As of today, there are no more OG WTPAs!
The last 20 or so (of 200) took forever to get out the door.
Thanks, everybody, for helping make this happen. Thanks for all the feedback, and for the patience, and for giving me my first less-than-wack experience designing a product.
Hats off,
TB
(Note, there are still lots of benighted and lonely bare PCBs and microcontrollers for the H4RDC0R3)
Oh Snap! There’s the goofy silkscreen I promised last time. But don’t worry, it gets better :-)
So I’ve done my best with the above Still-Life-With-Nerd collage to try and convey, in a meaningful visual way, all the cool stuff that’s happened with WTPA since last week. One really perceptually-difficult-to-convey-yet-great thing is that I’ve put my proper rent-paying clients on hold for the time being to make room for this project full time. It’s scary, but it feels really good! And as rebellion goes I suppose it beats buying a Camaro.
Outside of that, the BOARDS ARE HERE! Sort of.
The bad news is, I found a copper bug (my fault) pretty much right away. With as many hardware revisions as I’ve done this was really embarrassing. It led to a natural dilemma — it was a small bug that could be easily fixed with an exacto knife and some jumper wires, so should I you pass that fix off to you, the kit builder, or should I pony up for an ENTIRE NEW SET of boards so that they’d be perfect?
I debated, then reordered them. This also allowed me to fix a half a dozen little cosmetic and noise-floor / routing things that I wasn’t happy with anyway. I wasn’t nuts about dropping another grand on boards, but I’d be less happy knowing that the final kits were going out half-assed. You can’t pay too much for pride :-)
Silver Lining: This now allows me to sell bare boards, which a ton of people have asked for. Originally I hadn’t planned to do this, but now I can sell the flawed boards (for cheap) with an errata sheet to those among you who are exceptional broke asses and not mess up the math and parts counts for the complete kits. It’s a small consolation, but it’s better than making them drink coasters.
Cosmetically, the boards are flawless! I got a not-quite-perfect board from PCBCart before this (for another job) and let them hear about it, and they bent over backwards to make this one dead-on.
Taiwan Alpha also came through — the pots (all 2000 of them) showed up from China early and perfect.
Then there was Dorkbot which was a blast. Above you can see me in front of a page of C code (looks like the ISR) apparently casting some kind of spell.
People geeked out, I gave away some free PCBs, I laughed, I cried, it was better than Cats.
Finally, social business done, it was back to the Fortress of Solitude with some espresso and a dream. Two great things have come out of this so far:
One:
WTPA now has a banked sample system! This means that instead of holding a loop, WTPA can hold an arbitrary number of loops (theoretically, anyway) and can do anything it is able to do to any or all of those loops independently and all at the same time.
Practically speaking, I’ve pinned that “arbitrary” number at 2 :-). There was a lot that went into this! A huge portion of the code had to be re-written — basically all the audio and memory handling parts. The audio system now grabs data from the ADC and passes it to however many “virtual samplers” for recording, and then sums together whatever output they have before putting it back onto the DAC. Better still, the different banks can use different clock sources! Meaning that you can be triggering events with midi and controlling pitch arbitrarily one one bank, and twiddling knobs and generally being a caveman on the other, with a totally independent samples.
By far the hardest part though was having to wrap my head around implementing a memory manager (ever think you’d have to write malloc? Me neither) which was quite challenging. To be honest, I copped out a little, and it is because of this that WTPA uses only two banks for now.
All this cool functionality also has a totally new (and much more intuitive, I think) menu system. Finally, I’m in the midst of getting rid of “modality” in WTPA so that there’s no such thing as “MIDI mode” and “Manual Mode”. Anything you can do with WTPA you can always just do, without mucking around in a menu.
Two:
I crunched the money numbers! As of today, I know exactly how much all this crap has cost me, and therefore how much these magic beans will cost YOU, dear reader. I’m not spoiling the surprise, but I will say that although I have definitely screwed up some estimates in my time, I was pleasantly surprised with how this one came out. And you should be too.
I’ll keep you all posted on the nerdy revelations better for this last week. Don’t expect total coherence or an Infinite Jest command of grammar, but I got you. Oh, and I think I’m going to LA to talk about WTPA at the end of the month, so if you’re on the West Coast come say hi! More details on that to come.
Xoxoxo,
TMB
These last days of March have been decidedly un-lamb-like. Last week I got in the test boards for the final WTPA and yesterday night I assembled them. They look clean. Nice and small. I did some preliminary testing, but decided to played hookey tonight and bend up this Magick Tuxedo out of ABS. She looks good in black, right?
WTPA makes her first pre-release public debut at Dorkbot Chicago, the first DB meeting in fact since Deadtech closed its doors. I’m honored and excited and also nervous.
The version seen above is a barebones copy of the final version I ordered so I could keep coding with the latest hardware while I was waiting for the real-deal-Hollyfields to come from China, but those crafty fabricators at PCBcart are fast! They’ve already shipped! Expect this cursed soldermask-drought to end and pictures of something with a goofy silkscreen soon.
Unfortunately (???) March has seen an upswing in this whole “Business” thing which I feel obligated to pursue in order to “keep organic peanut butter on the table”, and I’m not as far along on the new audio functions as I’d like. But I’m obligated to have at least some cool new effect (and not just smartly registered MIDI jacks) to show off at the dorkbot meeting, so I’m thinking I’ll work out this granular synthesis thing I sketched out a couple weeks ago. Stay tuned for clips….
xoxoxo, TMB
God, it’s been so long I hardly know what to say. But I believe the big banner above says the most important thing :-)
It is with excitement and not a little trepidation that I am announcing WTPA’s booting out of workbench land and into the hard, cold world.
That’s right: The wait is almost over — the real deal kits WILL BE out for the Bent Festival in New York this April! Not my usual, waffly “soon”. But on a real, fixed, finite date!
That’s exactly one year since the proto came out, and would be embarrassingly slow if the latest WTPA wasn’t head and shoulders better than its forefather. But. Lest you think I’ve been idle, know that since my last post I have done several things:
The first run of kits will number 0-199. This figure made the most sense considering all the number crunching I did, at least for now. The retail price will be announced on or around the release date, but for the curious it will be nestled snugly somewhere between Mssrs Grant and Benjamin.
There may, at some point, be another distributor besides Narrat1ve for this kit, but they will not likely be onboard by the release date. The kit will come BYO-enclosure, although I will probably sell some parts on the site to make it easier for those of you who want a little of the guesswork taken out. The website will (has to, basically) get beautified to accomodate info for the people building the kit, and not so much my gibbering. Finally, on (or right around) the release date, you’ll be able to get ahold of the source, schematics, instructional videos, manual, and theory of operation docs all from right here.
The hot mess you see above is the test pressing of the final WTPA boards (it’s a picture of the gerber files, complements of GEDA’s Gerbv, which (sadly) unlike most of GEDA, totally rules). The real thing gets here Monday for requisite twiddling.
This is the third and last (hopefully) major hardware revision WTPA will go through. The second WTPA totally slayed the first in audio quality, latency, functionality and pretty much everything else. This last rev cleans up the rough spots that were still left on the second rev, and adds a sprinkle of small new features.
Mostly, however, it is the physically smallest and most simplified of the WTPAs to come out yet and is geared to make the kit easier to build and cheaper to sell. There is very little fat left on this design in my opinion.
Technically, WTPA has returned to single-MCU design. Shortly after I made the two-MCU rev I learned about a device called an I/O expander, which is cheaper, simpler, and more robust than a goofy UART link with a second MCU. Shortly after beginning to do battle with the I/O expander I did some much needed forehead-smacking and figured out how to rearrange the databus and replace the whole nasty expander / MCU / mess / with another parallel latch. Which of course was the Right Answer. Pie-simple, cheap, effective.
This WTPA also has its two analog subsystems (the input/output amps and the VCO / CV section) isolated with separate ground planes and ground returns to the main regulator. The last WTPA was not noisy, but I expect this one to be even better. The goofy emitter follower in the front end has been removed. This should result in better audio response, more headroom, and fewer parts.
The jitter generator has been moved into the realm of software. This does a lot for us. Most importantly, it makes the jitter work right (and sound cooler). It also introduces less HF noise onto the board, and further reduces the parts count. Finally it allows the jitter to be controlled by MIDI! This is obviously good for playability reasons, but it’s “orthoganally good” as well because the jitter clock was the only effect left exclusively in the analog domain. Other than the gains, everything on WTPA is now controllable from both the knobs and switches AND the MIDI in.
Finally, all this hardware juggling allowed me to free up a few extra pins which I assigned to a spare UART / SPI module. I have no immediate plans to expand WTPA, but if I ever did, this would be a great way to do it (say, to talk to other instruments or to add an SD card interface or the like).
This all means that the hardware is basically done changing. It also means I’m getting down to the wire on software business, too. WTPA will not go gently into the aforementioned good night — expect to see LOTS of updates here for the next month while I pull all-nighters getting this monster ready for her catwalk. There will be some ugly fixes, a huge rush of features, sample banks, scope traces, the whole nine. Exciting stuff!
And hey, thanks so much for sticking around this long. Xoxoxo.