Question for Atma-sphere, will expensive power cables improve your amplifiers?

@mitch2 Yes! You also want good solid connections at either end so they don’t heat; heat means a Voltage loss.

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If you want an inexpensive means of building a power cord, use the kind of AC power cord used by an electric dryer or stove. Put a set of decent connectors on either end so you don’t get the connections heating up (which represents a Voltage drop) and you’ll have a very competent power cord.

Of course you have to watch things like which side is hot and which side is neutral so an electrician might have to be the one to do the work for you.

Any tube amp has in addition to the high Voltage power supplies, also a filament supply which is usually not regulated. So when there’s a Voltage drop across the power cord, not only is the B+ Voltage on the power tubes a little lower but the tube is less efficient since the cathode (heated by the filaments) is running at a lower temperature since the filaments are running cooler.

Put another way this means that tube amps are generally more sensitive to power cords than solid state amps are. But solid state amps can be affected too. The more regulation that is used (for example, in our MP-1 preamp where all the power supplies are tightly regulated) the less sensitivity you’ll have to the power cord.

One variable I've not mentioned yet: In a power supply there are rectifiers that convert AC from the power transformer to DC and filter capacitors that are charged by that DC. But the rectifiers only conduct when the output of the power transformer is higher than the Voltage on the other side of the rectifier. The filter capacitors retain a charge from one iteration of the AC power waveform to the next, so the only time the rectifiers conduct is at the peak of the AC waveform. At that time, the current has to move swiftly to charge the cap and so there is a current spike when the AC Voltage is at the peak. This might only be for a few milliseconds. If the power cord has troubles with what is essentially a higher frequency (due to the steepness of the current spike itself) it could limit the charging time.

That could result in a lower power supply Voltage with more noise. Some power cords are better at this than others.

That is why you can hear differences between power cords. Anyone that says otherwise clearly has not measured the effect they can have on equipment. IOW what I’ve said here can be backed up with measurements.

Power cords are (mostly) three runs of stranded copper wire with PVC insulation, twisted together (sometimes with filler material for damping), and encased in a PVC jacket. The main variables that affect power transmission are the wire gauge, shielding (or not), and connectors.

True for the majority of OEM mass produced power cords.

For power amplifiers they may sound fine. For digital equipment not so much.

Most audiophile power cords are not built using three stranded wire conductors.

Solid vs stranded conductors will make a difference. Very few audiophile cables made today use stranded wire.

Method of conductor and cable geometry used can change the sound heard from an audio system.

Shielding can make a difference. Sometimes for the worse in sound. Depends on how it’s implemented.

Type of the wire used, therein the Hot and neutral current carrying conductors, can make a difference.

Agree the connectors used, male plug and female IEC connectors, can make a difference.

Wouldn’t that be a case for keeping component power cords as short as possible?

For OEM power probably. Depends on the wire gauge used. For an audiophile power cord not really. 5ft - 6ft seems to be pretty common.

Very few audiophile cables made today use stranded wire.

@jea48 Just so you know, solid core wire for a power cord is illegal and for a good reason! On that account, I'm pretty sure your statement above isn't correct.

@atmasphere

@jea48 Just so you know, solid core wire for a power cord is illegal and for a good reason! On that account, I’m pretty sure your statement above isn’t correct.

Yes, a single solid core #14awg or a single solid core #12awg wire, or a #10awg solid core wire would not meet electrical safety code for a power cord.

Several smaller gauge solid core wires individually insulated grouped in parallel together for the Hot and neural conductors, for use in a power cord, will/does meet NRTL safety testing.

AudioQuest was making power cords back in the 1980s paralleling multiple small gauge solid core insulated wires together to make a combined equivalent single gauge conductor for the Hot and neutral conductors.

I sill have a couple of non shielded AudioQuest AC-12 power cords. It’s equal to a 12awg X 3 cable using four separate solid core 18awg cu OFHC insulated wires conductors for the Hot conductor and four for the neutral conductor. A 12awg stranded green insulated wire is used for the EGC, Equipment Grounding Conductor. The conductors were assembled together in what AQ called a "Hyperlitz design".

The individually insulated eight #18awg solid core wire conductors were placed surrounding the #12awg stranded insulated EGC. That design had to be the EE in Bill Lowe. It cancels out the EM fields from the hot and neutral current carrying conductors from inducing a voltage onto the EGC.

Fast forward to today high end audiophile power cords manufacturers are still using AQ’s use of using individually insulated solid core wire conductors. Though the wire gauge size of insulated solid wire varies in the design. I’ve read where some will have a mix of 18awg and smaller solid core individually insulated wires, and some add Lintz (insulation) wire in the mix.

The geometry construction of the power cord has greatly changed as well since the 1980s. And most of the building of the cable is done by had, from my understanding.

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Do power cable have to have UL certification? Just curious