All Questions
66
questions
2
votes
5
answers
435
views
Do audio impedance mismatches cause reflection (ie, 8-Ohm output to 20kOhm input) ? Does it matter?
I understand that audio source⇒input impedance mismatches are normal, and this answer provides a good reason as to why. However, having worked with RF more than audio, mismatches cause reflection that ...
- 2,088
1
vote
2
answers
35
views
Why does the volume of the preamplifier change when a second audio signal is mixed? [duplicate]
I have two audio signals leading to the amplifier input: the first one comes from the preamplifier, the second one from the audio output of a smartphone/tablet device. Both have a resistor and a ...
- 53
0
votes
0
answers
35
views
Impedance matching: headphones out / hijacked op-amp pin -> guitar input
I have a Vox "amplug" pocket amp which has a female 1/4" mono input, it's supposed to be dangling directly from the guitar's output jack, and has 3.5mm TRS headphones out. I'd like to ...
- 113
1
vote
2
answers
1k
views
Line-out vs headphone-out impedance
I'm thinking about the example of two output jacks on the back of a computer, one for line out and one for headphones. I understand that the line out in generally an "unamplified" signal and ...
2
votes
2
answers
106
views
Something about the impedances of charge amplifiers
it is my understanding that due to the effect of virtual grounding, the input impedance of a charge amplifier is basically zero. If that's the case, then is there any reason to even worry about the ...
0
votes
1
answer
618
views
Increase Input Impedance for Guitar Pedal
I'm designing a guitar pedal circuit. I've received feedback that my input impedance is way too low in regards to my output impedance and I was wondering how I could go about increasing it.
To keep ...
- 113
1
vote
0
answers
64
views
What op-amp can I use in this output filter recommended design?
I'm working with the Cirrus Logic CS42448 codec and would like to implement an active filter output to differential audio signals.
The output should be line level to be connected directly to external ...
- 423
0
votes
1
answer
414
views
What does the "impedance" value of audio transformers specifically mean in terms of inductance?
So I've searched the web, looked into other questions here (e.g. this one), but I am not really any wiser.
What does the impedance of a transformer specifically mean? I.e. how can I deduce the ...
- 22.5k
3
votes
2
answers
238
views
Running a 70V amplifier without load
I have a 70V (Pyle PMX3500PH) connected to six speakers drawing 30W each connected through an OSD volume control (SVC 300). Since it's a transformer-based volume control, when you turn it all the way ...
- 33
1
vote
2
answers
356
views
Twin-T notch filter with high input impedance and low output impedance using one op-amp
I have a very space and power constrained application, where I want to apply a twin-T notch filtering to an audio signal and add a little gain of about ~10x.
The following filter section has the ...
- 22.5k
0
votes
3
answers
1k
views
What effect does a splitting an audio signal using a y-cable have on that audio signal?
Given a clean instrument-level audio signal of reasonable amplitude passing from point A to point B via a TR/unbalanced cable, what effect would replacing that cable with a TR to dual TR cable running ...
- 103
1
vote
4
answers
554
views
Help needed reading an audio transformer wiring schematic & impedance table
I am trying to link a transformer's schematic to its impedance table. I have trouble linking the values to the indivual pins.
For now I would like to use it exactly like in the picture. My ...
- 115
2
votes
2
answers
384
views
Driving Multiple Balanced Audio Runs Off Single Differential Op-Amp Circuit
I am working on an audio project that needs to drive 16 balanced xlr cable runs with stereo differential audio. For this purpose I am using the following op-amp circuit to produce a low impedance ...
- 495
0
votes
2
answers
288
views
Speaker Line Supervision
I want to design a circuit for 100V loudspeaker line control. I want to periodically check if the line is short circuit or open circuit and receive notifications in case of any short/open circuit.
I'...
- 1
3
votes
3
answers
429
views
How should I probe when measuring output impedance? Why do I get inconsistent readings?
I am trying to measure the output impedance of a commercial headphone amplifier, but the results seem to change depending on how I probe it. When I plug a 1m cable into the device and the other end ...
- 209