iTrip Amplifier




DISCLAIMER: This tutorial is for educational purposes only and is against FCC rules.  Owning and.or using one of these devices may not be legal in your area, check your local laws before creating.  I am not responsible for anything you create from this tutorial.


I purchased an iTrip off eBay for $30 shipped.  I wasnt expecting it to work good due to the many negative reviews I have read about it.  I started off by pulling the antenna out of the case for a better signal.  It did increase the performance, but not enough.  I found this article and decided to make one.  First off, Radio Shack was only good for2 things, battery snaps and a battery.  I purchased everything from  The article linked above describes using a 12v car adapter, I wanted to make it portable so I am using one 9v battery.  I had a 12v 200mA AC-DC adapter, it fried 3 transistors so I dont recomend that. T Here is the part list for, but keep in mind that the resistors and transistors have small minimum amounts for purchasing 


Description< xml="true" prefix="o" namespace="" ns="urn:schemas-microsoft-com:office:office">

Part Number


2n4401 Transistor



220 Ohm Resistor ½ watt



10k Ohm Resistor ½ watt



0.001 uF Capacitor



10 uH Choke



Circuit Board






9v < xml="true" prefix="st1" namespace="" ns="urn:schemas-microsoft-com:office:smarttags">Battery Snap



 It all comes to a total of $6.65 plus $7.00 for shipping coming to a grand total of $13.65, there is a minimum piece number for most of the supplies but it is very reasonable(minimum of 10 resistors that are $0.05 each).  If you search the part number in the search bar it will bring up the parts, but some of them have more then one result so make sure you get the correct size. It say to use a 65-85 cm antenna in the schematic for the ampifier, but the 23 inch(58 1/2 cm) should be fine. 


Here is the schematic, taken from


It was a very simple circuit to complete and can be put on a very small board if needed.  I decided to put mine in an Altoids can.  I installed the antenna by drilling a hold and putting a screw through it holding the antenna in.  There is no nut for the antenna so I had to solder it down  and remove some casing with wire cutters and nibblers.  Be sure you insulate your case before putting the circuit in, no need for a short circuit.  Here are some pics:

I have never used a choke and didnt know anything about them, so I raised it off the board so it would disperse heat, but it doesnt even get warm.  I didnt mount the board to the case because I might make some changes to this.  I may end up putting another 9v battery in and wire it in parallel so I have double battery life.  As for range, it was good before and is much better now.  I was about 50 ft away from my stereo with has a 3 foot wire across the back of my entertainment stand as an antenna, and it would cut in and out and had a ton of static.  I hooked the aligator clip on the iTrip and it became crystal clear.  Hackaday has the original article for this mod, but it also has a comment section and has negative comments for this.  Its great for around the house, I find the station receiving the least signal and tune to that.  It cant take over a station, but can interfere with it.  I got some help from about improvements and added a .001uF capacitor between the positive and negative lines:

 "It keeps the power supply voltage steady so the transistor can work properly. Without the capacitor then the power supply voltage jumps up and down at 100MHz reducing the output of the antenna."

I added the second 9v by wiring them in parallel.  Here is a diagram for those who dont know what parallel or series is:

I added a switch in the case so I dont have to unplug anything when done using it.  And the last change is the board was cut in half .  I still need to mount the board which I will probaly end up hot gluing it in.





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