YM : Everything works except for filter page 2 ( FIXED PT2399 backwards)

Hi all

just built a YM and it runs great, MIDI, sounds etc , but page 2 of the filter doesnt affect anything, I do hve the system set to DLY by the way. Something I am overlooking?

have you connected the output expansion port?

The second 6 pin connector? if so, yes I have

maybe first check those solder joints.

ok will do

i tried it without the 2nd mal/female connector between the 6 pin connector and it sounds identical

Ill just redo that soldering on both boards and see what transpires

( i was supposed to clip the connector on the 6 pin also right? )

you’re using a second male/female in between? just cut them so you can put the boards together without applying too much pressure.

ok i did that right then

lemme check the solder job

solder looks good, i redid them just to be sure

here is the YM

pls be something easy that I overlooked :slight_smile:

You inserted the pt2399 backwards
let’s hope that it’s not fried…

C4 and C8 (100n caps) seem to be missing on the bottom of the digital control board.


Check all lines from the ATMega to the 4822 - there must be something wrong as the 4822 produces the CVs for the Delay which you control by the 2nd Filter Page

the problem is definitively related to the pt2399 being inserted in the wrong direction :wink:

ok i double checked the chips on the filter board and re inserted them ( scientific I know) and i still getthe same results BUT

If I have the boards connected and I turn filter level to max I get a ticking sound like repetitive static at about 10-15 HZ

gah i forgot to hit refresh my apologies!

ffs im a moron :frowning:

This dot at the “wrong” end of the chip is a trap. What matters is the notch.
And when there’s no notch, then you take the dot into account …
Don’t worry, I’ve seen this mistake countless times… you’re not the first and you’re not the last.
Maybe we should add a “backwards chip inserter” in the Shrutiversum Caste System™?

ok turned the chip the RIGHT way and its working fine , frack I was so careful about putting them the right orientation too next board might be my last at this rate :frowning: Thanks a lot gang, I must say Im quite embarrassed :frowning:

re: dot/notch thats what got me , now comes the fun part, painting and assembly!

MicMic id buy you a beer if I lived close , cheers

Backwards inserter aren’t worth being in any Caste :wink:

You’re welcome dude163. I really don’t think it was worth a beer :wink:
By the way, you can think of adding the 2 100n caps close to the atmega644p if it ever freezes from time to time. You can solder them from the atmega’s side, a bit harder to achieve but you seem to do well with an iron. If you do so, be careful that the legs are short enough so they don’t touch the screen circuitry.