A Virginia DEF CON community
We haven’t met in a public library since 2019! And here we are.
Gum Spring Library, Meeting Room B, 6:30PM on Monday. Since it’s the evening before Halloween, well, if you feel like a bit of holiday participation, please feel free. This meeting is open to the public, or at least as much public as we have room for. Let’s get to know each other without a strict agenda. But we do expect there will be some badge design discussion.
A while back I made an executive decision regarding my modular collection. I decided that I wanted the setup to be as portable as possible. The problem with that is that the year prior, I had bought a TASCAM DP-24SD. Yep, I had all my modules’ audio outs going to a full-sized mixer. I even had a 16-channel submixer in a 1U rack. I’m not sure what I was thinking, but I had managed to fill every input.
So I picked up the WMD Performance Mixer, just after they decided to cease manufacturing. I loved how I could do effect send and return, lots of out options, cue, and it had plenty of channels. Not as many as the Tascam, of course, but I really don’t need that many.
I sold the DP-24SD, and that left me in a quandary as to how to record my glorious synth grooves that nobody understands but me. I picked up a DP-006 for a really good deal and that seemed fine, except that it’s very cumbersome to use. You have to record to it, then before exporting a song via USB, you have to master it, which takes as long as playing it. Here’s my shitty opinion. If you’re recording on a dated, sub-$100 digital recorder, you probably don’t need on-board mastering.
I used it, frustrated a few times, then realized, holy fuck, I still have a DR-07 that I used to use to record live concerts. Dug it out, recorded a session, straight to MP3, and it transferred over with ease and sounded great. Nice to breath life into that old thing. Other advantages: While the DP-006 inputs are 1/4″ and required adapters to come out of the WMD Performance Mixer, the DR-07’s line in is 1/8″ stereo and I can go direct with no adapters!
So we talked about weird-ass 1.8″ drives, and now let’s look at the other end of the spectrum. Dell has been putting these out on servers lately. I especially like them on the T350 tower server line. There’s a barely-perceptible opening on the faceplate where the carrier bracket slides out.
It’s the BOSS-S2 module. A weirdly engineered, SATA connected M.2 controller. What’s weird about it, you ask? Well, the module has two slots for a pair of M.2 carrier cards mounted in opposite orientations. The module has a built-in RAID controller, which makes it perfect for an OS boot “drive.” A pair of M.2 drives in a RAID 1 configuration makes a great choice, and frees up all your front-panel drives for storage.
One of our members picked up a server for a homelab recently. It was a good deal, an R730XD populated with a decent amount of RAM, two SSDs for OS boot, and eight spinny drives for storage. I helped set it up.
It was ready to party right out of the box, and we installed ESXi on it right away. But the server was outfitted with something I’ve never seen before.
So let’s count the drive bays on this monstrosity. 2x 2.5″ bays in the back (for the boot SSDs) — this is actually a great arrangement in my opinion, to keep them separate from the storage drives. On the front, two rows of four (or is it four columns of two?) totalling 8x 3.5″ drive bays. I like 3.5″ drives for storage, because you can fill it up with the 12Gbps high-capacity SAS drives, and they’re super-affordable.
What’s weird about that? Wait for it…
Above the 8x 3.5″ drive bays are 18x (!?!?!?!?!?) 1.8″ drive bays (?!?!?!?!?!?!). First of all, I’ve been doing this for a minute. What the fuck are 1.8″ drives? They must have gone obsolete as soon as they were released, because I’d never seen them before.
We’ll be meeting at Social House this evening. Trying out a new thing where we offer small custom souvenir collectibles to folks that show up at meetings. Gotta catch ’em all. We’ll see if this takes. It fits well with our upcoming “library tour” plans.
Social House in South Riding, VA. Approximately 1830. Look for the table of nerds.
I’ve found these Lanner 1U network appliances incredibly useful. Nice small factor, lots of network ports to do fun things with. They make fantastic Linux routing appliances. They’re kind of old-school, though, they have these LCD panel modules with four buttons.
I’ve been using them off-label for so long I can’t even remember what the panels were originally for.
See, the first thing I do is connect serial, boot to USB and install something modern on it. Rocky, Ubuntu, whatever.
Last week I went to explore the LCD panels, and see if I could make use of them. Maybe as a periodic status display or something. For the first time in years, I consulted the actual manual for these devices. It turns out, they’re connected to the motherboard internally via an internal parallel port.
The manual suggests using the drivers found at https://github.com/majodu/plcm_drv_v013 but they are so old they’re meant for Linux kernel 3 and below. So the first thing I did was clone the repository. After looking at it for a few minutes I realized I didn’t need everything it was delivering, I just needed the kernel module itself, which is compiled via the “boot” argument. Looking at the Makefile it was pretty clear what the logic was in “boot:”
boot:
ifeq ($(KVER3),3)
$(MAKE) -C $(KDIR) M=$(PWD) modules
endif
ifeq ($(KVER),2.6)
$(MAKE) -C $(KDIR) M=$(PWD) modules
endif
ifeq ($(KVER),2.4)
$(CC) $(MODCFLAGS) -c plcm_drv.c
endifSo the first thing I did, since my installed platform used kernel 5, was change the KVERS3 line to ifeq ($(KVER3),5) so that it would run the make on my kernel.
I was able to compile the kernel module. It barked at something else it was trying to install, but since all I really needed was the test executable and the kernel module for now, I ignored that.
Then I ran into an issue loading the newly-created kernel module. It didn’t like the major number associated with the driver, 248. Looking at /proc/devices I could see that 248 was in use by ptp, so I edited the Makefile and plcm_drv.c to use 239 instead, since that was available. I recompiled, and was able to load that kernel module just fine. After that, the plcm_test executable successfully ran and displayed stuff on the LCD panel and accepted button presses.
Good enough for now, at least I know I can write something in C to display something and receive button presses. Now to think through a good use case for this silly hoop I just jumped through…
I’ve been mucking around with synthesizers and sound for decades. Still, when I broke out of semimodular into full modular, there was still a missing piece of the puzzle.
The first modules I got were somewhat complete, with a gate or trigger in and audio outs, sometimes both left and right. It wasn’t until I got my first “pure oscillator” style module, which happened to be Castor & Pollux, that I scratched my head, realizing I had descended into the next level of the rabbit hole of synthesizer deconstruction. The module had no gate in, just CV controls for pitch and PWM. There are audio outs for Castor, Pollux, and Mix, and outs for the different waves. So I had to quickly learn how to shape sound in the modular world.
I learned that what I was looking for was an ADSR and a VCA. The ADSR shapes the envelope, and that envelope goes into the CV level control of the VCA alongside the audio, and shapes the audio to match the selected ADSR.
Being (a) a beginner, (b) cheap, and (c) simple, I quickly settled on a combined module, the WMD ADSRVCA. It’s got a gate in, audio in, audio out to make the simplest connection with the least patching. Patch audio to IN, patch a gate signal to GATE, and OUT to my mixer, and bam. I have tamed my Castor & Pollux. I can shape the sound with the ADSR knobs.
I quickly realized I would need more of these. First of all, there are two signals in Castor & Pollux. I’ll want to shape both of them, perhaps differently.
Holy crap, this is going to be expensive and take up a lot of space.
Next I latched on the Doepfer A142-2, a dual env-controlled VCA. Most of the benefits of the ADSRVCA, but for two channels, and with the added flexibility that both can be triggered by single gate. And for not much more HP. LOVE IT.
Also, it keeps me from the complication of buying separate ADSRs and VCAs and patching them together. LOL, I save money on patch cables, right?
Well, it works. And it works great. But to be honest, the A142-2 doesn’t shape with as much granularity as the ADSRVCA. I’m spoiled now, because the ADSRVCA is the first, and how is anything going to live up to that.
To me, the whole envelope thing is one of the most confusing aspects of getting started in modular. Not every oscillator module has a gate in. Hell, they don’t even all have a CV-controllable level into which you could pipe an ADSR in. Us newer modular folks are definitely spoiled, because so many of them are usable as standalone modules with gate and already-shaped sounds that we get used to that, and it’s almost a surprise when you get something like the 4ms ensemble and go “shit, I need another envelope or two.”
You quickly find that it gets complicated and expensive to add more. There don’t seem to be any good, dense solutions available. I’m looking at the After Later QARV next.
| Module | ADSR/VCA channels | HP | Price | Notes |
| WMD ADSRVCA | 1 | 6 | 160? | Discontinued |
| Doepfer A142-2 | 2 | 8 | 120 used | |
| After Later QARV | 4 | 20 | 224 |
The main complaint about the QARV seems to be knob density vs playability. This is how schizophrenic we are in modular. We want rack density, but then it makes it hard to fit our fat fingers in there and twiddle the knobs. Also we blow up our power supplies.
On the one hand, I’m sad that WMD shut down. If they hadn’t, those ADSRVCAs might be more affordable and I could just get more of those. On the other hand, I think quality ADSR/VCA combos are a relatively untapped market, and the hardware person that gets it right could make TENS OF DOLLARS.
I’m still new at this. While I’m technically aware that I can detangle envelopes from VCAs and use them to shape other things, I haven’t run into a real use case for that yet. Until then, I’ll keep twiddling and blowing my kids’ inheritance on pieces of synths, eventually resulting in a $20,000 synth setup that sounds almost as good as a $3,000 commercial synth.
What the fuck is wrong with me?
Update: There is also a somewhat tempting option by BASTL, the SKIS II, a dual ADSR VCA in a 5HP footprint. The downside? The only knobs are for Decay. Interestingly, it looks like it can be switched between linear or exponential decay, and between gate and trigger mode, by jumpers on the back.
The HP is right (5), and the price is right ($118).
UPDATE: I picked up a BASTL Skis II. It arrived today, and it works just fine for what I’m doing with it. I piped the two outputs from 4ms Ensemble into the two inputs on BASTL, then took two channels from Pamela’s New Workout, each at 8x with RSKIP set to 59, set the decay up around 2:00, and the signals offset and fade into each other quite nicely. Plus I got the BASTL for just $100.
The current plan is to meet in the basement again on Monday 4/10 in the usual 1830 timeframe. If you’ve been there before, you’re welcome to join us again.
We’ll be in person on Monday, for the first time in a while. 1830 eastern time, at Social House in Chantilly.
Come visit, even if it’s your first time. We don’t bite, and we’re tolerant of most flavors of weirdos.
I managed to shrink a whole bunch of data into a single-page, semi-coherent dashboard. The only thing not automated on this whole thing is weight. I have my Withings scale communicating with Health Mate which is tied to Google Fit, and Oura is supposed to swing with Google Fit, but that intermittent weight data isn’t it making it into Oura. So I’m using the “Tags” feature fo the Oura app to enter my weight every morning, and my script recognizes the data type and inserts a MySQL row for it. I have less than 30 days of data at this point. I can’t wait to see what 90 days or even a year looks like. I’ll probably be making these graphs even more pretty and useful as my time and experience with Grafana increases. A week ago was the first time I touched it.
