[Voodoochile]

So I had a bunch of toroids hanging around, including four matching 36v units. So I thought I could make a real light balanced power supply for running my transport and dac from, wiring them back-to-back. But the toroids were just not large enough, so the sag was a bit too much to deal with. This is the initial version:

The project was to net me a balanced power unit, and also use up some extra transformers. But I ended up buying another toroid in the end. An 800VA unit with dual 115v primaries, and dual 60v secondaries. Kind of big, but it has great regulation.

It was just a bit too hot on the output, so I untaped the toroid, and removed about 20 windings from the secondary. It's some pretty big enameled wire in there. I removed some windings, checked the output, removed a few more, checked again. When finished, I removed the enamel and reattached the leads, then re-taped the transformer. That took quite a long time

. I was careful in removing the polyester, and rewound it like a small roll of tape (no adhesive), so I could pass the roll through the opening easily. It's easy to wind it very tightly, just tedious.

The outlet holes were cut with a greenlee chassis punch. Inlet is a neutrik powercon. I'm sick of cutting IEC openings.

There is an NTC resistor at the input to limit the inrush a bit. No blown fuses. When I installed the big toroid, I went ahead and added a third outlet. The two outlets near the power cord connector rin through two-stage isolation filters. These are for the transport and DAC. The third outlet is directly connected to the output of the toroid, that one is for the amp. I may recase this and add two more outlets, so I can attach the phono stage and turntable as well.

I've been thinking of doing this for a long time, and when I saw Yikes' version, I was prompted to get going finally. Mine has no Siltech cabling or output meters, but it's getting the job done nicely. The chassis is from John at Par Metals. I have not decided on a pilot lamp yet, but have been running it for several weeks now.

 

[morsel]

Looks great, VC. Can you tell us more about the power filters you used and post a schematic?

Yikes Balanced Power Supply
Yikes Balanced Power Supply 2nd thread

 

[Voodoochile]

Thanks, Morsel. The two links Yikes gives have a lot of info on them. There is another Equi=Tech page which has a lot of links to other articles on it, tons of information here also.

In addition to those links, here are a couple other that I spent some time on:

This one I followed fairly closely, it includes the info on the NTC resistor for that same transformer. I essentially used this idea, skipping the caps across the outlets, and I used different powerline filters.

This link is to a post on AA by Jon Risch referencing the small transformer back-to-back idea. Interesting in that you can add filtration between the two, at the low voltage point. He uses traditional transformers there, however. It looks like it would be excellent for isolating a digital source.

Finally, this link has info on the Plitron transformer, which looks very good also.

I did not use the filter caps directly across the outlets, myself. It seemed a bit redundant after the schematic of the two filters show a cap at the last stage. I read quite a few data sheets on the Corcom website. There are many power line filters for many different applications, ranging from $10 to nearly $100. Some single-stage, some two-stage. I'm using an intermediate two-stage filter on two outlets, and nothing on the third outlet (for the amp).

Even though a headphone amp is more like a preamp as far as load on a BPU is concerned, my amp has a small filter built into it, so I did not want to double up on that.

 

[nikongod]

hey voodoo, where did you get that case, and what is the part###?

i need a "week off from work" project, and a balanced power thingy.

 

[n_maher]

Just looks like a bone stock standard Par Metals 20 Series case to me.

Mark,

Glad to see you put the Powercon to good use

. And, uh, could you refrain from setting the DIY performance standard any higher for the near future? Most of us are still trying to recover from the Custom Ear thread

.

 

[Voodoochile]

Quote:

Originally Posted by nikongod hey voodoo, where did you get that case, and what is the part###? i need a "week off from work" project, and a balanced power thingy.

Yeah it is from the series that Nate poited out. That particular one is 16"x12"x3". He sometimes sells this one on ebay under the store name of "Antek" (I think). His username is johnango, iirc. It might be less to buy it on ebay that directly, I don't know because I have never bought this size from Par Directly. John works at Par. I got it through him on ebay because it was ready to ship, and the price seemed reasonable, about $60.

I need to take a pic of the front panel. It's got an 1/8" lip all around the faceplate, and the faceplate is 1/8" thick as well. Not flush like the Par photo on their website. That picture they post is horrible, it's a wonder anyone would ever buy it after seeing that.

Quote:

Originally Posted by n_maher Glad to see you put the Powercon to good use . And, uh, could you refrain from setting the DIY performance standard any higher for the near future? Most of us are still trying to recover from the Custom Ear thread .

Awww, no one will want to build one of these... there's no blue LED!
Maybe nikongod will use a red one. Or an orange one. Or a red-orange one.

 

[MisterX]

Quote:

I need to take a pic of the front panel. It's got an 1/8" lip all around the faceplate, and the faceplate is 1/8" thick as well. Not flush like the Par photo on their website. That picture they post is horrible, it's a wonder anyone would ever buy it after seeing that.

lol, yeah it is.
You do bring up a good point though.
Have you ever seen a Par-Metals 20 series case that looked like the one they have on their website?

Here is the link to aforementioned Ebay store:

http://stores.ebay.com/Antek-inc

 

[morsel]

Thanks for the links, VC. With commercial units going for $2-3K, this is a great choice for a DIY project. The toroids Equi=Tech is selling on their website have the Plitron logo on them, btw.

 

[flecom]

Quote:

Originally Posted by MisterX lol, yeah it is. You do bring up a good point though. Have you ever seen a Par-Metals 20 series case that looked like the one they have on their website? Here is the link to aforementioned Ebay store: http://stores.ebay.com/Antek-inc

I have ordered some xformers from them... they are pretty good... heavy as hell since most of them have very high current ratings...

 

[nikongod]

Quote:

Originally Posted by Voodoochile Awww, no one will want to build one of these... there's no blue LED! Maybe nikongod will use a red one. Or an orange one. Or a red-orange one.

im not cool enough to put a blue led in anything i make and i know it.

but i am going to put current and voltage gauges in the beast.

 

[Voodoochile]

Quote:

Originally Posted by nikongod im not cool enough to put a blue led in anything i make and i know it. but i am going to put current and voltage gauges in the beast.

Cool, can't wait to see it. I looked for a bit, but did not find any that suited me.

The nice thing about this, especially with an independent faceplate (meaning you can remove it without disassembling the entire chassis), is that you can easily drop the front panel, cut some openings for meters, switches, or pilot light, and then wire it up and reinstall the faceplate. No need to get the whole project.

I'd also considered a timed/sequenced outlet turn-on, but decided that it is just as simple to turn the three items on myself in whatever sequence I wish. Sometimes I just have to reel myself in when adding stuff like that. It's easy to add it for the sake of having it. The other bit is that quite a bit of gear stays in 'standby' mode, and having switched outlets can defeat that, if that is something you like.

I am likely to install a master switch on the front, or maybe the side near the front, so that I can disconnect all the gear with one switch if I want to. And I'll probably do a pilot lamp, but it will be a dim one. I don't want to have a headlight shining out into the living room.

Morsel- yes, this is a great DIY project (insert any and all warnings about working with line voltage here- it can kill you with ease), and the link for the "cheapskate balanced power unit" in particular is good, as you can obtain balanced power for little more than the cost of the transformer. The guy's use of a junction box, while not up my alley, is ingenious, and also avoids the need for a gigantic drill bit, chassis punch, or nibbler. If you had a suitable masked location for the box, the junction box would be just fine. And cheap... I saw them at home depot for about $16.
Quote:

Originally Posted by MisterX lol, yeah it is. You do bring up a good point though. Have you ever seen a Par-Metals 20 series case that looked like the one they have on their website?

Sadly, I have. The first one I bought from them. The textured black paint job was also horrible. I bought another one and asked them to anodize the whole thing in black, and countersink the screw locations throughout. Finally, if you don't ask for a thicker faceplate, the standard one comes flush cut. Suddenly it was $75 instead of $35. But it does look great, then.

 

[FallenAngel]

Very impressive build Voodoochile.

Although one question has been nagging me about this type of project. This is the way I figure it, most people have standard (aka very cheap and low quality) power wiring in their house installed ages ago by the builder. It runs into the home from the huge main line. It then meets a regular (see description for standard) circuit breaker and goes out again using "standard" wire to all the different standard wall outlets in the house.

It just never made much sense to me to have what I could only consider as an "extention cord" of extreme quality and guage. "Extention cord" is also known by others as a power cord, but since it only extends from the regular cable running in the walls to the equipment, it's very much an exntention cord).

I'm sure you've caught on what I'm getting at here, so without further delay... when it comes to building power components like this very nice power supply and insainly expensive $200+ power cords that I've seen, all using "hospital grade" $30 power connectors, does it really make sense to and why when it gets plugged into cheap $5 power outlets in the wall which get run using "standard" AC wire to the circuit breaker?

So my main questions would be, at which point in the power wiring should things begin? Is it really worth having an expensive power "extention" cord?

I always heard that equipment should be fairly evenly matched and upgrading one part to the extreme while keeping others lowly wouldn't make sense.

Your input would be greatly appreciated since I was thinking of upgrading the power to my setup and these concerns have made me very skeptical about which parts to update.

Thanks in advance.

 

[Voodoochile]

Well, that's a really hot topic for discussion, for certain. It usually goes so far sour that people start calling names and talking about each other's mom.

Anyway, without getting into it directly, Rod Eliot has some very interesting material on his website, as does Jon Risch. Both come right up with a google. Finally, the Equi=Tech link I posted above has some great pages discussing grounding, system noise, etc., complete with diagrams. Their content is fairly plainly worded so the masses can grasp it. The articles are not that long, either.

Once you read the articles on noise and grounding, and see how even a normal filtering device shunts noise to "ground", you quickly realize that it's an uphill battle. Noise isn't really "attracted" to ground. If a circuit is leaky, then the ground can actually acquire some potential. This is where a GFCI will save your bacon. Balancing your power neatly addresses most of these issues very well. Check out the Equi=Tech link, it's pretty enlightening.

As for the outlets and cord, again, it's hotly debateable. But I will say that even within the scope of the normal outlets you just buy and stuff into the wall, the quality level is widely variable. Not just between Hospital Grade and "Regular Grade". There is actually specification grade, contractor grade, commercial, heavy commercial, and others. These range from $1 apiece, to $8, to $20, and even $40. Not for "audiophile" or "cryo treated", either, I'm talking ordinary outlets. A Hubbell Hospital grade duplex outlet (not isolated ground, just 15a hospital grade) is around $15-$20 depending where you get it.

My house was wired with nice breakers, and thoughtfully laid out circuits, but the contractor used junk outlets and switches. I have replaced many of them over the past 18 years, many of them in less than 10 years. These outlets have a limp grasp on the plugs inserted in them, and some have even cracked near the ground lug. I replaced many with Leviton industrial nylon outlets, and they are really tight!

My point, without directly going at the $200 powercord subject, is that I believe that you can obtain much (not all, but much) of the benefit of boutique powercords by simply assuring that you have very clean and tight connections right up to your powersupply in your gear; and also by assuring that the cord is of adequate construction. Some of it is so poorly made that it's just adequate for a lamp.

I do have a nice Venhausen PC on my DAC, but even that is something like $100. There are powercords costing in excess of $1,000. Are they better? I would not be surprised if they are. But I doubt very seriously that it would be noticible in my setup, or with my hearing. Most of my powercords are heavily built with nice quality plugs and good cable that holds it's form well, but nothing esoteric. I just want a solid and reliable connection, and am familiar with the connections back to the service entrance.

Another interesting place to do some reading on grounding, specifically, is Mike Holt's Code Forum. It's like Head-Fi, only all relevant to the NEC. He has a ground-specific area.

 

[nikongod]

parts are rolling in for the "box."

sofar i have purchased:
a box.
a transformer.
6 single outlets (cheap home depot, i got them because they are circular and i can drill a circle)

i am contemplating the idea of putting my +/-15V supply and a steps i got into the box too. i think there will be ample room, and room for connectors too.

as a note to the "questioners" of this device. if it does only 1 thing, at the minimum it will do this: it will without a doubt remove dc from the lines. dc screws up all sorts of ac parts when it should not be there. think of a transformer for example... i think it will help in other ways too, but eeh, we have time to play...

 

[nikongod]

major bummer.

irdered a 2X56v transformer, because my house runs hot, so it should give the appropriate 115V output.

i got a 2X50v. argh. i am talking with the seller now to sort this out, but i wanted to build this beast this week.