Free MediaDesk In-Rush Limiter Upgrade

Blue Sky International recently began adding in-rush current limiters to all new production units of MediaDesk. In-rush current limiters are semiconductor devices that reduce high power-up currents without restricting normal operation and are routinely used in big power amplifiers, vacuum tube amplifiers and computer power supplies. In the case of MediaDesk this new in-rush current limiter also eliminates in-rush related fuse failures.

Although we have had only a very small percentage of users experience fuse failures at power-up, we believe the benefits of this upgrade should also be offered for free to those that have already invested in Blue Sky’s MediaDesk system.

It is important to point out that this MediaDesk In-Rush Limiter Upgrade is only for MediaDesk and only applies to those serial numbers listed below. If your serial number doesn’t fall within the ranges shown below, your unit already includes the in-rush limiter within the MediaDesk power amplifier. Additionally, units which were in our warehouse, when this upgrade came available, may include the external in-rush limiter cable or adapter, and this can be confirmed by the fact that an addendum titled either “MediaDesk In-Rush Cable Adapter” or “MediaDesk In-Rush Cable” has been included with the MediaDesk documentation. These two addendums can be viewed in Adobe Acrobat Format by following the links below.

MediaDesk Manual Addendum
120 Volt US / Canada – See Link at the foot of this page

230 Volt EU / rest of world – See Link at the foot of this page

Additional Information – How To Request The Upgrade
Go to our Product Registration page where you first enter your contact details* and, afterwards, the MediaDesk system serial number. Our web program automatically acknowledges serial numbers that qualify and will send you a confirmation email advising how we will contact you to arrange shipping (Please Note – Even if your MediaDesk doesn’t qualify for a free in-rush limiter it’s still a good idea to register your ownership anyway – we can then keep you posted about future developments). *If you’re already a Blue Sky Member, simply login as we already have your details.

Once ordered, US customers should receive a replacement power cable in approximately a week. The replacement power cable has an in-rush limiter installed in a thermally shielded housing within the cable. This cable replaces your current power cable. 230V users will receive an IEC to IEC cable approximately 12 Inches in length. This cable sits in-line between your current power cable and MediaDesk. Within this cable is the same in-rush limiter, as in the US cable. Both the 120V cable and the 230v adapter also include one spare fuse.

For those US & Canadian users who have experienced a fuse failure: While you are waiting for the delivery of your in-rush limiter upgrade, we recommend the following fuse. Radio Shack fuse 5x20mm 4 amp Slo-Blo PN 270-1066. This fuse seems to handle in-rush currents at power-up without issue.

Qualifying Serial Numbers
01000001 to 01001550
01001651 to 01001850
01001852 to 01001939
01001951

Note 1: The above are MediaDesk “system” numbers. Individual speakers and the subwoofer have “A”, “B” and “C” suffix – these are not required when registering the system.

Note 2: If you have already registered your MediaDesk system in the past, please resubmit your serial number, so it can be checked against the list of serial numbers affected.

Click the magnify glass beneath the image opposite to obtain ahi-res image showing the Location of Serial Number, on the MediaDesk subwoofer:

Frequently Asked Questions
Below is a short list of what we believe may be “frequently asked questions”. If you have any additional questions, don’t hesitate to contact us. Phone and e-mail contact information is located at the bottom of this page or, or ou can e-mail engineering@abluesky.com.

  • Q – Do in-rush related fuse failures result in a fire, shock or other safety hazard?
  • A – No. In-rush fuse failures are purely a nuisance.
  • Q – My fuse hasn’t blown and I am not having any problems, do I still need to add the MediaDesk In-Rush Cable Adapter?
  • A – Yes, we believe it is best to add this adapter to all units affected. This will increase long term reliability and stop nuisance fuse failures.
  • Q – How does the in-rush current limiter work?
  • A – The in-rush limiter is a temperature sensitive device which has a high resistance when cold and a low resistance when hot. These devices are inserted in series with the power switch. When MediaDesk is first powered on the in-rush limiter is cold so it has a high resistance which blocks high currents from flowing. As current flows through the in-rush limiter, the device heats up, its resistance drops and it allows normal operation of the amplifier. When MediaDesk is powered down, the in-rush limiter cools down and resets itself for the next power up cycle.
  • Q – I am using an external switch (like a Furman) to power MediaDesk. Do I still need to use the adapter?
  • A – Yes. Even with an external switch the inrush current stills puts additional strain on the MediaDesk components and can still blow the fuse.
  • Q – Will the inrush limiter affect the sound of MediaDesk?
  • A – No. After the power cycle, the resistance of the inrush limiter drops to a fraction of an ohm removing itself from the circuit.
  • Q – Is MediaDesk with the factory install in-rush limiter better that the one with the adapter?
  • A – No. Both use the same part and the inrush limiter is added between the wall and the power switch. There is no difference.
  • Q – I have a 230 volt unit and am not blowing fuses. Should I add the inrush adapter?
  • A – Yes. Even though the inrush current is approximately ½ the inrush at 120 volts, the inrush limiter will reduce stress on the power components.