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Using AD825 in audio pre-amplification

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Jun 22, 2001
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Anybody have experience by the use of this op-amp in audio pre amplification?

I check the net but could not find any interesting information.

Any information or link is welcome.




ad825 audio

Hi hot_chmock

audio preamp for what? and why AD825?
Audio preamp is not "one size fits all" circuit :
low-z mics (50-200 ohms) preamp are quite different from line or hi-z mics, so, to optimize noise ,frequency response performances etc ,you need to match at least what different sources couples as load.(eg. 10Kohms for low-z mics versus 1Mohms or more for piezo,single coil guitars pick-up,47Kohms for MM phono pick-up, less than 50 for MC and so on)
Usually, with low-z sources, if you don't want to consider to use x-formers, bipolar op-amp do the best, while fet imput op-amp works fine on hi-z sources,so, mics preamp front-end, have commonly 2or more transistor acting as transimpedance section, followed by op-amp,because there are on the market few and not exactly cheap op-amp that can be succcesfully used as mic preamp.(but good xformer are more expensive than best op-amp)
Analog Devices SSM series and AD797 ,That's op-amp,Jensen devices are very very good as low-z mic preamp,while for line amplification, low noise precision op-amp are a less rare thing.Op285,Ne5532 are example of low cost dual op-amp with one third of noise respect single AD825. (although single devices shows better noise performances than duals).
Filters works at line level, so,medium to high speed low noise op-amp are preferred.

Theory,app. notes and working circuit are available from the above brandname and following links:

**broken link removed**

Wireless World collected many milestones and at least very interesting articles in the past on audio preamp circuit, from single stage to entire mixing consoles.

hope help

ad825 op amp

AD825 for audio amplifier or modify your CD?try ad827 also.if you use for pre audio amplifier,use a good positive and nagtive power ,high enough,low noise,big capacitor(low ESR).and you must use low noise accurate resistance.good luck!

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