[Stephonovich]

First, yes, I did use the Search function, and didn't find all too much.
My Alpha wire is enroute, so I will soon be re-building my CMoy (for the fourth time). I have a Hammond case, and plan on running it off 2 or more 9V batteries. I also have a DC power jack, with a battery cut-off switch; and I also have a AC-DC wall wart from Rat Shack. It only goes up to 12v, though, so split it + -, and I have 6 volts. I believe Tangent stated on his website that most opamps work best on + - 15 volts.
Is it feasible to build a power supply? It should provide + - 15 volts, enough amperage to run any amp with plenty of headroom and then some, and shouldn't cost too much. Ah yes, I'd prefer a linear regulated PS.

(-:Stephonovich

 

[jamont]

Do you want to build a PS, or do you just want more volts?

If it's the latter, you could get a good wall-wart, like the Elpac WM071, or you could get an open-frame linear PS from ebay. Either of these options may be cheaper than building one from scratch.

But if you want to build one, it's easy enough. Look at the datasheets for the LM317/337 regulators or look, for example, at the power supply circuit for the SDS amp project on Headwise. If you build it you'll learn something and (hopefully) have fun, but you may not save money.

Edit: correct Elpac part no.

 

[Stephonovich]

Ah, so it may be a bit expensive... I was wrong in my thinking, then. I think I may build one at some point; likely about the time I build a Meta42. (Or a PPA, if it's complete then)

Thanks for your help, though.

(-:Stephonovich

 

[guzzler]

homemade supplies are well easy to make, but yes you might not save money, but since when has that been a concern??

search for Voodoochile's Power Supply **** series of threads, thats as good a board as any!

Or, welbourne PS-1 is an excellent kit choice

g

 

[tommyatkins]

Well, I wanted to looked it up so here's Voodochile's Power Supply. Hope that saved you a search.

TA

 

[Tomo]

Hey,

It is real easy. You probably can wire them yourself. Besides, you can buy PSU kits for some rediculously low price. I got my board for like 15~20 bucks and filled it with hifi-gear. Total cost was like 30. Ain't bad. (PS-1? gimme a break I wouldn't pay that much)

Key is find kits at obsecure places. Never ever buy brand name board.

Tomo

P.S.
Voodoochile is an agent!?
Remember, there is no spoon ... Only Zool!
(Excuse me if you don't know Ghostbusters)

 

[ofb]

a few more links to a simple psu. first, erix's son of psu **** thread. his pics are gone, darnit. so go over here for a sketch of the same at sijosae's. and some more pics yonder in my thread where i stumbled through building one.

can't say it was expensive. got everything from digikey, except for sinks, which i had. and they're overkill. i imagine any cheap sinks will do. the TE62063-ND tranny was only $30 up here, and would be rather less in the states. i think it makes a nice first psu, and my meta sounds fine with it.

 

[Stephonovich]

Well, as I said, I'll likely build one at some point soon, but for now, I'll live with battery powered. This entire summer is booked for me anyway, so I wouldn't have any time to build anything new.

The board posted by Voodoo Chile looks pretty good. Think I might try that... later... (The process has begun, it seems. I'm already making plans to go in with my brother and buy our sister some KSC-35's for her very belated Birthday/Christmas present. Maybe convert her from the dark side)

(-:Stephonovich

 

[10SNE1]

I took the info from the article Universal Power Supply at:

http://www.zero-distortion.com/start.htm

and designed a PCB layout to integrate the design with dual PCB transformers. The foil layout can be altered with a photo/paint editor to produce a transformerless board, or to use a toroidal transformer. Dimensions of board are 4" x 4 3/4".

I substituted values of some of the caps to make use of on-hand components; lots of mil-spec grade parts I got inexpensively from a local source. I used 3300uf for the rectifier output filtering and 2200uf for the regulator output. Instead of 47uf, I used 10uf tantalum. The rectifier snubber caps are .068uf. The fixed voltage divider resistors in the VR adjustment section are 301 ohms.

The circuit is very similar to the first two stages of the Gilmore Class A amp PS. It does not have a tracking stage; although I will be using it in a future Gilmore build, I feel that since this is a highly regulated design with essentially two independent (+) and (-) circuits, once the voltages are adjusted and stabilize, the rail voltage absolute values should stay fairly close since the current capacity is high compared to the Gilmore demand.

 

[Stephonovich]

Wow! That's an impressive project you've put together there, 10SNE1. I'll definitely remember that one.
As a thought on my previous comments, though, I've been reading _High-Power Audio Amplifier Construction Manual_ by Randy Sloane, (I've liked some previous stuff he wrote) and he commented that the benefits of a linear PS are out-weighed by the cost and size. He says a good switching PS, combined with a good design, can give you just as good quality. I can't disclaim or verify any of this, but it's definitely something to think about.

(-:Stephonovich

 

[10SNE1]

>>the benefits of a linear PS are out-weighed by the cost and size.<<

Since when have these issues ever mattered to the rabid headphone audiophile?

Seriously, there have been several past threads and opinions voiced about switching vs linear, size vs cost, noise and regulation etc. I find that for DIY, there are fewer design/build issues with linear designs.

You can start a holy war on this subject.

 

[Stephonovich]

What I like about this author (Sloane) is that he doesn't claim that something won't work, or is useless. On the subject of audio cables, for instance, he states that he's believes a lot of them are simply a bragging right than anything else. But he always maintains that if you want to have it, go ahead. He's just coming from the Team Broke angle, so he's trying to save money.

(-:Stephonovich

 

[Voodoochile]

Mister Anderson... you have a choice to make. (hey Tomo)

In a nutshell, if you are going to stay with a single-supply wallwart, I wouldn't bother upgrading to one a little bigger. At least not in a cmoy.

Stephonovich, re-read Tangent's little article on PS quality issues. He mentions that a little RS switcher, though it shows noisy specs, actually sounds pretty decent. And the Elpac would be even better.

That's where this all gets sticky, though. The cheap wart is cheap, and OK. The Elpac is another $20 or so above that, and better. Not too bad.

But then you are in the territory of making a small dual-rail, which is you are going to spend $35, then only $15 more will get you there, perhaps. I feel that if you are going to go with line power, which has it's drawbacks, at least try to gain the maximum benefit by going dual rail. But I've never been one to enjoy wading in the pool too much- I prefer to swim or not swim. Not always a good thing by any means.

So, you start at around $15, and end up at $50 on up... depends on your tolerance for pain, and how often you tend to upgrade. If you go a long while between upgrades, then spend more, of course! I think if you upgrade fairly often, you are going to screw yourself along the way, with outmoded stuff being sold off to finace the new. AKA, the pain cycle.

 

[PeterR]

Quote:

Originally posted by Stephonovich As a thought on my previous comments, though, I've been reading _High-Power Audio Amplifier Construction Manual_ by Randy Sloane, (I've liked some previous stuff he wrote) and he commented that the benefits of a linear PS are out-weighed by the cost and size. He says a good switching PS, combined with a good design, can give you just as good quality.

As the title says, he's talking about high powered amps to drive loudspeakers, with output ratings several orders of magnitude above the headphone amps we're dealing with. For our purpose the lower efficiency of regulated supplies is insignificant.
But IIRC he's not a big fan of switch-mode supplies either? Has been a while, though...

 

[Stephonovich]

Quote:

Mister Anderson... you have a choice to make.

Reloaded rocks; I don't care what the reviewers said...

Quote:

As the title says, he's talking about high powered amps to drive loudspeakers, with output ratings several orders of magnitude above the headphone amps we're dealing with.

Yes, he is. I think 12 designs; from 50-500 watts, or something like that. I don't have a speaker system (although would like to one day), but am seriously considering building an amp for a car stereo system. I've found a distinct lack of good info on quality car stereos. Most of it is, "how many >= 12" subs can we fit in there?"

Quote:

Stephonovich, re-read Tangent's little article on PS quality issues. He mentions that a little RS switcher, though it shows noisy specs, actually sounds pretty decent. And the Elpac would be even better

Yes, I realize he said it's not too noisy. Sloane stated that the quality difference you're going to get from a linear and a switching is minimal. But as I said, he never says, "don't do this". He encourages you to be insane if you want, going with the highest quality everything, even if you can't hear a difference; just so you get bragging rights

I don't upgrade often, due to [currently] no income. I need a summer job. My next purchase is likely going to be some KSC-35's for portable use.

(-:Stephonovich