Lil' Erebus DIY Kit

The Lounge Other Gear
65

Thanks for the info guys! Unfortunately I live in the middle of no-where and have no friends that are handy with this sort of stuff so I thought I’d post here incase anyone knew.

Just tested - My TL 074’S IC’s are currently reading a -23.4v and +23.4v? Is this fixable or have i fuc**d it up? My other IC is reading +4.5 but that’s not within +/-.05v. Is this fixable too?

Edit: Im going to re-flow my resistors and see the outcome, hopefully this is enough.

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Nae luck! It’s now reading 23.6 + and -…

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All this info is handy for me too , i’m Very slowly putting mine together.
I’ve learnt a lot from YouTube so far.

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This question might be stupid, but: Is it possible that you have measured the voltage BETWEEN pin 4 and pin 11? If so, the result should be in the 24 V range, (and your values might be fine), but this is not what you want to test.
It is a little bit misleading, as pin 11 on a TL074 is labelled GND, but in your Erebus, this pin should have -12 V (And pin 4 gets +12 V). Make sure you find a ground somewhere else (e.g. on the pin header for your power supply cable) and put your black probe there.

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69

Nice work - that does make sense. It’s notable when the measured value is some multiple of the desired value (in this case 2x). I agree that the OP should look for a ground point on the board. Power ground is an easy one, but I bet there is a labeled ground point on the board.

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70

Wish you all the best with your build. If I can do anything to help i’d be more than happy.

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71

Hi Jenne,

Thanks for the reply. Not stupid question at all because that’s exactly what I’ve done… :roll_eyes:

I’m going to try what you suggested right now and see the outcome. Just to clarify - are GND on all 12 pin headers in the same place or do they differ from each?

EDIT: How can I test the GND on the PINS if the unit needs to be powered by the ribbon - which in turn covers the pins? Am I being silly here…

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Ground pins are standardized for Eurorack. You could touch your probe to the tip of the header pin that is on the back side of the circuit board.

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erebus_test
erebus_test.jpg3840×2160 944 KB

I think you could touch any of the 6 black marked pins with your black probe, and leave it there during your measurements. This is your ground you are measuring the voltages against.
With your red probe, you should measure:
-12 V on the upper row of red arrows (pin 11 on any TL074)
+12 V on the lower row (pin 4)
+5 V on the left (pin 1 on IC4922)
As I do not have my erebus here, I could not test this myself right now, so please double check with the documentary from Dreadbox.

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74

I can confirm this was correct and my voltages were too. Thanks for the help! Now to the tuning part… :smile:

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