jvphotog

Code you write yourself. You'll have to: open a file find its size using the size() function allocate that much memory in PSRAM using extmem_malloc() load the file into the allocated memory using read() close the file repeat for your other files...

Only you will know he answer to that, and then maybe only if you try it out… No idea. There may be someone here who knows enough about both to give some sort of answer, but a lot will depend on your own priorities and skill. For a one-off...

Almost no difference between K and M - I simply had the wrong 1.8V regulator specified on L. L & M have the extra buffers on MCLK and WCLK and an extra pin on the Expansion header to more easily enable 32x32 mode. All three revisions work...

Very cool! What are the board K to M differences? How are the mic-line preamp boards panning out?

Hi All, Two updates. 2-stage DAC Biquad filters added to repo - code and arguments are based on Teensy Audio filter_biquad.h More boards are available on Tindie - with the WCLK and BCLK buffers + an extended expansion header for the...

Here’s a thread where latency is not only discussed but actually measured for the unmodified system, and practical experience of reducing it touched upon. Teensy is very fast, so for 6 effects you may be able to clock it more slowly to reduce...

I've been using this on Palmerr's new Teensy8x8AudioBoard. I couldn't get it to work until I realized the amp expected a stereo stream. I made a mono amp version of the RTNeural_F32. All your controls and implementation are super impressive! I...

Looking at the space allocation on the board, I have naive noise related questions to ask: it seems the 9v power is very close to an output jack, similarly the T41 board is in the middle of the board, why not prefering a digital+power signals...

Yes, that looks correct. BTW, I'm working on a stackable 4 channel mic-line preamp board. Very low noise, individually switchable phantom power, individually switchable -30dB pad (for pro-line inputs) and 20dB gain to bring the level up to where...

Holy moly this 2776 is small! Just want to confirm this is the correct orientation. Thanks!

I've rewritten HPF to accept any cut-off frequency up to 5kHz. 0 still sets the filter off. Verbose( ) now controls HPF( ) diagnostic printing. Enjoy!

A code update overnight fixes the gain and HPF issues. Use HPF( ) instead of setHPF( )

Pulled in, seems to be working fine for me. I've done a bit of work on the F32 library and put in PR #27 which adds conversion of an F32 audio stream to / from two I16 ones containing the MS and LSwords. This can be used to get 24-bit TDM I/O -...

Yes, I've been using the platypus logo on musical instruments and technology for more than 15 years. I thought I'd bring it across!

That all sounds great - thanks so much for your effort on this, I hope it turns out to be worth it. The multi-TDM code doesn’t directly support larger transfers, though as noted above it could be coerced into doing it using pairs of 16-bit...

Another option is to add a pin to the Expansion header. It can be fly-leaded to 32 on the main PCB and patched where needed on slaves. It's the only extra signal now that each board has BCLK/LRCLK buffers. The OUT1A / OUT1C patch is already...

Not derailing at all - the whole reason we build the hardware and software is for people to use it in interesting ways. Good to see that there's a use case for 32x32. BTW Polymod looks cool - right out of the 70's or 80's! As you can see above...

palmerr, as I work through my own project goals, I’m definitely learning a lot from your work—thank you for sharing it. I wanted to ask if you’ve decided on a license for the board. I’ve been wrestling with this myself; as you know, projects like...

Jonathan, I'm updating the commissioning notes for 32x32 mode for the next gen board with MCLK and LRCLK buffers on board: Is this the correct text for 32x32 mode? I'm still not quite clear on the correct SAI1 mappings.

Just wanted to say that this is a super cool project, thanks so much for documenting it. Found this thread while trying to troubleshoot my own 6-input, 4-output PCB comprising 3 x SGTL5000s (which seems very basic after reading this!). I'm...

Getting steadily more bonkers. 64 output channels, with a different frequency / waveform combination on each one. As shown it's taking 22% CPU and 64 audio blocks, plus ~770mA from the USB ( :eek: ). I can reduce the CPU to 5% by using sine and...

Good to see that you got them working without much trouble! I forgot to mention - 13mm x 3mm tapped spacers work well for board stacking. I'll add some construction notes to the repo in the next day or so.

Two up...

First one working

Let the fun begin!

The Main board and Wings are now live on Tindie if anyone wants to procure via this channel rather than buying boards direct from JLCPCB. Pricing is $US. Tindie: 8x8 Teensy Audio Board Sadly, I couldn't find any cheaper postage, so best to...

All buttons are illuminated! Below the mod control is the fixed control for filter resonance. Back

Degenerator.2 in action..

All buttons are illuminated! Below the mod control is the fixed control for filter resonance. With the buttons Mod 1-4 a different modulator source can be selected and controlled with the Modulation controller.

Yes, it's always a trade-off. Once you're 'inside the box' it's less important to use balanced lines, as you have good control over interference and a solid earth. The noise impact (less than 3dB) is trivial compared to the PGA's rise in N+D at...

The THAT 1510 and INA217 both have single ended outputs though, right? Would that be less than ideal since it's possible to have balanced inputs into the TLV's?

…and so do I. I’ve spent much more effort and cash on the Teensy community than I have on the Pico… Even if not directly benefitting PJRC and Teensy, this effort does make use of the Audio library, and may well result in improvements to it that...

There is no separation of digital and analog supplies/ground on the Audio adapter, and the SGTL5000 isn't high-end.

Yes, all that is quite possible, though I'd probably create a custom wing board with an input and output IDC cable. Why not just use the SGTL5000 board for this as it seems that you are only using 2in and 2 out?

I did! But it was way too noisy - plus very sloppy mic preamps, and no balanced inputs or PGAs. I dont possess your PCB design skills! Anyways, I dont want to hijack your thread, just letting you know some of the ways people might use your board :)

^Sorry, I probably should have elaborated. It would be cool to use this in a powered speaker. With one combo wing board, you could have two un/balanced inputs, that would take a 1/4"/ xlr in. And then have an xlr out and 1/4" out - by hand wiring...

I've run some further input tests to explore jvphotog's question about mic preamps. Here's the N+D and ENOB at the input level where distortion starts to rise at each gain setting. The source is a sine wave from a pro 24-bit audio interface...

Yes, it's two layer! Only the top is populated. As above, I went for a slightly larger PCB for adequate ground planes, rather than 4 layers.

Super - thanks. Big moment of panic this morning, especially as JLCPCB took about 2 minutes to "check" the design and lock it down...

jvphotog You could use 100uF all around if you want as long as they fit. The only reason I specified the smaller caps for inputs is that they're driving into 30 k Ohms and will take longer to equalise voltages on start-up as VCOM rises. There's a...

You pulled a switcharoo on me! Haha I am able to download it now, thank you! Im not sure what I did on JLCPCB, but I think I selected assembly for both sides and it was looking for c11, c12, and c13 - which I assume is the optional -5v supply? On...

There are no back components in the BOM or placement files. Everything is on the front for the standard set up. You will need to purchase and mount all the connectors, as these are not cost-effective for PCBA. Also, the cost to do one board...

I cant seem to download your file. Im also having some issues with the back components on your BOM at the jlcpcb website. Sorry, Ive never ordered a pcb before! Are you only getting the top side assembled?

Here's a test with an ancient Electrovoice RE80 that hasn't been dropped too often (despite mainly being used as a bass drum mic). I've left the audio as recorded - Teensy peak indicators were at about 0.8 at the loudest part. The red line in...

Awesome! How do you like it? Were you able to test it with a dynamic mic by chance? How's the noise? Great job on this, incredibly impressive!

The board files are now uploaded to the hardware repository, with full JLCPCB PCBA files for the main PCB and gerbers for all the Wing boards. https://github.com/palmerr23/Teensy8x8AudioBoard Apart from the main PCB, BOM files are indicative...

Great news. I was using a fairly clean environment because I’d had teething issues with a clash with the original Teensy Audio library, so didn’t have the CMSIS library in scope. When I’m back at the keyboard I’ll do a dual-core example, with...

Thanks great!

New PCBA boards have just arrived. A quick test shows CODECs are being programmed and audio inputs / outputs are working. More to follow after more thorough testing. Jonathan, I'll post the PCBA files on the repo as soon as the boards are...

Mod Encoder is blink.. :)