Hot answers tagged

6 votes

Why do some audio amps use AC while others use DC

Is AC current fundamentally better as a working current when it comes to amplifying audio signal? No. If anything, using an AC power supply makes it more difficult to have low noise. The circuits ...
  • 1,568
5 votes
Accepted

Why do some audio amps use AC while others use DC

The type of current is actually completely irrelevant as all transmitted power is AC. Unless you are driving your amplifier from batteries, everything has to be converted at some point to DC. The end ...
  • 8,695
3 votes
Accepted

How to wire signal return on balanced input?

I would read return of signal as the presence of an audio signal on any input (well, a signal above -40 dBu). There seem to be an alternative to wake up the amplifier from sleep mode which is to short ...
  • 2,784
3 votes

Why is Compression and Expansion of Signal to Noise Ratio used in Wireless System signal transmission?

Compression followed by expansion is often called "companding" and is used in various fields to reduce noise. It is effective in reducing the final level of noise that is introduced between the ...
  • 2,110
2 votes
Accepted

Generate signal with sinusoidal change of frequency

I'm presuming you mean something like this (the blue waveform): - The red waveform is amplitude modulation and the blue waveform is frequency modulation. This should be the formula you need: - y(t) ...
  • 2,106
2 votes
Accepted

How to wire a mono signal to a stereo jack so both channels are the same

You need to divide the part of the mono cable dedicated to the Tip into two equal copper cables and solder one to the Tip and the other one to the Ring part of your TRS jack (stereo) the other cable ...
  • 1,095
2 votes
Accepted

Cable vs wireless connection from amplifier to speaker

The role of an audio power amplifier (be it a traditional hi-fi amplifier, the embedded amplifier in powered loudspeakers, or the small amplifier that drives the headphones of your smartphone) is to ...
1 vote

Is it possible for Matlab to read and decode an mp3 file?

Supported codecs and containers for the audioread function of matlab can be found at: https://www.mathworks.com/help/matlab/ref/audioread.html
  • 8,695
1 vote
Accepted

What causes voltage potential to alternate in a ground loop?

Thing is, that if two points in a circuit are actually "ground" (i.e. 0V potential) then by definition, no current can flow between these two points. When current does flow between two arbitrary ...
  • 8,695
1 vote

What causes the spike in PCM signal?

These spikes are high frequency components contained in the resulting signal decode. There are two possible reasons for this. Method one uses a low pass filter which removes these components. Method ...
  • 8,695
1 vote

How do I keep my guitar signal from clipping in logic pro x with UA Apollo Twin?

You can't change the signal level that that's recorded from Logic, Logic will record the signal it gets bit for bit. You can change the monitoring level in Logic and that's what you're hearing when ...
1 vote

Low Passed Sound Quality, Connecting Pro Soundcard to Consumer Hifi Amp. Level matching?

A balanced line-level output usually has TRS (tip-ring-shield) 1/4" connectors. Connecting them to an unbalanced input requires the use of mono cables which short R with S (ring/return with shield) ...
1 vote

Weird noise from amplifier

Sounds like induction whine to me, certainly not a ground loop, which is always at either 50 or 60Hz, depending on what country you're in. 50Hz can be seen on a guitar tuner as roughly G#, never ...
  • 7,762
1 vote
Accepted

Can I use an AKG WMS40 wireless system to transmit a signal coming from a headphone jack?

According to the service manual (available on the AKG website) the phantom power is 3.9v and is connected to pin 3, so the microphone connector should have pins 2 and 3 shorted. If I understand this ...
1 vote

Can I use an AKG WMS40 wireless system to transmit a signal coming from a headphone jack?

With a condenser microphone the 48-volt DC is applied to both audio lines, so it cancels out because the signal is sent as a difference between those two lines. With a headset jack the signal for each ...
  • 141

Only top scored, non community-wiki answers of a minimum length are eligible