4558 replacement (WAS: [sdiy] 4136??)

[Happy Harry]

In a lot of cases the TL072 can sub for the 1458/4558. Usually
instability can be cured with a small picofarad cap in the inverting
feedback. Try it and see... nothing to lose in a bluebox it ain't gonna 
explode on a 9V battery !!!

H^)


>From: Martin Czech <czech at Micronas.Com>
>Reply-To: Martin Czech <czech at Micronas.Com>
>To: ajhuovil at cc.hut.fi
>CC: synth-diy at node12b53.a2000.nl
>Subject: Re: 4558 replacement (WAS: [sdiy] 4136??)
>Date: Fri, 16 Mar 2001 15:15:42 +0100 (MET)
>
>Basically the 4558 is a dual NPN diff input stage, two stage device with
>A/B class output stage. Topology similar to 741, but lower noise.
>
>The 071 has a jfet input stage. i.e. input parasitics are completely
>different. Also possibly common mode range and latchup. The gain bandwidth
>product and slew rate should be higher. In other terms: completely
>different machine.
>
>Perhaps the circuit will run, but strange things may happen
>on turn on/off, overload, stability and other stress situations.
>First read and understand and compare all of the data sheets,
>then think about possible problems, then build, then test
>the problem situations. That  might give you some good safety.
>
>It was already described by others what a "hot swap" can do...
>
>m.c.
>
>
>:::Date: Fri, 16 Mar 2001 15:23:26 +0200 (EET)
>:::From: Antti Huovilainen <ajhuovil at cc.hut.fi>
>:::To: Martin Czech <czech at Micronas.Com>
>:::cc: synth-diy at node12b53.a2000.nl
>:::Subject: 4558 replacement (WAS: [sdiy] 4136??)
>:::
>:::On Thu, 15 Mar 2001, Martin Czech wrote:
>:::
>:::> Just a few comments to the swapping IC business:
>:::>
>:::> I had a look into IC OP AMP genealogy yesterday.
>:::>
>:::> 741,101,1458 are NPN diff input stage, two stage devices.
>:::> A/B class output stage.
>:::> Very similar.
>:::
>:::Speaking of which, is there anything special to 4558 (as used in MXR
>:::Bluebox, http://www.compassnet.com/~cjlandry/schems/bluebox.jpg) or 
>should
>:::I just read it as "a dual 741 which is a bit faster and has higher 
>output
>:::current limit" and use a TL072 as a subsitute.
>:::
>:::Antti
>:::
>:::"If you don't eat yer meat, you can't have any pudding!
>::: How can you have any pudding if you don't eat yer meat!?"
>:::   - Roger Waters
>

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