Hi,
If you're using a 401 Gyro and a S9254 Servo, then 99.9% that you're using a Step-Down regulator for your Gyro servo. This is the cheapest way on how to make your own regulator for lesser cost.
http://www.helifreak.com/showthread.php?t=43934&highlight=1n4001Thanks to HeliFreak.
Cheers