Who can build me a power supply?

[julesd68]

A project that I have for early next year is to have an upgraded power supply built for my Source TT.

I actually have a hand-written circuit diagram from the ever helpful John Gordon, formerly of Source-Odyssey!

I don't have the skills required to build such a beast - does anyone have any suggestions who could do a really nice job for me?

Cheers.

[jostber]

I bet Avondale could do it, check Custom Designs:

http://avondaleaudio.com/

[julesd68]

Thanks, good suggestion - have now emailed them. :thumbsup:

[The Vinyl Adventure]

what about asking Mains Cables David?

[YNWaN]

Hmm..you might be better telephoning Les at Avondale - email doesn't always seem to find him.

Making it from a circuit diagram isn't difficult as long as it shows the type and value of all the components - designing it from scratch is another matter.

[sq225917]

Are you sure it's worth building, worth checking better doesn't already exist, the source is rather old.

[YNWaN]

If it is an AC motor there is a good chance that it can be run from any of the various power supplies developed fro the LP12 over the years.

[julesd68]

Thanks for all your input chaps!

I was lousy at electronics at skool so really need my hand-holding here ...

Here is a pic of the circuit diagram John Gordon supplied -

5737

John added the following proviso -

< 36v is at the top end of the input voltage range, and with variations in transformer output tolerances it puts an excessive strain on motor board components. I would use a lower voltage, between 24 and 30vdc which is still higher than the small psu. The bonus is not in the voltage but in the transformer size. >

And here is the psu I am using now -

http://www.ebay.com/itm/SICO-SIC-PA59-AC-POWER-ADAPTER-/320685181694

Is is possible I could get something suitable that's already built?

[Reid Malenfant]

I have no idea why there are two toroids wired in parallel in the diagram :scratch: Not unless the toroids he specified couldn't supply the current needed on their own.This would indicate a lowish VA transformer & poor tranformer regulation (which looks like has already been mentioned).

Do you know how much current the TT will draw?

That really is about as simple a PSU as you could get ;)

[Ali Tait]

I would ask Nick (Lurcher) to build you the supply. In fact he could probably improve on it once he has a look. Won't charge you a fortune either.

[John]

If you want the best speak to Paul Hynes he relly seems to know his stuff around power supplies. Plus Paul contributes here too

[Welder]

What John wrote ;)

[sq225917]

It sort of looks like an Armageddon clone, much better can probably be achieved with active electronics these days and PH is the man to ask.

[Reid Malenfant]

Guys, I don't think you read Jules post properly ;) Whoever gave the information stated that the PSU in the record deck wouldn't like to be fed too much voltage. So obviously there is on board regulation.

Now we know Paul Hynes makes super supplies, but it hadly seems worthwhile fitting some kind of PH regulator to have all the hard work & low noise destroyed by the on board regulation. If one was to be fitted it ought to be instead of the on board regulator.

That PSU would be fine, in fact fit an LM317T & trim the output to 24V DC as mentioned & all of a sudden there would be two sets of reasonable regulators which should result in better performance than feeding one with much higher ripple voltage.

It doesn't need a ton thrown at it as the on board regulator will be the limiting factor..

[Welder]

I think Paul Hynes will build whatever is required, ie, with or without regulation and may even have some suggestions for improved on board regulation if he thinks it worthwhile.

He seems rather good like that ;)

[Reid Malenfant]

I think Paul Hynes will build whatever is required, ie, with or without regulation and may even have some suggestions for improved on board regulation if he thinks it worthwhile.

He seems rather good like that ;)
Ok, I'll keep out of it then ;)

Just ignore the fact that for a good 8 to 10 years my occupation was designing, testing, repairing & modifying power supplies :eyebrows:

[julesd68]

That PSU would be fine, in fact fit an LM317T & trim the output to 24V DC as mentioned & all of a sudden there would be two sets of reasonable regulators which should result in better performance than feeding one with much higher ripple voltage.

Mark - please stay around!

Sorry for being so thick but when you say "that psu would be fine" are you suggesting sticking to the original suggested design?

cheers.

[Reid Malenfant]

It depends on how much money you are willing to spend :)

If you just want a better external PSU & rely on the internal regulation of the TT then you won't need to spend a great deal.

All you need is a fairly beefy transformer (you don't need two unless they are underated for the job), a bridge rectifier & a healthy dose of reservoir capacitance. Oh, a fuse in the mains side wouldn't go amiss either :eyebrows:

You could improve things by having a 24V (or around that figure) regulator on this new PSU which will then feed almost ripple free DC to the internal regulator - which will improve the performance as that won't need to deal with huge amounts of ripple voltage.

Again that could be done quite cheaply!

LM317T ICs cost about £1, a few other components & a small bit of veroboard maybe another £5 at the very most. It's the transformer & reservoir capacitor that will set you back the most. I'd also fit a bigger reservoir cap than 10,000uf but that's just me.

Just out of interest a certain manufacturer of a PSU for a Technics 1210 uses an LM317HVT (high voltage) type regulator in his £450 PSU ;) Yes, all £1 of it :D



Just don't expect it to seriously outperform what you have at the present. The limiting factor will be the quality of the internal voltage regulator, however by feeding it a less corrupted DC signal there should be a reasonable bit of improvement.

[julesd68]

Cheers Mark, that is most helpful indeed and in language I can understand!

I will look for someone to build me a PSU along those lines - I'm not expecting my system to be transformed; will be most happy with a modest improvement for sensible money!

[MCRU]

Cheers Mark, that is most helpful indeed and in language I can understand!

I will look for someone to build me a PSU along those lines - I'm not expecting my system to be transformed; will be most happy with a modest improvement for sensible money!

Sensible being the operative phrase I think. :)

[Paul Hynes]

Hi Julian,

I do not know the details of the circuitry used for motor control in the Source so any comments here are hypothetical and based on experience acquired by upgrading the power supplies of a very wide variety of electronic equipment including many record decks with DC motor control systems.

Firstly the proposed DC power supply shown by John Gordon is very simple and has limited supply line rejection and load regulation. Replacing it with a well-designed regulated supply should provide a noticeable sonic improvement. The reason for this, irrespective of whether there is an on-board regulator supplying the control circuitry, is the additional barrier to supply line interference provided by this regulated power supply. Also feeding the on-board regulator with a regulated voltage will render it less susceptible to input voltage variations caused by dynamic load current swings as well as protecting it from over voltage when the mains voltage rises. So you should aim for a high quality regulated master power supply for these reasons.

As Mark has stated the overall improvement to sound quality will be limited by the performance of any on-board regulation on the motor control board, so for the best result you will need to replace any low quality an-board regulation with something of better quality. This applies to any item of electronic equipment. Improve the power supply, improve the performance.

Using an LM317 may provide a sonic improvement in some areas of performance and will cost little to try. However the overall performance will not be great. I use an LM317 based charger to charge my car battery but would never use it for any audio related power supply. In fact I stopped using it for audio power in 1980 when, encouraged by others, I found better solutions for audio power supplies and have progressively developed them since. The LM317 is an old design and was designed in 1970 for general-purpose industrial use. It has no place in high end audio.

Regards
Paul

[julesd68]

hi Paul,

Thanks for your input - in terms of a power supply designed as you suggest, is this a custom made job or do you provide something suitable "off the shelf"?

cheers.