Audio Amplification Problem

Audioguru again

Joined Oct 21, 2019
6,826
Speaking about badddd audio, why are there horrible sounds from TV discussions with people at home hiding from the virus?
I suspect that they are using Skype.
 

Audioguru again

Joined Oct 21, 2019
6,826
In the crossover distortion photo, the LM358 opamp has a +2.5V and -2.5V supply with a 2k load to 0V. The photo shows a symmetrical peaks to 1V so the load current is only 0.5mA max which is far from its maximum limited current of 10mA or 20mA.
The datasheet shows that at 0.5mA its maximum negative output swing is +0.7V above its negative supply and is -1.2V below its positive supply. Then it is far from clipping.

The design of the output stage has only 1 emitter resistor instead of the usual 2 emitter resistors which shifts the crossover notches a little towards the negative supply.
 

Thread Starter

SamR

Joined Mar 19, 2019
5,491
Perhaps this opamp handbook might give you some more insight in to opamp parameters.
Actually I found it in an old TI book published by Newnes. Op Amps For Everyone Design Reference ISBN-13:978-0-7506-7701-1 ISBN-10:0-7506-7701-5 1. Operational amplifiers. I. Mancini, Ron
1606084238739.png
etc.
Pretty thorough coverage.
 

AnalogKid

Joined Aug 1, 2013
12,143
Back in the day, the gold standard library for all thaings analog was the stuff from National Semiconductor. Tons of it online. Separate from my dearly beloved print copies, my NS folder is 750 MB.

ADI and Burr-Brown put out excellent materials, but their stuff tended toward less generic topics: extreme-performance amplifiers, multipliers, instrumentation, industrial control, etc. NS was king for the rest of us. Note that ADI had the best seminars; more meat, less marketing.

ak
 
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