Forum Rule: Always post complete source code & details to reproduce any issue!

Search:

Type: Posts; User: Blackaddr

Page 1 of 7 1 2 3 4

Search: Search took 0.01 seconds.

  1. Replies
    6
    Views
    249

    I'm surprised the extra bit of polybleps math on...

    I'm surprised the extra bit of polybleps math on the edge transitions are killing your performance. Maybe it's not implemented quite right? By re-writing polyBleps to eliminate division, or used...
  2. Replies
    1
    Views
    140

    Try turning off the CODEC's HPF. A number of...

    Try turning off the CODEC's HPF. A number of codec have dynamic HPF that attempt to to remove the DC offset but the that that the filter is not static results in noise artefacts. The SGTL5000 does...
  3. If you're worried about damage, the problem isn't...

    If you're worried about damage, the problem isn't using headphone outputs to drive something you're not supposed (people do this all the time in the real world. Sometimes you break stuff, sometimes...
  4. Replies
    154
    Views
    57,319

    Hi Frank, Congrats on building your board!...

    Hi Frank,

    Congrats on building your board! When you switch to HB, and you get the interference, if you turn down the volume knob does it go away? Cheaper guitars aren't known for the best wiring...
  5. I can also vouche to take a look at Chip's...

    I can also vouche to take a look at Chip's OpenAudio extentions rather than start from scratch.

    However, many effect developers also find it easier to simply convert to/from float in side their...
  6. As someone else mentioned, the program button is...

    As someone else mentioned, the program button is also available on header pins on the T4.1. I would highly recommend bringing this signal out to an enclosure mounted button. A small tactile switch...
  7. Replies
    154
    Views
    57,319

    RA9 is not populated, I added the footprint in...

    RA9 is not populated, I added the footprint in case I needed some frequency tweaking options, but didn't end up using it.

    The circuit structure between the op-amp and the ADC input on the TGA Pro...
  8. Replies
    6
    Views
    344

    Hi PerM, just to give you a heads up, the SNR of...

    Hi PerM, just to give you a heads up, the SNR of the ADC for the WM8731 is spec'd at 90dB. To convert this to bits, divide by 6db. 90 / 6 = 15 bits. (NOTE: 6db = a factor of 2, ie. one-bit).

    So...
  9. Replies
    4
    Views
    346

    No idea, but there seems to be a dedicated IC for...

    No idea, but there seems to be a dedicated IC for everything the days. I'm sure I've seen something, somewhere, sometime in relation to audio protection ICs. But it seemed overkill. The dual diode...
  10. Replies
    154
    Views
    57,319

    Hi Frank, I still use the TL072. This is a...

    Hi Frank,

    I still use the TL072. This is a very common op-amp used in guitar pedals and is very low-noise and allows for every high impedance input (very important for guitar). It's a great op-amp...
  11. Replies
    4
    Views
    346

    Most codecs are designed for good performance at...

    Most codecs are designed for good performance at roughly around 1 Vrms as the normal operating point, however the SGTL5000 datasheet specs @ 3.3V supply a max input level of 2.83 Vpp. It's not clear...
  12. Wow, this looks awesome!

    Wow, this looks awesome!
  13. Replies
    2
    Views
    332

    Hi Takashi, I think I may be misunderstanding...

    Hi Takashi, I think I may be misunderstanding your question, but it sounds like you simply want both Serial and Audio over Teensy USB? Have you tried setting the USB type to "Serial + MIDI + Audio"?...
  14. Replies
    39
    Views
    2,109

    You can also look at drop in pin-compatible...

    You can also look at drop in pin-compatible switching modules to replace LM7805. This will often be the most expensive option but can be the easiest.

    Take a look at this article.
    ...
  15. Replies
    39
    Views
    2,109

    Thanks for checking the math! I'm way too tired...

    Thanks for checking the math! I'm way too tired today to get simple multiplication right. Agreed, still too hot!
  16. Replies
    39
    Views
    2,109

    You are definitely stressing the regulator. A...

    You are definitely stressing the regulator. A linear regulator effectively drops the voltage by converting excess energy into heat (slightly over-simplified).

    Let's say you are pulling 0.25A at 5V...
  17. I think the T4 I2C does not yet support DMA which...

    I think the T4 I2C does not yet support DMA which means, when you are sending large blocks of pixel data, you are blocking the entire CPU while those bytes are very slowly pumped out using the...
  18. Replies
    8
    Views
    744

    16-bit resolution is more that adequate if you...

    16-bit resolution is more that adequate if you use it correctly (i.e it's fine for transport, not always for intermediate math). The extra precision w.r.t. saturation and non-linear processing (i.e....
  19. Replies
    12
    Views
    655

    There are float as well as integer versions of...

    There are float as well as integer versions of most CMSIS functions. There are also DSP functions for converting to/from float. If you've got lots of CPU to spare, that's a good approach. If you...
  20. Replies
    12
    Views
    655

    Representing audio filters as cascaded biquads is...

    Representing audio filters as cascaded biquads is very common. Some google searching will provide lots of examples, and even some online web tools to convert frequency specs into the coefficients for...
  21. Replies
    524
    Views
    73,365

    Normally castellated holes are used for SMD...

    Normally castellated holes are used for SMD soldering a PCB down to another one, but that only works when there are no components on the bottom side, so that unfortunately isn't an option for Teensy....
  22. Replies
    944
    Views
    38,257

    Hey guys, is the USB-C connector for programming...

    Hey guys, is the USB-C connector for programming on the microMod board itself or are those pins brought out the the M.2 connector? Being able to to do our own USB connector on a custom carrier board...
  23. Replies
    3
    Views
    392

    The very short answer is yes, there would be too...

    The very short answer is yes, there would be too much overhead to process audio in blocks of 1 sample at a time, performance would be very poor. There is a direct tradeoff between latency and...
  24. Hi Paul, I've been very interested in this new...

    Hi Paul, I've been very interested in this new feature and the limitations are okay with me. Is there any examples on how to use this with the onboard flash? I couldn't find examples of the following...
  25. If you need even more I/O pins then are broken...

    If you need even more I/O pins then are broken out on the TGA Pro, you can solder wires to directly to any unused pins on the TGA pro socket (the solder joints that are on the opposite side that the...
  26. Replies
    524
    Views
    73,365

    This is very similar to what I need for a high...

    This is very similar to what I need for a high volume product I'm working on. I've been looking at having to spin my own Teensy board because I need:
    - the USB programming interface broken out to a...
  27. Replies
    35
    Views
    2,776

    Hi Edwin, no, I think I made a mistake. My...

    Hi Edwin, no, I think I made a mistake. My previous post was on a phone via email link and I thought the comment was directed at me (misread, my fault = apologies), but I think they were intended for...
  28. Replies
    35
    Views
    2,776

    Hi Edwin, thanks for the feedback. I've tried to...

    Hi Edwin, thanks for the feedback. I've tried to answer all your questions comments below.

    "In the schematic I see failrly low values of capacitors on the outputs of the voltage regulators,...
  29. Replies
    35
    Views
    2,776

    I designed a high-quality, low-noise audio board...

    I designed a high-quality, low-noise audio board for use with guitar and Teensy. The schematic is freely available in the boards documentation. You can use that as a reference.

    Teensy Guitar Audio...
  30. It less likely the noise is getting from the I2C...

    It less likely the noise is getting from the I2C stream into the I2C stream (digitally) due to SW bug. It's probably more likely the noise is coupling from the digital circuits into the analog...
  31. Bumping this again. @Paul Any chance of...

    Bumping this again. @Paul

    Any chance of getting his update permanently added to the Teensy's platform.txt? It's seems it should be low risk, shouldn't break anything and bring it up to date with...
  32. Replies
    8
    Views
    946

    I'm also interested in I2C DMA for T4. I've got...

    I'm also interested in I2C DMA for T4. I've got an I2C OLED that I'm using as a simple display for an audio effect. Driving an I2C display requires pushing a moderate amount of data, but as a result...
  33. Is it the proprietary protocol for a specific...

    Is it the proprietary protocol for a specific product you're asking for?

    I'm not specifically familiar with how those devices are recognised but there are a few possibles, all of them an...
  34. Teensy does have a MIDI library. You would need...

    Teensy does have a MIDI library. You would need to make a board to hold your Teensy and add midi output circuitry (it's not complicated). Make sure you pick a Teensy that will have enough analog...
  35. Replies
    35
    Views
    2,776

    In case anyone is examining the schematic, the...

    In case anyone is examining the schematic, the Teensy actually uses an LDO to generate it's 3.3V, but since that supply is feeding all the digital circuits on the Teensy, the loads induce noise on...
  36. Replies
    3
    Views
    460

    The POG is believed by some to use a standard...

    The POG is believed by some to use a standard vocoder structure, but with quite a bit of secret sauce in how to separately handle transients vs harmonic content and deal with short FFT intervals,...
  37. Replies
    35
    Views
    2,776

    Most guitar pedals don't need to have resilient...

    Most guitar pedals don't need to have resilient power supplies because most have no digital circuits inside them. When powered by batteries, you get lowest PSU noise because batteries have no noise...
  38. Replies
    35
    Views
    2,776

    Ground loops tend to pick up 60Hz hum from the...

    Ground loops tend to pick up 60Hz hum from the mains, lighting, nearby refrigerators, etc. They are less likely to pick up digital interference. Digital interference is picked up by analog wires...
  39. Replies
    21
    Views
    2,677

    Sounds like you aren't linking the proper object...

    Sounds like you aren't linking the proper object files in your project and it can't find the constructor function. I would recommend you try to use the Arduino IDE first, and when you get that...
  40. Replies
    20
    Views
    1,426

    Anyone have issue with adding links to associated...

    Anyone have issue with adding links to associated 'maker boards' that use Teensy Audio Library and supported hardware? There are a number of related community-driven projects on Tindie, codec boards...
  41. I found out personally that Kickstarter is not...

    I found out personally that Kickstarter is not very friendly for international sellers, but I didn't know it had issues with international backers too?
  42. Replies
    35
    Views
    2,776

    I've created a very low-noise Teensy Audio Shield...

    I've created a very low-noise Teensy Audio Shield so I can assure you it can be done. Take a look here for full details, including the schematic: TGA Pro

    For starters with PJRC Audio Board, you...
  43. Yes, can power from your PCB, or via USB but NOT...

    Yes, can power from your PCB, or via USB but NOT at the same time. As long as you never do that you should be fine.

    I also have made a Teensy guitar pedal and while it's not that difficult to get...
  44. Replies
    16
    Views
    1,308

    The SNR of the WM8731 codec is 90dB, but you'll...

    The SNR of the WM8731 codec is 90dB, but you'll never get that in a real guitar circuit. Every component in the entire signal chain add some kind of noise and the CODEC is the lowest source of noise....
  45. Replies
    16
    Views
    1,308

    You didn't mention what you are using it for?...

    You didn't mention what you are using it for? Line-level signals? Guitar signals? Microphone?

    I have a Teensy shield that is optimized for low-noise and guitars but can also used with line level....
  46. Replies
    13
    Views
    966

    Hey Pio, for what it's worth, I think your...

    Hey Pio, for what it's worth, I think your existing approach to floats is the best compromised approach. Using floating point from end to end is wasteful of a lot of computation. 16-bit transport...
  47. Replies
    21
    Views
    2,677

    Looks pretty cool! I'll have to give this a try....

    Looks pretty cool! I'll have to give this a try. What is the processor usage % on the T4?
  48. That TI part you've selected looks pretty good...

    That TI part you've selected looks pretty good based on what you're asking for. Personally, I'm partial to the WM8731, mainly because it's decently priced, comes in a TSSOP package (easier to solder...
  49. Replies
    3
    Views
    611

    If you're going to be using a SPI memory you...

    If you're going to be using a SPI memory you probably want to be using DMA for transfers so that the CPU doesn't waste cycles busy-waiting. However, DMA only helps you if you've got something else...
  50. You might also want to take a look at the TGA Pro...

    You might also want to take a look at the TGA Pro Audio Board. I specifically designed it for handling both line-level or guitar signals and helping out people who don't want to deal with a lot of...
Results 1 to 50 of 322
Page 1 of 7 1 2 3 4