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MIDI Vampire II troubleshooting

PostPosted: Wed May 20, 2015 7:17 am
by mixbat
Hi, just received the MV2, it doesn't seem to be functioning. Want to make sure I am not missing anything, I'd much rather get it working than return it...

So, I have tried plugging it into the midi outs of a Focusrite 2i4, a Midiman 3x8 thru box, and a Behringer BCR2000. All places I get the same thing - no response to midi messages, the only audio is a low-volume, high-pitched whine.

I didn't cut any of the traces to set the channel, so I expected it to be receiving on channel 1, but I tried all channels 1-16.

I tested all of the MIDI outs with a meter, and am getting good +5V on all of them.

Thanks for any suggestions, and thanks to Mark for assisting me with forum issues.

Re: MIDI Vampire II troubleshooting

PostPosted: Wed May 20, 2015 1:32 pm
by guest
what midi messages are you sending? it only responds to note-on on notes 32-35. if you have a multimeter, you can measure the voltage across C1, and make sure its 3V, but if its humming, its probably getting voltage. the other thing would be to look for data on R1. do you have a scope by any chance?

Re: MIDI Vampire II troubleshooting

PostPosted: Wed May 20, 2015 9:01 pm
by mixbat
It is working, I was sending the wrong notes. Never noticed before that different keyboards label octaves numbers differently. I made a test pattern in Ableton using what I knew as notes 32-35: G#1-B1.
But on the Ableton keyboard those are G#0-B0. I googled 'midi note numbers' to make sure I was not crazy, never noticed how that numbering is not consistent.

Guess that's why in the wiki you refer to the notes as being in the "third octave".

So now a different question: Could I put the module in some sort of shielding to lower the noise floor?

Re: MIDI Vampire II troubleshooting

PostPosted: Thu May 21, 2015 9:37 am
by guest
yes, you can put it inside of a metal stomp box or something, but it may not reduce the noise floor. it all depends on the type of noise you are getting. first off, its only an 8b drum machine, so there is going to be a white noise at -50dB that is unavoidable. if the noise you are hearing is 60Hz pickup, then a shielded box might help. if the noise is digital noise on the midi cable, or pickup noise from the midi cable, then a shielded box wont help.

glad to hear it is working for you!

Re: MIDI Vampire II troubleshooting

PostPosted: Fri May 22, 2015 8:12 am
by mixbat
I will try that. I feel silly complaining about noise considering what you put together for 35 bucks.

This weekend I will program a bcr2000 preset for it, so much more fun with knobs. I can upload it if it is of use to anyone.

These are the label strips for it:
Image

Re: MIDI Vampire II troubleshooting

PostPosted: Fri May 22, 2015 10:10 am
by guest
youre right, it definitely needs knobs.