.. What on earth are these mounts meant for? Tried to pre-fit the new rectifier to the TT. Now this guy is in the way.. :brickwall:
Now need to cut this away.
https://dl.dropboxusercontent.com/u/70345924/2014-02-10%2018.21.22.jpg
Thats different - never seen those bosses before.
Hacksaw should see them off. :)
belloire
10-02-2014, 20:38
a few pics of mine. all done for me by Setting Son of these forums.... total cost was about £50, and i think £12 was for the green LED :)
inside the SL1210
http://i1233.photobucket.com/albums/ff393/belloire/insidetechy_zpse08eee88.jpg (http://s1233.photobucket.com/user/belloire/media/insidetechy_zpse08eee88.jpg.html)
inside the PSU (case is a very cheap one, as it will be going in a wooden 'sleeve' to match the plinth)
http://i1233.photobucket.com/albums/ff393/belloire/insidepsu_zpsa34f097f.jpg (http://s1233.photobucket.com/user/belloire/media/insidepsu_zpsa34f097f.jpg.html)
Rear of PSU showing XLR type plug for psu to turntable
http://i1233.photobucket.com/albums/ff393/belloire/psurear_zpsce823cbb.jpg (http://s1233.photobucket.com/user/belloire/media/psurear_zpsce823cbb.jpg.html)
Well done Darren, nothing wrong in getting a little help.
It looks the part, but what do you think about the performance?
belloire
11-02-2014, 09:07
haha, a little help! i might have made a coffee :)
my psu was already off-board, which i think is the biggest win here, but Lee did 3 psu's at the same time, mine, his and Steve's (who i don't think is a member here)
the better reg etc did make a difference to mine, as the whole sound seems more 'solid'. the difference on the other 2 machines was more noticeable, especially in the bass.
i think this must be one of the best upgrades going, for the cost. what else comes close at £50?
hmm.. regulated output gives me 27.2. Rectified was okay. What could cause the high output..
Best wait for Jim to come along on this question Sindre.
You say the rectified output was ok, what does it measure?
Try measuring accross the leads entering the regulator ie Input and ground.
Rectified output is high? Something is probably wired incorrectly. May we see a well-lit, in-focus photo? :)
Jim it is the Regulated output that is high.
Rectified was ok whatever reading that was?
I sugggested Sindre measure the input on the regulator board to rule out anything on the main PCB effecting things.
His supplier sent 1N4007 Diodes instead of 1N4002 but I can't see much difference in spec other than the 07's can handle higher voltage.
Rectified:
https://dl.dropboxusercontent.com/u/70345924/2014-02-12%2016.18.58.jpg
Regulated:
https://dl.dropboxusercontent.com/u/70345924/2014-02-12%2016.27.16.jpg
To add some more info:
The LMT 317 stays dead cold after 20 seconds. Isn´t it suppose to go warm? Faulty?
All the components for the regulator is not from Farnell (totally forgot em when ordered.) So got all from E-bay (mostly UK)
The 10uF Capacitors seems a bit weird, Like oval in shape instead of circular (like they have been squashed) Any thoughts?l
Also, my Metal film resistor on R1 has different color coding than Alex´s board.
Mine is B O B B B. Online calculator chart gives me the answer of 130 Ohms 1% on this resistor.
So many possibilities here. :)
Oops, I meant 'regulated output'. Sorry. :)
The difference between 4002 diodes and 4007 is completely inconsequential for this application, so no worries there. :D
Anyway,
Occam's Razor says that the zener diodes are not the value you think they are...
Murphy's Law says that you probably have to unsolder them to read the numbers... Do you have a spare of the same ones?
The diodes will have some numbers on them, for example a series like "1N4788" or perhaps "BZX79C2V4"
Can you tell us those numbers? Please be very careful un-soldering, you can easily lift a trace.
4741A on the D3 diode. The other has no numbers.. Maybe it´Chinese?
FYI here are the e-bay links:
http://www.ebay.com/itm/181312193820?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649
http://www.ebay.com/itm/171118796897?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649
Maybe i need another expensive shopping trip to Farnell so im sure i get the real stuff..
Good, a 1N4741 is an 11V zener.
And the other orange diode?
The other one has no markings. as i said in previous post. Seems bogus.
I'm sorry, I didn't see that about the second diode...
Please send me a PM with your post address, I will send you the diode and some new caps (yours should not be oval...)
I have received a qty of Aluminium spacers for the Regulator PCB.
Sindre (Berg1) has very kindly donated them to the project. :thumbsup:
I will be shipping one with each pair of PCB's while they last.
My project is coming along nicely.
My transformer is putting out 32.8Vac, which is a little higher than QWins (32.5Vac) - I guess my line voltage is a bit higher as the difference is only 1%. DC voltage out from the PSU board is a little on the high side too 42.8Vdc (41.6Vdc), or about 3% - is this within the expected tolerance? I selected the resistors on the PSU board with a resistance test and they were all bang-on value.
Tomorrow we'll see what the post reg voltage is, but I'm going to stop for the evening.
Regards,
Alex
Before removing transformer and voltage selection PCB
http://farm8.staticflickr.com/7301/12550330645_eb23017e1d_c.jpg (http://www.flickr.com/photos/14548229@N07/12550330645/)
2014-02-15 14.42.05 (http://www.flickr.com/photos/14548229@N07/12550330645/) by alexmastersuk (http://www.flickr.com/people/14548229@N07/), on Flickr
And after
http://farm6.staticflickr.com/5544/12550465973_ca651457dc_c.jpg (http://www.flickr.com/photos/14548229@N07/12550465973/)
2014-02-15 15.09.35 (http://www.flickr.com/photos/14548229@N07/12550465973/) by alexmastersuk (http://www.flickr.com/people/14548229@N07/), on Flickr
Voltage after rectification
http://farm8.staticflickr.com/7360/12550780554_4e21ea80ff_c.jpg (http://www.flickr.com/photos/14548229@N07/12550780554/)
2014-02-15 22.49.34 (http://www.flickr.com/photos/14548229@N07/12550780554/) by alexmastersuk (http://www.flickr.com/people/14548229@N07/), on Flickr
I stripped down, cleaned and relubricated the bearing while I was at it. Previously there was some dried up oil accumulated at the top and bottom of the sleeve. The shaft has a very fine polish on it, as does the sleeve - no signs of scoring or wear at all. After cleaning carefully, adn relubricating it, the shaft will slide in and out of the sleeve when tilting less than 10 degrees off horizontal. Nice - much better than before. Friction is reduced by quite a bit.
https://farm6.staticflickr.com/5496/12551271415_8f710afbe5_c.jpg (http://www.flickr.com/photos/14548229@N07/12551271415/)
2014-02-15 15.28.33 (http://www.flickr.com/photos/14548229@N07/12551271415/) by alexmastersuk (http://www.flickr.com/people/14548229@N07/), on Flickr
The thrust pad has a slight wear dimple but nothing to worry about.
http://farm8.staticflickr.com/7397/12550299385_18c07c8a88_c.jpg (http://www.flickr.com/photos/14548229@N07/12550299385/)
2014-02-15 15.20.38 (http://www.flickr.com/photos/14548229@N07/12550299385/) by alexmastersuk (http://www.flickr.com/people/14548229@N07/), on Flickr
Your voltages are fine, under no load everything will be on the high side. Things are looking good. :)
I'll second that, looking good and the voltages are fine.
I found the output varied depending on time of day as my mains supply fluctuates slightly.
Bound to be slight differences due to manufacturing tolerances as well.
well guess what.. Wasn´t the Zener´s nor the Caps. It was the 100 Ohm Metal Film Resistor that didn´t do the job. Did measure as i replaced each ones and when i replaced the metal film, Voltage finally correct. Thank´s for the help Jim never the less.
Now.. I have another problem.I have assembled everything, and finally was ready for my test run. It lights up, Whopee.. joyous times.
Here is a picture of the Tech.
https://dl.dropboxusercontent.com/u/70345924/2014-02-15%2001.12.45.jpg
Sooo.. time to test fire it. And oh no. Speed is not constant.
So now it seems to have a hard time to regulate the voltage. For instance, when i brake the platter to full stop by hand, you see all the lights dims down (drops voltage) and does not go up.
The pitch, when left spinning, wobbles (as can be seen on the strobes.)
So what is correcting the voltage for the deck, and what should i check?
On another note that might help:
I did change the C1 filtercap to a 1000uf 50v.
The stock rectifier as i mentioned before had the two 223k transistors mounted under the mainboard.
Picture:
https://dl.dropboxusercontent.com/u/70345924/2014-02-11%2020.47.29.jpg
I assumed they were to be removed. Picture shows one of them unsoldered and removed.
So much problems with this project, but i want to pull through.
Am I seeing things, or are there only two wires to the regulator rather than three?.
edit - Ahh, I think I see the black wire now.
Regards,
Alex
Yeah there is a ground there..
Hi Sindre,
Sorry to hear you're having difficulties. I'd suggest monitoring the PSU voltages at the output to see if there is any change there to try to see if the fluctuations are from the supply voltage sagging, or whether the problem is with the regulator or the TV board. I haven't got to that stage myself yet, so I can't offer any specific advice. My board doesn't seem to have any components under the board as yours has - your board also had a different rectifier layout, didn't it?. Check the PSU output and report back....
Here is a picture of the underside of my board - there are obviously some differences between versions
http://farm6.staticflickr.com/5479/12600206573_50be5b39c2_c.jpg (http://www.flickr.com/photos/14548229@N07/12600206573/)
20140217_230221 (http://www.flickr.com/photos/14548229@N07/12600206573/) by alexmastersuk (http://www.flickr.com/people/14548229@N07/), on Flickr
Regards,
Alex
Hi Sindre - The 223K are capacitors not transistors. :)
I have fitted these mods to two decks one with std 470uf cap and one I had changed to 1000uf as you did, it should not and did not make any difference on mine.
The voltage output seems to vary on different designs of regulator, between 20v and 21v Jim aimed for 20.5v in his design which is also what KAB output on their regulator. My two builds put out 20.6v which is close enough to what he was aiming for on paper.
I monitored the regulator output voltage under load/start up and when putting finger resistance against the platter while running. I only saw a momentary dip of a couple of volts on start up and under braking, litrally 1 to 2 seconds and it returned to normal. The voltage was stable when running and even when a fair amount of presure was applied against the platter rim, it only dropped at the point just before the platter was forced to stop rotating. :scratch:
Is quite weird that under no load, it flutters and does not remain stable, like it struggle to find optimum voltage. Sometimes it shakes wildly for a second.
If memory serves right. Voltage was 20.4 out or close too 20.5.
Will try monitor and see how it fluctuate on load as you said Ken.
connected the stock regulator back. It is now stable.
Voltage was varying while running.
A quick update and a question...
I have tested the PSU and regulator - DC output is 20.6 Vdc exactly. I nearly had an accident in that I reversed polarity as I soldered the PSU leads to the board, but picked this up on a final end to end check before powering up - a note to other builders to check and double check everything!.
I had a quick test run and the deck powers up fine, and seems to run at a stable speed, so everything seems to be working ok.
QWin - I am now delayed by trying to source longer screws to a cure the regulator board. Do you know what size, thread type and length I should be using, and a source for them?. I can't get hold of them without the specs.
Sindre, looks like you need to do further work on the regulator board. What is the output voltage of the stock regulator?. Hard to diagnose what the issue might be with your build - I'd be tempted to strip it down and start again with a fresh set of components. Could the LM317 be faulty?. Maybe start there..
do you know what Vin and Vout are at the regulator? I'm wondering if there is something dropping the Vin so that the regulator hasn't got enough headroom to maintain a steady output under load. If you can check, I can compare with my readings. I am wondering if there is something different in the design of your board revision that is causing an issue...
Regards,
Alex
Alex - Check out post #7 for the screws.
They are not an exact thread match pitch/angle but are close and easy to get hold of.
I have used them a few times to replace the technics originals without any problems.
Thanks Ken - I missed that post!.
Cheers,
Alex
Yes Alex, i suspect it is the LM317. It´s pretty much the only thing left on it that i bought on Ebay.
i bought these screws and they fit great
http://www.ebay.co.uk/itm/HOT-BODIES-HB-D8-ATSUSHI-94388-CAP-HEAD-SCREW-M3X16MM-10PCS-GENUINE-NEW-PART-/380836901679?pt=UK_ToysGames_RadioControlled_JN&hash=item58aba5f32f
Hi All,
Just thought I'd post a quick update since quickly fitting the longer self - tappers securing the reg, and doing final fix of the internal cabling.
Firstly, everything works as it should, which is a relief!. First impressions of the sound are that vocals are clearer and more easily distinguished. The voices of Lou Rawls and Ray Charles in 'that's where it's at' from the LP 'At Last' were superbly rendered, with seemingly much better resolution.
I'll post more once I've had a chance to listen a bit more, but first impressions are quite encouraging. As an aside, I might be imagining this, but the strobe pattern on the side of the platter does seem a little more stable - I did do some bearing maintenance at the same time, so this might be having an influence, or it could be the better regulation and current capacity of the PSU increasing stability of the motor and servo circuits.
Thanks again to Ken, Jim, François and the other contributors to this excellent VFM DIY project.
Best regards,
Alex
Sindre - Did you resolve the regulator problems?
I find myself listening to my 1210 more and more - the sound is really quite a significant improvement on what I had before. Although I hadn't really perceived it clearly before, I can now tell that there was something really holding the deck's performance back before.
I wasn't sure if my cartridge wasn't ideally matched with the arm or phono stage, or that I needed a better pre-amp or that my setup was just lacking, but this mod really has improved matters greatly and I'm hearing a significant improvement in clarity, tonal colour, detail and sound staging. It is as though the sound has taken a small but significant step forward across the board, and the sum of the improvements is greater than the individual constituents. The consequence is that I want to listen to it more and more, wheras the sound was previously a little ho-hum and lacking in those little pieces of 'ear candy' that suprise you when listening to familiar recordings that you thought you knew inside out.
All in all, I couldn't be more pleased with the outcome of this little project, especially considering the mimimal costs (<£80?). Really a stupendous value for money improvement - I can't commend it highly enough for those who have some basic soldering and DIY skills and a bit of time.
Thanks again to the orginators and contributors of this project for a really fantastic outcome.
Best regards,
Alex
DarrenHW
09-04-2014, 07:46
Hi Guys,
I recently purchased a modded second hand SL 1210 which came with a Time Step PSU, under the hood it has one of these;
12024
(http://uk.rs-online.com/web/p/products/2238500/).
I'm guessing combining the 2 25V secondary's results in a 50V output? If this is correct would the output of 50V would be too high for the rectifier board and if so would something like this (http://uk.rs-online.com/web/p/products/2238550/) with 2 18V secondary's be suitable?
I have attempted to take a reading from the transformer (with / without load) but cannot get a stable voltage :scratch:.
I only ask as I have eventually acquired a Aluminium housing for the PS and fitting this tansformer would be; i, easier, ii, provide better shielding(?), iii, allow me to fit the stock transformer in the spare SL 1210 for re-sale. Is this worthwhile perusing or with my limited knowledge should I just leave things as they are (if it ain't broke...)?
If it's a full wave bridge rectifier the output will be 25v x 1.414 or 35.35v
From that you need to take into account the TX regulation under load, say 10%, diode forward voltage drop and ripple voltage depending on the size of the smoothing cap and current draw.
Hi Guys,
I recently purchased a modded second hand SL 1210 which came with a Time Step PSU, under the hood it has one of these;
12024
(http://uk.rs-online.com/web/p/products/2238500/).
I'm guessing combining the 2 25V secondary's results in a 50V output? If this is correct would the output of 50V would be too high for the rectifier board and if so would something like this (http://uk.rs-online.com/web/p/products/2238550/) with 2 18V secondary's be suitable?
I have attempted to take a reading from the transformer (with / without load) but cannot get a stable voltage :scratch:.
I only ask as I have eventually acquired a Aluminium housing for the PS and fitting this tansformer would be; i, easier, ii, provide better shielding(?), iii, allow me to fit the stock transformer in the spare SL 1210 for re-sale. Is this worthwhile perusing or with my limited knowledge should I just leave things as they are (if it ain't broke...)?
Darren,
If you are not confident with playing with electrickery, leave it be!
It's not worth the risk, unless you have someone close by who knows what they are doing.
What exactly are you trying to do?
Darren - Bear in mind electronics is not my field but..........
Do not use the combined secondaries of 50v it is too high a voltage.
Using the formula that Neal has given to show the increase in voltage that the rectifier process produces you will end up with 70.7v less some losses. This is too high for the LM317 which while having no real limit on input voltage does have a limit on the differential between input and output, which is an absolute maximum of 40v difference according to the spec.
We are outputting 20.6v so anywhere near 70v input has to high a differential (approx 50v).
I think what Neal is saying is that just one of the 25v secondaries is enough to do the job as it will produce a rectified 35.35v less some losses along the way. This will be ok for the regulator to further reduce to 20.6v as the differential is now down to approx 14v.
The stock Techie Tranny does produce more than required as was said further back. The result of using a smaller input voltage at the regulator will be less heat produced by the reduction process.
You could certainly try using a single 25v secondary without harming anything and see what the regulator produces before connecting its outputs to the board.
I have simplified things and not taken load etc into consideration but I think it should work.
But do not connect the secondaries and use 50v.
If someone more knowledgeable sees a flaw in what I am suggesting please jump in.
DarrenHW
09-04-2014, 16:05
Thanks for the input guys and thank you Ken for putting this in a language I can understand! With this in mind is there are advantage in using one of the toroidal secondary's at 25V? Is ~32V from the stock tranny better than ~25V from the toroidal? Does higher voltage provide more overhead / redundancy or will the lower voltage allow the rectifier and regulator to run more efficiently?
I will hook 1 x 25V secondary to the PCB (disconnected from the motor board), take some readings and report back.
Thanks everyone.
Ken, you are spot on in your caluulations.
The LM317 has much less 'dropout' -- the voltage lost to the regulator itself, the minimum input voltage required to get a certain output, than the stock discrete regulator. Usually the LM317 needs just a couple volts (2-3) more on the input than the output you ask of it. SO, as we only need 20.5-21.0V on the output, if the input is as low as 24V it will be just fine. Some similar regulators have only 1V of dropout. Cool.
Darren, if your unregulated PSU voltage is in the 24-35V range, you will be fine.
Now, as to the transformer, don't hook up only one secondary, but parallel them. Red+Yellow together, that's your AC1, then Black+Orange, that will be AC2
Does higher voltage provide more overhead / redundancy or will the lower voltage allow the rectifier and regulator to run more efficiently?
Higher voltage is less efficient, as the regulator needs to burn the excess voltage into heat. (That's it's job) So more is not better in this case.
But do not connect the secondaries and use 50v.
If you connect them in series, I.E., Red AC1, Black + Yellow, Orange AC2. That would give 50V
The Grand Wazoo
09-04-2014, 18:14
The AoS warning about working on the mains is wisely posted at the beginning of this thread. However, I think it is worth posting a reminder here.....I promise you that even the very best upgrade will be a total waste of time if you have to listen to it from the inside of a coffin at the bottom of a 6 foot deep hole in the local cemetery.
STOP!
Before you put yourself or others in danger, think very carefully about whether you are qualified to carry out any of this work.
Art of Sound Electrical Safety Advice
The Art of Sound is an open forum for music lovers and a place where all members can share their views on music and the equipment used for its reproduction.
The forum also caters for those who are interested in the DIY aspect of everything related to the audio replay chain, and therefore there will always be a healthy number of DIY articles and discussions in threads across the forum. Given the number of these, it is not possible to monitor or moderate all technical aspects of posts made by members.
The Art of Sound would therefore like to remind all who read such articles that while we encourage discussions on all audio related DIY we cannot and will not accept liability for the information given on any DIY related matters contained in any thread or posts herein.
We strongly advise extreme caution when considering any modification or building projects described, especially those concerning any mains voltage related upgrades, earth modifications and/or any other high voltage related modifications or building projects.
Unless you are suitably qualified or otherwise capable of carrying out such modifications/suggestions, then we strongly advise you consult qualified personnel.
We would also like to remind all our members and readers that some or all of the modifications found within the threads and posts of the forum may not be legal in certain countries and therefore advice on the legalities or otherwise should be sought before carrying out such modifications.
You'll get about 32v out of the 25v secondary with full wave rec and smoothing cap. So will drop about 11v across the reg. I think power draw is what 120mA for the 1210? Call it 150mA @ 11v or 2w as near as...heat sink it well.
DarrenHW
09-04-2014, 18:47
Safety warning received and understood, I take full responsibility for my actions and all reasonable precautions to avoid a Darwin nomination.
DarrenHW
09-04-2014, 18:51
Hi Jim, Thanks for the response.
Now, as to the transformer, don't hook up only one secondary, but parallel them. Red+Yellow together, that's your AC1, then Black+Orange, that will be AC2
This is how the tranny was originally hooked up but I couldn't get a stable reading on the multimeter, any idea why? I could correctly read all voltages from the stock tranny.
DarrenHW
09-04-2014, 19:47
Mystery of fluctuating voltage solved! A case of user error with the multimeter, I had it set to dc not ac :doh:
With the multimeter set to ac the tranny reads a constant 31.5V in parallel. Thanks for the input and sorry to have wasted everyone's time.
Now just got to fit it into the new enclosure, boy do I feel like a cock :o
Stratmangler
09-04-2014, 19:55
Mystery of fluctuating voltage solved! A case of user error with the multimeter, I had it set to dc not ac :doh:
With the multimeter set to ac the tranny reads a constant 31.5V in parallel. Thanks for the input and sorry to have wasted everyone's time.
Now just got to fit it into the new enclosure, boy do I feel like a cock :o
Did the same thing with my DMM yesterday - talk about having a senior moment :doh:
At least you found the cause of the problem.
I'm pretty sure you are not the only person to have done that. :) :) :)
But what's even more frustrating is when you have a DMM with a faulty battery (that you haven't figured out yet...) and you can't get a consistent reading for love nor money...
DarrenHW
10-04-2014, 06:51
Should have checked my work first, lesson learnt measure twice, post once!
Despite making a fool of myself again (you'd think I'd be used to it by now:)) I'm happy I've got everything in place to proceed with the project. One more question; As I will be using an Aluminium enclosure is there any advantage to grounding it to the mains earth and if so should the shied drain attached to the ground on the motor board also be grounded here?
Yes Darren, safety! You should also fuse it as well. I'm concerned now.
The Grand Wazoo
10-04-2014, 07:44
Indeed - I think you need someone who knows what they are doing to get involved here Darren. With the greatest of respect, it sounds as though you are in way deeper than you should be.
DarrenHW
10-04-2014, 07:52
Yes Darren, safety! You should also fuse it as well. I'm concerned now.
Hi Neal / Chris, I don't think I've explained myself properly. Please see post #30 this is how my PS is currently wired after you noticed I was switching on the Neutral. I will be removing the stock Technics transformer and replacing with the Toroidal, other than that everything will stay as it is. My question is whether I should now take a cable from the earth on the (female) IEC and connect it to the body of the new Aluminium enclosure, not possible with the current enclosure as it is ABS. And if so should the shield drain:
12028
then be attached to the mains earth or left floating?
Hopefully this makes sense and thank you for the concern, I will not be moving forward with this until I am 100% certain that what I am doing is both correct and safe.
Hi Darren, yes, I understood that ;) Your new enclosure is metal, you need to make it electrically safe by earthing it and fusing the incoming live. You should also insulate any exposed live contacts like the IEC terminals. TBH I'd advise to seek help on this.
BTW whats wrong with the original Transformer, its perfectly adequate for the job in hand.
DarrenHW
10-04-2014, 13:28
Nothing wrong with the original transformer, I'm more than happy with my PS as is (apart from the current enclosure), I had planned on rehousing it in a steel enclosure but picked up an Aluminium one for nothing. I just need to source another transformer for a 1210 I have with no transformer so makes more sense to me to buy a new toroidal for £15.00.
I know we have to ere on the safety side but come on chaps give the guy a break and some helpfull feedback.
Darren is quite correct in thinking the stock Techie does not, in common with many devices these days, have an earth connection, it is a double insulated device.
The Technics transformer which is mains powered is bolted to the metal chassis which is confusing to many people and I think where the confusion has stemmed from.
Earthing his external metal case is of coarse a sensible thing to do and this will also act as a screening drain.
As for adding a fuse, last time I looked, there was one in the three pin plug, which if he uses an earth will have to be fitted.
Confusion about earthing and grounding is a common thing.
Not having a dig guys and I am no expert but he was asking some fairly strait forward questions that wern't really answerd and left him like me a little bewildered. :)
DarrenHW
12-04-2014, 08:28
Thanks for the confirmation Ken, hoping to get this assembled and tested today, will upload photo's once done.
I know we have to ere on the safety side but come on chaps give the guy a break and some helpfull feedback.
Darren is quite correct in thinking the stock Techie does not, in common with many devices these days, have an earth connection, it is a double insulated device.
The Technics transformer which is mains powered is bolted to the metal chassis which is confusing to many people and I think where the confusion has stemmed from.
Earthing his external metal case is of coarse a sensible thing to do and this will also act as a screening drain.
As for adding a fuse, last time I looked, there was one in the three pin plug, which if he uses an earth will have to be fitted.
Confusion about earthing and grounding is a common thing.
Not having a dig guys and I am no expert but he was asking some fairly strait forward questions that wern't really answerd and left him like me a little bewildered. :)
Sorry Ken, I take issue with this. I did give helpful feedback and given the way Darren had wired the PSU previously (sorry Darren) and his question about earthing with a metal enclosure the alarm bells went off. The fuse in the mains lead just protects the lead, the PSU should also be fused with a correctly rated one for the load and all exposed connections insulated. Mains can be lethal and safety comes first if this isn't seemingly understood then I feel Chris and I had every right to point this out in the strongest terms.
Darren when you come to earth the box create an earth post with a bolt/screw and use serrated washers so they cut into the aluminium and form the best possible bond.
The Grand Wazoo
12-04-2014, 09:34
I know we have to ere on the safety side but come on chaps give the guy a break and some helpfull feedback.
Sorry, but we have to consider not just those following the thread here and now, but those who come later to read it. This will remain available for anyone to see for a long time after we've all forgotten about it and although we'd like to think AoS members have a little sense about such things, there are a hell of a lot of idiots out there.
DarrenHW
15-04-2014, 06:53
Updated photo’s of my PS, they’re not great as only taken with my phone as I was working on it. I’ve tried to show all my work but did struggle to take some photo’s (no Macro option) so apologise for the poor quality. If anyone see’s any mistakes / room for improvement please let me know.
First up soldered connections to IEC including new chassis ground wire.
12063
This is the same IEC connector form my old enclosure and one of my first area’s of confusion in the last few posts. This is fitted with a 250ma slow blow fuse, which I took from the stock Technics PCB, is there something wrong with this / should I replace it with a fast blow fuse?
Soldered connections insulated and showing grounding to chassis.
12064
I had done this prior to Neal’s post;
Darren when you come to earth the box create an earth post with a bolt/screw and use serrated washers so they cut into the aluminium and form the best possible bond. so revised the mounting to provide a better bond to the chassis, thanks for the input :). This is the other area that caused confusion, this is all I wanted to achieve, is this ok?
12065
Soldered connections to switch.
12066
DarrenHW
15-04-2014, 06:57
The wires coming from the Toroidal are tiny single core wires, I made a few attempts at soldering these to the PCB but just couldn’t get a good solder. I did give it a bloody good try and testament to the quality of Ken’s board’s it stood up to the abuse well, but it just wasn’t happening. Taking inspiration (and parts) from an old Onkyo Amp I have in my HiFi “Boneyard” I decided to solder mounting pegs (I don’t know what they’re really called) to the board to wrap the wire’s around. As the wire from the tranny is such a **** (insert favourite expletive here:steam:) I wanted to solder the wire first and then solder the pegs to the PCB. This is where we get to the point where another electrical safety warning should probably be inserted! To do this I “modified” one of my soldering irons to turn it into a solder bath, wrapped the wire around the peg, fluxed and then dipped it.
12068
I haven’t yet been able to get a good photo of this, there was some heat damage to the outer but this has only distorted it nowhere is the wire exposed.
12069
Time to take a reading.
12070
Fluctuates between 40.7 – 40.9 Vdc.
Everything mounted and insulated showing the connection to umbilical, the shield drain is not currently grounded to the chassis as I couldn’t get a 3 pin connector at the weekend, I will revist this when Maplin have more stock.
12071
12072
DarrenHW
15-04-2014, 06:59
12073
12074
Okay, so I know anodised red won’t be to everyone’s taste and I wouldn't have chose it myself, but this started life as a Horticultural Lighting Ballast which I pulled it out of a skip attached to a very large light, (I think this used to be owned by an enthusiast Tomato farmer :)) so it cost me absolutely nothing! I'm not sure if I'm imagining it or not but there may be a further reduction in background noise, I don’t know whether this is due to better shielding from the toroidal, lower voltage output, grounding the chassis or just good old fashioned placebo effect?
Venting will be added to the bottom of the chassis as soon as I have picked up a round file, I've been testing it with the lid off. Marco came round yesterday for a 7 hour "sesh" / setup and the PSU performed without fault.
Thanks for everyone's input and help with this :respect:.
Well done Darren, that looks much better. Did you continuity test the earth connection with the box? The transformer wires are enameled they can be a pain as you noted. If the soldering iron won't burn the enamel off you need to resort to fine wire wool or that green cleaning stuff to scrape it off prior to soldering.
Darren - did you try scraping the single strand of copper before soldering. It may have been coated wire like they use on windings. A scrape with a blade usually removes the coating and allows easy soldering. If you keep aplying heat the coating will eventually burn off which I think is what you may have done when you managed to achieve the joint - bear this in mind if you have trouble in the future as solder takes well to good clean copper, if it doesn't there's usually a reason.
Jazzy looking case. :)
edit: I see Neal said the same thing while I was typing.
DarrenHW
15-04-2014, 07:47
Well done Darren, that looks much better. Did you continuity test the earth connection with the box?
Thanks Neal. Yes. continuity tested. After reading your post I used one of the serrated washers to scrape all the anodising off so the connection was to bare metal, there is also (as you suggested) a serrated washer beneath the earth ring which is not visible in the photo.
The transformer wires are enameled they can be a pain as you noted. If the soldering iron won't burn the enamel off you need to resort to fine wire wool or that green cleaning stuff to scrape it off prior to soldering.
Darren - did you try scraping the single strand of copper before soldering. It may have been coated wire like they use on windings. A scrape with a blade usually removes the coating and allows easy soldering. If you keep aplying heat the coating will eventually burn off which I think is what you may have done when you managed to achieve the joint - bear this in mind if you have trouble in the future as solder takes well to good clean copper, if it doesn't there's usually a reason.
I see, and again highlighting my lack of knowledge for which I do appreciate your input and concern. Explains why they were such a git to solder, maybe if I'd known this first I could have soldered directly to the PCB I assumed I was struggling to get a good joint as the wires were so much smaller than the "hole" in the PCB.
Cheers :youtheman: !
You did the right thing by using a PCB 'pin' to solder to Darren, the fine wire makes a better connection to these than to the PCB directly. http://theartofsound.net/forum/images/icons/icon14.png
DarrenHW
15-04-2014, 07:58
You did the right thing by using a PCB 'pin' to solder to Darren, the fine wire makes a better connection to these than to the PCB directly. http://theartofsound.net/forum/images/icons/icon14.png
:yay:
Well thats the last of the boards posted today.
All 30 sets have gone and hopefully will bring the benefits of this great set of Mods to some lucky Technics owners.
I won't be making any more as they were very labour intensive and ate up a lot of my time in the making.
If anyone wants to make their own boards in a none commercial way, I can let them have a copy of the artwork I used.
I covered how you make a PCB in a project on my web site which can be found here:
http://www.jkwynn.co.uk/PCB_HTML/PCB_Thumbs.html
There's nothing particularly difficult in the process and I had done nothing like this before, I just researched it on YouTube - The internet is your friend - So give it a go. :)
Sindre - Did you resolve the regulator problems?
No i haven´t. Currently keeping that on ice as the stock regulator does the job nicely. Maybe sometime in the future.
I can post it to someone for checking it if they want to.
Hi Sindre
I've more or less wound up my efforts on this project and moved on to other things.
I went through my parts bin and I have a full set of the correct parts for the regulator including the LM317.
You are welcome to have these if you want them?
I know you were unsure about the parts you got off fleabay and didn't want to put a small order into Farnell due to the min charge they levy.
I think after your kind gesture of donating the heat sink spacers to the project its the least I can do in return.
I would strip out all the old parts and fit these new ones paying carefull attention to parts orientation ( I'm sure you would anyway) and make sure the insulator is seated centrally between the LM317 and the heatsink spacer (Will also send a mica insulating sheet).
You seem to be the only person that has had problems and I think it was just down to the parts quality. I am keen for you to get a positive outcome from your project.
Let me know if you want me to send these parts, I still have your address. ;)
Hi Sindre
I've more or less wound up my efforts on this project and moved on to other things.
I went through my parts bin and I have a full set of the correct parts for the regulator including the LM317.
You are welcome to have these if you want them?
I know you were unsure about the parts you got off fleabay and didn't want to put a small order into Farnell due to the min charge they levy.
I think after your kind gesture of donating the heat sink spacers to the project its the least I can do in return.
I would strip out all the old parts and fit these new ones paying carefull attention to parts orientation ( I'm sure you would anyway) and make sure the insulator is seated centrally between the LM317 and the heatsink spacer (Will also send a mica insulating sheet).
You seem to be the only person that has had problems and I think it was just down to the parts quality. I am keen for you to get a positive outcome from your project.
Let me know if you want me to send these parts, I still have your address. ;)
If i remember correctly, the LM317 is the only part left on it that is from Ebay. Feel free to send it (with the others if you wish) and i might try when i have time to start on it again.
Ken - what was the type of cable you used for the umbilical between the PSU and the TT? It looked like 2-core but screened?
What kind of rating would be required given the voltage and current requirements?
Would something like van damme mic cable be suitable? (given it's designed so it can handle phantom power @ 48v in Microphone applications - but not sure if current specifications would be good enough?)
Sorry for all the questions!
Chris.
Ken - what was the type of cable you used for the umbilical between the PSU and the TT? It looked like 2-core but screened?
What kind of rating would be required given the voltage and current requirements?
Would something like van damme mic cable be suitable? (given it's designed so it can handle phantom power @ 48v in Microphone applications - but not sure if current specifications would be good enough?)
Sorry for all the questions!
Chris.
That's what I used - as there are four conductors I twisted them into pairs to double the current capacity. I have no idea if that was necessary or not.
Regards,
Alex
Don't worry about asking questions Chris. :)
I used havy duty screened Microphone cable I picked up off Fleabay and ran the screen to the earth pin on the UK three pin plug which is not used for the transformer, but would be used if you have a metal case, both for safety and as a screening drain.
Remember we are talking low current DC through this cable. The conductor cross section on the cable I used was greater than the original Technics cable from PSU to main board. The original cable looks quite chunky till you peel back the thick insulation and see the thin conductor. It's carrying approx 32VAC from the stock PSU in the unmodified deck as the rectifier is on the main board. We have rectified externaly so its approx 42VDC being carried into the deck.
I looked at the current carying capabilities on mine and I seem to remember it was more than twice that required.
Just satisfy yourself you have as much copper as the original cable, The primary insulation used is suitable and the earthed screen keeps it nice and safe.
Edit: As Alex points out you could use 4 core and double up on conductors, but it isn't necessary if the copper is thick enough on each, I got 3 core and didn't use one.
Thanks for the info Ken.
Progress so far today thanks to your boards plus threads and instructions from AOS contributors:-
12583
Am thinking of finding a suitable plain stealth enclosure for the PSU and then fitting a missile-style flip up red cover with a big toggle switch underneath like this just for a bit of fun! :)
12584
Chris.
DarrenHW
31-05-2014, 05:48
... missile-style flip up red cover with a big toggle switch underneath like this just for a bit of fun! :)
Quality! :respect:
Looking good Chris.
Just make sure you use a good quality switch with low contact resistance and no neon power on light.
You don't want to add additional noise to your incoming supply.
Missile switch :D
So made some progress recently. I'd appreciate some opinion of the measured voltages incase any are adrift of normal.
Output from the stock Transformer - 33.6vac
12606
Output from Ken's PSU - 43.7vdc
12607
Output from Ken's Regulator - 20.2vdc
12608
Do these sound acceptable?
Alas the missile switch cover is a no-go as it's sprung loaded mechanism just turns the switch back off! :)
Thanks as ever.
Chris
Voltages are fine Chris. :)
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