Wave Trigger Intermittent sampling 'stepping sound' when reading MIDI notes

Sensors Sound & Audio
1

I use a Wave Trigger board as a small sampler to read incoming MIDI notes

from a musical project. All my notes are sampled stereo 16bits .WAV files

and stored on a 64gigs micro SD card that the Wave Trigger reads.

The 12vdc power supply is stable.

The firmware has been upgraded to v1.34 and

I do not exceed the board’s max 14 notes polyphony. Ok.

Now, here is my problem:

While playing incoming MIDI notes to the WT board I get Intermittent sampling ‘stepping notes’

in the song… It sounds like 20 notes played very fast and stuck together.

I attached a .MP3 file (.ZIP) that plays an external synth on left channel

and the Wave Trigger board on the right channel so we can hear

that the problem is only from the WT board. The external synth notes

are rock solid meaning the MIDI info is correct.

I started to suspect the lenght of my filenames and shrunk them

with no more than 7 characters like for example: 030-F#1.wav

But that didn’t cure the problem… Still some stepping intermittent notes

that insert in the played song…

Here is the wavtrigr.ini file information included on the SD card:

#MIDI 1

This file was generated by the WAV Trigger Init File Maker v1.20

It is only required if you wish to over-ride default settings. You

may add your own comments below this line →

Any one who actually had that problem ?

Thanks for your support.

Jean-Pierre Desrochers

Wave Trigger Board reading errors.zip (668 KB)

Wave Trigger Board - 64g micro SD card.pdf (61.3 KB)

Wave Trigger Board - firmware ver1.34.pdf (105 KB)

2

I note that your card is a 64GB card that likely came formatted as XFAT, which is not supported by the WAV Trigger. Did you reformat to FAT32, and did you make sure that the allocation size was set to 32K when you did so?

3

Yes, Reformated the card to FAT32 and using 32k allocation size.

Yeah, these two I made sure they were correctly set…

So that’s not the problem here…

4

I used a small program called guiformat.exe to reformat my big SD card

basicaly coming formated exFAT and reformat it to FAT32, 32k alloc. size.

5

It’s a little hard to tell what’s going on with those samples. Can you create a 440Hz sine wave file and just trigger that by itself and record the output?

6

I had that problem with 4 different set of 88 .WAV files

All showing the same intermittent buzz on the playback.

If that can help you all the MIDI songs that showed this behaviour

were about 2 min and a half in lenght.

Some 3 - 4 min max.

What ever waveform is played will somehow show this buzzing thing.

I suspect the max polyphony of 14 voices.

I can go up to 12 - 13 voices sometime but not over that.

And when the buzz occured I checked the polyphony value

and it was always around 8 to 10 voices max.

For now I took the Wave Trigger board aside and replaced it

with a small MIDI piano module from Yamaha (P50m)

and all the song I play (from the same MIDI stream as the Wave Trigger)

play perfectly without any intermittent glitch or buzz.

That’s all I can say to you… sorry.

7

What I could do for you is to attach a MIDI file of one of the songs

that showed more often the buzz problem…

Then you could play it many times until the buzz occurs…

8

If what you’re saying is that the buzzing only occurs when there are over 8 or 10 voices playing simultaneously, then I suspect the limitation is the microSD card. While the WAV Trigger supports 14 voices, the usable number depends on your microSD card’s ability to deliver random access reads quickly, and not all cards are the same in this regard. Did you happen to try another card?

If you haven’t already, please see a couple of articles about microSD cards on my website:

https://www.robertsonics.com/blog/2021/ … ard-update

9

No I didn’t try another card…

Look at my first post on this topic.

You will see an attached .ZIP file named

Wave Trigger Board - 64g micro SD card.pdf

Showing the actual micro SD card I’m using.

I don’t think that’s the problem…

If it is please let me know the actual specification on that card

that makes it not usable for the Wave Trigger…

Then I’ll try another one.

10

I did look at your first post and have already ordered that card. The requirements for cards are described in the series of articles I linked to above. Manufacturers typically do not publish the maximum random read access time, which is the critical parameter for polyphonic streaming audio.

11

In one of your post on the ‘2021 microSD Card Update’ web page you stated:

<<< FAT32 has a limit of 32GB, so almost any card larger than 32GB will be formatted XFAT.

<<<The only way to use such a card is to reformat to FAT32, therefore rendering the card to be a 32GB card.

Well this is not true if you use a ‘high size Card’ FAT32 formater

like this free small FAT32 formater program → https://fat32format-gui.en.lo4d.com/windows

I formated my 64gigs micro SD card with this program and … boom ! FAT32 with 64gigs ! No size lost.

12

I will wait for your future suggestions on ‘reliable’ micro SD card to buy.

Thanks.