How Big of a Difference?

@johnnycamp5 - I hope the following provides answers to your questions

I always wondered about the improvements from cables but never (not yet) went down that road.

My biggest unanswered questions are on “power cables” Are these more like a “device” than just the correct quake cable?

And what about the approx. 100’ of romex cable in between your service panel and Gigi rig?

 

Do the high end power cables somehow eliminate those cheap, solid core copper lines?
These are sincere questions …not trying to be a wise guy.…

First - that 100’ of romex is actually pretty good at conveying electricity

• It is solid core - not stranded cable. In power applications stranded cables cannot handle as much current as solid cables, so when those transient spikes hit, a stranded cable will not work as well as solid core
• The copper in Romex is actually pretty good quality, so don’t mistake the cheapness of romex for poor quality
• the line from the distribution panel to the outlet should be a continuous run without any breaks
• so a dedicated line is a better approach than perhaps other outlets that may be part of a spur that attaches to more than a single outlet

Please don’t shoot the messenger with this next comment, but this is how I interpreted the explanation given to me,

• where you have a connection point, (e.g. the wall outlet), the only "electrical attribute" present at that connection point is the VOLTAGE.- Current only comes into play once a load is connected
• So when you plug in a power cable, the current in THAT CABLE is impacted only by the cable’s electrical attributes (see below)
• so if you use a crappy power cable into your component, the result would be quite different than if you used a very good cable
• Even though everything else is EXACTLY the same
• What does carry forward to the component is noise, because noise is a fluctuation of voltage, which is present at every junction point

So if you consider the "construction" of a really great cable

• most use UP-OCC copper and the best use a solid core wire, which translates to faster response to transient current demands - so better dynamic performance
• most use advanced insulation types (e.g. foamed teflon) which has a lower dielectric constant value, which results in less noise being generated within the conductors - so improved clarity
  • Basically, each conductor acts like a capacitor and the charging/recharging of the insulation as the voltage swings through +ve and -ve cycles, creates noise within the conductor - crappy cables use wire with a higher dielectric constant and therefor produces more noise
• finally, the very best cables employ a cable geometry that either puts space (e.g. an air gap is best) between the individual conductors in order to prevent induced noise between conductors OR use a geometry that reduces the amount of parallel conductors in the cable. Braiding is an example of a more advanced cable geometry and it results in a lower noise floor

For other examples of cable geometries take a look at the following links

http://image99.net/blog/files/54c02c12532d31f960ee85a6ed674b01-83.html

https://www.in-akustik.de/en/cables-and-accessories/reference-air/power-cables/

I hope that provides some insight into the inner working of a good power cable

Regards - Steve

@williewonka 

Thanks that helps!

@williewonka that all sound correct and true.

The only part that has me chin scratching is:

• most use UP-OCC copper and the best use a solid core wire, which translates to faster response to transient current demands - so better dynamic performance

Is there really any transient current demand that is even measurable? We have the AC crossing zero 120 times a second, and then amplifiers power supplys generally have a bank of capacitors that are holding the energy for output transients.
So clearly any high freq transients that happen when the input voltage is crossing zero, needs to come from the cap-bank.

So is there much happening on the input in terms of transients?

I recall when the VTLs were working, that they would run for many seconds after the power was switched off… basically they would play music until the heaters glow went away.

Or does the effect of the supply side get more important on specific amps with less in terms of the power supply capacitor banks?

@holmz - lets start be looking at the process at different points in the audio system

At the speaker

• the power required to satisfy the volume level selected has two components - voltage, and the current drawn, which is a product of the speaker impedance

The amplifier circuit

• so the amp circuit attempts to build a voltage signal that will operate the speaker at the required volume and the speaker places a current draw on circuit which must be satisfied (ultimately) by the power supply
• if there is enough energy reserves in the power supply, the signal is created as it should be, with the required voltage and current to move the speaker cone to its required displacement
• if there is not enough energy reserves to provide the required current then the peak voltage is not achieved - and performance suffers
• and ALL of this has to be achieved in the blink of an eye

The power supply

• is always replenishing it’s power reserves via the power cable
• the faster the power cable is at conveying electrical energy, the faster the power supply can replenish energy reserves and satisfy the demand of the amplified signal
• But on the mains supply side of the power supply, the voltage is simply 120v flip flopping at 50 (or 60) Hz as you pointed out
• However, if you could plot the current draw on the mains side, it too varies in a similar fashion to the musical signal, so when the bass guitar slaps or the bass drum beats, the transient spike is in the form of current drawn and not voltage.

So those mono-blocks with the massive power supplies are more able to handle transient spikes in the signal.

However with smaller components, the power supply tends to be less capable, so connecting a quality power cable to a source component will appear to provide more of a benefit than connecting that same power cable to an amp

For best performance

• amps require the very best power cables in order to observe noticeable improvements
• source components will provide more of an improvement with a power cables that is perhaps a little less capable than those selected for Power Amps

So, when selecting power cables for any component I look for those that use UP-OCC copper, because it will provide excellent dynamic response. Silver is better, but a lot more expensive.

But, bear in mind that all of this is all happening at lightening fast speeds, so even in the best mono-blocks - good power cables will improve their performance.

Hope that helps - Steve

Hope that helps - Steve

Thanks, but I am probably a bit slow.

I understand the speaker’s voltage and current draw relationship.

And also the amplifier trying to get to a specific output voltage in a closed loop feedback fashion. 

So it is just the power supply and power cord relationship that has me slowed up.

But, bear in mind that all of this is all happening at lightening fast speeds, so even in the best mono-blocks - good power cables will improve their performance.

About 11-12% of the time the mains voltage is too low to pulse any current into the power supply (Assuming that the rail is at ~28V).

Or the 60 Hz, being rectified, is operating at 120 Hz, or ~8 msec peak to peak. And the time that the voltage is too low to flow into the power supply is about 1msec.

If it all happened in the blink of an eye, then how is it the tube monoblocks ran for many seconds (!10 Seconds) when the power switch was shut off?

Additionally if the power cord had, say a bit ferrite bead on it for RF suppression, then that would limit the bandwidth down. And limit the “blink of an eye” speed down as well. And other noise filtering would also slow the bandwidth of the incoming current down. (Which probably is really only needing to be at 120 Hz, or some power supply feedback circuit that has a bandwidth of maybe 20 kHz or less?)

So, when selecting power cables for any component I look for those that use UP-OCC copper, because it will provide excellent dynamic response. Silver is better, but a lot more expensive.

How does the silver result in any the electrons getting into the power supply any faster?

The resistance of copper and silver is pretty close to zero, and the speed of the electric field is pretty fast.

So it seems like the dynamics would be primarily governed by the power supply.

It seems like the city and house wires, and power cord, are only bringing the goods to the power supply?
Or… if the cord from the wall outlet to the amp input were made shorter and shorter, then the power cord effectively goes away?
If I have 100’ from the pole to the house, and 100’ from the box to the outlet, then how does 3 feet of silver result in anything more dynamic happening?

If the power cord is doing some other stuff like filtering noise, then I could understand that as a goal.