[Chazro]

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?

[Clio09]

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.

[Roger A. Modjeski]

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.

[Chazro]

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!;)

[srb]

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

[Chazro]

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....

[Speedskater]

Coiling a wire makes an inductor, but coiling a cable (that has both the send and return wires) does not make an inductor.

[Ericus Rex]

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?

[Folsom]

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.

[Speedskater]

...since the induced magnetic fields cancel each other out, right?

Exactly!

[Roger A. Modjeski]

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.

[Ericus Rex]

Hi Roger,

Is it possible that power conditioning benefits components with less robust power supplies like cd players, dacs and some preamps?

[Folsom]

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.

[Roger A. Modjeski]

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.

[G Georgopoulos]

what's the point here (hum) pi type filters do the job quite well
if you look over the internet they are universal...

cheers

[Folsom]

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.

[Speedskater]

We should note that 50 Ohms is the impedance of the "Line Impedance Stabilization Network" (LISN) used in power line EMC compliance testing.

[rbwalt]

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.

[Goosepond]

Well, when bad weather gets too close, I start unplugging things. Then I'm really sure. Nothing is 100% safe. 

Gene

[rbwalt]

good point! i am to lazy for that.LOL! power around here can fluctuate  when it wants to.

happy listening!