音频均衡器电路图及选择
First of all, hello everyone. I'm relatively new to advanced (also relatively) electronics and this is my first more expensive and more complex project. I want to add a good sounding and nice looking 10-band equalizer to my stereo. I've searched the Internet for quit some time and came up with three different solutions:
1. Use a couple of all-in-one ICs like LA3600 in series to get 10 bands instead of 5. They are cheap, simple to use etc. But the THD is .03% typ and .1% max and filter frequencies are not adjustable as they are fixed to condenser values (which aren't always a perfect match).
http://www.dz3w.com/foreign/audio/7333.html
2. Do the same thing but from separate components. Something like this with TL074 for the filters and NE5532 for output op-amp. This approach costs a bit more but allows to fine-tune filter resonant frequencies and the total THD (I suppose) is much smaller (even the "noisy" TL074 has .01%, compare to .03% of LA3600).
3. Replace op-amps in filters with transistors like this . This would lower the total price a lot but I'm concerned about transistor poerformance/noise in such applications. Do op-amps have any real advantages in this situation?
So which design should I choose? Any suggestions and hints are welcome. Thanks in advance and sorry for my crappy English.
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