[rklein]

Hi All:

I would greatly appreciate someone's help regarding the below info.  It looks very easy to build this board, but I just need some guidance on it.  I posted this over in Paul Hynes' circle on the thread regarding his regs for the Buffalo II DAC and the IVY III Output stage.

http://www.audiocircle.com/index.php?topic=77455.20A

Fellow AC'er multibit16 shared a great diagram showing what he did in employing these regs to his Buffalo II and IVY III.  He uses 6 boards containing a rectifier + smoothing cap to go with the Z1P regs made by Paul Hynes.  Below is his quote:

PR3G2 or Z1P  can be used as a regulated psu, if using Z1P you need a rectifier + smoothing cap

I would very much appreciate if someone could explain in a little more detail how the unregulated psu's on vero board using discrete diodes for the rectifier and a suitable sized electrolytic cap for the filter are built.  I tried looking for them from Multibit16's posted pics but it seems they are under the PH regs for the IVY III.  Paul Hynes emailed me and said he has PS1 boards with Schottky barrier diodes and Panasonic FC energy strorage capacitors.  However, they cost $40 each.  While I will probably end up buying all of Paul's regs that Multibit employs in his DAC, including the PR3G2 for the Buffalo II board, I would like to build the 6 boards containing the rectifier and filter cap for the IVY III to keep the cost of this Buffalo II down.

Thanks,

Randy

[Niteshade]

Interesting subject!

Why not use 78 series regulators? They can provide up to one amp alone, or with a TIP41 acting as the output stage, substantially more (depending on how large you want the heat sink).

It looks like a 7812 and 7815 would do it for 12 & 15 volts output.

If you want a variable version, go with the LM317.

These are analog regulators requiring a minimum external parts count that should do the job very well. The power supply circuit looks overly complex to me and I am always looking for ways to simplify (AKA: Make better) designs to increase performance, understandability (in case of future repairs) and longevity. It's something serious to consider.

[rklein]

Hi Blair:

Thanks for the response.   However.... you are flying on some planes substantially higher than mine   While others here may know what you are talking about, I unfortunately do not.  While I am reasonably competent in building from kits, I do not know the why's and why nots on alot of this stuff. 

Could you "dumb it" down for me?

Thanks,

Randy

[Niteshade]

I'm sorry about that. What's being done looked more complex than what I was suggesting.

Look at this:



These will accept a DC input of between 16 and 24 volts and provide a very clean regulated 12V output. Different regulators in the 78 series put out different voltages: I.e. 7805 (5V), 7812 (12V). They have the prefix "LM" in front of the "78___" meaning they're linear regulators. The circuit is simple because most of the components are inside the TO-220 package. There is a T0-3 package as well and you will see it represented from time to time. T0-3's are about nickle sized and have mounting ears. T0-220's are small, rectangular packages with one mounting screw hole on the rear heatsink.

[Niteshade]

Randy, here is a completed power supply: (Just sub a 7812 for the 7805)



Instead of using single diodes to form a bridge, it would be better to use a bridge rectifier.



The main filter capacitor before the regulator should be rated for about 50 volts @ 3300uf and as the first diagram shows, a 1000uf cap after the regulator isn't a bad idea.

[rklein]

Hi Blair:

Thanks for the added explanations!  It makes sense now.    The unintended consequences  are what to do concerning direction I take in regards to these regs.  DIY'ers rave about Paul Hynes' regs and PS's in general whether on AC(Mike Galusha, Anand, Multibit16 and others) or guys over at DIYaudio.  What you are proposing looks decent as well, but again, if I am going the DIY route, I want the best sound I can get.  I will have to think about all of this as multibit16 has also graciously answered my original question concerning the rectifier + smoothing cap on the thread on Paul Hynes circle.  I might do a combination of PH regs and what you are proposing.

Any comment or thoughts from others would certainly be welcomed.

Thanks,

Randy

[Niteshade]

I don't want to dissuade business from someone else.

What I would do: Find out the differences between this traditional way of making a regulated supply and that of the alternative you mentioned. I am unfamiliar with PH regulator boards but very familiar with traditional LM series IC's. How either system works depends on the system's power demands. I'd like to know more about your DAC and what you're trying to do. Does it have issues?

[rklein]

Blair:

The DAC has not been built yet.  It is the Buffalo II offered by Twisted Pear.  There are no issues with the DAC.  Just me being inexperienced in this regard.   Give me a diagram or photo with instructions and I am reasonably confident in being able to complete the build.  I was just trying to get more info on the board that contained the regulator and smoothing cap.

I will probably just do what multibit16 showed in his diagrams and photos he graciously shared on the High Performance Regs for the Buffalo II and IVY III over on Paul Hynes' circle.

BTW, in getting to know you in regards to dealing with you concerning the building of my amp and pre, I certainly know that your intent was to help answer a question and not try and take business away from another vendor.

Randy

[Paul Hynes]

Hi Randy, Blair,

The reason people are using aftermarket regulator upgrades is for the improved sound quality that can be had by using regulators that are designed specifically for the job in hand. There is plenty of well-documented information about this improved performance available on the audio forums, both DIY and commercial.

LM78 and LM317 type regulators were originally designed for general-purpose use in low cost industrial applications where accuracy requirements were not as stringent as the accuracy required for high performance audio analogue and digital supplies.

If you look at the datasheets for these 78 and 317 regulators you will see that they have limited operating bandwidth, poor line and load transient response, rising impedance through the audio band and beyond and they are relatively noisy. In fact their regulation capability reduces as frequency increases virtually ceasing to regulate around 10 MHz. It is possible to achieve much better performance than this without adding to the actual circuit complexity. If you were to look at the internal circuits of the 78 and 317 regulators they are not so simple. Their application is simple as the regulator circuitry is all inside a three terminal package.

Most of the aftermarket regulator upgrade modules on the market are as easy to apply as 78 and 317 type regulators, which still require the same support circuitry (rectifiers and capacitors) to create a working supply.

Regards
Paul

[rklein]

Hi Paul:

Thanks for sharing your views on this subject.  I will be ordering your regs very soon.  Many people speak very highly of them who's ears I trust.

Blair:

Thanks again for responding and trying to help me out with this question.

Randy