74HCT14

[peterious]

Hi,

Having a bit of a problem sourcing a SN74HCT14N. Would a SN74HC14N be a valid replacement? Pretty new to this stuff.

[gmcn42]

Hi @peterious!

Would a SN74HC14N be a valid replacement?

Unfortunately no, as the 74HCT14 acts as a level shifter from 3.3V (from the Pi) to 5V (MIDI voltage). In general, 74HCT* parts running at 5V are fine to be driven by 3.3V logic while 74HC* aren't. (That said, you can get lucky with some parts as there are some tolerances and 3.3V is "on the edge" for a 5V-supplied 74HC. I wouldn't recommend this though as you might end up with random lost notes and stuff like that.)

Having a bit of a problem sourcing a SN74HCT14N.

Don't know where you live but in the US, Mouser has them in stock. In Germany (and probably EU-wide?), Reichelt has got them. Also sometimes random sellers offer batches of them on eBay and Co. Don't ever pay more than $1 apiece. ;)

74HCT14 are very common and generically produced parts. You do not need to stick with SN74....N which would be Texas Instruments. Other manufacturers may call theirs CD74HCT14, MC74HCT14, etc. As long as their is 74HCT14 somewhere in the name and (important!) its in a DIP-14 housing, you're golden.

Also depending on your use case, maybe you could also leave it out for now?. The 74HCT14 is required for MIDI Out and/or Thru. MIDI In will work fine no matter if the 74HCT14's socket is empty or not.

Hope this helps!

[peterious]

Excellent, thanks for the info. I actually was not planning on using the MIDI out right away (though I have plans to eventually) so this is very helpful. The hex inverter was the only part I was still missing so I’ll finish assembly and give it a shot. Appreciate the help!