WTPA 2.0 date



  • Finished updating the MIDI functions to allow access to SD card related playback.
    WTPA has three-channel MIDI controlled polyphony now -- the two sample banks in RAM, plus simple MPC-style playback streaming direct from the SD card.

    So you can now sequence drum beats or the like from the SD card while messing with live samples on two separate banks.

    ...Also, with that, I am done with all code for the first release of WTPA2.
    I'm getting a cup of coffee then I'm going to start writing the manuals.

    It really looks like this will get out the door in 2014, and sooner rather than later. I'm excited. Hope you long-suffering bunch are too.

  • "Good things come to those who wait"

    I knew this was going to be worth waiting for

    So Todd, have your self a nice cup of that "Gourmet shit" that Jimmie has in Pulp Fiction

    In the meantime I have been using this 8 bit, 9 kHz sampler for the ZX Spectrum
    I made a demo of it here, and made the preset samples available on my site

  • Moly moly. Saw an update on twitter so decided to stick my head back in here and see what's up.

    Once this is finally out, I think I will have to buy/build one to accompany my oldschool WTPA1, even if I'm more a laptop boy nowadays.
  • Any Update?
    Should we heat up the soldering Iron?
  • http://i40.tinypic.com/2mxluyq.gif
  • Yes. Two noteworthy updates.

    First, there's one fewer WTPA2 trophy t-shirt out there, the sample packer has been ported to Python, so you should be able to use it easily from a Mac, Windows, or Linux machine.
    Second, the operations manual is done! Here it is. There's still time to give feedback, so feel free to comment and help a brother out before the release!



  • We in there.
  • OK, how about this: would it be possible/useful in the SD card menu to have two different buttons for each loading samples to/from banks? So button 1 would load the current SD to Bank 0 and button 2 would load the current SD to Bank 1. Buttons 3/4 would suck down the sample in Bank 0/1 RAM to the SD. It might be useful, maybe semi-trivial, possibly impossible. Just tossing it out there.
  • Also, there doesn't seem to be a lot of info about the SD bank in this here manual. I remember some post where duophony ("power chords, yo") was mentioned. Is that still the case? Page niner says the banks are monophonic. Say it ain't so. So you load the sample and then MIDI notes received will play it duophonically with some sort of note stealing routine? Or does the SD bank act like the DPCM mode where it's like a drum sampler and notes in correspond with MIDI notes? Or is it strictly one shot, one kill like the Man With the Golden Gun?
  • >OK, how about this: would it be possible/useful in the SD card menu to have two different buttons for each loading samples to/from banks? So button 1 would load the current SD to Bank 0 and button 2 would load the current SD to Bank 1. Buttons 3/4 would suck down the sample in Bank 0/1 RAM to the SD. It might be useful, maybe semi-trivial, possibly impossible. Just tossing it out there. >>>

    Id say just have the samples work as is, but if shift is held it will perform the operation on the opposite bank. So bank 1 is selected, hit shift and one, and it then loads the sample to bank 0

    We dont really need more than one exit combo.
  • Todd do you have a (preliminary) BOM to share already?
  • You guys are the best.

    @bleo @herrprof --
    Re: SD loading/saving
    Good ideas. I'll play with the interface and make it so you can access banks 0 and 1 from the SD card menu in some easy way.
    There are plenty of buttons left and the code is easy to implement.
    This will also allow you to quickly "copy" a sample from one bank to the other which is oft-requested but there wasn't really a good way to do it before now.

    There's an "exit combo" from DPCM mode, and that same combo is PANIC in normal mode, which removes all effects.
    In the SD card menu, any button (or combination of them) that isn't already assigned will exit the menu.

    I do have a BOM around somewhere. It'll be in the assembly instructions which are the last time-consuming thing I need to make.
  • @glitched
    Word. Good to see you here again.
  • edited December 2014
    if you bomb out of dpcm mode, you are probably in some stripped down version of the classic os where you cant write/read to the sd card until you reboot with a formatted card right?

    In DPCM mode can you use the ram live sampling features or is strictly a dpcm sample player? Whats the DPCM mode polyphony?

    Is streaming normal samples from the sd card monophonic, and if you try to play another via midi it will choke the currently playing sample? I can see instances where it would be cool to play duphonically with power chords with the same sample, with different ones, or even unison with the same or different samples layered.

    And to second bleo did the mode where you play a two note chord in bank 0 and steal a voice from bank 1 make it to the release version?
  • @herrprof (from Twitter)
    @peterswimm There isn't really a max sample rate. The VCO only goes up to 30-something kHz although you could tweak it to be different if you wanted to.
    Recording from MIDI you could probably set the sample rate to be really high.

    Max length, of any sample, is 512k. The SD card samples must be compatible with the ones in RAM so they're capped at 512k.

    Come to think of it, I'm not sure how I handled trying to load two incompatibly large samples into the two separate RAM banks. Guess we'll find out.

    It would be possible, although a PITA, to make a different sample concept which streamed arbitrary length samples from the SD card. You'd probably only be able to load those with the packer.

    No packer screenshots yet. Dooley ported some of the packers (thanks!) to Python already, so they'll look different than mine. It would just be confusing now. Besides, it's a command line tool. They all kinda look the same.
  • Actually, why the hell not.
    Here's what the packer looks like as of now:


    Because GUIs were the beginning of the end.
  • edited December 2014
    Just found the post where I said I implemented BANKs stealing each others' cycles for duophonic playback.
    I totally forgot about that. I'll look in the code. Not sure if it made it or not. I pretty much re-wrote the sample engine so it might not have.

    You can always play power chords with two banks.

    The right way to do it (in MIDI mode) would be to make a bank polyphonic so you could play chords with the same sample in one bank. Which would, admittedly, be awesome.
    But it would be significant change to the sample engine.

    Might have to wait until WTPA3. Lemme check though.

  • @herrprof
    Exiting from DPCM mode reboots the WTPA2.
    If you bomb out of DPCM mode and you keep the DPCM card in the slot, you'll jump right back into DPCM mode once WTPA2 recognizes the card.

    You'll go back to sampler mode if you pull the card and reboot or pull the card and put in a "proper" sample card.
  • ah so it isn't really exiting dpcm, its more a soft reboot....

    I always imagined very large samples would be only loaded with the packer, but hadn't considered what would happen if you tried to load bigguns.

    My sample rate question was more for midi re: the max sample rate... but I guess its just a matter of math and time...

    You can always assign the two sample banks to the same channel right? Maybe you can have a special case that if this is configured like this, it will play sample bank 1 when 0 receives another note? Toggle-able in case some one wants to be two osc sample synth guy.
  • OK, so just for clarification: MIDI in for SD streaming is monophonic and melodic (not drum mapped like DPCM)? Basically like an sk-1 with a 10 year's old voice saying "fart" mapped to a keyboard?

    Also, I have some free time ahead of me the next few nights if you need some more beta banging. :D
  • damn. reading that manual made me really excited
  • So this "WTPA2 can also take a control voltage input for the master sample rate VCO, and can be interfaced to modular synthesizers" means that the CV In will control the pitch (I'm assuming more in a 'wacky vibrato' kind of way, rather than a 1V/Octave kind of way) of sample playback, right?
  • Long time reader (hehe), first time caller.

    Will it be possible to control the CV input of the VCO with Hz/V ala the MS-20? Also, would you still consider WTPA2 "circuit bender friendly?" I read the current iteration of the manual and see no mention of circuit bending the device.

  • @herrprof --
    There's probably a way to do it, but it will take some messing around.

    MIDI SD card playback is "drum mapped" NOTE ON for Note 0 plays the sample in slot 0. They aren't pitched.
    And I'll post a zip tomorrow so anybody with WTPA2 hardware can beta test.

    CV controls the pitch, yes.
    Currently, sadly, the pitch is nothing even close to 1v/oct.
    Wish I had thought to do that. The eurorack version will have it :-)

    Any old voltage can control the WTPA2 -- so yes. However, Hz/V and V/octave are both scaling factors. WTPA2 doesn't really have a scaling factor, so you won't get any kind of "equal temperament".
    And yes, WTPA2 is circuit bender friendly! If anything, friendlier than WTPA1 -- the chips are less exotic.
  • Funk yes.
  • So, furthering the clarification, the loaded banks can be played chromatically/melodically via MIDI (even though the SD card sample cannot), correct?

    That's cool about the CV. I'd be happy to play notes via MIDI and just use the CV as a frequency modulation input. Or yeah, just save me some space and make that Euro version!;)
  • @prickly--
    That's correct.

    Do you think people would really want a euro version?
  • Also, as promised --
    Here's the firmware for anybody capable of beta testing (there are a couple of you, I think):


    Give 'em hell!
  • @ToddBailey

    Yeah, you can guarantee someone will convert it to eurorack whether you expect it or not. Modular gear is very popular, especially eurorack. One possibility is resellers wanting to purchase your kits to sell to modular users if the conversion were easy enough.
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