hey everyone!
i havent really seen this discussed to much here so i would like to start a thread and maybe get some ideas on this...
as we all know, much of audio equipment is way overpriced... one such item is power and line conditioners. they basically take your nasty AC input from the wall, and make it into a perfect 120VAC/60hz output for your equipment. however, these things are AT LEAST $1K. thats a LOT for basically a good power supply.
well, i was on ebay, and you can get non-audio versions of these made for industrial use (which is where paul mcgowan from PS audio originally got his idea from). i picked one up for $30, in great condition. there are MANY on there for around $50, and they look fine and are working great.
the concept behind these must be quite simple i imagine, but im gonna open mine up and see if i can figure out how it works.
is there any of these in the DIY realm? i think these would be a GREAT thing for us to use because of our sometimes sketchy power supplies of our amps and such. even for bench testing, they would be perfect.
so, basically i just want to open up some discussion about these. i would like to maybe integrate them into some amp designs. when i build my aleph2's, i plan on making SOME sort of line conditioner built in. they can probably be made cheaply.
btw - the new PS audio amps (hybrids) all have power conditioners built in now... supposedly they are AMAZING (according to stereophile).
i havent really seen this discussed to much here so i would like to start a thread and maybe get some ideas on this...
as we all know, much of audio equipment is way overpriced... one such item is power and line conditioners. they basically take your nasty AC input from the wall, and make it into a perfect 120VAC/60hz output for your equipment. however, these things are AT LEAST $1K. thats a LOT for basically a good power supply.
well, i was on ebay, and you can get non-audio versions of these made for industrial use (which is where paul mcgowan from PS audio originally got his idea from). i picked one up for $30, in great condition. there are MANY on there for around $50, and they look fine and are working great.
the concept behind these must be quite simple i imagine, but im gonna open mine up and see if i can figure out how it works.
is there any of these in the DIY realm? i think these would be a GREAT thing for us to use because of our sometimes sketchy power supplies of our amps and such. even for bench testing, they would be perfect.
so, basically i just want to open up some discussion about these. i would like to maybe integrate them into some amp designs. when i build my aleph2's, i plan on making SOME sort of line conditioner built in. they can probably be made cheaply.
btw - the new PS audio amps (hybrids) all have power conditioners built in now... supposedly they are AMAZING (according to stereophile).
Jon Risch's notes:
http://www.geocities.com/jonrisch/index2.htm
And an implementation:
http://www.audioasylum.com/audio/general/messages/4987.html
I've been thinking about building one of these with remote control to switch amps, etc. (beats getting off the couch!) and to clean up some of the mess behind my rack.
I'd be happy to hear opinions on J. Risch's designs or even the value of line conditioning (beyond just an isolation transformer) in general. It seems like something one should be able to achieve without shelling out $1,500 for a PSAudio Power Director.
http://www.geocities.com/jonrisch/index2.htm
And an implementation:
http://www.audioasylum.com/audio/general/messages/4987.html
I've been thinking about building one of these with remote control to switch amps, etc. (beats getting off the couch!) and to clean up some of the mess behind my rack.
I'd be happy to hear opinions on J. Risch's designs or even the value of line conditioning (beyond just an isolation transformer) in general. It seems like something one should be able to achieve without shelling out $1,500 for a PSAudio Power Director.
Cheap Soloution
Hi Cow (whats yer name)
Yup, the first thing to do is run an AC power filter feeding an isolation transformer and then the equipment.
This enables a balanced (grounded CT) or floating secondary.
Power factor correction (snubbing networks) completes the deal.
The system earth connection can be isolated at the transformer, and a dedicated earth stake connection made to the system.
Some of this has been covered recently.
$1000 boxes are not required, just a decent qualty surplus iso trannie and AC filter.
A quiet, low power factor system power feed is the key.
This gives a much cleaner, more immediate and quieter resultant.
Regards, Eric.
Hi Cow (whats yer name)
Yup, the first thing to do is run an AC power filter feeding an isolation transformer and then the equipment.
This enables a balanced (grounded CT) or floating secondary.
Power factor correction (snubbing networks) completes the deal.
The system earth connection can be isolated at the transformer, and a dedicated earth stake connection made to the system.
Some of this has been covered recently.
$1000 boxes are not required, just a decent qualty surplus iso trannie and AC filter.
A quiet, low power factor system power feed is the key.
This gives a much cleaner, more immediate and quieter resultant.
Regards, Eric.
I picked up a 1.8kVA line voltage regulator that uses a ferroresonant transformer to maintain constant line voltage and filter out noise, etc. from the line.
It seems to work, but I can't hear any difference in my audio system. I mainly use it to protect my video projector from lightning induced surges. I have read that all ferroresonant transformers buzz and run hot, and mine certainly does both.
It seems to me that one could make a low budget power source that regenerates AC by buying a computer UPS (very, very cheap these days), disconnecting the battery and AC input, then connect a high current 12V supply in place of the battery. The thing would think the power was dead all the time and would operate in battery power mode. You'd have to check to see how ripple on the battery input affects the output voltage, and check to see if the unit is heat sinked well enough to operate full time in battery mode at the power level you're going to pull through it.
I wouldn't think it would be any problem at all to run a preamp/cd player/etc. from such a supply.
Of course, I don't believe it will make any difference in your systems sound, but hey, whatever floats your boat...
MR
It seems to work, but I can't hear any difference in my audio system. I mainly use it to protect my video projector from lightning induced surges. I have read that all ferroresonant transformers buzz and run hot, and mine certainly does both.
It seems to me that one could make a low budget power source that regenerates AC by buying a computer UPS (very, very cheap these days), disconnecting the battery and AC input, then connect a high current 12V supply in place of the battery. The thing would think the power was dead all the time and would operate in battery power mode. You'd have to check to see how ripple on the battery input affects the output voltage, and check to see if the unit is heat sinked well enough to operate full time in battery mode at the power level you're going to pull through it.
I wouldn't think it would be any problem at all to run a preamp/cd player/etc. from such a supply.
Of course, I don't believe it will make any difference in your systems sound, but hey, whatever floats your boat...
MR
Re: Cheap Soloution
yeah, what i figured...
if you look at like grainger or something like that, you will see that $400 can buy you a nice line conditioner. one that does all you mentioned below. they only get into the thousands once it gets like over 2.5KVA or so.
the one i bought is like 1.4KVA, and will handle my 5 channel amp just fine. might need to upgrade it for 2 aleph's.
once i get mine, i will definately test improvements, and see if this is a worthwhile project. if it is, i will work on some projects maybe making scaled down versions to be built into amps.
it all comes down to one simple fact: the amp was designed to operate using 120VAC @ 60hz. it was NOT designed to operate with noisy and varying current. so, in theory, it must improve something.
btw, my name is Robert Cowan btw...
yeah, what i figured...
if you look at like grainger or something like that, you will see that $400 can buy you a nice line conditioner. one that does all you mentioned below. they only get into the thousands once it gets like over 2.5KVA or so.
the one i bought is like 1.4KVA, and will handle my 5 channel amp just fine. might need to upgrade it for 2 aleph's.
once i get mine, i will definately test improvements, and see if this is a worthwhile project. if it is, i will work on some projects maybe making scaled down versions to be built into amps.
it all comes down to one simple fact: the amp was designed to operate using 120VAC @ 60hz. it was NOT designed to operate with noisy and varying current. so, in theory, it must improve something.
btw, my name is Robert Cowan btw...
`mrfeedback said:
a little knowledge goes a long way...
...it's seems that the term "power conditioner" is used very losely in this thread. There are many types of "power conditioners" that all loosely fall into two classes - these are online and offline.
Offline power conditioners are often the cheapest as all they do is try to remove power fluctuations. They are usually shunt filters (using capacitors to create a high frequency short to ground) and often include chokes that attenuate common mode interference.
Online power conditioners are much more expensive and justly! They have the mamoth job of creating mains power - yes creating it! They are infact highpower amplifiers that output a 50/60Hz (dependant on country) sine wave and therefore act as if they are an independant (mains) source.
Anyone who has knowledge of electronics will know how expensive (not to mention difficult) it would be to make a 1000W (approximate) amp that outputs up to 240V!
I hope this helps?
If anyone does have designs for an online power conditioner please let me know I would be VERY interested!
...it's seems that the term "power conditioner" is used very losely in this thread. There are many types of "power conditioners" that all loosely fall into two classes - these are online and offline.
Offline power conditioners are often the cheapest as all they do is try to remove power fluctuations. They are usually shunt filters (using capacitors to create a high frequency short to ground) and often include chokes that attenuate common mode interference.
Online power conditioners are much more expensive and justly! They have the mamoth job of creating mains power - yes creating it! They are infact highpower amplifiers that output a 50/60Hz (dependant on country) sine wave and therefore act as if they are an independant (mains) source.
Anyone who has knowledge of electronics will know how expensive (not to mention difficult) it would be to make a 1000W (approximate) amp that outputs up to 240V!
I hope this helps?
If anyone does have designs for an online power conditioner please let me know I would be VERY interested!
some have line filters in them, but that only keeps out noise. it doesnt necessarily reconstruct the power for you.
im not really sure how a UPS works, but maybe it could be modified so that even if the voltage sags a TINY bit (like 119.7VAC), it would kick in the battery, and bring that back up to 120VAC. but i dont think it could even do that.
the best bet is line conditioners or power regulators. they are REALLY cheap if you buy industrial versions on ebay. i have plans to move mine into a different casing, making it LOOK like its a regular audio component...
plus, keep in mind, power conditioners for stereos are made to keep our amps and preamps running with good juice. industrial versions are made to keep equipment running, and medical equipment running (to keep people ALIVE). if i were in the hospital dying, and they gave me the choice of an industrial application power regulator, or a PS audio power plant to run my life support system, ill tell you which i would choose.
im not really sure how a UPS works, but maybe it could be modified so that even if the voltage sags a TINY bit (like 119.7VAC), it would kick in the battery, and bring that back up to 120VAC. but i dont think it could even do that.
the best bet is line conditioners or power regulators. they are REALLY cheap if you buy industrial versions on ebay. i have plans to move mine into a different casing, making it LOOK like its a regular audio component...
plus, keep in mind, power conditioners for stereos are made to keep our amps and preamps running with good juice. industrial versions are made to keep equipment running, and medical equipment running (to keep people ALIVE). if i were in the hospital dying, and they gave me the choice of an industrial application power regulator, or a PS audio power plant to run my life support system, ill tell you which i would choose.
Keep it away from the main stuff
All ferroresonant transformers have a big airgap in the core e.g. a 2kVa one has about 3/16 inch the last one I saw. The magnetic field across this is VERY strong even at no load so make sure the tranny is in a steel box and situated well away from your main amplifer because I expect any fringing field from that airgap would be significant. Also, keep audio and video tapes well away too!
GP.
All ferroresonant transformers have a big airgap in the core e.g. a 2kVa one has about 3/16 inch the last one I saw. The magnetic field across this is VERY strong even at no load so make sure the tranny is in a steel box and situated well away from your main amplifer because I expect any fringing field from that airgap would be significant. Also, keep audio and video tapes well away too!
GP.
Re: Keep it away from the main stuff
understood this is the priciple working of how a tranformer, well, transforms.
however, i am guessing it will be somewhat shielded, as it needs to be used with other equipment, and no shielding would really kinda defeat its purpose.
and what are audio and video tapes? those labels for dvd's and cd's?
understood
this is the priciple working of how a tranformer, well, transforms.however, i am guessing it will be somewhat shielded, as it needs to be used with other equipment, and no shielding would really kinda defeat its purpose.
and what are audio and video tapes? those labels for dvd's and cd's?
Circlotron said:
my heretical thoughts on line conditioners
I think that
if you are concerned with this power quality stuff,
and you are building your own gear,
then it probably makes more sense to build a power supply with a buck-boost switcher, an H-bridge, a small transformer for isolation, and then whatever floats yer boat after the trafo, be it switchmode or linear output regulation, or maybe none at all. Forget about 60 Hz. If you keep the switching frequencies high, then only the highest order intermods from the switcher get into the audio band, and being high order, they aren't very powerful.
Or am I all full of BS?
On the other hand, if you have to power something that was designed for 60 Hz, then it might be worthwhile to consider using a buck-boost regulator that is used to power a big class-D amplifier that makes a decent 60 Hz sinewave output after filtering.
Use of high switching frequencies would really make the components a lot more reasonable, and also give you another excuse to buy some killer low impedance capacitors ...
I'm guessing this is what the PS Audio amplifiers do. And the Halcro.
Or, you could take a big dose of placebo and use Bybee Quantum Purifiers. But when I am in the mood for weird trippy stuff, I study math. Or rather, I wistfully remember the days when I had TIME to study math.
As far as Stereopile goes, too often in there are phrases like "of course the lowly $500 Wombat can't possibly compete with the $175,000 Wolverine, but for the price ..."
The use of price as a second-order quality metric is becoming ever more maddening as technology evolves. Look at the prices of consumer electronics that actually do incredible signal processing: $60 DVD players or hard disk drives ... look at the prices of Athlon motherboards that have compact little power supplies that produce 60 A for the hungry processor...
(those power supplies _do_ use stuff like OsCon caps, but only what is necessary.)
Which reminds me to ask another silly question:
has anyone got any experience with the rather pricey polymer electrolytics from Panasonic?
I think that
if you are concerned with this power quality stuff,
and you are building your own gear,
then it probably makes more sense to build a power supply with a buck-boost switcher, an H-bridge, a small transformer for isolation, and then whatever floats yer boat after the trafo, be it switchmode or linear output regulation, or maybe none at all. Forget about 60 Hz. If you keep the switching frequencies high, then only the highest order intermods from the switcher get into the audio band, and being high order, they aren't very powerful.
Or am I all full of BS?
On the other hand, if you have to power something that was designed for 60 Hz, then it might be worthwhile to consider using a buck-boost regulator that is used to power a big class-D amplifier that makes a decent 60 Hz sinewave output after filtering.
Use of high switching frequencies would really make the components a lot more reasonable, and also give you another excuse to buy some killer low impedance capacitors ...
I'm guessing this is what the PS Audio amplifiers do. And the Halcro.
Or, you could take a big dose of placebo and use Bybee Quantum Purifiers. But when I am in the mood for weird trippy stuff, I study math. Or rather, I wistfully remember the days when I had TIME to study math.
As far as Stereopile goes, too often in there are phrases like "of course the lowly $500 Wombat can't possibly compete with the $175,000 Wolverine, but for the price ..."
The use of price as a second-order quality metric is becoming ever more maddening as technology evolves. Look at the prices of consumer electronics that actually do incredible signal processing: $60 DVD players or hard disk drives ... look at the prices of Athlon motherboards that have compact little power supplies that produce 60 A for the hungry processor...
(those power supplies _do_ use stuff like OsCon caps, but only what is necessary.)
Which reminds me to ask another silly question:
has anyone got any experience with the rather pricey polymer electrolytics from Panasonic?
The upshot of my thoughts are that ideally, we would design decent power-factor-corrected switchmode power supplies into gear,
and I think that a good thing for power conditioning would be to use a class-D amp to make a 60 Hz sinewave, and to power the class-D amp from a power-factor-corrected switcher.
But I need to think about what good tradeoffs might be.
Certainly though it should be possible to get away from ferroresonant transformers, and other large heavy (and expensive) things, in favor of inexpensive things and clever design, to make the power that comes out not care much about the power that goes in; 60 Hz is glacially slow; there's time to manipulate it.
I need to read more about power factor correction. And about SMPS design in general.
There are plenty of other worthwhile approaches; the ones that require "big iron" work, too, and have been around longer than switchers.
and I think that a good thing for power conditioning would be to use a class-D amp to make a 60 Hz sinewave, and to power the class-D amp from a power-factor-corrected switcher.
But I need to think about what good tradeoffs might be.
Certainly though it should be possible to get away from ferroresonant transformers, and other large heavy (and expensive) things, in favor of inexpensive things and clever design, to make the power that comes out not care much about the power that goes in; 60 Hz is glacially slow; there's time to manipulate it.
I need to read more about power factor correction. And about SMPS design in general.
There are plenty of other worthwhile approaches; the ones that require "big iron" work, too, and have been around longer than switchers.
interesting. like ive said before, once i get my power conditioner in the mail (all 40+ pounds of it...) i will open er up and snap some pics. i have a digital, so we can all have a look
and if it actually improves my sound from my system, maybe we could play with some sort of way to impliment the general design into an existing power supply for an amp?
once again, ideas.
and if it actually improves my sound from my system, maybe we could play with some sort of way to impliment the general design into an existing power supply for an amp?
once again, ideas.
Here's something to stare at, to get an idea of some of the issues.
This app note presents a circuit that only solves the first part of the problem. Nevertheless, it's a start.
http://www.fairchildsemi.com/an/AN/AN-42032.pdf
Although this is a very complex design, it isn't rocket science. It has some nice features: high switching frequency, decent efficiency, and (mostly) inexpensive parts.
Add a 60 Hz sinewave oscillator and class-D amplifier, ...
You could synthesize the 60 Hz digitally, and build something like a sigma-delta DAC for the output class-D part.
You probably wouldn't want to use a textbook sigma-delta architecture though, becaue I think that with very little modification of the textbook s-d arch. you could have it regulate the output better, making up for any remaining slop left by the PFC input circuit and the varying load.
If only there were TIME.
This app note presents a circuit that only solves the first part of the problem. Nevertheless, it's a start.
http://www.fairchildsemi.com/an/AN/AN-42032.pdf
Although this is a very complex design, it isn't rocket science. It has some nice features: high switching frequency, decent efficiency, and (mostly) inexpensive parts.
Add a 60 Hz sinewave oscillator and class-D amplifier, ...
You could synthesize the 60 Hz digitally, and build something like a sigma-delta DAC for the output class-D part.
You probably wouldn't want to use a textbook sigma-delta architecture though, becaue I think that with very little modification of the textbook s-d arch. you could have it regulate the output better, making up for any remaining slop left by the PFC input circuit and the varying load.
If only there were TIME.
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