Frequently asked questions

What is the difference between level 2 filtration and level 3 filtration?

In Level 2 filtration, electrical current passes through level 1 filtration twice. In Level 3 filtration, electrical current passes through level 1 filtration three times. In general, higher filtration cleans out more noise, but requires more filter core.

What is power factor correction?

Power factor correction corrects the phase angle of the voltage and the current, thus providing voltage and current more in phase with its SIN wave. Power factor correction allows for more efficient power delivery. The ideal power factor value is 1. In general, the power factor value coming from the power plant is between 0.7 and 0.9. Power factor correction brings the factor value closer to 1, thus delivering the power more efficiently.

Can I plug a Lightspeed rated at 110~125VAC into a 220~250VAC environment?

Never plug a 125VAC Lightspeed into a 220VAC+ environment. Doing so will cause the internal circuit board to be burnt. The Lightspeed must be serviced to the correct voltage environment if it is to be used in a 220~250VAC environment

Can I plug a Lightspeed rated at 220~250VAC into a 110~125VAC environment?

You should not plug a 220~250VAC Lightspeed into a 110~125VAC environment. Although doing so will not cause a burnout, any incoming surge between 125~220V will be unprotected. The Lightspeed should be serviced to its correct voltage environment as soon as possible if it is to be used in a 110~125VAC environment.

Can I plug digital equipment into the analog outlet or the power-amp outlet?   Can I plug analog equipment into digital outlets?

In general, you should not plug analog equipment and digital equipment into the same group of outlets. Why? All digital processors in digital equipment produce noise as they decode digital information. This noise feeds back into the analog equipment, causing poorer analog performance.

Can I plug a 20-ampere unit (i.e.: CLS 605, 705) into a 16-ampere outlet?

Yes, you can plug a 20A Lightspeed unit into a 16A household outlet. When there is a surge, the 16A circuit breaker in the service box will shut off before the 20A fuse(s) on the Lightspeed. The following can also be done because the lower power circuit breaker will shut off before the higher-powered fuse(s) on the Lightspeed. AC =110v ~125v - Plugging a 20 ampere unit (i.e.: CLS 605, 705) into a 15 ampere outlet
- Plugging a 30 ampere unit (i.e.: CLS 805, Cinema 6.0) into a 20 ampere outlet
- Plugging a 30 ampere unit (i.e.: CLS 805, Cinema 6.0) into a 15 ampere outlet
AC = 220v ~250v - Plugging a 16 ampere unit (i.e.: CLS 605, 705) into a 10 ampere outlet
- Plugging a 20 ampere unit (i.e.: CLS 805, Cinema 6.0) into a 16 ampere outlet
- Plugging a 20 ampere unit (i.e.: CLS 805, Cinema 6.0) into a 10 ampere outlet

Can I upgrade an old Lightpseed from mark one to mark two (first to second generation)?

There is no upgrade from an earlier generation to a newer or current generation. An upgrade would involve replacement of the filter core of the Lightspeed. This type of service would cost more than purchasing a brand new Lightspeed since it involves much more labor than normal production.

I have “hum like” noise in my system.  Will the Lightspeed remove the “hum”?

The Lightspeed will probably not remove the “hum-like” noise in your system. This is known as the ground loop problem. It occurs when too many components share the same ground. To remove hum from your system, you must use a cheater plug or several cheater plugs to separate ground. This means that one or some of your components will have to be on floating ground. To do this, plug a cheater plug into one of your components, or plug several cheater plugs into the power chords of several components, starting with pre-amplifier. Do this until the hum disappears. Sometimes a bad dimmer switch or a bad fluorescent light sharing the same line can also cause the hum.

I have “buzz like” noise in my system.  Will Lightspeed remove the “buzz”?

The Lightspeed will probably not remove the “buzz-like” noise in your system. In fact, it may make the buzz more apparent as background noises are filtered out. A buzz is often a sign of bad tubs in tub-amplifiers or bad interconnects.

What does the term “piggy-back” or “daisy-chain” mean?

The terms “piggy-back” and “daisy-chain” are terms used to describe a way in which one unit is plugged into another. For example: a first unit is plugged into the wall outlet; a second unit is plugged into the first unit. This allows the second unit to achieve a double stage of filtration. However, never plug a higher amperage unit into a lower amperage unit – don’t overload the first unit. Plugging a lower amperage unit into a higher amperage unit is safer. Plus, if possible, try to plug the higher filtration unit closer to the wall outlet.

Does Lightspeed still work if one of the LED or two of the LED does not work?

The LED’s are meant to indicate the functional state of the Lightspeed. However it is possible that the LED may have some how burnt out and the Lightspeed is still functional. To verify its functionality, the Lightspeed must be check internally after being unplugged.

Can I order a longer power cord?

Lightspeed can manufacture longer power cords. However, longer cords may result in poorer sound quality, for as the length of the cord increases, the more the cord acts like an antenna. It will begin to pick up all of the background RF noises. Be sure to ask your local dealer to request a desired length as a special order through Lightspeed. Note: all special orders are final sale only.

Can I order a shorter power cord?

Lightspeed can manufacture shorter power cords as well. Be sure to ask your local dealer to request a desired length as a special order/custom order through Lightspeed. Note: all special orders are final sale.

I have more digital equipment.  Where do I plug when I do not have enough digital outlets?

If the provided outlets are not sufficient, you can use a “cube-tap” to increase the number of outlets. A cube-tap is an adaptor that has three copper prongs on one side and three set of extra outlets on the other side. Be sure not to over load the electrical line. Do not use a power strip because the extra long cord will act like an antenna for noises.

Can CLS Reference be fitted with a detachable power cord?

No, CLS Reference should not be fitted with IEC detachable connector. Each additional connection adds more noise to the line, thus drastically reducing the superior performance of this top-of-the-line product. To maintain its premium filtration qualities, the CLS Reference must have a minimal number of connections.

What can I do to get rid of the annoying “pop” that my speakers produce when I turn the power ON and OFF?

Unfortunately, you will always hear a “pop” from the loudspeakers if the procedure is not correct and/or when the background noises are filtered out. When powering on the system, turn ON all of the front-end components first (CD, DVD, Pre-Amp), then turn ON the power-amplifier. When shutting down the system, turn OFF the power-amplifier first, and then turn OFF the front-end equipment after. If you turn anything ON or OFF when the power-amplifier is ON, you will most definitely hear a “pop”. This is often the side effect when other noises are no longer noticeable and the “pop” become louder than the background noises.

Can I plug my power amplifier into a line conditioner even though the manufacturer says not to do so in its instruction?

Just about all power amplifier manufacturers will say not to plug power amplifiers into any line conditioners. However, no one mentions why. Most line conditioners are transformer based and/or coil based. These two types of devices will reduce the dynamic performance of the power amplifier, thus preventing the amplifier from performing optimally. The Lightspeed power line filters have neither transformers nor coils in them, so they will not reduce dynamic performance in any power amplifiers.

Can I plug a "Lightspeed" rated at 250 volt into a step up transformer (from 110VAC~ up to 250VAC~)?


Can I plug a "Lightspeed" rated at 110 volt into a step down transformer (from 250VAC~ down to 110VAC~)?

No. If the "Lightspeed" is intended to be plugged into a step-down transformer, the "Lightspeed" must be special ordered with a different type of circuit board for the step-down configuration. Standard 110v circuit board may possibly suffer some damage from the step-down transformer. It is important to make this request during purchase.

Do Lightspeed products require any service or any maintenance over time?

We recommend that Lightspeed should get a surge-protection update-service every five years. This will ensure optimal functionality of the surge protection system as it is being stressed over long periods of time.



Michael Chang, engineer and stereophile, designed the Lightspeed Powerline Filters after being disappointed with the powerline filters available on the market. Mr. Chang's design eliminates AC contamination without the use of lag/noise inducing transformers or coils. In 1991, Michael and his sister Stella founded Chang Audio Corporation.


A small staff of technicians hand assembles and tests each unit from quality parts before it is shipped out. The combination of this care in craftsmanship, with the effectiveness of filtration and the units' low cost, has won Chang Lightspeed Powerline Filters acclaim and buyers worldwide.