A choke is an iron core inductor used in the power supply of a guitar amp as a filtering element. Looking a lot like a transformer a choke only has two leads coming from the housing. They are designed to block AC while passing DC. Their purpose in guitar amp filter supplies is to smooth out the ripple in the rectified DC.


In some guitar amplifiers a high wattage resistor is used instead of a choke. A resistor in place of a choke saves money and to a certain degree manufacturing time.  The drawbacks of using a resistor is there is more residual AC ripple in the power supply after rectification resulting in a little more background hum in your amp. One example is the 5E3 Fender tweed Deluxe. It does not have a choke in its filter supply.

Chokes have ratings of voltage, DC current ( measured in milliamps), resistance (measured in ohms) and inductance (measured in Henries). A typical choke for a 50 watt guitar amp is rated for about 500 volts and 50 milliamps. The resistance measures in the 250 ohm range and inductance between 10 – 20 Henries. The inductance of the choke coupled with the capacitance of the filter capacitors determine the bass response of the amplifier. A larger inductance value choke will have a better bass response than a smaller value choke. An amplifier with a power supply choke will have a deeper, crisper bass response than one that uses a resistor instead of a choke.

To sum up in simple terms using a choke in the filter supply the result is less background hum and cleaner, better bass response. Using a resistor manufacturers save time and cost and there is a bit more background hum and a looser bass response.

300Guitars Shop

My shop is located at 1 Executive Dr Unit L Toms River, NJ 08755 Please feel free to email me if you have any questions or are in need of some tech work.
  • Monday: 10am - 5pm
  • Tuesday: 10am - 5pm
  • Wednesday: Closed
  • Thursday: 10am - 5pm
  • Friday: 10am - 5pm
  • Saturday 10am - 2pm. (I am in every other Saturday).
I am also an Eminence, Mercury Magnetics, Mojo Musical Supply dealer. I do all the tech work myself so you deal directly with me. I am a one man shop and my hours can vary so please contact me to confirm that I will be open. Email me: billy@300guitars.com Call or text me: 848-218-0362 Shipping Info for all repair work: Please ship all repairs to: 1 Executive Dr Unit L Toms River, NJ 08755
I am currently offering all phases of guitar work which includes:
  • Set-ups
  • Fret dressing
  • Re-fretting
  • New hand cut custom bone nuts & saddles
  • Electronics work
And amplifier work which includes:
  • Basic maintenance
  • Bias adjustment
  • Repairs and restorations
  • Modifications
  • And more....
David Nicholas - The 20watt amp is sounding fantastic! Delivered the goods at the gig and I'm finding cool tones all over the place with it. Love the cab w Emenince Tonkerlites too- perfect for my sounds! Makes the 12 string sound like a grand piano!
Peter Lacis - I had an audition for something recently that was all about Led Zeppelin I -- my custom Pennalizer BLEW THE MINDS of the guys I was playing with. They couldn't believe the sounds coming out of that amp. That album was never in my mind when I came up with the idea....so that's yet another testament to the amazing work that you do.
Scott Goldberg - I am very satisfied with the set-up, and the fast turn around.  With the "lower" action it feels easier to play.  I will definitely spread the word.