Home Forums GuitarPCB Build Support Mini-Me IC Substitute

This topic contains 5 replies, has 3 voices, and was last updated by  Barry 1 week, 6 days ago.

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  • #6822

    Cybercow
    Moderator

    I know the Mini-Me calls for an LM358 at IC4 location, but with an identical pinout and nearly the same slew-rate (358 slew-rate = 0.3V/µs and the 1458 has a slew-rate of 0.5V/µs), I should be able to replace the 358 with an LM1458 dual opamp – right?

    Or am I better off ordering some LM358 dual opamps?

    #6823

    wilkie1
    Moderator

    Hmm.  I think the LM358 has a lower current requirement if I am reading the spec sheets correctly.  But since this circuit has 2 separate ground planes, there may not be a noise issue.  Otherwise you may be OK.

    #6824

    Cybercow
    Moderator

    Wilkie1 – thanks for that. I examined both datasheets as well and seeing as the current draw difference between them was small, (358 [0.7mA typical, 1.2mA max] – vs – the 1458 [3mA typical, 5.6mA max]), I am thinking along the same lines; considering that opamp is part of LFO circuit and is on a separate ground plane. I just wanted to ask and see if anyone had any experience with this particular opamp x-ref. Still, I’m going to order a few 358s and see what gives when they are exchanged. After I get it built and try out both opamps, I’ll report back. Hopefully before 10:00 next summer. 🙂

    </tip-o-the-hat>

    #6825

    wilkie1
    Moderator

    See?  Great minds think alike.  That means we get into trouble together.

    #6826

    Cybercow
    Moderator

    Wilkie1 – LOL! Sure enough. 🙂

    It also occurred to me to ask about the solder side jumper notes for the BBD IC. The notes say that the 3207 is not compatible with this Mini-Me build, but the solder-side has a small note regarding how to place the jumpers for using either the 3007 or 3207 BBD IC. That lends to a bit of confusion on my part. Or is it that the notes in the build docs refer only to the “CoolAudio” version of the 3207 as not compatible?

    #6829

    Barry
    Keymaster

    This board version is not officially released yet so you are not reading the correct document. Get with me on details you need depending on chip.

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