Archive for the ‘diy’ Category

mod report: oktava mk-012/mc-012 microphone

Oktava has some great microphone designs. But the quality of the components can be pretty random, particularly in the used market, since a nontrival number of those were made in the early post-Soviet era. My two 012s sounded pretty different – one in particular rather unpleasantly harsh – so I implemented Recording Magazine’s recommended component upgrade* on the harsh one, which we’ll call Nr. 1.

Nr. 1 may have been modded a bit before. It’s certainly been opened before; one of the three screws was stripped and useless, the other was jammed badly. I had to drill both out, so I’m hoping I can order replacements. The third was fine.

As soon as I had the microphone open, I saw what Recording meant by random components. The key transistor was a make so old that it had a metal shield ground cap, and separate lead to that cap, something I haven’t seen in gear made after about, I don’t even know, 1978? I also saw what they meant by “fragile circuit board,” because wow, you could lift these circuit board traces with an overly-aggressive hair dryer. Take care!


Comrade!

Still, it was mostly a matter of being methodical and not rushing things, and in good time, I had the key components upgraded, with no surprises other than the transistor’s extra lead.

These are three unmodified before/after snippets in one recording – recorded under identical conditions other than the internal microphone electronics – of Oktava mk-012/mc-012 nr. 1 in my studio. Even on laptop speakers, I can hear the harshness, particularly in the first sample. In all cases, it’s pre-modification first, then post-modification after:

Oktava MC-012 nr. 2 sounded very different to nr. 1, before; opening it, I could see that the components used were of a significantly more modern variety. It may well have been made later, which would be part of that. Now, the two microphones sound much more like each other, indicating that nr. 1 really was meaningfully different in component quality.

Here is a recorded comparison of nr. 2 (still factory) and nr. 1 (upgraded). These recordings were made simultaneously, with the two microphones right next to each other. The differences are much subtler, but I think the upgraded nr. 1 has a bit more presence – or maybe sense of stage – than the factory nr. 2. Despite being mono recordings, it’s almost like there’s a slightly better stereo image in the modified nr. 1… but give a listen and hear for yourself, see what you think.

You’ll definitely need headphones to have any chance of hearing anything interesting here. Factory nr. 2 comes first in all cases:

So, all in all, very glad I did this to nr. 1; pretty sure I’m going to go ahead and do it with nr. 2 as well, though I expect a much less dramatic change.

The only thing I’m thinking about now is – there’s a bank of capacitors in back. They’re good ones – Philips, not generic, which have a good durability and spec-compliance record. (I don’t know whether they’re original; some Oktava 012s shipped with quality caps already in place, and their track record has improved with time.) So I shouldn’t need to upgrade them – and the article at Recording Magazine says not to bother if you already have “improved” capacitors.

But I don’t know how old these are, and electrolytics have a lifespan. That’s measured both in calendar time (years), and in use – tho’ the latter is in tens of thousands of hours, and these mics are certainly nowhere near that.

The small downside is time spent, the large downside is the possibility of circuit board damage, which wow I don’t want. The upsides would be 1. possible sound improvement if they are aging already, and 2. Never having to think about it again, in practical terms.

So I dunno. Get it out of the way, or leave sleeping caps lie? Hm.
 
 


*: errata for the linked article: Capacitor “C6” in the parts list is actually capacitor C1; there is no “C6” in the build description or circuit diagramme; I assume this is a typo.

Also, some of the items in their parts list are no longer made, but they have exact replacements. R1/R2 exact replacement part number as per my October 2016 Digi-Key invoice: MOX200J-1000ME-ND. Capacitor C1 (listed as “C6” in parts list, see previous paragraph) current part number: 445-4737-ND. Capacitor C2 current part number: 399-1418-ND. Capacitors C3 and C4: 4073PHCT-ND. Capacitor C5: 4047PHCT-ND. Mostly, the substitutions are lead-free versions replacing earlier versions with lead.

hard, hard candy

I made a thing! It’s called a focus knob. It’s quite simple and normally you’d built it into an electric guitar as a guitar mod, but since I don’t have an electric guitar, I built it as a pluggable external box.

Basically a mild high-pass filter that serves to pull out ‘boominess’ from instruments, it puts a bit more of an edge on an instrument’s sound – the more you turn it up, the greater the change. As effects go – on my zouk, anyway – it’s pretty subtle. But it’s also the kind of shift that is multiplied by later effects added in, and changes how later-in-chain boxes like distortion pedals work.

As you can see from the instructions here, the wiring takes all of about 20 minutes’ time. But it’s good warmup for making a bunch of component upgrades to my Oktava 012s, and I already had all the parts from the Great Radio Shack Lootfest of 2014. Plus, hey, cool hard candy tin!

So I have a a HARD CANDY knob now. It goes from Hard to Candy. Yum. 😀

This Is Neat: the Collidoscope

Several months ago, I saw online a prototype of a sampling synth with waveform editing and a uniquely cool physical user interface. I don’t remember whether I blogged about it at the time or not, but I certainly talked about it on social media and such.

It’s not so much that it does anything you can’t already do; you can do everything it’s doing with a modern digital audio workstation, for example. But the physicality of the interface looked delightful, and that sort of thing really, really matters in instruments. Including synths. It made sample synths look fun to play in a new dimension – one far more instrument-like than I’d seen before.


Collidoscpe v2

I wondered at the time if they were looking for a commercial application, to build them to sell. But if they were, they’ve ditched that: it’s gone open-source. Not just source code for the software, but instructions and 3D CAD files if you want to build one yourself to their physical specs.

Admittedly, the case-build instructions are… a tad sparse. But that’s half the fun, right? Component-wise, it’s basically a cakewalk. (Silly me thought the waveform display was some fancy custom thing HAHAHAHAHAHA NO IT’S A STANDARD LCD MONITOR BEHIND A FRAME HAHAHAHAHA etc. But that’s the smart way, so.)

Anyway, yeah! Project!

h/t: Klopfenpop for the link

not so bad after all

Well, that was neat – the “warmup” storm was the big one, the big one swerved north at the last minute and weakened, mostly missing us, and then surprise-collapsing over Victoria. Still, we did lose power and were offline most of a day, so if you missed Friday’s post about recovering damaged recordings – a bit of a geek-out, really – that’s what happened.

I took advantage of the unexpected uptime to finish up that project, by the way. It was interesting, and I learned stuff, like usual. The condition of the tape (and damage in the recording) varied all over the place, and arguably too much even to try to split it up into a million shards. Though there was a lot of this kind of crap:


This is one phrase of lyrics

That’s a combined automation of level and compression ratio. Here’s what it looked like over a larger area, about 3/4 of the way through. Yes, meaningfully more got added to this:

And the sad thing is, that’s just me trying to attain listenability throughout. I’m not trying for “good” – that isn’t attainable, but less noise and less distortion and fixing dynamics over time, that I can do.

Some of the tape wasn’t really that bad! I mean, it’s a 23-year-old cassette recording made on some sort of portable device set on what sounds like two different autolevelling schemes – it changes once when the recording was stopped briefly, I suspect the operator changed modes and I really wish they hadn’t – so “not really that bad” comes with a lot of caveats. But still, not that bad. Lots of hiss, lots of tape rumble, small dropouts, and so on, but not unintelligible. Fatiguing to listen to over time.

Here’s a short sample of “The Crawl,” early on, direct from the tape. Hissy, some sort of mid-band distortion that isn’t too bad in short doses (but really gets annoying over time), off-centre sound placement. But otherwise not that bad. You can hear stuff.

So I ripped the hiss off, did some work to improve dynamics, pulled out what I could of the distortion, threw on EQ to bring back out the low end, re-centred and smoothed it a bit, and here y’are.

Then there are other sections. After that mode switch got thrown, the whole recording got weirder. “The Profiteers” was particularly bad. Here’s the original. I know the lyrics and I still can’t make them all out here. But I can in the restoration. It’s not good, but you can make things out. This is where I needed that whole stack of plugins I talked about on Friday.

And just as importantly – and something short samples like the above won’t give you – it’s listenable over time. Some of these problems are really hard to tolerate over the two hours of this recording. They’re not bad in short doses, but they grate.

Like, the original seems to have more high end, right? But it’s not real. Eventually your brain figures out it’s just hiss, with your audio centre filling shapes into it, and it’s wearying. In short comparisons, the brightness is attractive, and the restored version sounds kind of dull in contrast at first – but as with light, your ears adjust to recordings, and that goes away with listening.

Similar are all the damn-autolevel-to-hell level changes. They’re not necessarily so bad in short doses – some of those are like punches to the face, but most aren’t. But even with that, EVERYTHING REALLY LOUD PUNCTUATED BY surprise underlevelling is also wearying.

So the restoration maybe doesn’t sound good, on any kind of normal scale – but I got it to the point where, particularly on laptop speakers, it sounds pretty okay. I can listen to it. Occasionally – just occasionally – it even sounds musical. And there’s enough there there to remind me how much I miss this Great Big Sea.

There was one thing I couldn’t fix though, no matter how I tried. And that’s during “Excursion Around the Bay,” wherein early in the song, some fucker orders espresso at a George Street bar. And so you get that espresso machine foam blast noise right in the middle of a verse.

WHAT. THE. FUCK. YOU WANT COFFEE, GO TO STARBUCKS.

Gods damn you, espresso man – gods damn you.

visual artists do this all the time, why not musicians?

Lots of artists (including a few I follow) livestream their drawing sometimes, usually showing their desktops so you can see what they’re working on. A fair number of them do this on Picarto, which is pretty visual arts focused, but says it’s for creators in general.

So I decided hey, maybe music? And they even have a category for it. Yay! And I’ve set up an account here on Picarto, and will stream sometimes, probably announcing on Tumblr and Facebook on the band page.

I’ve only tested it once and it was a little weird but I think it worked most of the time? The wifi in the part of the studio where I have to put the laptop is a little wonky tho’, and it cut out at least once. If people come by I’ll work on fixing that.

It’ll mostly be rehearsals/practice but might occasionally be me mixing something or writing something. I dunno! I’ll probably turn it on later today, I completely upended my planned VCON set and I’ll want to try that out this afternoon. And I’ll check the chat window every so often, too.

edge cases of the apple ios ecosystem: musicians

So the new iPhone is out, and as predicted, it does away with the standard, unencumbered, unrestricted-by-patent 3.5mm audio connector. You can read about the release on BuzzFeed’s pretty decent writeup if you like. And this matters, even if you have an older phone, or an Android phone, because Apple is the kind of 10,000-pound-gorilla that can shape markets in this area. Even if you’re not an Apple user, this throws expectations around for the future.

There is an adaptor – really, a mini-interface-card disguised as a cable adaptor – to let you use 3.5mm devices with the lightning port. It has to contain a D/A converter and a small amplifier. One will be included with the new phones, and it costs $9 and doesn’t make your cable weird – it’s not some big block like the previous 30-pin to Lighting interface, and it’s not $30.

I have concerns about how good a job a $9-retail D/A converter and amp unit is doing to do at rendering quality audio. It will be very tempting to make it deliver “meh” quality output, and push people to new gear. That’s short-sighted, but let’s not pretend that stops anyone.

Countering that concern is the fact that at least at one point, Apple required a specific D/A converter for the Lightning audio standard: this one. I have no idea whether that’s still a requirement. But if it is, I’m willing to assume a baseline of competence for it – anything else would’ve been suicidal for the spec right out the gate.

I’ve heard a lot of people talking about whether the new interface is built for digital rights management (DRM) as the long goal. I genuinely don’t think so, because it doesn’t really add much capability they don’t already have. Sooner or later, you have to go to analogue, and unless they want to remove the capability to connect to high-end audio equipment – and Bluetooth does not cut it for audiophiles, or necessarily even mid-philes – there has to be a way to hook up to standard, not-Apple gear.

You can’t get around that. Lest people forget, an Apple-provided solution for this already exists in the form of the dock – shown on the iPhone 7 front page, too. It’s not going away. And the reason it won’t go away is that while audiophiles are not a big market, they are exactly the kind of lifestyle market Apple wants and needs in order to support its brand, and more importantly, its markup. That’s not tech; that’s image management. Even without Steve, Apple knows its image.

Similarly, they can’t cut off concert musicians and DJs from plain old analogue output. There are too many audio pros out there using phones now, and while that market isn’t actually large, it’s a market Apple still invokes in image, and it’s too perceived as cool for Apple to throw overboard without throwing another serious wrench into its branding.

And frankly, with the recording industry betting what’s left of the farm on streaming, they don’t really don’t seem to care much about DRM on plain audio anymore. The RIAA destroyed the value of owning music, so from their point of view, who cares? Music is the billboard, not the product. I just really can’t see this as “HDMI for audio.”

So from a consumer standpoint, mostly I see “Apple has made your headphone cable annoying.” Even that’s assuming you’ve got your own headset and aren’t using the one Apple included, which most people do and will continue to do.

Now, this does get more complicated for musicians and DJs. Even if the included little cable adaptor is good – and let’s say it is straight up great – then you can’t trivially run the new devices on power and interface directly to performance gear anymore. That’s a headache. “Oh shit, I forgot to charge my phone” becomes a critical failure. Best case is you get a new device for that – and the dock is not suitable, you need something you can’t knock over or drop – which means one more damn thing to buy and carry around and/or lose.

Let’s also say you’re using some sort of audio software on the phone, and it doesn’t have a way to save files that you can transfer to other devices. (Even the software I have which does this doesn’t do it easily or well, it’s kind of a pain in the ass and I don’t do it. I use the headphone jack.) And a lot of software – like 8-bit emulator sequencers, and like Animoog, which I have actually used on multiple released tracks – just doesn’t do it. So that just got more annoying on newer hardware too. Another dock or another cable or another whatever. It’s one more step.

But, interestingly, not on the iPad. So far, I’ve heard no rumours that the iPad will drop the 3.5mm connector. And the iPad – particularly the iPad Pro – has very un-phonelike things like a keyboard case and special connector, and art stylus/pencil, and so on.

So what I’m thinking – particularly with the Pro – is that Apple is seeing a differentiation opportunity between “phone” and “pad,” and that they’re pushing “iPhone” to “purely consumption device,” paralleling their attempt to push “iPad” towards “creation device.” That’s not the actual usage out there – lots of people use the iPhone to make things – but it’s coherent market segmentation, and marketroids love their market segmentation.

Also, the iPad isn’t nearly as space-constrained as the iPhone. It’s just not comparable. On the iPhone, replacing that jack space with bigger battery and camera means vastly improved camera and about an hour extra battery life. On the iPad, it’s not a big enough percentage of space to care.

If the next generation of iPad keeps the 3.5mm analogue headphone jack – while adding support for the new Apple wireless headphone specs, of course – I’ll take that to be pretty solid supporting evidence. We’ll see.

if you’re having trouble with paypal today

I’ve heard that some people are having trouble with PayPal through Bandcamp? If that describes you, drop a comment and I’ll contact you in email about alternative arrangements. We can do this, I promise.

Anybody else going to PAX today? I’ll be showing up with the shiny new PocketCHIP I supported in Kickstarter! I just got it, barely know how to turn it on, the flail will be hilarious in the handheld gaming area. But I’m bringing it! 😀

NEW SINGLE HERE! Read about and play it!

ubuntu is not and will never be desktop ready

Today, Ubuntu Linux has decided I don’t get to log in to the desktop.

I can log in via a command line just fine. Just, you know, no GUI for me today.

It let me log in a couple of hours ago, but for WHO EVEN KNOWS reasons, I was getting a bunch of XRUNs suddenly, even when I just tried to copy a track internally. (XRUNs are buffer overflows or underflows resulting in lost data.) I think that’s because the software updater decided to restart itself after I disabled it. I even uninstalled it from the command line, but I think there are secretly two of them, one command-line based and one GUI based, because WHY WOULD YOU DO THIS WHAT IS WRONG WITH YOU?!

So I went through in the GUI and disabled that version too (because when it starts, it hits the disk for obvious reasons, and when you’re recording to disk, as I was, that’s bad), and while I was at it made Dropbox not autostart anymore since the first thing I always do is turn it off until I actually need it.

Then I ran apt-get update/apt-get upgrade manually (like I do always) and restarted.

Now, no GUI for me. Oh, it gives me a graphic login, and it looks like it starts to log me in, but then it says “eh, no” and blanks the screen and throws me back to login with a big HA HA FUCK YOU GUESS WHAT YOU GET TO DO TODAY INSTEAD OF WORKING ON MUSIC.

Ubuntu is not and will never be desktop ready. I know I’ve spent a lot of time talking about using Linux and running Ardour, but you know what? Ardour also ships for the Mac, and I am done with this horseshit. I have literally spent more time this last month working on making Ubuntu Linux work again after some new damn explosion than anything I might ever conceivably release, and this isn’t a one-off, Ubuntu just fucking explodes every so often now, and this isn’t worth it.

So, yeah. My job today is fixing this piece of shit OS again. But my other job is: start saving for a studio Mac. This insanity simply isn’t worth it.

eta: Y’know what? Two hours of failed searching later, this is stupid. I have a system partition image from less than a week ago. Maybe it wasn’t the system patches, maybe it was some other damn thing. I’ll restore the boot partition from that and pray it doesn’t happen when I reapply the security updates.

Hey, I don’t have any better ideas. I lose today regardless, so why not?

eta2: Restored previous boot partition, booted up fine, applied the security updates (apt-get update / apt-get upgrade), hosed again. It’s definitely the security updates.

i guess that’ll teach me to use a drum machine

hey guess what

hydrogen – a linux-based drum machine – has decided that its 151 beats per minute should be much faster than ardour’s 151 beats per minute.

i gotta tell you, this is turning into a “why do i even try” week. really is.

so hey, usb chipsets totally matter

In yesterday’s post, I posed a question: do USB chipsets matter in the 2.0 environment? I had reason to suspect they might.

The answer is holy crap yes they matter they matter so much it is unbelievable.

First, let me talk about what prompted this research, so you’ll know why this matters.

On my old sound interfaces I had live monitoring in hardware, so I didn’t have a lot of need to care about latency. Since that won’t mean much to most people, I’ll explain; when recording, it’s good if you can hear yourself, in headphones. If you’re multitracking, it’s critical.

My old audio interfaces did this with direct connections in the hardware. Whatever came in the microphones also went out the headset. There are advantages to this method, but also disadvantages, in that you aren’t actually hearing what’s being recorded, just what’s being sent in the microphone jack.

But now, I have this shiny new 1818vsl, which doesn’t do hardware monitoring under Linux. Higher-level kit generally doesn’t provide that; they’re assuming you have enough computer that your computer can send back what is actually being recorded, effects and all, and that you’ll do that instead.

This means I now have to care about latency in my system. Latency is basically delay, between mic and computer, and computer and headset. And if the computer is feeding my monitor headphones, that delay matters. You want to hear yourself live, or close to it, not with, oh, a quarter second of delay or something horrible like that.

Now, the good news was that straight out of the box on Ubuntu 16.04 (the latest long-term support version), I had better, lower latency numbers on my new 1818vsl than on my old hardware, when I was using that on 12.04. I could get down to a buffer size of 256 samples, and three frames, which gave me about 30ms basic latency – roughly half what I had with my old hardware and old install. I could use it as-was.

But I couldn’t go any lower on those buffers. One more setting down, and even playback would lag. It’d be okay until the system had to do anything else, then you’d get a playback pause, or a skip, or if recording – presumably, I didn’t bother trying – lost sound. That’s unacceptable, so 30ms was the lower limit, and I wasn’t sure it was a safe lower limit.

And that’s what got me doing all that chipset research I talked about yesterday, and I ordered a new USB card (plugs into PCI sockets) based on that research. I was hoping for a couple fewer milliseconds of latency, that I wouldn’t actually even use; I just wanted a safety margin.

So that new card arrived on Sunday, with its OHCI-compliant chipset made by NEC, and I popped it into the machine and started things up with normal settings.

At first, I was disappointed, because I only saw about half a millisecond less lag, instead of the 1-2ms drop I’d hoped to see. But across tests, it was more consistent – it was always at that same number, which meant I could rely on that 30ms latency in ways I wasn’t sure I could before.

They I decided to see what would happen moving the sample buffer setting one level lower, into what had been failure mode. And the result was 1) it actually worked just fine, where it hadn’t before, and 2) when running analysis, tests showed much lower latency at that setting than with the previous USB ports.

That was an ‘oh ho‘ moment, because it implied that the 256-sample run rate was basically the spot at which the on-motherboard USB could just keep up, and trying to run faster wouldn’t actually produce any actual processing improvement. It’d try, but fail, and time out.

So I did a couple of recordings on that, and they all worked. Then I dropped it another level, until finally, I just said hell with it, let’s just set it as far down as the software will allow and see how hilariously we explode.

I just successfully recorded test tracks four times with these settings, on the new card:

0.7 milliseconds isn’t even something you think about on USB 2.0. 2.8ms, maybe, okay. I’ve seen that managed a few times before, and that’s genuinely indistinguishable from realtime/hardware monitoring. But 0.7ms?

Seriously, this is well into “…is that actually possible?” territory. I’ve never even heard of someone running over USB 2.0 at latencies this low.

So, I guess it looks like the chipset matters a whole lot. Maybe not for most applications, and maybe not in the same way as in USB 3.0 or in FireWire, were there are serious compatibility issues. But in the 2.0 world, in realtime audio, it appears that the chipset makes all the difference in the world.

And yet, I can find this nowhere online. I’m beginning to think nobody bothered until now. Certainly when I’ve asked about it, the response has “why are you on USB get firewire” or “why are you on USB get PCI” because sure I want to throw out all this hardware and start over THANKS NO.

I think USB users have been trained just to accept it and deal. But surprise! You don’t have to! You can actually get a better USB card, if your system allows it, and it’s $30 instead of $1300!

So, HELLO, OTHER SMALL-STUDIO MUSICIANS! You want a chipset that uses OHCI on the USB 1.1 level even if it’s a USB 2.0 card or later because the 1.1 layer still matters, and still gets invoked by the higher-order drivers for card management. See previous post for why that’s important.

This means avoid Intel and VIA chipsets, and look for NEC or SiS – or anything else that loads OHCI drivers and not UHCI. If you’re on Linux, you want to:

cat /proc/interrupts | grep usb

If you see “uhci_hcd” in there, you have a UHCI chipset running your USB port and getting a new USB card with an OHCI-compatible chipset (and disabling whatever’s already installed) might help you with your latency issues.

Good luck!

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THE NEW SINGLE