Puffin Firmware V1.20

Changes:

  • Added Magic pop and click minimizer
  • Added Grade which is a record grading function
  • Added DeRumble function (200Hz/12dB)
  • Added RoomEQ function (de-mud cut filter: -6dB Q=2.6 at preset frequencies)
  • Added new clip alerts with asterisk * at Volume (output/DAC clip) & Gain (input/ADC clip)
  • Doubled the Volume settings with finer adj resolution
  • Changed TF to fx. Think like "effects" or f(x)
  • Lowered 2H Tube distortion (7%THD at full signal)
  • Fixed 3H Tape distortion (3.5%THD at full signal)
  • Removed "2H&3H" setting from fx
  • Moved Noise to fx (PinkNoise)
  • Updated Levels to include tenths dB resolution for azimuth adjustment
  • Added Out function and merged SPDIF code, though Out:SPDIF is disabled on non-modded Puffins
  • Lo filter changes: 5Hz, 10Hz, 15Hz, 20Hz, 25Hz (default), 30Hz, 35Hz, 40Hz, 45Hz, 50Hz, 70Hz, 100Hz, 200Hz, & 400Hz
  • FPU stack memory bug fixed. Possibly have caused intermittent "no sound from Puffin" when changing settings and goes back to V1.10

    Puffin User Manual V1.20

    Magic: Removes a lot of crud from your vinyl. But doesn't whack it over the head with processing either. The goal is a simple control that is On or Off. I've tried to make it very gentle and non-digital sounding, and actually used an analog-like technique. This is intended to be used all the time and makes your best LPs sound better. Like they're extra clean. Scratched up records will receive some help, but don't demo Magic using them - use the good stuff.

    Grade: Use this to grade your records - either to sort out dupes or find which records may need to be upgraded. Turn Grade on after the music fades in and turn off just as the music fades out. This cuts out all the noise in the beginning and runout grooves which affect the grade. Uses the American Grading System: A+, A, A-, ... D-, F. So you grade each side. Note that Grade is unaffected by Magic (i.e. grades it without the Magic corrections).

    DeRumble is a true rumble filter using the Macaulay Method of summing the low bass to eliminate out-of-phase vertical rumble from the turntable.

    RoomEQ compensates for the room's main resonance that ends up muddying the bass. Just roll with 300Hz or use a free octave RTA on your phone and the Puffin's fx:PinkNoise to find where it is located in your listening space. The RTA apps usually have peak search on as default, so couldn't be easier. I staggered OFFs between the different frequencies (200Hz to 400Hz) so that you could switch back and forth (before and after).

    Clip detection: this is an asterisk that shows up at Volume and Gain. Definitely adjust Gain down if clipping as you are over-driving the input. Occasional clips at the DAC (Volume) are less of an issue as they are software handled.

    TF fixes: Wow - I really screwed up the harmonic functions in the previous release. I had a semi-bad bug in the harmonic code with versions 1.04 and earlier, but the fix in V1.11 I caused the 2H code to be much more aggressive and the 3H code to not work properly at all. Should be good now.

    The code is unified now, so this will work with either a regular Puffin or a SPDIF modded Puffin.

    My general thoughts: Magic is fantastic but reminds me of anti-lock brakes. You turn it on and forget about it. It's only when you turn it off that you cringe and turn it back on. Grading, on the other hand, is an active feature - even a game of sorts - that you interact with. I really, really, love grading my records. When it tells me that my copy of Led Zep III is an F (and I kind of assumed it was), it gives me permission to get a new copy. And you can use it to test your cleaning methods, too.


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    How to Update the Puffin's Firmware

    Using the supplied allen key and USB cable, the Puffin can be updated via an internal micro USB header with either a Windows or macOS system.Note that updating your firmware will erase old settings saved in the Puffin's memory, so write down any current settings that may help you set up after flashing the new firmware.


    Windows Method:

    Note: Skip step 2 for recurring firmware updates (i.e. you only do this step once).

    1. Download and unzip the latest Puffin firmware: Firmware V1.20

    2. Download and unzip puffin.zip from the website: http://www.parksaudiollc.com/puffin.zip
    3. Then unzip puffin.zip and run "STM32 ST-LINK Utility v4.2.0 setup". This installs the programming software in your program list and also loads the USB driver.

    4. Unscrew the four corner screws on the Puffin top plate. This requires a 5/64" Hex Driver or Allen Wrench (supplied with Puffin).
    5. Connect USB cable (supplied with Puffin) to Windows computer. Connect USB-Micro connector to Puffin board - connector has sticker marked L432KC. No power is needed as it is powered via USB.
    6. Run the STM32 ST-LINK Utility from your program list or Desktop shortcut (ie the program, not the installer again).
      1. Select Target>Erase Chip.
      2. Select Target>Program & Verify and choose "V120.hex" (located in Downloads folder or where unzipped).
      3. Select Start.
    7. The Puffin has been upgraded after "Verification...OK". The green LED will continue to blink, but programming is finished and disconnecting the USB cable is OK. You'll need to disconnect all power (USB as well as the 12V DC if you had it plugged in) to exit programming mode as the power button will not turn the unit on while in programming mode. Place the Puffin back into the chassis and you can then verify that the firmware flashed correctly by plugging in the 12V DC power and noting the firmware splash screen at startup. Then disconnect the 12V DC power and screw in the four main screws.

    macOS (10.11 & higher) Method:

    Note: Skip steps 3 & 4 for recurring firmware updates (i.e. you only do these steps once).

    1. Download and unzip the latest Puffin firmware: Firmware V1.20

    2. Start the Terminal app using either of the following methods:
           a. Press Command+Space and type Terminal and press return key.
           or
           b. Finder>Applications>Utilities>Terminal. Double-click on Terminal.

    3. Cut-n-paste (Command+C then Command+V) the following highlighted text into the Terminal app:
      /bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install.sh)"
      and press return key.
      If the screen prompts you to enter a password, please enter your Mac's user password to continue. When you type the password, it won't be displayed on screen, so just type your password and press return key. Then wait for the command to finish.
      This step installs Homebrew: a macOS installer package. This permits loading the update software and USB drivers in the next step.

    4. Cut-n-paste the following and run in the Terminal app:
      brew install http://www.parksaudiollc.com/stlink.rb
    5. Unscrew the four corner screws on the Puffin top plate. This requires a 5/64" Hex Driver or Allen Wrench (supplied with Puffin).
    6. Connect USB cable (supplied with Puffin) to Mac. Connect USB-Micro connector to Puffin board - connector has sticker marked L432KC. No power is needed as it is powered via USB.
    7. Cut-n-paste the following text and run in the Terminal app (note: change the word Downloads to Documents or Desktop if you moved the hex file after downloading.:
      st-flash --format ihex write ~/Downloads/V120.hex

    8. The software should say "Flash written and verified! jolly good!" if the Puffin has been upgraded. You'll need to disconnect all power (USB as well as the 12V DC if you had it plugged in) to exit programming mode as the power button will not turn the unit on while in programming mode. Place the Puffin back into the chassis and you can then verify that the firmware flashed correctly by plugging in the 12V DC power and noting the firmware splash screen at startup. Then disconnect the 12V DC power and screw in the four main screws.

    Rev history:

    V1.00
    5/16/2018
    Initial release. SP

    V1.01
    6/8/2018
    Added flash saves at Set?>OFF, Set?>LOAD, Set?>SAVE, and main menu Gain change. Moved phase polarity to pre-DSP so we can get 2H cancellation. SP

    V1.02
    6/15/2018
    Fixed Load setting bug where 200 ohms setting could be overwritten to 47k. SP

    V1.03
    8/25/2018
    Screen refresh timer was active during standby sleep. Would cause faint flicker on LCD if Puffin turned off with main menu set to Set? or Signal Levels. SP 

    V1.04
    2/11/2019
    Added immunity to static electricity discharge that could put unit into Standby state. SP

    V1.10
    8/18/2019
    Changes:
    -Added adjustable RIAA eq function
    -Added adaptive Bass Boost
    -Added Pink Noise for Room EQ
    -Added Null to Phase controls
    -DSP code re-written for speed in assembly SP

    V1.11
    8/29/2019
    Fixed Tube 2H function. Right channel had bug which could add extra non-2nd harmonic distortion. SP

    V1.13
    4/18/2020
    Saved FPU registers to stack during DSP interrupt that could have caused "no sound from Puffin" when adjusting menu.
    Adjusted Tube 2H and Tape 3H constants for much less distortion. SP

    V1.20
    5/26/2020
    Changes:
    -Added Magic pop and click minimizer
    -Added Grade which is a record grading function
    -Added DeRumble
    -Added RoomEQ
    -Added new clip alerts with asterisk * at
    Volume (output/DAC clip) & Gain (input/ADC clip)
    -Changed TF to fx: think Effects or f(x)
    -Lowered 2H Tube distortion (7%THD at full signal)
    -Fixed 3H Tape distortion (3.5%THD at full signal)
    -Removed 2H&3H from fx
    -Added Out function & merged with SPDIF branch
    but Out:SPDIF is disabled on non-modded Puffins
    -Fixed FPU memory stack bug
    -General bug fixes and tweaks
    -Added many new Lo filters SP