LTC MIDI In light stays lit

[whomper]

I have a core with SID that works great.

After connecting an LTC module without the MAX as I am using the core midi in, the MIDI in light of the LTC stays lit no matter what I do.

If I connect a LED directly to PINs MO and MI of J11, the core will not boot and will send tons of midi our messages.

does anyone have an idea what might be wrong? is using the LTC the best way to get proper MIDI in led activity or is there a quicker way?

Thanks,

Whomper

[smashtv]

Hi Whomper!

I finally had a chance to tinker with my own hardware to eliminate a possible cause for this....

After connecting an LTC module without the MAX as I am using the core midi in, the MIDI in light of the LTC stays lit no matter what I do.

There are several possibilities:

1) Connection/wiring-if the MO/MI pins on the LTC are not connected they will float (causing erratic or always on/off behavior)

2) Reversed/backwards C5 and/or C6 caps

3) Bad 7400 chip

4) Wrong family of 7400 chip (a 74F00 or 74LS00 etc. might not play well here)

Does the other LED work as expected?  If so my money is on #2 above, C5 reversed.

If I connect a LED directly to PINs MO and MI of J11, the core will not boot and will send tons of midi our messages.

Dont do this, you are connecting your MIDI IN and OUT to each other through an LED.  (depending on the MIDI isolation of the other devices on the MIDI chain this could possibly fry some parts)

Let us know what you find!

Best Regards

SmashTV

[whomper]

Thanks SmashTV for your ideas, aparently, I got a 74LS00 and not 74HC00, which made the difference. Bought two 74HC00 and now everything works as intended!

I was not aware it required exactly the HC model.

Whomper