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Author Topic: TL071 Preamp  (Read 5204 times)

Kirkiisi

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TL071 Preamp
« on: October 25, 2007, 06:49:42 AM »
HI,

I've been working with preamp that includes 10 band eq. and TL071 opamp. Im using 2 pieces of LA3600/KA2223 and opamp front of them and between them. How do u think this will work?

And is there major differences between LA and KA? first 5 band eq. is for low frequences and other one is opposite. Do u think that i should use one of these in "low" section and other one in "high" section?

Pardon my crappy english.

Jussi Koivuranta

teemuk

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Re: TL071 Preamp
« Reply #1 on: October 25, 2007, 08:20:13 AM »
IC is of course just a small part of the circuit but if everything else is correct it should work fine. Infact, likely much better than an identical discrete solution.  My only gripe against those "special" ICs is that they tend to get obsolete rendering any repair work impossible.

KA2223 and LA3600 are essentially identical circuits and I think you are stressing yourself too much with this. The datasheets are your friend too. Ones form Sanyo and Samsung indicate only minor differences such as:

KA2223:
- Higher maximum power dissipation (700 mW versus 300 mW)
- Noisier (7uV, typical versus 2uV, typical and 30uV, max versus 20uV, max)
- Lower THD (0.03, typical versus 0.02, typical)
- Higher gain at "flat" mode (10.5, typical versus 10, typical)
- Lower operating voltage range 5V-13V versus 5V-15V (max rating is same for both)
- Recommendable supply voltage 9V versus 8 V

The last parameter is "important" since it indicates that the chips have been tested with different supply voltages. It might as well explain all the minor differences in noise, THD and gain. Note that most of those are just typical values anyway and will even out with the variety of real-life components.

So, with this knowledge I'd say that the chips are internally 99,9% identical. I don't really know what explains the weaker power dissipation of LA3600 but it's likely some packaging issue independent of circuit topology. However, you shouldn't be running these things nowhere near the maximum power anyways. If you really want to choose a specific one of the chips for high and low frequency circuits then just find out which one those has more losses. Use KA2223 in that one.

Personally, I think the bigger issue is which one of the chips you can get - if any of them...

Nice to see more finnish people here. Your english is very good.

Kirkiisi

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Re: TL071 Preamp
« Reply #2 on: October 25, 2007, 08:37:30 AM »
[Personally, I think the bigger issue is which one of the chips you can get - if any of them...
[/quote]

Thanks.

Getting these chips ain't big problem. Already found all of these.

Kirkiisi

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Re: TL071 Preamp
« Reply #3 on: October 29, 2007, 05:27:25 AM »
Ok, im going with the LA3600. And i made little mistake, i meant TL072 not TL071 pardon me.

And i will post some schematics and pic's of project when i have time for that.
« Last Edit: October 29, 2007, 05:29:26 AM by Kirkiisi »

 

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