Author Topic: Aion Eclipse (what about pin 1,2,3 of 4558?)  (Read 289 times)

divanorosso

Aion Eclipse (what about pin 1,2,3 of 4558?)
« on: April 17, 2019, 08:07:56 AM »
Hello,
I note that in the Aion schematic the part of 4558 (IC2, pin 1,2,3) is not present.
Wanting to redo everything myself, I ask myself the question: will those pins, on the pcb, be grounded or not connected?
As a newbie I answer that they are not connected. Am I wrong?

https://aionelectronics.com/project/eclipse-korg-sdd-3000-preamp-pcb/

Thank you.

bluebunny

Re: Aion Eclipse (what about pin 1,2,3 of 4558?)
« Reply #1 on: April 17, 2019, 08:18:34 AM »
I can't imagine Kevin would have left those unused pins unconnected on his PCB, and neither should you.  You'll probably find he has pins 1 and 2 connected to each other (and to nothing else), and pin 3 to some convenient voltage level.  Since this is a bipolar design, ground would be a good idea.  You could ask Kevin: he's "aion" at this forum.
Ohm's Law - much like Coles Law, but with less cabbage...

divanorosso

Re: Aion Eclipse (what about pin 1,2,3 of 4558?)
« Reply #2 on: April 17, 2019, 01:49:27 PM »
I can't imagine Kevin would have left those unused pins unconnected on his PCB, and neither should you.  You'll probably find he has pins 1 and 2 connected to each other (and to nothing else), and pin 3 to some convenient voltage level.  Since this is a bipolar design, ground would be a good idea.  You could ask Kevin: he's "aion" at this forum.

Yes, I don't want to leave them disconnected and I thank you for telling me not to do it.

For what follows, read it keeping in mind that I'm a newbie and I'm learning.

1) Looking at the original schematic of the sdd3000 (in service manual) the tl072 is the ic-1, the 4558 is the ic-11.
Now, on the ic-11 (as you rightly thought) the pins 1,2 are connected together and isolated.
I am therefore almost certain that pins 1,2 must be connected together and left isolated.


2) It is more complicated for me to understand pin 3. The schematic is large and I am not an expert.
Pin 3 ends up on pin 6 of the same ic + it ends up on pin 1 of a pot (that i suppose it is grounded)
Hope I didn't make a mistake reading the schematic


« Last Edit: April 17, 2019, 03:36:59 PM by divanorosso »

PRR

Re: Aion Eclipse (what about pin 1,2,3 of 4558?)
« Reply #3 on: April 17, 2019, 09:51:11 PM »


divanorosso

Re: Aion Eclipse (what about pin 1,2,3 of 4558?)
« Reply #4 on: April 18, 2019, 03:10:58 AM »
Thank you for the confirmation. I am happy that my assumptions are right, it means that I am learning (I think).