New Dedicated Line - Almost No improvement

Isn't it against code to put 240V outlets in most rooms in the home? If so a good electrician won't do that for you.

 

I have my doubts a cheap sine wave inverter will be noise free. That's a giant switch mode power supply. Audiophiles are obsessed with perfect AC sine waves. It makes no sense.

My system sounds exactly the same at any time of the day when I am on holidays. When I am not it swings with my mood.

@laynes , I did not see anywhere where you indicated you have a specific noise issue that you hear?  I disagree with Steakster in terms of what electrical noise will sound like in an all analog system. Noise does not enter an all analog system and cause the issues that were described. If you are hearing nothing in silent passages with an all analog system, then you do not have a power issue. Power noise does not create distortion in an all analog system. It creates noise that is not correlated to the signal.

erik makes a good point. A dedicated line does not prevent noise that appears on your electrical box from getting to your equipment. All those items on their own dedicated lines, which is most of the high power are not helped by a dedicated line. They have benefit when to avoid items like dimmers.

I see many people suggesting multiple dedicated lines. This is more often than not a bad idea. The most important connection for a single piece of equipment is normally line and neutral. The most important connection when several pieces of equipment are hooked together is the ground connection. If you run multiple dedicated lines with separate grounds you have just made grounds loops worse.

You are running a tube integrated, so most of your connections are a single box. It is a good brand, likely with a well designed power supply. If you can't can't hear noise that appears to be power related when silent, then it is unlikely you have a power issue. If the AC is on, the sound noise of the AC is probably much worse than electrical noise.

I do not know what the obsession is with Rhodium in connectors. Audiophiles have some crazy ideas about how things work. If it was better, the military\aerospace would use it in all their connectors. I started out working on military\aerospace electronics. Rhodium is rarely used as a surface material. There are two properties you typically want in a connector interface material. Corrosion/oxidation properties are good, and it is malleable so that is maximizes the contact surface lowering resistance. Two other properties to consider are self lubrication (related to malleability) and wear resistance and impact resistance. You will notice I did not says electrical resistance. The coatings are so thin, 10-200um, that conductivity does not matter much. For any low power connection, gold is a great choice. High corrosion resistance, malleable, some self lubrication. For most power connections, silver is a good choice. Malleable, self lubricating, good corrosion resistance. Only concern is it oxidizes but that oxide is very thin and conductive. Connector wiping action removes typically. Palladium is the next used. It is corrosion resistant, but hard. The hardness in this case is a plus as it can be used when connector ends may be easily damaged. Alloys are also good in arcing conditions (anywhere you plug in live). Rhodium was used in one and only one application. Very rough service, i.e. field items where the contacts could be easily scratched/damaged. If I remember it was always plated on nickel, not for metal diffusion, but because it is brittle and could literally crack off.  There is nothing about a connection anywhere in audio where Rhodium makes sense.

I hope you fix your noise issue if you have it. Erik seems to be on a good low cost path.

 

@clearthinker those pre and phono amps used batteries build into the units or connected to a DC power inlet. That is different from using a cheap AC inverter running from batteries. I could word that differently. A cheap, high powered switch mode power supply.

The conversation has degraded to burning in AC power outlets. I think we have lost the plot on the conversation already. The op has not even verified there is a problem yet, but everyone is rushing to solve it without even knowing if there is a problem, or what it is.

This is what the inside of one of those low cost inverters looks like:  http://www.kerrywong.com/2017/10/01/teardown-and-testing-of-an-800w-puresine-inverter/  It is a high frequency switch mode power supply that generates the high voltage (~170V) and then a PWM stage, and then a filter. I don't see a lot of capacitors or filtering on the DC side, so there could be RF coming out. I don't see any FCC on most of these. YMMV

Old school ones with the big huge transformers are probably not as noisy.

 

I will take that bet @jea48, friendly of course. I am sure there are lots of phile reports of Rhodium sounding wonderful. Not hard to find many listening reports from philes are are simply impossible. Has not been a barrier since the start of audio.  We are not the most skeptical bunch.

@carsbad. Pure sine wave inverters are not very expensive at all really. I can buy a 1000W unit out of Asia that will produce a fairly accurate sine wave for < $100. They are a dime a dozen on Amazon, Alibaba, etc. At light loads they produce good sine waves. At heavy loads there is some distortion. I even quickly found a DIY link for a 1KW pure sine wave based on old technology. The person built it for <$50 of parts. Probably not much of a market for those big old transformers so they are cheap.

Rhodium is an adequate conductor of electricity for a coating that is 10-20um. You would need very good equipment to measure the resistance of a coating that thin. It is poor because it is very hard.

You can’t install 240 outlets willy nilly. The NEC is written to prevent that. They can only be legally installed to support a device that requires that level of power (not voltage). Those appliances you have have 240V outlets because they require the power that 240V can deliver. It is NEC 210.6 (in complete) that specifies this.

On come on @westcoastaudiophile , you don’t need and unlimited budget. The average audiophile product includes more than enough budget to implement an adequate power supply. The issues are often not the power supply at all or just require good design practices, not even a lot of cost.

How are you finding those Ampere Time batteries @ricevs ??  Saw them on Amazon. They seemed at the time a bit lower cost than others but not much difference between the brands. I have built up my own 24V batteries for my big boat using 200aH LiFeP04 3.2V cells, and an off the shelf BMS. Too many BMS failures. I wanted something that in a pinch I could bypass in and keep operating.  Been looking for some 100Ah or 200Ah for the fishing boat.

A good presentation @jea48 but not without questionable recommendations and some questionable interpretations of how things work, but still vastly better and debunking so much of what gets posted.

@theaudioamp You’re new here. What an insulting statement.

And you don’t read well. My comment was not to the person who posted the link, obviously, but to the person who put on the non-peer reviewed presentation to the AES that was linked. There are absolutely some questionable things in that presentation that would not stand up to scrutiny. Questioning the accuracy of what someone links to is not rude, and being here for a long time does not make your posts any more accurate than anyone else and immune to criticism. This is not a professional forum where the accuracy of someone’s posts are validated by equally qualified people.

At higher frequencies, where inductance dominates, using thicker wire has virtually noeffect on impedance. At 1 MHz, replacing the #12 wire with a ½” solid copper rod has little effect (as noted in the plot).

• Misleading and erroneous in the framework of the discussion. For a single wire, in free space, this is true. However, we don't use wires in free space, we use conductors. For a given insulation thickness, increasing wire diameter reduces inductance by increasing area between the two wires. For instance, 2mm wire, with 1mm insulation (4mm on centers) would have about 50uH/meter inductance. If I increase the diameter to 10mm, but keep the same insulation thickness, the inductance

Conduit Transformer (Voltage is directly proportional to load current, wire length, and rate of change in current or ∆I/∆t)

• For a transformer company, I would have hoped they understood transformers better. If you look at their drawing, the output of the transformer is 1.5K in series into a volt-meter, with a 2.2nF load. Essentially that is an open circuit. If it is a transformer, the open loop output voltage of a transformer is independent of the frequency. i.e. in their experiment, the output voltage should not have changed with frequency. If they had shorted the output (very low resistance), then the output voltage would be affected by frequency. They didn't, so their experimental results do not match their proposed transformer model.
• What would match their model? -- parasitic capacitance. I expect there are aspects of both. Either way, their experiment is flawed which means any conclusions are suspect.

 

They assign the source of all noise to this "conduit transformer" and discuss lamp dimmers. The also say leakage current are very small as a partial justification of this. Use a 2.2nF capacitor as an example

• At 60Hz, impedance = 1.2M ohm
• at 70KHz, impedance = 1000 ohms

When you swing 120V (or 220) with 1000 ohms impedance, you can no longer claim low leakage current. Parasitic capacitance provides a nice path for noise in the line/neutral to get into the ground.

• As a point of discussion, a dimmer can also generate audible noise in an audio device with no ground connection.
• 90 degree conduction angle for a dimmer is 50% voltage, not 50% brightness. I think it is closer to 10%. Yes, I am being intentionally pedantic.

For most cord connected equipment, 2 or 3 prong, the leakage limit is 0.5mA and 0.75mA, but again, that is pedantic to the discussion. I am just illustrating a trend.

Even installing a “cheater” (3-to-2 prong adapter) or cutting off a safety ground pin from one of the power cords would still leave as much as 3.5 mA flowing in the interface cable ... that’s 10 times the current of the previous 2-prong example, so a serious noise problem would still exist ... as well as a much more serious safety hazard!

• Both unlikely to due real limits on leakage in 3 prong audio equipment, and practically wrong as well. How many ground loops have been eliminated by clipping a ground pin? The reason is the configuration of EMI filter capacitors and typical parasitics causing case ground to now be equipotential between line/neutral and little current to flow through the capacitors into chassis ground. However, don't disconnect the safety ground. It is a bad idea.

Zcm tolerance of real-world drivers typically determined by ± 5%
series resistors and ± 20% (or worse) coupling capacitors

• Appropriate for this point is that the tolerance of the coupling capacitors is only important w.r.t. the impedance at the frequency of interest. i.e. in audio, at 60Hz, we would typically ensure the capacitance is large enough, so that the impedance is low enough that tolerance is not a significant factor. 20% of 0 is still 0 (exaggerating obviously).

Strange that cable manufacturers still don’t “get it” ... they seem to think “floobydust” is more important.

• I don't have any issue with this. I just think it is funny. I like them even if I disagree with some of what they say. I think the discussion on cables is really good. I think most cable vendors could learn something from it.

Keep cables short and do not coil the excess

• The reason for not coiling is due to coupling of external magnetic fields into the cable. While obviously this is 100% true for a single wire, a coiled cable is a common mode inductor so will reject most external magnetic fields.
• I will give the benefit of the doubt for any cable with a double terminated shield as that would be worse coiled.

 

Page 150

• This absolutely could provide benefit. It all comes down to implementation. If a short RCA is used between the single ended equipment and the transformer, then effectively there is no ground voltage on the single ended side to cause a ground loop noise issue even if high current flows in the ground.

Page 202

• While technically true, in most equipment, the capacitors are not parasitic but intentional for emi and noise.

 

Page 211

• Accuses others of fear mongering while doing some himself. Any half decent designed equipment has ESD and similar protection on I/O lines. Since the I/O lines are high impedance w.r.t. ground, the protection circuitry limits the excursion for the required amount of time.

Page 212

• Series suppressors do dump current into the safety ground, they just do not dump as much. Simple logic should reveal that. If the inductor is connected to an open circuit, the full voltage is transmitted. Hence there must be a low impedance path for the current.

The wire didn't break in @jwmorris , you did.

 

 

Maybe that BX wire is just keeping the EMI in and allowing it to transfer to the ground?

From Bill Whitlock,  (https://www.prosoundweb.com/author/bill-whitlock/)

 

"In reality, most of the reports of fantastic noise reduction attributed to earth ground rods are actually the result of the separation of various ground wires and their connection to a single point. It is the separation of the ground current paths that eliminates the common-impedance coupling of noise from noisy equipment into quiet equipment. It is extremely rare for an additional earth ground connection to solve a noise problem."

@jea48 , while I agree in principle that an earth ground connection is generally not the cause of noise, it is not always not the cause, and when one considers emitted EMI, it can be critical. The earth ground connection (in theory) holds the metal in the equipment, cable shields, etc. to the same potential as earth, but we can call it a ground plane. Now as noted, that connection is more than just cable resistance, it is also impedance. If you remove the earth ground connection, then all the metal floats, and it floats in comparison to earth ground, which means you have a capacitor to earth ground and a "new" path for EMI that you would not have if connected to earth ground. This will never be an issue at analog audio frequencies, but it can be an issue at higher frequencies even with the higher impedance to earth ground.

 

You know what is really foolish? Those ground boxes filled with dirt that don't connect to anything.

You are at the mercy of the people who designed your equipment @papafrgog.