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Operational Amplifier in Marshall 5010 scheme

Started by Szcz, March 17, 2019, 03:43:51 PM

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Szcz

Hi,
I found a scheme for a Marshall 5010 ss amplifier, that I'd want to make. There is a problem, that I don't know which operational amplifier should exactly be according to this scheme. There are two of them and both of them aren't named. Does anybody know what should it be?
Thanks
P.S. If I wrote anything wrong and you don't understand the question, write me about it and I'll write it again. English isn't my 1st language.

tonyharker

It doesnt really matter. Any dual op amp eg TL072, NE5532, JRC4558 etc will work.

Szcz

So the only thing that will mater here is that op amp should be dual? Ok, thanks

Szcz

#3
Oh, and if there are two op amps on the scheme and they are mono(?), then shold I use one TL072, or two TL072?


Dino Boreanaz

In the top-right corner of the schematic it specifies that IC1 is an MC1458.  This is a dual op amp that provides the two gain stages shown in the schematic as IC1a and IC1b.  Pin 8 connects to the positive rail as shown and Pin 4 (not labelled on the op amp) connects to the negative rail as shown below R7 in the schematic.  This is the same op amp application used in many solid state Marshall amps of this era.

As suggested, this circuit can use a variety of dual op amps.  I've read about people trying many different dual op amps in these applications.

I've been considering building this amp too, and would be interested to follow your progress.

Szcz

Yes thanks, when you wrote it, I almost finished scheme in kicad, but if you can, do you know where is the plus of the bridge? Cause it's a little bit confusing here and I don't know did I did it right.

Jazz P Bass

The + of the bridge rectifier is marked 'A'.
The - is marked 'D'.