Hello,
I have WAV Trigger boards from 2023 and 2022 direct from SparkFun that unfortunately have the known problem of random audio glitches when playing via MIDI. It typically happens after 2 to 4 minutes of play. It makes a ‘crackling’ glitch sound over the note playing.
This same problem is acknowledged in an old post on the Robertsonics website from 2015 https://www.robertsonics.com/blog/2015/ … and-update) in a statement from Jamie saying, “I also nailed a couple of subtle issues with interrupt priorities that caused random audio glitches when maxing out 14 voices repeatedly, such as rapidly playing lots of MIDI notes/chords with long release times.”
It would seem this problem persists. It’s making the WAV Trigger unusable for my application. Are there further fixes for this issue? I’ve spent weeks trouble shooting this to no avail.
It seems truly random. For instance I can play the same arpeggio of single notes continuously through the WAV Trigger for 2 to 4 minutes, and then suddenly there is an audio glitch that sounds like crackling for lack of a better description.
Setup details:
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board powered by 9V regulated power to barrel jack - multiple different 9V regulators trialed, or 9V battery power to barrel jack, also tested 6V regulated power to barrel jack
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headphone out
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trialed numerous MIDI controllers sending the note in commands
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trialed multiple WAV Trigger boards
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trialed several different commercial MIDI in optoisolator boards including SparkFun
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trialed several different SD cards including the NAND 32GB card recommended on the Robertsonics website https://www.robertsonics.com/blog/2021/ … ard-update.
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trialed different config settings
Current config settings (the simplest possible to reduce processing):
#MIDI 1
This file was generated by the Robertsonics Configurator v2.00
for use with the WAV Trigger firmware. It is only required if
you wish to over-ride default settings. You may add your own
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I would love to resolve this audio glitch problem so I can move ahead with using the WAV Trigger. I really like this product. As is, I won’t be able to use it. I really want to fix this.
Sincere thanks for any help,
-J
Does the same issue occur without maxing out the # of voices?
Do you know the ohm rating of the ‘headphones’?
Thanks for responding!
Yes, it occurs without maxing out the voices. It happens when playing one note at a time at a rate of 90bpm with some tails overlapping, but I’m not sending in even 2 notes at once. The same sequence can be left to play continuously for several minutes. Suddenly and seemingly randomly after 2 to 4 minutes there will be an audio glitch.
It happens with the single note arpeggios on Koss Porta Pro headphones which are rated at 60 ohms (but ranging up to 85 at normal operation according to the internet), Sony MDR7506 cans rated at 63 ohms, as well as running into an aux in on a powered speaker (I don’t have the impedance for that and have not measured it).
You also posted on the Robertsonics website, but I’ll respond here so there’s no confusion.
I use a testing setup for both the WAV Trigger as well as Tsunami which is as follows. Track 1 is an 8-second 440Hz sine wave seamlessly looping. Tracks 2 through N are 8 seconds of silence which can be started, stopped and looped polyphonically to increase the active voice count up to the max number of voices. Silence takes as much CPU and microSD bandwidth to play as non-silence - it’s just that the data is 0.
I run the sine wave output into a PC using a high quality audio interface and I’ve written an application which performs a real-time FFT on the signal and analyzes the result to detect glitches. It’s sensitive enough to detect a single bad, missing or misplaced sample. It will keep track of the total number of glitches and display the waveform of the most recent.
In this manner, I can write an Arduino app that serially controls the WAV Trigger to start a sine wave looping, continuously start , stop or loop multiple voices as if I were playing and detect any glitches over a long period of time without have to be listening or watching continuously. This has become my best method to determine microSD card performance.
With a known good card, I don’t detect any glitches when I leave the test running exercising the max number of voices over a 24 hour period. With poorly performing cards, I definitely detect glitches. Unfortunately, any device that streams low latency audio from microSD is going to be dependent on the microSD card performance.
Also, the WAV Trigger hardware design and firmware is actually used in a commercial musical instrument, in which it would be catastrophic if it glitched. In that application, the manufacturer selects and qualifies the microSD card to ensure consistent performance.
I don’t doubt that what you are experiencing is frustrating. But based on my experience, and my testing, the WAV Trigger with the most recent firmware (which you are using, right?) is solid when used with a good microSD card. I’m always open to being proved wrong, but at the moment I don’t quite know what else I can do that I haven’t already done.
Thank you for responding. I’m using the the NAND 32GB card recommended on the Robertsonics website. Please advise anything further to try. The problem does exist.
I 100% believe that you are experiencing this issue. It’s just that all my testing has shown that, so far, it’s likely not a firmware issue. The only time I’ve been able to observe glitching is when it’s demonstrably the microSD card.
One thing to keep in mind is that the SP 2G NAND is a consumer grade card and it’s entirely possible that SP purchases and brands hardware from different manufacturers using different Flash controller chips. Just because it has the same exterior look&feel doesn’t necessarily mean it’s the same internal hardware with the same performance.
Where are you located? Would you be willing to send me your WAV Trigger and the microSD card? I unfortunately can’t fix something that I can’t replicate, and I don’t see any problem with the hardware I have available here.
I’m in the Atlanta, Georgia area. Yes, I can send you one of the WAV Triggers and SD cards I’ve been using for testing. I’m signing off for the night and will follow up tomorrow. Thank you. Have a good evening.
Send me a PM and we can take it from there.