Connect with us

substitute 4558 op amp for guitar compressor?

Discussion in 'General Electronics Discussion' started by scorp, Feb 24, 2014.

Scroll to continue with content
  1. scorp

    scorp

    18
    0
    Nov 29, 2013
    It's there a replacement for it? I'm uploading the schematic.

    Thanks
     

    Attached Files:

  2. davenn

    davenn Moderator

    13,764
    1,920
    Sep 5, 2009
    the 4558 is readily available, why do you want to sub it ?

    Dave
     
  3. scorp

    scorp

    18
    0
    Nov 29, 2013
    I didn't see one at local radio shack, and I want to work on it asap.
     
  4. scorp

    scorp

    18
    0
    Nov 29, 2013
    Also, would the pots be audio taper or linear taper?

    Thanks

    Found the answer to this..
    Thanks
     
    Last edited: Feb 25, 2014
  5. davenn

    davenn Moderator

    13,764
    1,920
    Sep 5, 2009
    see if radio shack have 1458 its the same chip different manufacturer

    DAve
     
  6. scorp

    scorp

    18
    0
    Nov 29, 2013
    Thanks I'll give it a try.....
     
  7. scorp

    scorp

    18
    0
    Nov 29, 2013
    The best kid I've built are ones that explain how the circuit worked. Since this circuit is not in kit form, can someone please explain how it works?

    Thanks for your time
    Jeff
     
  8. duke37

    duke37

    5,364
    769
    Jan 9, 2011
    Starting at the op-amp, this has a gain of 23. The output is rectified and smoothed to give a positive feedback voltage.

    The feed back voltage is fed to the second fet which is turned on when the gate is less negative. This shorts the signal to ground. So, the larger the signal, the more the attenuation. giving a more constant output.

    The first fet is there to adjust the effectiveness of fet2
     
  9. scorp

    scorp

    18
    0
    Nov 29, 2013
    Thank you
     
  10. KrisBlueNZ

    KrisBlueNZ Sadly passed away in 2015

    8,393
    1,270
    Nov 28, 2011
    They're not the same. The main difference is the GBP (gain-bandwidth product) but this varies significantly between manufacturers. A clear example is STMicroelectronics, who manufacture both types. Their 4558 has a GBP three times higher than their 1458.

    I think, from memory, that the 1458 is a dual 741. The 4558 is a newer design. It's also newer than the LM358, I think, which is probably the commonest pin-compatible device, but also has the lowest GBP.

    In this circuit you might not notice the difference, since the gain is only 23.
     
  11. davenn

    davenn Moderator

    13,764
    1,920
    Sep 5, 2009
    yeah i was kinda hoping it would do OK :)

    gosh I have dozens of 4558's here, use them in several commercial products I produce

    he must be able to find someone in his country that sells them in small numbers

    Dave
     
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day

-