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

[Martin Czech]

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