Hmm mine definitely get bright and I followed the pcb callouts except I put 10uf caps where it should be a 10 and 47. Might change it but might not lol it works
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My LEDs are possibly just old school.
I have the same problem with the LEDs, they are very low, the only time they are really visible is when I move into garbage mode territory.
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I think something else must be wrong. I went all the way down to 470 ohm and it made almost no difference. Now, I am using old school LEDs, but the same ones work just fine in several other LMNC modules including this one for the On switch.
That is weird! It could mean that the transistor is not switching⌠We could test with switching it âmanuallyâ by putting a voltage there, but I think we need to measure with an oscilloscopeâŚ
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It seems everybody loves inverting opamp circuits ⌠but what about plain (non inverting) op-amp circuits?
In your modification you are using 2 op-amps to add 2 signals together. Because the first stage is not only adding the signals but also inverting them, you need a second one to re-invert the signal. You could also use a one op-amp adder:
[Edit]: No need to correct the polarity / phase because it is not changed.
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People like inverting summing nodes because they keep the input voltages at zero, far away from the rails and far away from phase reversals, and they also make the calculations easier â the non-inverting node calculates the average of the inputs, not the sum, so you need to compensate by increasing the gain by the number of active inputs, and you have to change the gain if you add or remove inputs.
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which in most cases is a one time effort. Just saying âŚ
Thanks for your help with this - will try it this way next time!
Yep there is. Or there might be. According to the schematic all are connected to GND. Logically speaking if this GND is the same copper lane for all 4 and it is not at the 0 Volts level then all 4 are in trouble. I do not have the PCB so I can not check this.
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Hey, anyone have advice on mods to fix this into my eurorack setup? Ie, switching out the 1/4 inch jacks for 3.5mm mono jacks (I usually use the thonkicon ones) and modding/replacing the front panel to fit 3U?
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For the 3.5mm jacks you can look here. Front panel sounds a bit more difficult, mount it rotated 90° or something? 
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Ah washers, thatâs a perfect idea! What about on the wiring side? The pcb has 5 points, for stereo jacks I thinkâŚ? is that being summed down to mono? And which point is which?
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You are right, it is only mono, so only two pins are really used. You can see which ones on the tiny jacksocket pcb. But I think, you should not use this tiny pcb at all and just wire the 3.5mm sockets directly to the large pcb where the pin header usually goes.
The main PCB is about 175 mm high vs. around 110 mm available between Eurorack rails, so to get it in youâd have to rotate it to make a module either 175 mm wide (about 35 HP) or more than 175 mm deep. Either way making a new front panel would presumably be necessary, unless you could figure a way to extend its 100 mm width to 129 mm (and its length to exactly 35 HP if you care about gaps).
It all seems a bit much. You could just bang together a Kosmo case out of a few pieces of wood much more easily â youâd need a power supply, but you could do an FC Microbus for about $40. Then youâd be set up not only for this module but other Kosmo too.
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What did you find out about your low LED? Mine are low as well except when cranked. My second delay signal is hard to hear, might have to reflow some solder.
Didnât figure it out yet, but I do plan to poke around some more.
I also need to investigate, but I can not decide on which scope I want to buy xD (see Looking for a cheap oscilloscope )
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thanks sebastian for posting the pic so I didnât have to look it up . I got the washers from an auto supply place on EBay .
they are thin but being stainless steel they are pretty strong .
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Okai, mine are fine now! I have reduced the 100k resistors R4 R5 and R6 with 2.2k and they light up very nicely now! The exact values depend the LED and preference, I would say. Probably it also helped that I reduced the input resistors on my Filter from 100k to 20k as described in the the Performance Filter thread and I have a louder signal in general now. Going to do the wet-only mod now that I have it open!
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