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DIY Studio Power Conditioning / cleaning up dirty power

Member for

21 years
I'm wondering if I could build something to help with power conditioning, cleaning up hum/ dirty power for my project studio. Does anyone have a solid design or know of a kit that I could make that would work excellent?

Any suggestions would be great.


Member for

21 years

audiokid Wed, 03/18/2009 - 22:24
jammster wrote: audiokid, I had this concern for a time and thought by running a UPS battery backup or line conditioner it would solve the problem.

I still have not yet done anything to solve my concern. I run a small home setup. I need to do my math and find out how many watts I need. Here is an example of a system that runs 780W peak.


It seems to me when your dealing with power it may be better to have a device that is tested and backed by a warranty to keep your valuable studio functioning properly.
I hope this helps you,

Edit: scratch that triplite, its a bad product after reading some reviews at newegg, the the APC.

Hi Bret, I bought that exact APC at Costco, works great but see it only as a power backup and, hope it will save things from a surge.

Member for

12 years 9 months

dvdhawk Wed, 03/18/2009 - 22:30
How much current are you trying to condition audiokid?

I don't know which 'little Furman' you have iamfrobs, but I'm sure the power coming out of it is probably an improvement over the junk coming out of the wall.

A DIY project on the scale of what Remy is describing would require a massive 60V + 60V center tapped toroidal transformer and the means to lock the second leg 180˚ out of phase with the first, creating the 120V potential between the two legs.

There are numerous 20A balanced power commercially available, I'll be watching with great interest to see if you can build one any cheaper than you can buy one.

Member for

15 years 11 months

RemyRAD Thu, 03/19/2009 - 02:03
You can certainly do this with a much smaller transformer. Those American to European converter transformers are small and good for up to 20 amps. Get a couple of them, they're small.

I didn't use a Toroidial transformer, popular in balanced power systems but a Power Isolation transformer. This thing appears more like a large power supply transformer or a small UTC style audio transformer. It's not balanced in the typical sense of trying to evenly split the phase of 120 volts, in half.

The primary side has dual multi-tapped primary windings. The multi-tapped section allows for different primary voltages of 240/220/208/120/110/104 single phase or triple phase. The two primaries are tied together at the center. High side voltage is applied to each side of the primary inputs. No ground. No neutral. Just two hots. + & +, that's all.

On the secondary side, you want the lower voltage to power the equipment. So, those dual secondary windings are also tied together at the center tap of the two windings sets. The center tap then becomes your neutral. You then can use the multiple taps to extract 120/110/104 volts, as needed/required.

Because the power is connected to the primary of the transformer in a differential manner, all interference common to those power rails cancel out within the primary of the transformer. This provides you with clean, noise free power from the secondary windings. The frequency response of the transformer also isn't what we would call high fidelity. This works very much in your favor when dealing with high frequency electrical interference. It just doesn't make it through the transformer.

You don't have to feed the equipment balanced power to be using balanced power. It's quite funny to get Master Electrician's scratching their heads when you have no neutral & no ground tied into their shore power. No, I don't drive a stake into the ground either. I like the feeling of floating. Don't you? This ain't your grandmothers electricians electrical wiring. And not necessarily something you want built into your walls since it probably falls outside of normal wiring procedures & Building inspections. I can get away with murder for mobile applications like this. Maybe murder wasn't a good word to use?

I think I'm taking too much estrogen??
Ms. Remy Ann Davizzzzzzzap!......mumph.......

Member for

12 years 9 months

jammster Tue, 03/24/2009 - 13:44
Here is an Info page on which transformers to buy (read the text under style D models):

It looks like the transformer in my previous post only covers about 1500W peak, since in these directions they claim you need twice the anticipated load for spikes, so we up the ante to the 5000W model.

The good news seems to be that these transformers are built ready to regulate and surge protect without the need for stepping up and then back

Anyone else out there who can help on this thread? I'm thinking of getting this transformer for my studio soon.

Member for

12 years 9 months

dvdhawk Tue, 03/24/2009 - 22:14
I'd really like to have Davedog or another certified electrician weigh in on this.

Are you thinking this will work to step down from 220v to a 'clean' 110v?

Again, if you live in North America like I do, we don't have 220v - we have 2 legs of 110v which you can measure 220v between them. The specs on that site are kinda sketchy. The input plug looks like a european plug which might want a 220v hot and neutral. I'd want to confirm the configuratiion of the supply line and whether the 5000w is on the 110v side or 220v side of the transformer.

Member for

20 years 7 months

AudioGaff Fri, 03/20/2009 - 18:51
Remy has rit ight. You want or want something like Furman makes. I have the IT-1220 in use for many years now that has been 100% reliable. The newer models are even better.

Most power conditioners regardless of their claims, have very, very little power filtering. In the IT-1220 I own, it has beter than average filtering, but the balanced power thing makes the bigger difference as it reduces overall noise by several dB and takes care of most ground loop issues.

Member for

21 years

audiokid Fri, 03/20/2009 - 20:10
Thanks for the feedback, I've learned some important stuff here.

I'm looking at this beast.
Does this plug directly into a 110 volt/ 20 amp socket?

They have smaller, more affordable units but they don't specify being balanced and critical high end quality.

Member for

12 years 9 months

dvdhawk Fri, 03/20/2009 - 20:36
Yes, that's right audiokid. The IT-20 plugs directly into a 20-amp receptacle and has 12- filtered outlets on the back and 2 on the front. You use it just like any other power strip. But it's a really big 80-pound toroidal filtered power strip that can lower the noise floor of your entire system.

The IT-20 is the only balanced power unit Furman offers right now, but there are other manufacturers that make balanced power supplies. [Equitech & Monster come to mind]

Furman's smaller, more affordable units are not balanced power, but offer varying levels of filtering, surge protection and line conditioning all the way up to the AR-Pro which is actually pricier than the IT-20.

Member for

21 years

audiokid Fri, 03/20/2009 - 20:38
Man, maybe I'm looking at overkill. I've found this simple rack unit: PL-8 C


Can't track down where that noise is coming from? Your mix sounding flat? With Furman's advanced Linear Filtering Technology you'll lower the noise floor caused by the dirty AC power coming into your console or DAW. Furman's advanced advanced Series Multi-Stage Protection keeps your sensitive digital equipment from acting funny or burning up due to everyday spikes and surges. With a 15A capacity and eleven total outlets, it's enough to power your whole home studio.

Maybe I don't need all the amps I thought. "nough to power your whole home studio".

Member for

12 years 9 months

jammster Wed, 03/25/2009 - 08:29
Hello dvdhawk,
I live in Minnesota, so your question is easily answered that the line current is 110v. I am not sure about european current either, but I would imagine that it may be single phase 220v? Anyways, there is an adaptor that is an additional $2.99 that gives you a standard grounded plug on the order page.

So, yes this is a $140 transformer, no real huge investment here. But they do state in the info page I posted above that you want twice the headroom on your power so it can handle the startup surge that some devices have. I think that electric motors are among the highest surge, unless that motor has soft start.

The info page states:

"A notable feature of style D models is that they can be used for regulation alone without converting voltage. So you can use also them as a surge protector in any country."

It just seems too easy that this device is all you need to protect against a surge and clean power while regulating your current. Anyway, a small investment for a small studio makes sense to me. Do you agree?

Member for

12 years 9 months

dvdhawk Wed, 03/25/2009 - 09:13
Hi jammster,

I hope you don't think I'm just blatantly dumping on the idea, I'm as curious to see if this is a viable alternative as you are. I just have a lot of questions I'd want answered before I plunked down the cash. My training in electrical work is all informal and I don't claim to be an expert.

As you say, here in North America our line voltage is 110v/120v. Europe and Austrailia as Greener said have line voltage of 240v. But if I understand your intention is to not use the step-up or step-down transformer functions and use it more like an isolation transformer.

Even using it as a 1:1 surge protector, to get 5000w of 120v out of it, you'll have to plug it into 120v circuit that is 42 amps @ 120v or more. (I used 120v to get the lower result - it's 45.5A @ 110v)

The 2:1 allowance for the in-rush of an electric motor is a good idea, a high performance power amp is nearly as bad in terms of the surge it needs to energize at start-up.

I wonder why they Photoshopped in a new power switch?

Any electrical product that promotes replacement fuses next to it, makes me a little suspicious/nervous :)

Here's another link that might be of interest back to the DIY portion of the thread:

Member for

12 years 9 months

dvdhawk Fri, 03/20/2009 - 21:53
No, that's a proper 20-amp 110v/120v blade configuration. That's the female you're looking at. Lovely isn't she?

Furman and others sell a little pigtail to adapt it the standard parallel blade 15-amp config. They also mention in their manuals the reality that you may want to lop the 20A plug off and put on the more standard plug. But they strongly suggest you make sure your circuit is a 20A if you do that.

Even if your breaker is 20A, they assume you won't be dropping the entire load on one 15A receptacle.

Member for

12 years 9 months

jammster Wed, 03/25/2009 - 09:51
Ah, yes dvdhawk, thanks for your input.

I did read the article you just posted. You make a very valid point in posting that.

I did not notice the photoshop job on the switch and the use of the small fuses. :wink: The fact remains that it is a transformer that will isolate and effectively "clean" the current.

Yes, it looks like we should focus on quality components such as this new transformer you posted in the article. Perhaps the transformer/regulator in the bargain box I posted previously is not up to the job.

I will have to read this more later. I'm sure there is more info out there on regulating current also.
I hope to post more later,

Member for

15 years

taxman Wed, 03/25/2009 - 09:53
I think power conditioners are hokus pokus, unless you are running off a generator.

Your equipment already has a built in power supply and filter. For example, your laptop probably runs at 5volts DC. The laptop comes with a power supply that steps down the votage, rectifies it to DC, then limits it to the proper voltage with a zener diode, and then filters it with capacitor and inductor pi filters. I don't think much garbage from the AC power line makes it through this process.

No amatuer radio operator I know runs a power conditioner. They take minute signals from an antenna and amplify them significantly to hear them, without power conditioner. If it were at all beneficial, they would all be using them.

I think power conditioners are completely unnecessary, unless you have known power line interference. Even then, your first line of defense should be a complaint to the power company to clean up their act.