Product was successfully added to your shopping cart.

Go to cart page

You have successfully subscribed to this product. You will receive an email when the product is in stock.

7w mono audio amplifier

Velleman K4001: 7W Mono Audio Amplifier

Velleman K4001

In stock

+ -

Free ground shipping on orders over $75.
More info...

Velleman K4001 7W Mono Audio Amplifier (Electronic Project Kit -Soldering Required)

The Velleman K4001 kit is a small, but powerful multipurpose amplifier. The K4001 circuit using the TDA2003 integrated circuit that is thermally and short- circuit protected. Suitable for a 4Ω or 8Ω speaker and has an input sensitivity of 40mV rms. For a mounted version, view the VM144.



  • Music power output: 7W / 4ohm
  • RMS output: 3.5W / 4ohm or 2W / 8ohm
  • Total harmonic distortion: 0.05% (1W / 1kHz)
  • Frequency response: 20Hz to 20kHz (-3dB)
  • Signal/noise ratio: 86dB (A weighted)
  • Input sensitivity: 40mV / 150Kohm
  • Supply voltage: 15V DC (8 to 18V DC possible) / 0.5A
  • Dimensions: 2.2 x 1.4"


Additional Information

Difficulty Level 1
  1. 7W Mono Amplifier review by The Doctor on 8/23/2017

    I have purchased 5 of these 7W Mono amps so far and will buy more. These make great little Guitar Cigar Box Amps. I use them mostly with 3" speakers, but have also used them with 6" speakers. The bigger the speaker the better it sounds.

    I installed the Volume Pot, as per the instructions, and also added a 470 Ohm Potentiometer in place of the 470 ohm resistor, now I can adjust the Gain on the amp from clean to coarse.

    Great product, I highly recommend this item.

  2. I like this little amp review by Mitch on 6/19/2017

    I haven't tweaked this too much yet, but as built, this little amp actually sounds good and is reasonably loud and clean with just a guitar -> Boss Delay -> K4001 -> Weber C10Q 8 ohm speaker. That's running off a Boss 9V digital supply. Easy to build, instructions are clear. There is some extra hum when connected out of my tube preamp. But like I said, I may just need to tweak it with coupling caps, shielded cable etc.

Write Your Own Review

How do you rate this product? *





Parts list
English assembly instructions through illustrations, pictures, etc.

Assembly instructions
Written multilingual manual explaining how to build the kit

Info Sheets

Resistor colour code

Connection diagram of a 7W amplifier

Connection diagram of a 7W amplifier with a volume regulator

Overview of Velleman modules that are equal to D.I.Y Kits
This sheet is useful when you want to know which modules you could find in the do-it-yourself range of Velleman Kits and minikits.

Connection diagram of a simple supply for the 7W amplifier (K4001) using a transformer, a rectifier & a capacitor.

Frequently Asked Questions

Q. In order to adjust volume level, can I use a 100K ohm pot? I know manual says 47K ohm, but wasn't sure if other values would work equally as well.


We recommend sticking to the 47K Ohm potentiometer listed in the manual. Our tech support team has not tested the K4001 with a 100K Ohm potentiometer.

Q. Is the K4001 offered pre-built?


The prebuilt version is VM114.

Have a question?

* required fields

 Warning: this product can expose you to chemicals which are known to the State of California to cause cancer, birth defects or other reproductive harm. For more information go to: www.P65Warnings.ca.gov/product