#HOW TO DISTORT AUDIO INSTALL#
#HOW TO DISTORT AUDIO GENERATOR#
#HOW TO DISTORT AUDIO PC#
#HOW TO DISTORT AUDIO FREE#

Perhaps the easiest way to demonstrate this is by using a block diagram of my setup. The various components now need to be connected together, in effect forming a loop. 8О© dummy load with fixed attenuator in project box The enclosure came from the Maplins closing down sale and cost a couple of quid. You can just attach everything together temporarily but I made a little project box with permanent connectors for the amp inputs and the signal output as I had these already. In true (mis) Adventures in HiFi tradition, I got them the wrong way round to begin with.

Make sure you get the resistors the right way round (see image below) or the ratio will be out. I used 22K and 2.2K resistors as these were at hand. This can be achieved using a voltage divider and it was recommended that a 10:1 voltage drop would be suitable. The dummy load can connect directly to the sound card but it is prudent to attenuate the signal before it reaches the audio interface. You may wish to heatsink this but I bolted it directly to a metal case. I chose a 8О© 50W power resistor from RS Components. All that is required is a resistor that has the same impedance as your amplifier and is rated to handle the ampвЂ™s power output. The amp being measured needs to drive a load, so a dummy load simulating your speaker load needs to be made. UCA202 loopback with 1kHz tone at -6dBFS digital output level. These figures can be improved upon if required by using a better interface (Focusrite Solo has been mentioned as good and relatively inexpensive) and also an external low noise tone generator. As you can see from the image below, the device isnвЂ™t bad, with THD at 0.0045% and THD+N at 0.020%. It is worth calibrating your device in the soundcard preferences panel before commencing testing.

#HOW TO DISTORT AUDIO GENERATOR#

You can perform a вЂloopbackвЂ™ test to measure the harmonic distortion of your own audio interface by connecting an RCA cable between the output and input and using REW to generate a 1kHz tone (use the generator icon on the main window). UCA202 internal noise using laptop on battery UCA202 internal noise with laptop connected to AC power supplyДЄs you can see from the above images, the UCA202 reports self-noise, and thus the noise floor is at about -130dBFS with a 50Hz spike and harmonics when connected to the mains supply. This window has itвЂ™s own options on the right hand side and the image below shows how I set mine up, along with the display of the UCA202 internal noise.

From the main REW screen, click on the RTA icon to bring up the Real Time Analysis window.

#HOW TO DISTORT AUDIO PC#

Behringer UCA202 USB Audio InterfaceДЄt this point, with only the interface connected to the PC (and possibly just running off the battery if you are using a laptop), you can check the internal noise of your device. A review including measurements of this interface by the respected engineer NwAvGuy shows that for the price, this is a reasonable piece of equipment.

The choice of interface for me was simple as I already own an external soundcard, a Behringer UCA202, which can be bought for under ВЈ20. The input and output devices should be the sound card.

#HOW TO DISTORT AUDIO INSTALL#

Install the software and on the opening screen click on вЂpreferencesвЂ™ to configure your external interface once the device is connected to the laptop. Although the software is free, if you find it useful, please donate to the developer. The software, RoomEQWizard (REW), is primarily used for measuring and analysing room and loudspeaker responses, but it can also be used for measuring distortion in amplifiers. Rather than repeat everything that appears in that thread, I thought I would just outline the equipment and components I used and how I set it up.

#HOW TO DISTORT AUDIO FREE#

Essentially you can discover the harmonic distortion signature and the noise floor of your amplifier.ДЄs forum member XRK971 details in the first post in the thread, all that is needed at the most basic level is a decent internal PC sound card or external USB Audio interface, some free software, three resistors and some wire.

I thought this level of analysis would be beyond my ability and budget, but an interesting thread appeared on recently, concerning a cheap method of measuring distortion. However, I am also curious about the objective measurements of the equipment. I imagine I am typical of many DIY audio enthusiasts in that I build something and hope that subjectively it sounds good.

How to distort audio