Magic Jack Tech Bulletin - Making it work with more than one phone... from
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Magic Jack Technical Bulletin

NOTE: Our company supplies telephone equipment to phone companies.

 We DO NOT sell or support the Magic Jack, we don't know anything about the Magic Jack other than
what's in this bulletin, we don't recommend the Magic Jack for anything other than a cute toy, and...


The regular Magic Jack is a cute little dongle that plugs into a USB port on a PC with an operating system that it supports (Windows XP, Vista, Windows 7 and Intel MACs).

Magic Jack USB Phone Line Gizmo           Magic Jack PLUS

The Magic Jack PLUS is also a cute little dongle that plugs into a USB port on a PC with an operating system that it supports (Windows XP, Vista, Windows 7 and Intel MACs), or you can plug it directly into an Ethernet port on your network switch or router (after setting it up via USB on your computer).

It gives you a jack to plug a regular single line analog phone into, to make unlimited US and Canadian calls for $20 to $30 a year after the first year ($40 for the regular gizmo and the first year of service, and about $85 for the PLUS gizmo and the first year of service).

Well, it's not really unlimited. You can make all the "free" US calls you want according to Magic Jack, but it is limited.  Limited to 2 hours a call (after which they just cut you off).  If you make too many calls, they just turn off your service (you apparently have to abuse it a lot).

There are many reports that the sales tactics of the company behind Magic Jack are less than honest, but I think a lot of us have come to expect that of almost anything sold on TV and on the web. If you decided to buy from them, I'm sure you expected to lose all or some of the money you spent. There are many stories out there of fraudulent billing where they charge you for five years of service when you only wanted one, or didn't honor their money back guarantee. If you don't expect that dealing with any company that advertises on the TV or radio, or many web sites, you are way too trusting!

Here are a few of examples of billing problems (on YouTube) with the Magic Jack:

They charge you for 5 years of service even though you only wanted 1 year.

Can't stop the order once you fill in your info, and no moneyback guarantee if you use a debit card (they call it fraud if you tell them your debit card is a credit card?!?)

You CAN'T renew Magic Jack for the second year (because of the demand?), they make you buy a whole new Magic Jack

So if you're a gambler this is a really cute and amazing toy, and could save you a lot of money in phone bills.

To save the money you have to be a calm and accepting person, willing to put up with things that don't always work right (like Windows?), and calls that aren't always terribly clear (often much worse than a cell phone):

  • You must have a broadband connection to the Internet. Figure on one Magic Jack conversation taking up 128K of bandwidth in each direction (you can have more than one Magic Jack, each using its own computer). Almost anybody would have that much bandwidth, but not necessarily while you're using the computer for anything else on the Internet. It would be better not to use the computer or network the Magic Jack is connected to while you're talking on the Magic Jack. You'll notice that when you stop downloading porn while you're talking, the Magic Jack will sound much better.

  • There are two buttons to click on the top of the Magic Jack window, which select between normal and 3G use. If your call quality is bad, you could click the 3G button, which will use less bandwidth (the call might not be as clear, but it might not stutter and have dropouts). During my testing, it didn't work well with the 3G button pushed (it cut in and out) on Verizon's EVDO (data card), and when on Verizon's slower data service (National Access) it was totally unusable.

  • You must have a "real" USB port on your computer to plug the Magic Jack directly into (even for the Plus model, which needs to be setup on a computer). It won't work right with non-powered USB hubs (it gets its power from the USB jack, and it's pretty amazing how it uses that limited amount of power to let you dial, talk, and ring a phone or two). It will probably work on a powered USB hub (which comes with an AC power cube).

  • Your PC must be running 24/7, and not in sleep mode, in order to be able to make or receive calls on the Magic Jack. You can turn the monitor off. You need XP, Vista, Windows 7 or a newer MAC. The Plus model can be plugged into an Ethernet jack on your Internet router, and doesn't need to be plugged into a computer all the time.

  • Your broadband router must have the standard ports open for VoIP. Very few humans have the ability to muck around with their DSL or cable routers which act as a firewall to protect them from bad stuff on the Internet. Luckily, most routers will work without changes. Unless you really know what you're doing, don't let the nice people at Magic Jack support tell you to start programming your router or changing your Windows registry. You'll be really really really sorry.

  • Speaking of support, there is none. Well, actually there's something Magic Jack calls "support."  No phone number to call, no email address, just a button to push on their web site that will let you "chat" very slowly with someone who will appear to be a moron, but they're actually in a foreign country and have no idea what you're talking about - or what they're talking about.

    If your Magic Jack doesn't work, try a different computer, return it for a refund, or use it for a paper weight (it is really cute). Unless you have a prescription for Valium and take several beforehand, don't try to chat with Magic Jack support.

  • With the Magic Jack plugged into your computer's USB port you can make calls from a computer headset attached to your computer, or preferably on an ordinary single line home type phone plugged into the modular jack on the side of the Magic Jack. That's one phone. Not two, not three, not ten throughout your house. One phone.

    The reason I'm writing this bulletin is that we can't talk to end-users who want to connect the Magic Jack to a wall jack in their house and use it like they'd use a phone line from the real phone company. Is it possible? For the most part, yes. But it may require a couple of hundred dollars worth of gizmos to make it work.

    Magic Jack never says you can feed all the phones in your house. The fact that it will work with one or two phones out of the box is really quite amazing. Electronically, it does a better job than analog ports on some expensive phone systems. Whoever designed the electronics did a great job.

    This is critical...

    If you want to try to use the Magic Jack like a real phone line (it's always fun to beat the system), the most important thing to remember is to disconnect the Phone Company's line from inside the Network Interface (Phone Company's box) so you don't have miles of Phone Company cable connected to your Magic Jack and possibly damaging voltage coming from the Phone Company's Central Office into your Magic Jack (but the Magic Jack is made well and is very tough, and is unlikely to be damaged by foreign voltage - I tried).

    The best way to use the Magic Jack throughout a home is with one of the "cordless phone systems" with several handsets they sell at the Office Biggie store (for a lot of money!). The Magic Jack will think it's just connected to one phone, and will probably work as good as it's going to. It will not work with every phone ever made, it won't work with three or more phones, and even if it works - some of the calls will sound like garbage (even if you're not downloading movies while talking on the Magic Jack).

    People keep telling me that if they hook up too many phones a call won't ring-in, and won't go to their voice mail...

    On their web page FAQ Magic Jack says you may need a powered USB hub if you use multiple phones (available at computer stores), or to use a cordless phone system so that there's only one base plugged into the Magic Jack. That probably doesn't apply to the Plus which comes with its own power cube if you're using it on Ethernet?

    The Magic Jack PLUS comes with its own power cube so you can plug it into an Etherenet port on your home network.

    Amazon sells USB hubs. You should read the reviews and make sure a powered USB hub actually comes with a power cube (or it's useless):

    When the Valium wears off and you decide to rip the Magic Jack out of your computer and put it in the garbage disposal (makes a very satisfying noise after an hour of  "chatting" with Magic Jack support), you'll still be able to use that "cordless phone system" on the real line you have reinstalled (or sell the cordless system on ebay).

    By the way, I bought some used Magic Jacks for testing on ebay only to find that they won't let you use it to sign up for service after the year has run out unless you know the email address and password that was originally used - so buying a used one is a waste. The nice people at Magic Jack support, who I thought were morons because they told me to "Return the Magic Jack to ebay," actually didn't know what ebay is because they're in a third world country.

    From the Magic Jack Terms of Service that's pretty much impossible to read (like most Terms of Service):

    7. No Resale
    Unless expressly authorized in writing by magicJack, you agree not to reproduce, duplicate, copy, sell, trade, resell or exploit for any purposes any portion of the magicJack device or the Software.

    Read the entire Terms of Service from 6/09 by Clicking Here

    Read the entire PLUS Terms of Service from 11/11 by Clicking Here

    What's the strangest thing I found in the Terms of Service (that you pre-paid for)? You could just lose the phone number if you don't make a call!

    We reserve the right to reclaim any telephone number that does not make a call for a consecutive 90 days."


  • Some of you will find that your Magic Jack stops working and the program closes by itself. There are many reasons for this to happen (especially if you're using a Windows PC), but the most likely cause is a defective short USB extension cord that they ship with the Magic Jack.

    They are really junky, especially the earlier ones. If you move the cord or Magic Jack a little and the program closes, the cord is probably your culprit. Try plugging the Magic Jack directly into a real USB port (might be hard because of its size).

  • Once you get your Magic Jack working, you'll notice that the Magic Jack program keeps popping up in-front of you no matter what you're doing when you make or receive a call (the same thing happens with any "Screen Phone," which is not appropriate for most business use). If you have the Magic Jack connected to a number of phones around your house, that can really get old fast. Combined with the constantly rotating ads for signing up for more decades of Magic Jack at a reduced price or cheap International calls, it's extremely annoying.

    Luckily, a Magic Jack user has come up with a free fix if you're on Windows (not the Mac). MagicBlock is a small program you run that keeps the Magic Jack window from popping up, and also keeps Window's focus on the program you are working in, so you don't have to click back to go back to that program. Go to:

    I never tried it, so I'm not sure how well it works. The guy's website is gone, but the program is still on CNET and still might work (it's from 2008)?

    Here's another program that looks like it does the same thing (I've never used it):

    And another site that seems to sell software utilities for the Magic Jack (again, I've never used it):

    These types of programs will probably violate the terms of service that you agreed to when you signed up for the service. If that bothers you, don't use a MagicBlock type program. Or don't use Magic Jack.

  • Robert Reite sent an email that he successfully used his Magic Jack to feed all of the phones in his house for about a year, after setting QOS (Quality Of Service) in his router to give VoIP calls priority. He said it suddenly stopped working every couple of hours, after which he had to unplug it for 10 seconds to get it working again. He got rid of the questionable USB extension cable, and that didn't help.

    His search for a cure found that after a software update from Magic Jack, if he left the Magic Jack program minimized, the Magic Jack would go dead after about 2 hours. If he left the Magic Jack window on the screen (not minimized), it didn't go dead.

  • In some cases the Magic Jack won't play nice with your sound card, so you may have to go into the Windows Control Panel to make adjustments. The most annoying thing I noticed with their first version is the advertisement that changes every few moments in their window.

    On one Windows system, I had to go into "Sounds and Audio Devices" in the control panel to adjust the sound card device that was being used by the system, because I was getting a click through the PC speakers every time the ad changed in their window (like you do when you click something in a browser if you have sounds turned on). That was a few years ago when they did have telephone or email support, who told me what to do to fix it.

  • Yes, you need electricity to make the Magic Jack work. Your DSL or cable router needs electricity, your PC needs electricity, your powered USB hub needs electricity - and for the Magic Jack to work you need all of that working. Desktop PCs don't run very long on a battery backup, mainly because of the fans, the spinning hard drive, and the monitor (you can turn that off).

    Your cell phone is your friend if you decide to use the Magic Jack (especially when the power is out, especially if you don't know how to send smoke signals). Even though most cell phones have some crummy sounding calls and cut you off from time to time, it will look like a very dependable device after using the Magic Jack for a short time. The horrible support you get from a real phone company or cell phone company looks good compared to the Magic Jack support non-support.

  • The Magic Jack doesn't work with a rotary phone. It only works with touch tone (DTMF) phones. We're working on a Pulse to Tone Converter that will work with the Magic Jack, but there's not much current coming out of the Magic Jack for us to play with to run a line powered device (power cubes are expensive, and a pain to keep plugged in).

  • Robert Reite also mentioned that Caller ID didn't work on all of the phones in his house when he got his Magic Jack. To get Caller ID to work on the phones, he put a 100K Ohm Resistor across the line (from tip to ring).

  • If you have an alarm system in your house, don't get rid of your real phone line. The alarm system won't be able to communicate with the alarm company on a Magic Jack.

  • If you have a door box or gate entry system that calls your house phones when someone is at the door, you must run the Magic Jack to where the real phone line connected to the entry system. If you just disconnect the phone line at the Network Interface, and plug the Magic Jack into the nearest jack in your house, the electricity from the Magic Jack will be connected to the electricity from your entry system, and something is going to burn out. The door entry system will have a place to put a phone line (where you'd put the Magic Jack), and a place for all the phones in the house. If you see a puff of smoke, you'll know you didn't connect it to the right place.

  • I bought a lot of Magic Jacks to write this bulletin. It's very interesting that I've gotten the exact same recorded message as a voice mail on a number of the Magic Jack numbers, in different area codes, from a collection agency in Chicago.  From what I read on the Internet, this is a very dishonest collection agency that's apparently fishing for money by calling numbers and asking anybody who answers for personal information, to see if they can match them up with a debt they can try to collect.

    Never give anybody any kind of information if they call you... Not your name, address, credit card number, social security number, children's names, relative's names - NOTHING!

    Just hang up on them. 
    It doesn't matter what they say, how nice they sound, what they say they are selling, or what charity they say they're from.  SAY NOTHING!

So you really want to make your Magic Jack work on phones all around your house?  There are some solutions, but they range from fairly cheap to very expensive (to make a $40 gizmo work).

A phone man in Ft. Worth, TX, Weldon Swink, has this inexpensive suggestion:

The Magic Jack has a loop current of around 16 ma. As you probably know, the "Ringing Current" is not sufficient to "ring" a stand 2500 type phone with the traditional "electro-mechanical" bell ringer.

Recently, I purchased a GE Wireless Telephone Jack on e-Bay for $1 (they sell them at Radio Shack for much more). Plug the master and remote modules into the same power strip by the Magic Jack, then run a modular cord from the Magic Jack to the Master GE Unit, then a line cord from the 2500-type phone to the Remote GE Unit. It works.

The loop current is approximately 25-26 ma, The phone rings fine!  I realize this is an "el-cheapo" form of "Southern Engineering", but it works!

Thanks Weldon!

If your old style phone with a real bell doesn't ring with a Magic Jack, this is a really cheap and easy fix if you're brave enough to open your phone:

The old 2500 sets with double gong ringers, and 2554 sets (mini-wall phones) with single gong ringers, have a small bias spring to adjust the clapper on the bell. The bias spring was normally shipped in the high position so the bell wouldn't tap when a rotary phone was dialed, or another phone went on and off-hook - which can put out a spike that's enough to move the clapper a little.

You could try setting the bias spring to the low position to see if your old phone will ring with the Magic Jack (you've got a pretty good chance of making one 2500 set ring):

AT&T 2500 set from 1973

(or ITT, or Stromberg Carlson, or Comdial)  2500 Set


2500 Set Markings
(Usually no REN value listed)

The 5/73 in Orange is the date it was refurbished by Bell

Double Gong Ringer

          Bias Spring in Low Position

Bias Spring in High Position

As a phone man, the fact that the Magic Jack will ring a real 2500 set with just the voltage and current available from a USB port is totally amazing!

If your new phone (corded or cordless) doesn't ring with a Magic Jack, try this...

Some phones say 0.0 REN on the bottom of them, which essentially means they don't take any current from the phone line when ringing. If your phone says 0.0 or maybe 0.2 REN, try plugging a modular Y adapter into the Magic Jack, and plug a second phone that says 1.0 or so REN into the second jack on the Y Adapter.

Some fake phone lines won't put out any ringing if they don't see any current being drawn. I haven't tested this on the Magic Jack, but it does work on other types of VoIP ATAs (Analog Telephone Converters) and phone systems.

More expensive professional solutions for technical geeks:

Our company sells a Loop Current Booster™ that will boost the loop current coming out of the Magic Jack to 27ma (from 12 to 16ma depending on Magic Jack version, which isn't enough to run some phones). It will let you make calls from any kind of phone anywhere in a house when put in-series with the modular jack on the Magic Jack. $100 plus shipping.

During testing, I found that the Loop Current Booster™ also boosted the ringing current enough to ring two phones with bells, as opposed to one phone with a bell without the Loop Current Booster™. The Magic Jack ringing waveform is a square wave (not a sine wave like from the phone company), which looks like pulsating DC to the Loop Current Booster™. The Loop Current Booster™ boosts one side of that AC square wave (which is actually a pulse of DC), so you get a little more ringing current when it's on the line (nothing like our Ring Voltage Booster II™).

Our Ring Voltage Booster II™ gives you 90V AC sine wave ringing at 7.5 REN (the phone company only gives you 5 REN, which will ring 5 of the old style phones with real bells.). $125 plus shipping.

We'll sell these to you if you really want. We can't support end users. We normally sell these to phone men who don't need support.

We can't make money talking to end-users about trying to make a cheap piece of junk work (even if it is a cute piece of junk)... But we do have an incredible amount of technical information in our  Tech Bulletins  if you have several hours to read them and know a little about electricity (understand what current and voltage is). Or hire a local phone man to help you.

There are 5 Versions of the Magic Jack that I've found (as of January 2012):

Version 1 Magic Jack

Version 1 - the original Magic Jack.  It has the correct polarity coming out of it (see the green LED in the jack).  The blue LED is on the bottom right. The easiest way to tell the difference between the three versions is by looking just above the J in magicJack. This version doesn't have much there. There is a vertically mounted chip (U1) a little to the right of the J, extending up (hard to see in this photo).

Here are the numbers for Version 1:

  • 50VDC talk battery

  • 4.1VDC off-hook battery

  • 12.5ma loop current

  • 85VAC ring voltage, but I also read 63VAC from one of the Version 1 Magic Jacks


Version 2 Magic Jack

Version 2.  It has the correct polarity coming out of it (see the green LED in the jack).  The blue LED is on the bottom left. The easiest way to tell the difference between the three versions is by looking just above the J in magicJack. This version has a big white box with a solder blob.

Here are the numbers for Version 2:

  • 38VDC talk battery

  • 5VDC off-hook battery

  • 15ma loop current

  • ? ring voltage - I couldn't find one of this version I could call into since you can't buy/sell a used Magic Jack (Robert Reite emailed that he measured 60V for the ring voltage on his Version 2)


Version 3 Magic Jack

Version 3.  It has the wrong polarity coming out of it (see the red LED in the jack).  The blue LED is on the bottom left. The easiest way to tell the difference between the three versions is by looking just above the J in magicJack. This version has two horizontally placed surface mount components there (you can only see one in the photo).

Here are the numbers for Version 3:

  • 38VDC talk battery

  • 5VDC off-hook battery

  • 15ma loop current

  • 60VAC ring voltage


Version 4.  There is one out there, but I haven't found one to buy, yet. When I find one I might plunk down my $40 and test it, and put the results here.


Magic Jack Plus Version 1

Magic Jack PLUS (Version 1).  It has the correct polarity coming out of it (see the green LED in the jack).  The blue LED is on the bottom right (under a clear + sign), and it no longer has a clear front.

You no longer have to leave a computer turned on to use it! You plug it into your computer via USB to set it up with your account, then you are given the option to remove it and connect it to your network (with no PC associated with it) or keep using it on your USB port. You can switch back and forth whenever you want (you may have to start the Magic Jack program manually when you plug it back into your PC).

This is a slightly bigger dongle, with two ways to connect it.

1. USB into a PC to keep it running - just like the old ones.

2. USB plugged into the included AC power cube, and an included network patch cord into an open port on your network (Ethernet) switch. There is no connection to a computer when used this way.

Here are the numbers for Magic Jack PLUS (Version 1)... (same pitiful numbers as the regular Magic Jack):

  • 50VDC talk battery

  • 5VDC off-hook battery

  • 16.5ma loop current

  • 65VAC ring voltage

The above readings on the regular (not PLUS) Magic Jacks were taken with the Magic Jack connected directly to a USB port on a PC. On the first version, when I tested it with an unpowered USB hub, there was about 1.5ma less loop current, and 3 volts less ring voltage. If you must use a USB hub, use a powered USB hub (with a power cube)!

I tested the Magic Jack PLUS connected to the included AC power cube (the USB plugs right into the power cube), with the included network patch cord plugged into an Ethernet switch in our lab (pretty much just like the one you have at home). The readings from it were just as crappy as the regular Magic Jacks. It's not going to work any better if the old Magic Jack didn't work for you.

Most phones are designed to work with a minimum of 23ma of loop current, although they will usually work at 20ma. Below that, things get pretty iffy. You might see strange and/or intermittent problems (you're a test pilot, because the engineers who designed the phone never tested it to work below 20ma of loop current).

Don't use the Magic Jack in a business,
unless phone calls aren't important!

Ordering lunch or talking to your girlfriend? Use the Magic Jack attached to your PC if the IT guy has allowed stuff like that on the network.  Working on a million dollar deal?  Use a real phone.

If you're thinking about using VoIP in your business, take a look at these Tech Bulletins that could save you lots of headaches:

See the VoIP Research Tech Bulletin for things to think about before deploying VoIP at a business.

See the VoIP Checklist for a quick list of things to check before jumping into VoIP at a business.

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