Power needs of the Techie.

[DaveK]

My Paul Hynes old PSR3 based (IIRC) PSU for my Techie seems to have shuffled off into that great audio jumble place in the sky :( so I'm exploring the options for a new PSU for my SL1210. I seem to recall that it's maximum power demand, on start up, is 21v DC at around 170 to 180mA and around 130mA when up and running but I'd like to be sure before deciding what to go for - can anyone confirm my figures or alternatively what current draw I really need to cater for please?
TIA,
Dave.

[Paul Hynes]

Hi Dave,

Send the module back to me and I will repair it FOC.

Regards
Paul

[6L6]

Some links -

Making stock transformer off-board - http://theartofsound.net/forum/showthread.php?22954-A-quick-visual-guide-to-externalising-PSU-from-your-Technics-SL-1200

And - http://www.pinkfishmedia.net/forum/showthread.php?t=101356

Taking that external PSU and making it DC - http://theartofsound.net/forum/showthread.php?26620-SL-1200-DC-Power-Supply-DIY

Same idea - DC power - but prettier; http://theartofsound.net/forum/showthread.php?28607-DIY-PSU-amp-Regulator

A different version of the 317 regulator based solution. http://www.audiocircle.com/index.php?topic=106045.0

[DaveK]

Hi 6L6,
Thanks for your kind response but sadly I have zero (or even minus ;) ) soldering skills - my plan was to get a professional audio guy to do the work for me and I need answers to the questions I asked (current loads) so as to be sure that he made me something that would do the job.
In view of Paul's very kind offer it would seem that my need for the information has been removed but it would be interesting to know anyway if you'd be so kind.
Paul, I am extremely grateful for your offer and will almost certainly accept it - I will e-mail you with details shortly but, in case you have forgotten , can I remind you that you have already refurbished it once for me after I managed to put it down on a pair of pliers when live and managed to melt some of the tracks under the PCB. If this might make any difference to your ability or willingness to repair it please let me know.
TIA,
Dave.

[Paul Hynes]

Hi Dave,

My offer of free repair stands. Just send the module and I will check it out in my free time.

Happy Christmas.
Paul

[DaveK]

Hi Paul,
Thanks for your confirmation. As it does not make any reference to my update (by e-mail) I'll assume you have not yet seen it so I'll ask this question by forum post but feel free to answer by PM or e-mail if you prefer. I now believe the transformer may be dead as my DMM tells me that there is no AC (or DC) coming from either of the secondaries.
I do have a mint unused Rapid transformer, their P/N 88-3795, with outputs of 50VA 0-12V 0-12V so could you advise if this would have enough muscle to replace the present 'dud' transformer please?
TIA,
Dave.

[Paul Hynes]

Hi Dave,

What are the voltage and current specs of the suspect transformer? The Rapid transformer should give you enough current to get running and test the regulator module.

Regards
Paul

[DaveK]

Sadly Paul, the current transformer has no output figures on it - I bought it a good few years ago off a forum member IIRC who advised that it was a genuine Paul Hynes 'kit' that he had bought and not got round to fitting. The only ID on it, apart from stating which wires paired up for the primary, 1st and 2nd secondary, was a P/N 0120212, and as it now appears defunct on both outputs I cannot measure it.
Thanks for your continuing interest.
Dave.

[Paul Hynes]

Hello Dave,

The regulator modules have been revised and improved a number of times over the years they have been available. On the assumption yours has four rectifier diodes in a bridge rectifier configuration you would need to wire the new Rapid mains transformer with the 12 secondaries in series to give 24vac to feed the regulator module. If this is not the case and there are only two rectifier diodes get back to me and I will advise you further. Before powering up the re-build I would suggest that you wire a 1A time delay fuse in series with the wire from the transformer to the regulator to protect the transformer in case of a short circuit on the regulator module.

Any further questions I will be back on line later after some more time in the workshop.

Regards
Paul

[DaveK]

Hi Paul,
Sad to say I would not recognise "four rectifier diodes in a bridge rectifier configuration" if it was to hit me on the nose ;) but my guess is that that is indeed what I have got. Immediately adjacent to the two input spade terminals on my PCB are 4 little black and silver cylinders, each alternate one being aligned 180deg to the next one and I think these were new additions when you repaired it last time for me IIRC.
To bring you up to date I have swapped out the old defunct 18v transformer with the new and smaller 15v transformer, coupled everything up and I'm getting 21.1v out of the output end. I think I have somewhere a kettle lead input socket which incorporates a fuse so I'll see if I can find it and replace the present unfused input.
Given that the SL1210, IIRC, has a maximum demand of less than 200mA is there any possibility that the PSU as it stands at the moment can be relied upon to power my Techie?
Thanks for all your help and advice - happy to wait until a reply is convenient.
Cheers,
Dave.

[Paul Hynes]

Hi Dave,

A transformer with 15vac out will not provide enough headroom to regulate 21vdc with the PR3. This is quite an old module with spade terminals. Can you tell me the voltage rating of the large electrolytic capacitor so I can check if it will take 24vac from the Rapid mains transformer. A photo would be helpful too so I can check the configuration of this module.

Regards
Paul

[DaveK]

Hi Paul,
There are 2 capacitors, both 63v, one 2200uf and the other 1200uf.
As your module is tucked away in a corner of the PSU and, to get a decent pic I need to dismantle everything so I'll do that tomorrow if that's OK when the light is better. My wife is away from home for a couple of days ATM house sitting for our daughter but expected back tomorrow so I'm a bit busy catching up with the house keeping tonight ;) Thanks again,
Dave.

[DaveK]

Hi Paul,
e-mail sent with some pics of the PSU module as attaching pics to e-mails is less complicated than adding them to a post on here.
Cheers,
Dave.

[DaveK]

I have now coupled up the PSU to the Techie and switched on - everything lit up as it should so I then I pressed the 33 button. The platter immediately sprang to life and, according to the strobe, it is rotating rock solid on 33rpm. I left it running for a few minutes and then switched it to 45 rpm. Again rock solid on 45 revs. left that running for a few minutes and then switched back to 33rpm and left it running. It's now run rock steady on 33 for around 15 mins now and still no flashes, bangs or magic smoke so I'm now going to play some vinyl.
Keep your fingers crossed for me ;) .
Dave.

[Paul Hynes]

Hi Dave,

Now you are running fine and the caps are 63vdc rating do not worry any more. No need to send pics. Merry Christmas.

Regards
Paul

[DaveK]

Thanks Paul, for all your help and advice. At 22.45 everything is still running well but I still can't get a tune out of the bl**dy thing as now it looks as though my MM pre-amp has decided to throw an 'eppe' and it ain't doin' wot it should. I have no idea why other than the power LED isn't lit but the battery charge indicating LED is lit, so power is getting through to keep the battery charged but that power isn't getting through to the amp proper. Time to get a little professional help involved again I think - don't you just love vinyl!!;
Dave.
PS:
And a very Merry Christmas to you and yours - all the very best and thanks again.