PCB DESIGN - All In One v2.5 - 32 inputs with 74HC4851

[jman 31]

Have a look HERE. Those are both jumper locations. One for pedal impedance and one for polarity.That should clear it up. Let us know if it doesn't.

J

[timekeeper]

Have a look HERE. Those are both jumper locations. One for pedal impedance and one for polarity.That should clear it up. Let us know if it doesn't.

J

Thanks a lot my friend, that is exactly what I was looking for! Unfortunately, according to Synthex on the same page that you directed me, the Impedance switch is not implemented on the 2.5 pcb... Seems I have to do some extra soldering to get it working, but I don't have the time at the moment to go through the schematics... Anyway, thanks a lot.

[jman 31]

No problemo! I don't know that the pedal impedance will affect you though. I never had any problem with the different types of variable units that I tried. I used an optical switch and a potentiometer with mine and never had any trouble.

[timekeeper]

Question to Synthex or anyone else willing to help:
If I use PCD design 2.5 and inputs PCB 1.8, then connect pin2 of the input socket with pin33 on Atmega644 (with 100 Ohm resistor) will the Impedance jumper work???


EDIT: This modification is dead wrong since it connects input socket's pin 2 to Atmega's pin 17 instead of pin 33!!! Do not use it or else you will probably damage your Megadrum!!! Excuse me for my mistake!!!

[dmitri]

Out of curiosity, are there any compelling reasons not to use the official PCB design from viewtopic.php?f=3&t=266 ?

[timekeeper]

Out of curiosity, are there any compelling reasons not to use the official PCB design from viewtopic.php?f=3&t=266 ?

Because I find this design much more noob-friendly than the original... The use of 4851 over 4051+bat85+resistors requires less (difficult) soldering...

[dmitri]

Out of curiosity, are there any compelling reasons not to use the official PCB design from viewtopic.php?f=3&t=266 ?

Because I find this design much more noob-friendly than the original...

Doesn't look like it is.

The use of 4851 over 4051+bat85+resistors requires less (difficult) soldering...

If you use 4851 instead 4051 you can drop bat85 and resistors from the original design.

[timekeeper]

If you use 4851 instead 4051 you can drop bat85 and resistors from the original design.

Really? Mustn't I do some extra soldering to fill the circuit? I mean, with all these components missing, are all the traces connected?

[Firelord]

If you use 4851 instead 4051 you can drop bat85 and resistors from the original design.

Really? Mustn't I do some extra soldering to fill the circuit? I mean, with all these components missing, are all the traces connected?

With 4851's you will need to replace the input resistors with jumpers (i.e. wires). And there is no need for BAT85's (simply ignore those connections).

[timekeeper]

After hours of reading and learning I came up with these 2 editions, which both of them should now allow HiHat Impedance using Synthex's PCB 2.5 and Input PCB 1.8. Here they are:





I don't know which of the 2 I will use... If I can fit the cable between the DIP socket and the Atmega644 I will go for first design... Components needed from left to right on both designs, are:
1) 100 Ohm resistor
2) Piece of cable

Any advices, correction etc are most welcome!!!