So no electrical differences that would require, say, a different resistor value here or another cap value there?Voltor07 wrote:It should be an easy switch out. Just remove the LM324N and put the LM837N in its place.
Thanks! Yeah, I certainly will use a socket. If it's not socketed already, I guess I'm gonna have to to take the appropriate board out in order to de-solder the 324. So looks like a project for the upcoming weekend.muksys wrote:324, 837 & 074 are pin for pin the same. All are interchangeable. Shouldn't need any other changes. Be sure to drop in an IC socket for easy swappage in case it's not to your liking.
Thanks, great!muksys wrote:I'm out of town ATM, but I'll check when I get home tomorrow night.
Opened it up last night. Yep, U49 is where I was looking.slirak wrote:The replaced opamp is designated U49.
OK, thanks a LOT for looking! Saved me a bit of head scratching there...muksys wrote:Opened it up last night. Yep, U49 is where I was looking.slirak wrote:The replaced opamp is designated U49.
Just so to be clear, I have no idea if U49 is the IC that was replaced MotneN. The 837 is designed for audio and should be fine. I do not know if earlier voyagers used different IC's and were later changed to the 837, but if your's has the 837 in it already, I'd suggest leaving it, unless it is bad, then swap it out for the same. Plus the resistor change that Amos suggested.slirak wrote:OK, thanks a LOT for looking! Saved me a bit of head scratching there...muksys wrote:Opened it up last night. Yep, U49 is where I was looking.slirak wrote:The replaced opamp is designated U49.
Well, I read somewhere on this forum that three opamps could need replacing, to fix issues with the output section of early models. I'm just gonna have to try and find out which the other two are. If anybody have any ideas, it'd be greatly appreciated!
Anyway, if anyone's gonna do the U49 swap, you might consider changing two resistors too:
http://forum.moogmusic.com/viewtopic.ph ... U49#p34012
Thanks again muksys!
/Jonas
Right, maybe MotneN changed another opamp! Would be nice to know which one it was.muksys wrote:Just so to be clear, I have no idea if U49 is the IC that was replaced MotneN. The 837 is designed for audio and should be fine. I do not know if earlier voyagers used different IC's and were later changed to the 837, but if your's has the 837 in it already, I'd suggest leaving it, unless it is bad, then swap it out for the same. Plus the resistor change that Amos suggested.
slirak wrote:Right, maybe MotneN changed another opamp! Would be nice to know which one it was.muksys wrote:Just so to be clear, I have no idea if U49 is the IC that was replaced MotneN. The 837 is designed for audio and should be fine. I do not know if earlier voyagers used different IC's and were later changed to the 837, but if your's has the 837 in it already, I'd suggest leaving it, unless it is bad, then swap it out for the same. Plus the resistor change that Amos suggested.
I don't know if it was an 837 or 074 in mine to begin with, but the 837 that's in it now is new and the resistors are swapped. This was in an attempt to fix an issue with a 'crackling' noise, sort of like an old vinyl record crackle, or like a mild distortion.
Anyway, the swap didn't fix the issue, that's why I'm anxious to find out which other opamps might be suspected. Not sure it's an issue with an opamp of course, could be a cap perhaps. But an experienced synth tech suggested that it sounded just like a faulty opamp, after hearing a sample. And I know I've seen a post from someone who described the same issue and claimed it was fixed by changing three opamps and a couple of other components.
Can't say I noticed any difference at all after the swap. So maybe it was an 837 in mine to begin with.
MotneN wrote:slirak wrote:Right, maybe MotneN changed another opamp! Would be nice to know which one it was.muksys wrote:Just so to be clear, I have no idea if U49 is the IC that was replaced MotneN. The 837 is designed for audio and should be fine. I do not know if earlier voyagers used different IC's and were later changed to the 837, but if your's has the 837 in it already, I'd suggest leaving it, unless it is bad, then swap it out for the same. Plus the resistor change that Amos suggested.
I don't know if it was an 837 or 074 in mine to begin with, but the 837 that's in it now is new and the resistors are swapped. This was in an attempt to fix an issue with a 'crackling' noise, sort of like an old vinyl record crackle, or like a mild distortion.
Anyway, the swap didn't fix the issue, that's why I'm anxious to find out which other opamps might be suspected. Not sure it's an issue with an opamp of course, could be a cap perhaps. But an experienced synth tech suggested that it sounded just like a faulty opamp, after hearing a sample. And I know I've seen a post from someone who described the same issue and claimed it was fixed by changing three opamps and a couple of other components.
Can't say I noticed any difference at all after the swap. So maybe it was an 837 in mine to begin with.
Hi againMotneN wrote:MotneN wrote:slirak wrote:Right, maybe MotneN changed another opamp! Would be nice to know which one it was.muksys wrote:Just so to be clear, I have no idea if U49 is the IC that was replaced MotneN. The 837 is designed for audio and should be fine. I do not know if earlier voyagers used different IC's and were later changed to the 837, but if your's has the 837 in it already, I'd suggest leaving it, unless it is bad, then swap it out for the same. Plus the resistor change that Amos suggested.
I don't know if it was an 837 or 074 in mine to begin with, but the 837 that's in it now is new and the resistors are swapped. This was in an attempt to fix an issue with a 'crackling' noise, sort of like an old vinyl record crackle, or like a mild distortion.
Anyway, the swap didn't fix the issue, that's why I'm anxious to find out which other opamps might be suspected. Not sure it's an issue with an opamp of course, could be a cap perhaps. But an experienced synth tech suggested that it sounded just like a faulty opamp, after hearing a sample. And I know I've seen a post from someone who described the same issue and claimed it was fixed by changing three opamps and a couple of other components.
Can't say I noticed any difference at all after the swap. So maybe it was an 837 in mine to begin with.
