[Michael G.]

Just wondering about this, because it seems like so many people who try AC filtration or AC regeneration devices in their loudspeaker systems end up selling them. The complaint often seems to be that both types of devices can quash "dynamics" or "homogenize the sound", etc.., Suspicious that normal current delivery is being restricted or modified by these AC devices, they remove them and re-discover the lost "sparkle" and "dynamics" that were lost. Perhaps some people simply can't get used to the hash-free sound of clean AC?. Or perhaps, the sonic signatures of some audio components were created in the presence of bad AC in mind? Maybe the intended "voice" of some components is altered when clean AC is introduced into the system?

 

[markl]

There's a big difference between power conditioners and regenerators. Conditioners filter the AC (i.E. work by removing certain grunge and distortion), so their effect is subtractive. Power regenerators take the AC and completely recreate it in all its untrammeled and unpolluted glory. Unless one has hooked up a 1500 watt multi-channel amp up to a regenerator that can only handle 300 watts, there should be no loss of dynamics.

Power conditioning is going to be more effective where the power is dirtier (i.e. urban areas, or suburban areas where people are packed closely together, lots of EFI/RMI interference in the aire, etc.). In those situations, removing nasties can be a real help. OTOH, if one is out in the country, your power may be clean already, so adding a filter may actually appear to detract from the sound.

There's no component that's going to benefit from bad power or sound better with dirty AC. But in some cases, the "cure" provided by certain power conditioning devices may be worse than the disease. Not all power conditioners are created equal as well, so results will vary from unit to unit and installation to installation depending on what exactly is plaguing your AC.

OTOH, there's another possibility in that some distortion can sound good to some listeners. It's *possible* that some distortion can end up being euphonic, or that say, one listener likes the extra roughness, graininess, or jagged edges in the treble region (for example) because they can sound more "sparkly" or "vivid" with a more "exciting" texture or whatever with AC grunge present. I think that's possible.

 

[Michael G.]

Quote:

Originally Posted by markl There's no component that's going to benefit from bad power or sound better with dirty AC. But in some cases, the "cure" provided by certain power conditioning devices may be worse than the disease. Not all power conditioners are created equal as well, so results will vary from unit to unit and installation to installation depending on what exactly is plaguing your AC. OTOH, there's another possibility in that some distortion can sound good to some listeners. It's *possible* that some distortion can end up being euphonic, or that say, one listener likes the extra roughness, graininess, or jagged edges in the treble region (for example) because they can sound more "sparkly" or "vivid" with a more "exciting" texture or whatever with AC grunge present. I think that's possible.

I still think it's possible that some audio components were designed to (in effect) "synergize" with normal polluted AC, just as some components are designed to synergize with the cheap-o powercords they come packaged with. Or, sometimes manufacturers will recommend that a certain interconnect be used with their designs. I have heard of at least one amp designer who resented the use of aftermarket powercords with his product, because he claimed he had "voiced" his amps with the sound of the stock plain-jane powercord in mind. The bottom line is always that we must all get our systems to sound the way we like them to in our own listening rooms. But we should be aware that the intentions of the designer may well be at odds with the outcomes of our experiments.

 

[Sovkiller]

Well I use power conditioners myself, just for precaution, and because I have got them really cheap, but all I can say is, that if you have the funds go for them, as they will not harm, and they indeed protect you from surges, and anomalies of the line, but to what extend the benefits will be heard, this is not an easy question to answer, and all depends on how good or bad is the PSU design that you are hooking in, but if do not have the means to go for them (a really good one) better invest in more music, or a better designed amp, with a really good design on the PSU.

IMO, and in others as well, a good designed PSU has to be able to remove all contamination from the AC line, and this way you will have nothing to benefit from a power re-generator or conditioner, as the DC component at the output inside the amp should be really clean and noise free, of course good and well designed PSUs capable of cleaning, all pollution, are really expensive and hard to find inside of the majority of the "best buys" type receivers, you should go a little higher and even though.....

I know that many members will object, and there are tons of mythology articles written on the net, talking about the same, but I would like to see those writers in a really DBT listening to a treated line, that will feed a well designed amp with a really beefy PSU, and one hooked directly on the AC outlet in the center of Manhattan, in NYC....to see them fail miserably, same way as this DBT with the speaker cables, remember???...

 

[Michael G.]

Quote:

Originally Posted by Sovkiller I know that many members will object, and there are tons of mythology articles written on the net, talking about the same, but I would like to see those writers in a really DBT listening to a treated line, that will feed a well designed amp with a really beefy PSU, and one hooked directly on the AC outlet in the center of Manhattan, in NYC....to see them fail miserably, same way as this DBT with the speaker cables, remember???...

At least one amp manufacturer, Bryston, is renowned for the high quality of it's PSU designs. Bryston techs (and Bryston owners) claim that aftermarket powercords and other devices will not improve the sound quality of their amplification components because their PSU's are designed to handle most common AC supply problems. Indeed, some Bryston owners claim that aftermarket AC conditioning devices only degrade the sound.

 

[saint.panda]

One relatively cost-effective solution to get cleaner power is by using balanced power. While these devices don't regenerate power, they transform the usual 120V into +/- 60V (-60 on neutral and +60 on hot) and just like balanced cables help to remove certain unwanted interferences.

There's a DIY solution by Jon Risch and a kit from Transcendent Sound for $360. The assembled version goes for $460.

A FAQ by Equitech, maker of (rather expensive) balanced power devices: http://www.equitech.com/faq/faq.html

 

[helix]

most regenerators are actually putting square waves into a step-up transformers , it makes the rectification in a bridge rectifier even more non linear than just pluging in stright 60 hz ac hence the power supply will have more ripple.

 

[star882]

Quote:

Originally Posted by helix most regenerators are actually putting square waves into a step-up transformers , it makes the rectification in a bridge rectifier even more non linear than just pluging in stright 60 hz ac hence the power supply will have more ripple.

Only the really cheap ones do that. The high end APCs (1000VA or so) output sine waves using advanced PWM electronics.
But quality PSUs can very easily handle imperfect power, as long as it stays within specs. Indeed, most laptop PSUs and some desktop PSUs can handle anywhere from 100v to 250v. And as anyone who has taken a PSU apart knows, good PSUs have good line filters. In fact, I have a 200w Mitac (used in a homemade internet router) that went as far as using a preregulator. It would step up 100-250v to 400v and then step it back down to 12v, 5v, and 3.3v. It sounds like a step backwards, but I have talked to some engineers about this and they say that it actually makes design easier because the primary winding of the flyback transformer doesn't have to handle as much current.

 

[Tim D]

Disregarding power conditioners and regenerators, I would wager that many people have systems that suffer from ground loops, but they just don't know it. People assume it will always come across as some massively noticable 60 hz hum, but that of course is not true and can just be an insidious hash that adds grain to your midrange, etc.

IMO it is best to nip ground loops in the bud absolutely and completely before even worrying about the rest.

So yes I agree there are probably people out there attempting to voice their system around a preventable fault. Ground loops aren't the most intuitive problem to deal with either for the vast majority of folks that didn't spend years in college as an EE or trained to be an electrician.

I once used a rather simple switchbox in my signal chain that had as an input the output from the soundcard of my PC. Even if that input was not chosen however and I was listening to a different source, there was still a ground loop issue that added grain and hash to the current signal which persisted regardless of if the PC was even powered on I believe. It wasn't so noticable as to cause significant audible noise or hum, but was just added hash, etc.

Plus I'd have to wonder about 'meet' conditions which just brings a massive amount of equipment to be set up together in a day as well as the inclusion of switchboxes that could easily color and bias impressions of certain amps or sources over another because they employ different grounding scheme in a less than ideal environment, or luck of the draw, etc.

 

[helix]

imo regenerators are a waste of money, if your having power supply problems i think you'd still have them using a regenerator except now your wasting more power. why go ac to dc to ac then back to dc when you could just use things that have a real effect on the power supply such as bigger psu caps, chokes, ferrite beads, snubbers, a capacitance multiplier or a better regulator ic etc...


my first introduction to ground loops was when i was installing a cctv setup between two buildings, i thought my use of cheap coax instead of the custom $500 per 100' cable that the manufacture of the cctv system sells was causing the problem. i didn't have a scope so i couldn't tell what was going on. fortunately when i described the jumping vertical picture problem to a friend who was an old pro he reccomended me a video transformer that cost $125. that fixed the problem. i also built him a mic and pre amp and put it in a smoke detector that connected to the unused pins of cat 5 utp that we had already run across the street when we made the network and now the guy who hired me can spy on his employees.

 

[star882]

Quote:

Originally Posted by helix imo regenerators are a waste of money, if your having power supply problems i think you'd still have them using a regenerator except now your wasting more power. why go ac to dc to ac then back to dc when you could just use things that have a real effect on the power supply such as bigger psu caps, chokes, ferrite beads, snubbers, a capacitance multiplier or a better regulator ic etc...

If you haven't realized already, modern PSUs actually rectify AC to DC then convert it to high frequency AC and finally to low voltage DC. Because it runs at a high frequency (~100kHz) and the drive signal to the switcher transistors can be precisely controlled, the transformer can be made very small and light, and since there's less wire in the transformer, the efficiency actually increases. Some additional benefits include lower cost (particularly at high power) and very good regulation.
Of course, designing such a PSU is not an easy task, and my friend Christina Mahoney (a PSU engineer) actually uses a good amount of CPU power on a quad Britney "supercomputer" just to simulate various PSU conditions. In particular, the "worst case" simulation can often take hours or even days to complete on that really fast computer. Not to mention that some of the simulations require so much memory that the admins recently put 32GB of RAM in that computer. (Much fun unmounting the CPU cooling evaporators to access the RAM sockets, then installing the RAM, discovering that the new RAM blocks the TXVs in the evaporator assemblies, requiring a rework, and finally reapplying the sealant to keep out moisture.)

As for what I do, I use high quality PSUs along with APC UPSes and surge protectors. I can tell you that Antec PSUs are very good quality, although most will need a fan voltage mod (very easy) to keep it reliable. Nothing beats a PC Power & Cooling (except maybe one custom designed by Christina Mahoney), although those are very expensive. Fortron is regarded as the best "cheap" PSU.

 

[Jahn]

Yep, the only thing not fed into my PC1000 Monster Power is my amp. I plug it right into the wall - it sounds "cleaner" that way to me.

 

[Glod]

Quote:

Originally Posted by Tim D "Disregarding power conditioners and regenerators, I would wager that many people have systems that suffer from ground loops, but they just don't know it.People assume it will always come across as some massively noticable 60 hz hum, but that of course is not true and can just be an insidious hash that adds grain to your midrange, etc."... ..."Plus I'd have to wonder about 'meet' conditions which just brings a massive amount of equipment to be set up together in a day as well as the inclusion of switchboxes that could easily color and bias impressions of certain amps or sources over another because they employ different grounding scheme in a less than ideal environment, or luck of the draw, etc."

I think these are good points. Ground loops can be very difficult to sort out IME. Perhaps it is less of a problem in balanced systems?

I have never been to a meet, I have only experienced that systems newly set up need to settle in somehow for a good sonic result. That in spite of that the individual components might have been burned in previously.

 

[helix]

to star882:

what your descibing is a dc to dc converter or a switching power supply and nobody uses those in serious audio except for car amplifiers or class-d amps that are not even in the same league as real hi-fi gear. a switching power supply introduces a lot of crap into the supply rails, while that might be fine for your computer it's frowned upon in audio, thats why pro soundcards use seperate boxes for their adc/dac's. almost all the hi end makers of audio equipment use linear regulators in transports/pre-amps/dacs, even the power amp and tube amps mostly all use CLC style filtering. granted smps are harder to make than simple linear supplys but the point is they don't sound good. the reasoning behind smps is that they are cheap to make in quanity. that tiny little 2" toriod transformer switching at 100khz in your computer is about 1/100th the price of a real 500va transformer. and you say the switching transistor has to be precisely controlled, not true it's almost always a cheap power mosfet just turning on and off going into a hi speed diode to prevent back emf and then on to a choke and a cap for smoothing all controled by a 0.50 cent ic. if your friend needs a super computer to design smps supplys then i'd have to say What why doesn't he just look at the application notes on one of the many cheap ic's that are made to do the job, nothing hard about that. in short smps are used when you need to be cheap and also need efficiency. you almost never see them included in good audio products and their's a reason for that, they suck.


edit: i just have to add you don't need a supercomputer to run OrCad (the best sim out there) so your friend is probably ********ing just a bit about what he does, oh and i have made maybe 100+ power supplys, its easy. i find the less people know about electricity the more they imagine things.

 

[star882]

Quote:

Originally Posted by helix to star882: what your descibing is a dc to dc converter or a switching power supply and nobody uses those in serious audio except for car amplifiers or class-d amps that are not even in the same league as real hi-fi gear. a switching power supply introduces a lot of crap into the supply rails, while that might be fine for your computer it's frowned upon in audio, thats why pro soundcards use seperate boxes for their adc/dac's. almost all the hi end makers of audio equipment use linear regulators in transports/pre-amps/dacs, even the power amp and tube amps mostly all use CLC style filtering. granted smps are harder to make than simple linear supplys but the point is they don't sound good. the reasoning behind smps is that they are cheap to make in quanity. that tiny little 2" toriod transformer switching at 100khz in your computer is about 1/100th the price of a real 500va transformer. and you say the switching transistor has to be precisely controlled, not true it's almost always a cheap power mosfet just turning on and off going into a hi speed diode to prevent back emf and then on to a choke and a cap for smoothing all controled by a 0.50 cent ic. if your friend needs a super computer to design smps supplys then i'd have to say What why doesn't he just look at the application notes on one of the many cheap ic's that are made to do the job, nothing hard about that. in short smps are used when you need to be cheap and also need efficiency. you almost never see them included in good audio products and their's a reason for that, they suck. edit: i just have to add you don't need a supercomputer to run OrCad (the best sim out there) so your friend is probably ********ing just a bit about what he does, oh and i have made maybe 100+ power supplys, its easy. i find the less people know about electricity the more they imagine things.

I guess you don't know how far she does design. Yes, designing a PSU from a simple IC and some simple components isn't difficult (I've done it many times), but she actually designs the magnetic components (transformers, inductors), the board layout, and even the program that the controller runs (the controllers she uses in large PSUs are nothing like the common ones; she uses specialized controllers that are actually miniature computers on chips). Just try to design a 1U PSU that can supply 500W. It's not easy. Also note that at high powers and small sizes, heat becomes a big problem.
As for noise, note that it's possible to design a switcher that has very little noise on the output. It's also possible to follow a switcher with a linear to further reduce noise.