Reply 140 of 581, by SteveC
Hi all,
Just got my kit and built it only to find the LM358 dual opamp is missing.... I may well have dropped it and lost it though as I didn't check the parts before I started building. Anyway I thought I'd try an alternative opamp which is almost the same pinout - a CA3240 as that's all I had lying around. Only thing is one pin is gnd (lm358) vs -ve (ca3240) power. No idea if it'll work! I thought it can't break anything anyway (opamp inputs/outputs and vcc are the same) until I can try and get the right part tomorrow, and would just give poor volume or sound quality?
Anyway tried it on my PS/2 P70 and the test tool makes either horrible screeching sounds (EMS enabled) or silence (XMS or no EMM386). Anyone tried it on a PS/2 386 yet? Or is this due to the wrong opamp?
I'm now trying to get my oldest laptop working - an old P233 Thinkpad - to see if it works on that, but that already has a soundcard in it.
EDIT - Yes it works on this old Thinkpad! So now to see why it doesn't work on the PS/2 as that's where I want to use it 😀
Cheers,
Steve
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