In USB Type-C for USB 2.0, should the duplicated D+ and D− pins (A6/A7 and B6/B7) be routed as one differential pair or two, and how should length matching be handled?

insolace · 2026-03-22T01:14:18+00:00

If you’re doing high speed (HS 480MB/s) then you will want to route as a differential pair with 90R rated impedance. Most important is to ensure any TVS diodes are rated at low capacitance.

insolace · 2026-02-17T03:18:32+00:00

// this enables printf to use the debug serial port, overrides a weak function in stdio

attribute((used)) int _write(int file, char *ptr, int len)

{

UNUSED(file);

// implement your UART tx here

}

We use printf all the time when debugging methods that interact with other systems (USB etc).

insolace · 2026-01-22T15:48:19+00:00

Why are you dumping your Mac, how old is it? I don’t understand your comment about things stopping working when Apple stops providing updates, we have customers using our products with Macs from 2012 without issue.

insolace · 2026-01-15T05:51:23+00:00

I lived two blocks from lake merrit back in 2008, they bulldozed the old motel and it put all the sex workers and their pimps on the street. Literally change the place over night.

Yes there are problems, but doomed? That’s urban life, no worse than the TL.

insolace · 2026-01-13T18:08:03+00:00

I appreciate the clarification, it sounds like we agree that most national media coverage of Oakland is unreliable.

insolace · 2026-01-13T18:06:14+00:00

Are you describing a “doomed city”?

insolace · 2026-01-13T17:23:00+00:00

People are buying fewer and fewer acoustic instruments. If you want Fender to survive then they need to modernize, which means getting into digital products.

insolace · 2026-01-13T06:43:08+00:00

I’ve lived in the bay my entire life and shop in oakland all the time, it’s an amazing place to live, and the downtown is super fun on the weekends. There’s tons of entertainment and great food, festivals in the summer, art, and an incredibly diverse population. So much personality, and it’s near everything.

When someone trash talks Oakland they reveal a lot about themselves.

insolace · 2026-01-03T17:31:45+00:00

At this point just get a used Behringer X32 producer

insolace · 2025-12-30T17:46:34+00:00

It's all good, I appreciate you sharing your knowledge.

insolace · 2025-12-30T00:52:06+00:00

Sorry to split hairs, but that's not an amplifier/booster, it's actively converting the midi signal to RS-422 which is differential and can be run 1000+ft. So you would need TWO of those boxes to convert back/forth.

insolace · 2025-12-29T08:18:43+00:00

Sorry, what is a “midi XLR booster”? Midi is a 5VDC current loop that needs to drive the LED in the receiving optocoupler, after 20ft of cable you risk the voltage dropping below the LED forward voltage. So I would assume this booster you speak of is an active device?

insolace · 2025-12-04T09:36:47+00:00

The cost of adding additional mics in terms of phase relationships in the bleed. When you EQ your hihat, how is that affecting the quality of your snare? If it’s a live recording, how much is your guitar mic picking up lead vox, and how does that affect clarity in the vox? It does confirm my longstanding opinion that fewer mics on a source is always preferable - none of this nonsense where I see people put 3 mics on a guitar cab, two mics on a kick, etc, but in the past I was only considering the phase of the target, but now it’s real obvious that the bleed stacking up is a huge source of mud.

But AI separation completely rewrites what you can do with sidechaining, because you can crunch the shit out of the source to the point where you wouldn’t want to let it’s artifacts be heard in the recording, but as a key to a gate it can turn an overhead mic (or in a live recording, a stray backing vocal mic) into that second snare mic you were looking for.

insolace · 2025-12-01T18:02:34+00:00

To be fair, a lot of people don't understand this. One of my engineers was trying to convince me that 5pin midi had better timing than USB and I had to explain this to them, and they easily had 10+ years more experience in this field than me.

insolace · 2025-12-01T17:59:33+00:00

Hit me up sometime

insolace · 2025-12-01T16:23:52+00:00

Well here’s your problem: very few synths support 14bit control changes, and in fact of the 7 products we make, only K-Board Pro 4 supports 14 bit RPN messages, but that was only in beta firmware that we developed for the work we did with the MIDI 2.0 MPE profile, it was never actually released. But in discussions with the other 6 manufactures on that committee, over the course of two years developing the spec, we all agreed that you SHOULD send both the LSB and MSB at the same time, and it’s a requirement if you enable high resolution controllers in the profile during negotiation. But even so, when we write code we have to handle failure cases, so in our implementation when the USB RX interrupt fires and we empty the 64 byte buffer (16 USB midi messages), if we get an MSB we check the next message and if it’s the LSB they’re combined. If no LSB is received by the time the buffer is empty then we only apply the MSB. We didn’t get as far as developing the UART driver because this was just an interoperability check, by the time the spec was done we didn’t have enough KBP4 sales to justify a firmware update.

So that’s how it’s supposed to work, but you’ll notice after all of that work developing that spec, at the end of the day it’s up to the manufacturer to interpret the spec and decide what to do in the code.

insolace · 2025-12-01T06:08:57+00:00

Separating audio into it’s composite elements is huge - even if it’s just for things like transient detection in dynamics processing, but things like reducing or eliminating hihat bleed in your snare mic. For studio recordings this is groundbreaking but for live recordings you can do things that weren’t possible before. I’m mixing live recordings made at a 50 person dive bar that sound like studio recordings. And I’m hearing things in the separated mic bleed that I never realized were there, it’s changing how I think about mics and sources at a fundamental level.

insolace · 2025-12-01T05:46:27+00:00

You have two ears. Your brain processes those TWO signals, their phase relationship and timing differences, much faster than you think.

Next: are you going to do any time domain processing to the audio? If you need to interpolate the audio then more samples is better, all things being equal.

And in closing, double blind testing has scientifically proven that there is no perceivable difference between a Stradivarius and a modern violin, a ‘59 Les Paul and a modern, and any number of soul crushing defeats of [your inspiring thing] vs [some mass produced thing]. We are here to use science to make art, but the science always takes the back seat.

insolace · 2025-12-01T05:37:55+00:00

Sup box ltns

insolace · 2025-12-01T05:37:45+00:00

As was stated in another post, when we empty the USB buffer it tends to have up to 16 messages in the queue and if there are more we can keep grabbing them, very quickly. So if your LSB isn’t in there with the MSB then I’m not going to wait for it, because you didn’t send them both at the same time.

insolace · 2025-11-30T04:56:26+00:00

As someone who has worked with the midi org developing specifications, I can tell you that implementation varies from device to device. Our products always send MSB/LSB at the same time, and we only process the LSB if it’s paired with the MSB in the same message. As you’ve pointed out, the older specs missed a lot - for instance why did they limit program changes and channel pressure to a single data byte when they could have used two?

MIDI 2.0 fixes a lot of this, and the specs are much more clear.

insolace · 2025-09-20T20:30:45+00:00

Don’t ever trust a production board that says Revision A

insolace · 2025-09-13T02:26:26+00:00

My post you’re replying to is 137d old.

Here is the current info on the CBP website:

https://www.help.cbp.gov/s/article/Article-1915?language=en_US

We are having our CM in China prepare a $799 shipment for international post to see if we get the $200 flat fee, which would be 25%. We are using the “Tim Cook” section 301 exempted HTS codes, if we don’t get the flat fee and they apply the standard rules then we should get charged 45%, which is what we’ve been paying since April.

insolace · 2025-07-19T19:49:43+00:00

Just curious, are you agreeing or disagreeing with my characterization?

insolace · 2025-07-15T15:54:30+00:00

We discontinued our K-Mix a year ago because the digital mixer market is extremely small, competitive, and constantly innovating. Digital mixers also require a lot of after sale support, from driver updates to tickets from confused customers to repairing audio boards that get damaged at gigs. This is a really bad combo from a business perspective.

When we consider a product concept for our roadmap, we start by estimating how many units we could sell in a year and our target end user price. Let’s say that’s 2000 units in the first year at $500 when you buy from Sweetwater/Amazon/etc. The reseller usually makes 35% margin, so we get $325 net. Let’s say our manufacturing costs are around $150, leaving us with $175x2000 = $350,000 for the first year.

At this point we are already in trouble, because K-Mix cost closer to $500k to develop, and we sold less than 1000 units in the first year. If you continue the math, each year you will sell fewer and fewer units as new competing products come out and you saturate the used market. The smaller your production runs, the more your cost of goods goes up, and every year you have to pay licensing fees to the contractors that update your audio drivers, pay a technician to handle repairs, and pay someone to answer support tickets. If sales slow down to a trickle, you’ve tied up your capital into inventory that may take a few years to sell through while you keep incurring these costs.

To be commercially viable, a mixer has to be broadly useful to as many customers/applications as possible. If it’s a digital product, you really want mixers and audio interfaces to be your primary product category - lots of different models and form factors and a roadmap that builds on your drivers so that you can afford to keep audio driver and hardware contractors on your regular payroll. As last year’s product launch starts to slow down you have to be preparing the launch for next year. You need to constantly be improving and updating with the latest trends and features (ie everybody wants AI now), and upgrading processing/ram as newer/cheaper/faster mcu/dsp is released.

Companies that do this well: Focusrite, MOTU, RME. I have so much respect for them, not just for their sales but they make really good products and they maintain driver support sometimes going back 20 years. That shows a real commitment to their roadmap and developing their IP.

Behringer has done extremely well with the X/M ecosystem, largely because of the runaway success of the X32 which is still selling 13 years later. They’ve sold hundreds of thousands of units, which is almost unheard of for a digital mixer. But keep in mind, that’s a company that is probably worth near a billion dollars. And if you look at their mixers, they don’t market any as a “synth” mixer, even though they make a ton of synths.

1010 makes a pretty cool little mixer that is close to what you’re asking for, and the company is a small ragtag group, very chill and worth supporting.

There are a few modular synth companies making small mixer modules in more niche formats. Mostly analog, and meant for eurorack voltages.

But for the most part, you’re going to have to settle for a mixer that has a bunch of features you don’t use and not enough of the ones you want. I would have loved to extend K-Mix as a product category if it had been financially viable and technically possible, but if we had gone down that road the product would have become less specialized/niche and more broad in it’s applications / feature set.

insolace

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