Audiophiles have worked diligently to alert the rest of the world to products with superior sound quality, and to warn us away from expensive gimmicks that have middling features at best. Unfortunately, the downside of most high quality audio equipment is the sticker price. But with some soldering skills and a bit of hardware, you can build your own professional-level audio equipment around an ESP32 and impress almost any dedicated audiophile.
The list of features the tiny picoAUDIO board packs is impressive, starting with a 3.7 watt stereo amplifier and a second dedicated headphone amplifier. It also has all of the I/O you would expect something based on an ESP32 to have, such as I2S stereo DAC, an I2S microphone input, I2C GPIO extenders and, of course, a built-in MicroSD card reader. The audio quality is impressive too, and the project page has some MP3 files of audio recorded using this device that are worth listening to.
Whether you want the highest sound quality for your headphones while you listen to music, or you need a pocket-sized audio recording device, this might be the way to go. The project files are all available so you can build this from the ground up as well. Once you have that knocked out, you can move on to building your own speakers.
Continue reading “Professional Audio On An ESP32”
Why build your own stereo speakers? Some people like to work on cars in their garage. Some people build fast computers. Others seek the perfect audio setup. The problem for a newcomer is the signal to noise ratio among audiophile experts. Forums are generally filled with a vocal group of extremists obsessing on that last tiny improvement in some spec. It can be hard for a beginner to jump in and learn the ropes.
[Ynze] had this problem. He’d finished a custom amplifier and decided to build his own speakers. He found a lot of spirited debates about what was important for good speakers. He tried to wade through the discussions and determine which things had real practical value. The results and his speaker build are documented in a post that you’ll want to check out if you would like to design and build your own speakers.
Some of the topics ranged from solder type to capacitor construction and 700 Euro capacitors. [Ynze’s] goal was to build something that sounded good while keeping costs in line. He claims he spent about 250 Euro and wound up with speakers equivalent to 750 Euro store-bought speakers.
Continue reading “One Man’s Quest To Build His Own Speakers”
Slotting a modern media center into an old stereo usually means adding Bluetooth and a Raspberry Pi to an amp or receiver, and maybe adding a few discrete connectors on the back panel. But this media center for a late-70s Braun hi-fi (translated) goes many steps beyond that — it fabricates a component that never existed.
The article is in German, and the Google translation is a little spotty, but it’s pretty clear what [Sebastian Schwarzmeier] is going for here. The Braun Studio Line of audio components was pretty sleek, and to avoid disturbing the lines of his stack, he decided to create a completely new component and dub it the “M301.”
The gutted chassis of an existing but defunct A301 amplifier became the new home for a Mac Mini, Blu-Ray drive, and external hard drive. An HDMI port added to the back panel blends in with the original connectors seamlessly. But the breathtaking bit is a custom replacement hood that looks like what the Braun designers would have come up with if “media center” had been a term in the 70s.
From the brushed aluminum finish, to the controls, to the logo and lettering, everything about the component that never was shows an attention to detail that really impresses. But if you prefer racks of servers to racks of audio gear, this media center built into a server chassis is sure to please too.
Thanks to [Sascho] and [NoApple4Me] for the nearly simultaneous tips on this one.
As you know, here at Hackaday we take our audio equipment very seriously indeed. We’ve seen it all over the years and have a pretty jaded view of a lot of the audiophile products that come past our door, but once in a while along comes something that’s a bit special. That’s why today we’d like to introduce you to a new product, The Hackaday Passive Aligned Ferrite Active Quantum Crystal Nanoparticle Reference Sticker.
Here’s the problem: we’re surrounded by electrical noise. You can’t see it, you can’t touch it, and you can’t hear it, but your audio equipment can, and when that happens it will degrade your listening experience without your realising it. You might have shelled out your life savings on a top-end Hinari amp, Marc Vincent surround sound processor, Friedland carillon wire cables and a set of Saisho floor-standing speakers, but if you haven’t dealt with your system’s magnetic compatibility they’re never quite going to reach their potential and you’ll always be left wondering why your broader soundstage just doesn’t zing. You need an HPAFAQCNRS.
Continue reading “Introducing The Hackaday Passive Aligned Ferrite Active Quantum Crystal Nanoparticle Reference Sticker”
Down the rabbit hole you go.
In my particular case I am testing a new output matching transformer design for an audio preamplifier and using one of my go to driver circuit designs. Very stable, and very reliable. Wack it together and off you go to test and measurement land without a care in the world. This particular transformer is designed to be driven with a class A amplifier operating at 48 volts in a pro audio setting where you turn the knobs with your pinky in the air sort of thing. Extra points if you can find some sort of long out of production parts to throw in there for audiophile cred, and I want some of that.
Lets use some cool retro transistors! I merrily go along for hours designing away. Carefully balancing the current of the long tailed pair input. Picking just the right collector power resistor and capacitor value to drive the transformer. Calculating the negative feedback circuit for proper low frequency cutoff and high frequency stability, and into the breadboard the parts go — jumper clips, meter probes, and test leads abound — a truly joyful event.
All of the voltages check out, frequency response is what you would expect, and a slight tweak to the feedback look brought everything right into happiness. Time to fire up the trusty old HP 334A Distortion Analyzer. Those old machines require you to calibrate the input circuit and the volt meter, tune a filter to the fundamental frequency you are applying to the device under test and step down to lower and lower orders of distortion levels until the meter happily sits somewhere in the middle of a range.
Most modern circuits in even cheap products just go right down to sub .1% total harmonic distortion levels without even a thought and I expected this to be much the same. The look of horror must have been pronounced on my face when the distortion level of my precious circuit was something more akin to a clock radio! A frantic search began. Was it a bad jumper, or a dirty lead in the breadboard, or an unseated component? Was my function generator in some state of disrepair? Is the Stephen King story Maximum Overdrive coming true and my bench is going to eat me alive? All distinct possibilities in this state of panic.
Continue reading “I Think I Failed. Yes, I Failed.”
We have no intention of wading into the vacuum tube versus silicon debates audiophiles seem to thrive on. But we know a quality build when we see it, and this gorgeous tube preamp certainly looks like it sounds good.
The amp is an attempt by builder [Timothy Cose] to give a little something back to the online community of vacuum tube aficionados that guided him in his journey into the world of electrons under glass. Dubbed a “Muchedumbre” – Spanish for “crowd” or “mob”; we admit we don’t get the reference – the circuit is intended as a zero-gain preamp for matching impedance between line level sources and power amplifiers. Consisting of a single 12AU7 in a cathode-follower design and an EZ81 for rectification, where the amp really shines is in build quality. The aluminum and wood chassis looks great, and the point-to-point wiring is simple and neat. We especially appreciate the neatly bent component leads and the well-dressed connections on the terminal strips and octal sockets. There’s a nice photo gallery below with shots of the build.
As much as we appreciate the miracles that can be accomplished with silicon, there’s still magic aplenty with vacuum tubes. For more thermionic goodness, check out these minimalist homebrew vacuum tubes or these artisanal vacuum tubes.
Continue reading “Simple Vacuum Tube Preamp Results In A Beautiful Build”
About six months ago, we saw [tshen2]’s work on the DSP 01, a 2-input, 6-output DSP and crossover for extreme audiophiles, and we’re not talking about oxygen free rooms here. The DSP 01 turns a USB audio output into six outputs that will give you perfectly flat eq across bass, mids, and highs, integrates with a 6x100W amplifier, and compensates for room noise. There was a huge update to the project recently and [tshen] is more than happy to share the details
Getting to this phase of the project hasn’t been without its problems. To get the DSP communicating to a computer through a USB port, [tshen2] found a potential solution in the CP2114 USB to I2S Bridge. This device should function as a USB audio sink, translating digital audio into something the DSP understands. This chip did not work in [tshen]’s design. The CP2114 simply does I2S wrong; the I2S spec says the clock must be continuous. This chip implements I2S with a SPI, firmware, and a few other things, making it incompatible with to-spec I2S.
While there was some problems with getting audio in to the device, the core of the device has remained unchanged. [tshen2] is still using the Analog Devices DSP, with the interesting SigmaStudio being used to compensate for the frequency response of the room. This real, legit, science-based audiophile territory here, and an impressive development for a field that – sometimes understandably – doesn’t get the respect it deserves.