AudioCircle
Other Stuff => Archived Manufacturer Circles => Music Reference => Topic started by: Chazro on 22 May 2014, 08:28 pm
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I just read a thread where the majority seem to agree that ANY amp (SS or tube) sounds better plugged directly to the wall. MY RM9 has been plugged into a power conditioner due to the infamous on/off button failing to turn the amp on a few years ago. After pushing it on and off a few times it turned on but left me worried. I've read that the switch is inferior and could/should be replaced. I opted to plug into the PC, bypassing the switch (leaving it on), so now when I turn on the conditioner, it turns on the amp along with a few other components. All's been well ever since but this thread got me to thinking....so rather than chime in on that thread, I figured I'd come here and hopefully get an answer from the Man himself. Any thoughts Roger?
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Kudos for coming over here for your response. I am sure Roger can provide the information you need.
As an aside, I plug in my RM-10 direct to the wall. I use a nice inexpensive (by today's audiophile standards anyway)12 gauge PC with stranded copper wiring. In my opinion any well designed amp should incorporate enough filtration in the power supply to handle any noise or voltage fluctuations at the wall socket.
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I just read a thread where the majority seem to agree that ANY amp (SS or tube) sounds better plugged directly to the wall. MY RM9 has been plugged into a power conditioner due to the infamous on/off button failing to turn the amp on a few years ago. After pushing it on and off a few times it turned on but left me worried. I've read that the switch is inferior and could/should be replaced. I opted to plug into the PC, bypassing the switch (leaving it on), so now when I turn on the conditioner, it turns on the amp along with a few other components. All's been well ever since but this thread got me to thinking....so rather than chime in on that thread, I figured I'd come here and hopefully get an answer from the Man himself. Any thoughts Roger?
What you are doing is what I always wanted the user to do. However any simple power strip will do. Here's the tale of the RM-9 power switch.
Sorry about the switch, the dealers made me do it! I wanted to supply the amp without a switch as it complicate the otherwise perfectly unencumbered wood base. Being the first manufacturer to make functional wood I was a purist, i.e. no holes other than to attach the top and bottom. I never wanted a switch.
If you push in the switch and let it pop out it often unlocks. At least it locks in the on position. We put a rocker on the later units. Although rated at 15 amps it doesn't last forever. Then, being totally disgusted with switches I found a very expensive 70 amp switch with specially designed weld breaking contacts (that's why switches stick on, the contacts weld). We use the 70 amp, non welding switch on the RM-200 MK II. None have failed, I finally found a switch I like. If you know a good woodworker who can cut a rectangular hole in your base you can put one of these in. Anyway, my whole system is on a $5 outlet strip. Everything comes on at once, and you won't find any fancy power cords, cables or speaker wire.
As to power conditioners I am glad to hear people have FINALLY realized what I told them 30 years ago. Most power conditioners just make things worse, you can't make power better and a good amp doesn't care. Some of the power conditioner boys, like Richard Gray, have been exposed for their snake oil. I tested one of his "flywheel boxes" that you connected in parallel with the line. It drew 6 mA which means that's about all it could "flywheel" a fly indeed as 6 mA is 0.1 % of the current a 6 A. amplifier draws.
The Renaissance harpsichord makers often made one intentional mistake, often by leaving a decoration off of one keyfront on just one key. Their reason was that only God could make something perfect.
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Thx for the quick response Roger! I truthfully never heard much of a difference, if any, when I installed the PC into my system. I always thought of it more as a solution to the 'spaghetti'/cables problem. I'm a little OCD when it comes to neatness, always coiling and tie-wrapping trying the minimize the cable mess. Being able to plug everything into the PC helps out. Putting aside the RM9/switch thing, based on yr response, it appears that you agree with the opinion that an amps (or any component, for that matter) sound quality would improve by being plugged directly to the wall. Of course, it couldn't be an easier thing to test. But you know what, seeing as how I am and have been more than satisfied with the sound of my RM9 for the years that it's been plugged into the PC, I ain't messin' with it!;)
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I'm a little OCD when it comes to neatness, always coiling and tie-wrapping trying the minimize the cable mess.
It would be great to have a super-tidy cable arrangement, however when you coil a cable you are essentially creating an inductor to some degree and that's never a good thing.
I'm not sure in each particular cable coiling scenario how much or little effect you may create, but I tend to avoid it, particularly with AC power cords. I have seen power tools burn out when operating from coiled up extension cords. I certainly don't have that length of AC cable on my components, but ....
I also see people cable tie interconnects, speaker cables and power cables together in a tidy parallel trunk, but in reality they should cross each other at 90 degrees. Since I won't coil, and I can't get all cables to cross each other at 90 degrees, I just accept the random mess and figure I'm probably better off, electrically speaking.
Steve
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It would be great to have a super-tidy cable arrangement, however when you coil a cable you are essentially creating an inductor to some degree and that's never a good thing.
I'm not sure in each particular cable coiling scenario how much or little effect you may create, but I tend to avoid it, particularly with AC power cords. I have seen power tools burn out when operating from coiled up extension cords. I certainly don't have that length of AC cable on my components, but ....
I also see people cable tie interconnects, speaker cables and power cables together in a tidy parallel trunk, but in reality they should cross each other at 90 degrees. Since I won't coil, and I can't get all cables to cross each other at 90 degrees, I just accept the random mess and figure I'm probably better off, electrically speaking.
Steve
I hear what you're sayin'. I don't coil IC's and power cables together. I don't coil spkr cables at all. Been this way for yrs and again, I suppose it would be a simple test to uncoil/tie-wrap everything to see if I'll hear a beneficial difference. Maybe someday when I have the time....
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Coiling a wire makes an inductor, but coiling a cable (that has both the send and return wires) does not make an inductor.
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Coiling a wire makes an inductor, but coiling a cable (that has both the send and return wires) does not make an inductor.
...since the induced magnetic fields cancel each other out, right?
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Myths...
Good amplifiers still benefit from power conditioners. The difference is in the conditioner. The real problem is that when your sound improves in many ways, it shows you the lack in others. When you AB, if you can hear the difference right away, it's often that the music isn't as full, you might call it "dynamics" or a host of other things depending on your ear. But what's happened in many cases is that the refinement has reduced the bloat of poor information that was perceived as part of the music before.
When you're at that point, the type of resistors in key places, capacitors, circuit topology, it all starts to play a bigger role because the differences become more notable.
This is fundamentally obvious given that entirely passive parallel filtration will do this just like series active filtration will. Essentially many power conditioners take the blame for the let downs in your equipment. But I will say there's a fair amount of crap out there that's been sold as a power conditioner. The giant chokes by Gray did work, but no one ended up liking the sound, the resistance was through the roof too so they wasted a ton of energy, and his pricing may not have been very appropriate.
This all seems ridiculous to me since a system with a good power conditioner is a pleasure to listen too, and one without is a chore by comparison.
Also to note, almost no amplifier has any serious filtration to speak of. The design usually rejects a fair amount of RF and ground loops, but even very well designed units benefit from power conditioning.
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...since the induced magnetic fields cancel each other out, right?
Exactly!
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Myths...
Good amplifiers still benefit from power conditioners. The difference is in the conditioner. The real problem is that when your sound improves in many ways, it shows you the lack in others. When you AB, if you can hear the difference right away, it's often that the music isn't as full, you might call it "dynamics" or a host of other things depending on your ear. But what's happened in many cases is that the refinement has reduced the bloat of poor information that was perceived as part of the music before.
When you're at that point, the type of resistors in key places, capacitors, circuit topology, it all starts to play a bigger role because the differences become more notable.
This is fundamentally obvious given that entirely passive parallel filtration will do this just like series active filtration will. Essentially many power conditioners take the blame for the let downs in your equipment. But I will say there's a fair amount of crap out there that's been sold as a power conditioner. The giant chokes by Gray did work, but no one ended up liking the sound, the resistance was through the roof too so they wasted a ton of energy, and his pricing may not have been very appropriate.
This all seems ridiculous to me since a system with a good power conditioner is a pleasure to listen too, and one without is a chore by comparison.
Also to note, almost no amplifier has any serious filtration to speak of. The design usually rejects a fair amount of RF and ground loops, but even very well designed units benefit from power conditioning.
Sorry but I am not able to understand the point being made here. However I will qualify a few things that I know.
1, The Gray choke that I measured drew 6 mA from the wall. That is nothing, but then it did nothing, because it couldn't at that small current. If they "wasted a ton of energy" they would run very hot and the one I measured was stone cold. I doubt anyone would put up with a hot conditioner.
2. Any "passive parallel filtration" would have to fight the low impedance of the power line and would lose that battle.
3. I don't believe any filter can do squat against ground loops. The only way to solve ground loop problems is to break them with ground floats or go balanced as we do in the RM-200.
This I disagree with emphatically... """Also to note, almost no amplifier has any serious filtration to speak of. The design usually rejects a fair amount of RF and ground loops, but even very well designed units benefit from power conditioning""".
The truth is that the power transformer presents more leakage reactance (a good thing) than the chokes in power conditioners and 1000 uF of filter capacitance is a lot bigger than a the few tenths of uF that most line conditioners have. For the uninitiated, a line filter typically provides series inductance and parallel capacitance to filter out the high frequency noise on the line. However the values of these are much larger inside the amplifier than values that could be placed outside the amplifier. If these values were used outside the amplifier the parallel elements would draw serious current while the series elements would add to the primary resistance of the transformer and impede it's regulation.
The power transformer in an RM-9 or RM-200 is on the order of 1 ohm. I am proud to say that is very low. Now add in the power cord resistance (here is a slight positive for heavy power cords). However a 6 foot 18 ga power cord is only 0.072 ohms and a 15 ga cord is half that (good rule to know is that every 3 gauges is half or twice the resistance depending on which way you go). So either way we haven't added much yet. Enter the power conditioner boys. They wind chokes that go in series with the line. What is the resistance of those? They are typically wound with several feet of 18-15 gauge wire. There usually several on both sides of the line (2 minimum). Perhaps they add more than the power cord. This is why I don't recommend them period.
I cannot speak for other designers but all my amps and preamps have excellent RF filtering as any good engineer would do. All of my customers that I have spoken with have felt relieved to hear that I suggested they dispense with power conditioners.
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Hi Roger,
Is it possible that power conditioning benefits components with less robust power supplies like cd players, dacs and some preamps?
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Roger,
1. The Gray's measured at 50ohm or something ridiculous like that if I remember right, maybe I got that wrong.
2. No it doesn't work that way. The impedance of line is low, but it's 60hz and not a problem. Source impedance from noise causing devices is not often low. Plus several capacitors will have a very, very low impedance.
3. Filters aren't used on ground loops per say. Look up the Deno from schurter; I don't know of other AC ground devices that aren't lifts or obviously dangerous. And with components there are numerous ways to prevent ground issues that aren't necessarily 60hz safety ground associated. Like CMC's n parallel with a resistor (forgot his name, guy on DIYaudio came up with it) and old stand by's like resistors in certain places.
DC and AC filtration are almost not comparable. You can boast the numbers, like 1000x capacitance, but the reality is even with high end power caps, the result in sound difference is that the power conditioner wins in overall result to the listener. That's being said by someone that thinks most caps sound like craps, even some of the respected ones. What does it matter if the results are what they are, they trump all else because they're what you listen too.
That doesn't start to cover the affects of dirty power on smps supplies.
Read some reviews on Audience Adept units, universally people agree they don't hinder, and there's no starting noise floor that's too small to be not affected. The kicker? They don't even filter that much.
Also their resistance in there CMC's (like all the popular ones now), is negligable. In fact I believe they use ones rated at 8mOhms. I've never used one that was even above .3ohm.
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1. 50 ohms is the resistance. That would draw over 2 amps which it did not nor could not without burning up. It drew 0.006 amps due to the inductance. It was basically the primary of a large transformer. Why he ever thought it would do anything is a mystery to me. The problem we have here is education. The buyer needs to know what these electrical parameters mean. I believe the claim was that these devices provided a flywheel effect. 0.006 amps is not much of a flywheel in a 15 amp circuit.
2. It simply becomes a voltage divider with series resistance plus series reactance with shunt capacitance. All depends on the values. My point is that the power transformer does much more than the components in most filters.
8 milliohm is not much wire to make an inductor with. I measured a well built unit from Monster. The series resistance to the outlets was 400-500 milliohms. That's going to hurt regulation and a good reason not to put a power amp in those sockets.
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what's the point here (hum) pi type filters do the job quite well
if you look over the internet they are universal...
cheers :green:
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2. A lot of people don't like the sound of isolation transformers, and transformers in your equipment no matter how good, always get serious benefits from conditioning. The numbers are inconsequential to that, but for fun... Isolation transformers will do 50 or so db in the 10k+hz range. I make filters that start down at 1600hz. I'm not the only person that has made something with a bigger range. Have you seen other projects on this board? There's been a lot of success with these simple devices. The wheel is simple but no one is going to down play it's importance to a computer controlled car with active suspension.
What's your point with monster stuff? Yes high resistance is bad, hence most don't use it. But you're also criticizing the alternative. There is no perfect. But as a lot of people know there is improvements to be had.
Teflon capacitors in a simple RC device, the Audience Adept, makes a noticeable difference. It's a silly way to increase filtration with very diminishing returns, but it still works.
You're in the quick to dismiss because the compromises make you uncomfortable. But you've got all the same process in your other equipment of choosing what will work best based on compromise. You're just familiar with what you're dealing with and what the returns will be.
I don't like the "it can't be perfect so don't bother" approach; it's too deceatesr depressed go no where talk for me.
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We should note that 50 Ohms is the impedance of the "Line Impedance Stabilization Network" (LISN) used in power line EMC compliance testing.
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yes. i use a running springs jaco.. it cleans up the incoming electricity and protects against power surges and lightning strikes. now if you want to trust fuses in your equipment to protect against the former go ahead. i want added piece of mind especially living here in northern Va where we get big storms!
ps. just think of all the RF/EMI that piggy backs itself on the incoming power. maybe the filtering in your gear is good enough to get rid of it and then again it might not. always err on the side of caution.
just might take on it. rather be safe then sorry and sorry can be very expensive.
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Well, when bad weather gets too close, I start unplugging things. Then I'm really sure. Nothing is 100% safe. :thumb:
Gene
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good point! i am to lazy for that.LOL! power around here can fluctuate when it wants to.
happy listening!
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All of your gear with smps power supplies and relatively small transformers will introduce noise back into the power distribution system you use (at varying amounts, anything can, but those two are most likely, and motors). Whether or not it's filtered there, and not cycled in the system, is up to you.
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Well, when bad weather gets too close, I start unplugging things. Then I'm really sure. Nothing is 100% safe. :thumb:
Gene
At least your weather warns you it's coming. We Californian's get a BIG surprise every time there's an earthquake. Like this morning.....two of them, actually. A 4.6 and a 4.8 here in the desert, at about 10:00 AM. Gooood morning L.A.!
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BTW, I never got around to posting this back when I started this thread. Based on what I read here I decided to plug my RM9 directly to the wall. Here's what happened, but 1st, a little backstory!;) When I was living in GA. I was in a house and had the RM9 plugged into the PC. When I fired up the system everything was dead silent. A few yrs. back I moved to an apt. in FL., immediately upon firing up the system here I heard a hum. After checking all the usual suspects the hum persisted and I just chalked it up to the 'sharing the electricity' theory. Just figured it was due to living in an apt. vs. living in a house and simply accepted the hum, besides it was completely inaudible when playing music. Cut to this thread, after reading RM's response, I decided to give it a shot and plug the amp directly into the wall, you probably can guess what's coming! Plugged it in, buh-bye hum!!! What a pleasant surprise! The on/off switch has been behaving itself also! Listening to Ella Fitzgerald & Joe Pass as I type and life is good!!;)
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BTW, I never got around to posting this back when I started this thread. Based on what I read here I decided to plug my RM9 directly to the wall. Here's what happened, but 1st, a little backstory!;) When I was living in GA. I was in a house and had the RM9 plugged into the PC. When I fired up the system everything was dead silent. A few yrs. back I moved to an apt. in FL., immediately upon firing up the system here I heard a hum. After checking all the usual suspects the hum persisted and I just chalked it up to the 'sharing the electricity' theory. Just figured it was due to living in an apt. vs. living in a house and simply accepted the hum, besides it was completely inaudible when playing music. Cut to this thread, after reading RM's response, I decided to give it a shot and plug the amp directly into the wall, you probably can guess what's coming! Plugged it in, buh-bye hum!!! What a pleasant surprise! The on/off switch has been behaving itself also! Listening to Ella Fitzgerald & Joe Pass as I type and life is good!!;)
OK, but if the hum was inaudible while playing music, what did you gain by plugging the amp directly into the wall? Does you system sound better or worse now? If your PC had surge protection, you've lost that protection for your amp.
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You realize that is the equivalent of taking a cold/luke temperature shower/bath when you have a fever right? It seems nice but there isn't a "solved problem", because there's a wiring issue or grounding issue somewhere.
I'd prefer to knock out the problem and have conditioning on the amp (with a conditioner that does well with an amplifier, and many do).
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BTW, I never got around to posting this back when I started this thread. Based on what I read here I decided to plug my RM9 directly to the wall. Here's what happened, but 1st, a little backstory!;) When I was living in GA. I was in a house and had the RM9 plugged into the PC. When I fired up the system everything was dead silent. A few yrs. back I moved to an apt. in FL., immediately upon firing up the system here I heard a hum. After checking all the usual suspects the hum persisted and I just chalked it up to the 'sharing the electricity' theory. Just figured it was due to living in an apt. vs. living in a house and simply accepted the hum, besides it was completely inaudible when playing music. Cut to this thread, after reading RM's response, I decided to give it a shot and plug the amp directly into the wall, you probably can guess what's coming! Plugged it in, buh-bye hum!!! What a pleasant surprise! The on/off switch has been behaving itself also! Listening to Ella Fitzgerald & Joe Pass as I type and life is good!!;)
Hum is usually caused by a grounding or cable issue. Only the power amp should be grounded. I still like things plugged directly into the wall. No power conditioners in my house. I still contend that for power amps especially their added resistance is not favorable.
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Hum is usually caused by a grounding or cable issue. Only the power amp should be grounded. I still like things plugged directly into the wall. No power conditioners in my house. I still contend that for power amps especially their added resistance is not favorable.
And if there's no added resistance?
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And if there's no added resistance?
And what kind of conditioner is that?
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I often leave induction/resistance free sockets on ones I make, that still benefit from attenuation of noise by capacitors, ground care, and the fact that the other non-amps are filtered so that it doesn't feed nearly as much back for the amp to experience.
But to be honest when I use .008ohm resistance CMC's, I don't think any human could tell the difference for any kind of remote possibility of resistance.
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Maybe you should send Roger one of your conditioner's to try. :dunno: I'd be interested in his opinion and if it's something that he thinks is good I'm sure you would benefit from it too.
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Myths...
The giant chokes by Gray did work, but no one ended up liking the sound, the resistance was through the roof too so they wasted a ton of energy, and his pricing may not have been very appropriate.
This all seems ridiculous to me since a system with a good power conditioner is a pleasure to listen too, and one without is a chore by comparison.
Also to note, almost no amplifier has any serious filtration to speak of. The design usually rejects a fair amount of RF and ground loops, but even very well designed units benefit from power conditioning.
Are you talking about Gray's original device which was two wire choke that went in parallel with the power outlet?
My amplifiers have serious filtration and RF protection and very few problems with ground loops.
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Parallel?
What amplifiers?
Power conditioners are not actually for correcting obvious problems. They aren't for removing RF that you can hear in the speaker. The majority of obvious problems need to be fixed in a different way, unassociated with the AC power.
Power conditioners, what they actually do is reduce the stuff on the AC line that's affecting what you hear. You hear the removal of the affect, not a removal of a "sound" or "artifact". Simply... you should just notice you stereo doing everything better, and a reduction of fatique.
Fisher makes a little 'acoustic guitar' amplifier. If you play it into the wall it sounds fine with acoustic guitars. If you plug it into one of my musician conditioners then it sounds good electric or acoustic; but even more noticeable is the lack of a "splat" sound at the peak of every note replaced by a fully rounded note. Prior to that experiment no one knew there was a "splat" at the high end music store, but after it was gone you couldn't unhear it. The point being there wasn't an unwanted sound, or artifact (all of those were affecting amplification). It was the note the whole time, but the quality of it changed drastically even though the "sound" of the tuning, knobs, all that, was the same.
*explaining this to a musician is almost impossible, they're mostly insecure people scared that a power conditioner will change the type of sound their guitar makes... Because quality to them stands for the type of sound that's being made, not how well it's made.
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Parallel?
What amplifiers?
Is the Gray power conditioner of which you speak one that goes in parallel with the line...You do understand parallel?
http://www.richardgrayspowercompany.com/power.html
Patented parallel iron-core inductor technology is proven (after 1 million installations and counting) to provide instant current –on–demand to power efficiently today’s High Performance-Current hungry AV components and electronic systems.
Gosh did he really sell one million of these things... :roll:
What Amplifiers? My amplifiers.
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I'm not sure what's in them now. The early one was literally a giant choke.
What do you think the odds of me understanding parallel is, given that I make conditioners?
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I'm not sure what's in them now. The early one was literally a giant choke.
What do you think the odds of me understanding parallel is, given that I make conditioners?
As to your understanding of Gray I think there is some confusion, which I am trying to claify.
Yes the early one was a giant choke. From his website it appears that is what he is still making in various configurations. So how does one connect that? Series or parallel?
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I think he's claiming parallel, but also using series.
Maybe I got the new stuff wrong? People were buying giant chokes from PE for series, to duplicate his a long time ago.
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I think he's claiming parallel, but also using series.
Maybe I got the new stuff wrong? People were buying giant chokes from PE for series, to duplicate his a long time ago.
How about explaining what you said here in electrical terms. The giant chokes by Gray did work, but no one ended up liking the sound, the resistance was through the roof too so they wasted a ton of energy
In particular how did they work and how did they waste a ton of energy?
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A choke has two wires in parallel, they induct onto a core of sorts. Now the most common thing they are used for is a reduction in common mode noise (something often generated by small transformers that create capacitance between not well enough insulated layers). But some also work on differential mode noise. Line and neutral going through each side to cause these desired results.
The induction can cause resistance. Some of those bigger chokes were upwards of 50ohms.
Claims were that there were benefits for certain areas of the music. They were so interesting people would use them, then take them back out and be shocked at regained dynamics.
It's been forever, but it's the only origin story for anything but trashy consumer "filters" that add any real notable resistance. For example Audience Adept might have .008ohm per socket as well, or abouts. Reviewers with big amps haven't been claiming a loss of dynamics. I don't know if the Uberbuss adds any at all, either. Frankly I've just come to believe there's a lot of buzz around certain claims of power conditioning, not necessarily associated with use.
The other issue is that sometimes people find out their stereo was compensating too much for it's inadequate abilities without power conditioning. That's a rough one to deal with.
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Looking at what I can find on the new ones, parallel is a fib in a sense. They're in parallel until there's draw on the stored energy, then they become a source. That's based on how they claim to work, but don't include full disclosure of how it changes. Reviews still claim they help one thing, hurt another. And techinically when the inductors act as a source, resistance is probably pretty high!
Lot of talk over a something you wouldn't use anyway :lol:
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Looking at what I can find on the new ones, parallel is a fib in a sense. They're in parallel until there's draw on the stored energy, then they become a source. That's based on how they claim to work, but don't include full disclosure of how it changes. Reviews still claim they help one thing, hurt another. And techinically when the inductors act as a source, resistance is probably pretty high!
Lot of talk over a something you wouldn't use anyway :lol:
Gray seems to say very little these days. I guess selling one million units affords him that option.
His parallel unit is a single winding on an iron core, basically the primary of a power transformer. It is connected in parallel with the wall socket and is doing what the primary of your power transformer is already doing. It does not draw or waste heaps of power. It draws 6 mA and the resistance is a few ohms. I measured it.
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How do you explain such negative feedback? Shinyata's iron cores are not in parallel, an hence an explanation.
Also a bunch of his claims wouldn't be true unless the inductor is being used to store energy. Otherwise he's claiming regular AC functions are his doing.
I guess being him would still be good if he's really sold so many, as you pointed out.
Here's a question. What have you tried?
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Hum is usually caused by a grounding or cable issue. Only the power amp should be grounded. I still like things plugged directly into the wall. No power conditioners in my house. I still contend that for power amps especially their added resistance is not favorable.
What about lightning strikes, brown outs, etc?
My amplifiers have serious filtration and RF protection and very few problems with ground loops.
Do you have any recommendations for the DIY amp builder for filtration and RF protection?
What about "dirty" AC? I seem to have a problem with the AC in my apartment in that it can cause power transformers to hum/resonate. It happens randomly with some of my amps/ receivers and I've even noticed my variac do it. The ceiling fans in the apartment hum too. (100 year old building with regular 3-phase wiring according to my landlord) What's weird is that I have a couple of amps that don't seem affected by it and are always quiet.
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Try the Van Alstine Humdinger, sounds like you got DC going into your stuff... Not necessarily a power conditioner thing, but I can tell you there's probably a lot of noise on your lines given where you live. A lot could be as little as 4%. That's how little one reviewer of an Audience Adept unit had, but won't listen without a conditioner now (6moons article).
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Try the Van Alstine Humdinger, sounds like you got DC going into your stuff... Not necessarily a power conditioner thing, but I can tell you there's probably a lot of noise on your lines given where you live. A lot could be as little as 4%. That's how little one reviewer of an Audience Adept unit had, but won't listen without a conditioner now (6moons article).
I actually got one of those last year. Had no effect on my tube amp but did help my sub amp.
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I actually got one of those last year. Had no effect on my tube amp but did help my sub amp.
They are only for blocking DC, which causes a loud hum in transformers when it's bad.
Now if DC isn't your problem, look back to what Roger said, you probably got grounding issues. It's not easy to address, I know...
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They are only for blocking DC, which causes a loud hum in transformers when it's bad.
Now if DC isn't your problem, look back to what Roger said, you probably got grounding issues. It's not easy to address, I know...
With inputs shorted it's virtually dead quiet from the speakers. But the power transformer hums roughly 5db measured 1" from the transformer.
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What about lightning strikes, brown outs, etc?
Do you have any recommendations for the DIY amp builder for filtration and RF protection?
What about "dirty" AC? I seem to have a problem with the AC in my apartment in that it can cause power transformers to hum/resonate. It happens randomly with some of my amps/ receivers and I've even noticed my variac do it. The ceiling fans in the apartment hum too. (100 year old building with regular 3-phase wiring according to my landlord) What's weird is that I have a couple of amps that don't seem affected by it and are always quiet.
Sounds like you have some DC on the line. This is a big problem for torroids and transformers at high flux. Actually domestic power is called 2 phase 120/240V. Three phase is only found in industrial areas to run big motors. The phases are 120 degrees apart. I doubt you have 3 phase, but this does not matter.
Your Variac is basically a torroid and sensitive to DC on the line. To measure the DC on the line you have to remove the AC with a filter that you can make. Take a film cap around 0.47 uF or larger and put that in parallel with the input of the Digital meter. Put a 100 K resistor in series with the hot lead. Connect the hot and negative across the line, preferably the negative to the neutral and the 100 K to the hot. The neutral is the wide slot.
Set the meter to DC volts. Note what the DC is for various noises from your transformers and fans. The noise they make should be louder when there is more DC. Let us know what happens.
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With inputs shorted it's virtually dead quiet from the speakers. But the power transformer hums roughly 5db measured 1" from the transformer.
Transformers can also produce a "mechanical" hum, from loose laminates vibrating at the 60hz frequency. Because this frequency is so low, and it mimics the usual "ground loop" hum, many people pursue the problem and fail, because they did not realize the problem was a mechanical hum. Using a DC blocker wont help here obviously.
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Actually North American residential power is single phase with a center tap for Neutral. It's also known as split phase 120/240.
But corndog may live in a large building, serviced by 3 phase power.
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Actually North American residential power is single phase with a center tap for Neutral. It's also known as split phase 120/240.
But corndog may live in a large building, serviced by 3 phase power.
Yep, my building has over 25 units. I could be wrong but I'm pretty sure she said 3-phase. I know there are 240V outlets for in-unit washer/dryers.
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To measure the DC on the line you have to remove the AC with a filter that you can make. Take a film cap around 0.47 uF or larger and put that in parallel with the input of the Digital meter. Put a 100 K resistor in series with the hot lead. Connect the hot and negative across the line, preferably the negative to the neutral and the 100 K to the hot. The neutral is the wide slot.
Set the meter to DC volts. Note what the DC is for various noises from your transformers and fans. The noise they make should be louder when there is more DC. Let us know what happens.
Before I do anything I would just like to confirm that I understood what you wrote. Does this look correct?
(http://i576.photobucket.com/albums/ss207/corndog642/bdf1493afeac98935f57df0f4f616820_zpsa742335e.jpg)
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Before I do anything I would just like to confirm that I understood what you wrote. Does this look correct?
(http://i576.photobucket.com/albums/ss207/corndog642/bdf1493afeac98935f57df0f4f616820_zpsa742335e.jpg)
Yes...
This guy recommends a 10uF non-polarised capacitor.
you need a 100k resistor and a 10uF non-polarised capacitor, wired in series. Connect this circuit across the mains (power off!), and connect a DC voltmeter across the capacitor. This attenuates the AC enough to prevent the front-end of the meter from being overloaded, and the DC voltage is easy to measure. Expect to see the DC vary around the zero voltage, with a normal variation of +/-25mV or so (typical - residential areas). The alternative method is to measure the DC across the diode/capacitor network in the circuit of Figure 3. Do not connect or disconnect the meter with the circuit live, and use alligator clip leads to make the connections.
http://sound.westhost.com/articles/xfmr-dc.htm
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Before I do anything I would just like to confirm that I understood what you wrote. Does this look correct?
(http://i576.photobucket.com/albums/ss207/corndog642/bdf1493afeac98935f57df0f4f616820_zpsa742335e.jpg)
Your drawing is correct. I don't think 10 Uf is necessary. I go find mine or go build one right now and let you know. I am curious about my home too.
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Your drawing is correct. I don't think 10 Uf is necessary. I go find mine or go build one right now and let you know. I am curious about my home too.
Yes that will work. I found mine has a 1 uf capacitor and 560K 1/2 watt or greater series resistor. None of these parts are special or critical in value. When connected to the power line I measure 0.5 volts AC. That is low enough for the DC function to decipher the voltage on the line. The series resistor size will reduce the measurement by being a voltage divider to the meter. However the meter is usually 10 meg ohms (you should check the specs or with a known battery as the source). If the series resistor is 1 megohm the meter will read 10% low, 560 K will read 5% low. This is a simple voltage divider for the DC part. It is for the AC part if you calculate the reactance of the capacitor.
When you test the set-up see that your meter measures some small AC voltage. then turn it to DC and see what you get from time to time. My house has no DC, not even a few millivolts. To test I took a 100 watt light bulb and put a half wave rectifier in series with it. That combination put 0.22 DC volts on the line. It is always good to conduct an experiment to see that something reasonable happens when you load the system.
I was telling Ben that when I put 0.2 volts on the line all my neighbors on the same pole transformer got that too minus some losses from house to house, but I bet I could plug the lamp in my house and measure it in theirs.
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Ok, I measured 6.5VAC and -0.010 to -0.018VDC.
By the way, I picked up a used Hitachi Oscilloscope. Still figuring out how to use it. :scratch:
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Ok, I measured 6.5VAC and -0.010 to -0.018VDC.
By the way, I picked up a used Hitachi Oscilloscope. Still figuring out how to use it. :scratch:
OK, That's pretty small. Take another look when things start humming. I think I have seen hitachi owners manuals online for free. Which model did you get? I have one that has been working a long time, though I had to fix it recently.
Scopes are very similar and there must be some tutorials on line. The knobs all have names.