Build Your Own Professional-Grade Audio Amp on the Sort-Of Cheap
spectrum.ieee.org
spectrum.ieee.org
That said, and Ive mentioned this before on HN. My (now late) uncle had a bunch of audiophile friends in Dallas. He hung around folks who had spent upwards of 500,000 (yes you read that right) on audio gear. I can't forget the time I rolled up to a modest middle class home, only to find out that inside of this house was a pair of Focal Grand Utopias (selling retail for 250k at the time, though he said he paid around 60k for the pair). He had 2 750 watt tube amps, current era but the brand escapes me. For source material he had a heavily modified Technics SP-10 with 2 tone arm/cartridge combinations and a boutique tube phono preamp. This fed into a similarly heavily modified Dynaco tube preamp from the 1960s. When he really wanted to get serious, though, he had a studer 2" tape machine and a sizable collection of low generation master tape copies. If I hadn't seen this with my own eyes I would say my uncle was full of shit when he told me about it. You know what? it sounded freaking amazing.Im sure it is 90% placebo, and 10% the fact that he was able to play high bandwidth audio to concert levels with no stress or strain from the amplifiers. Was it worth 6 figures of money? not to me. But I am glad I got to hear it...
Most other factors are rarely an issue and/or inferior parts have a much lower magnitude of impact on sound quality. Sufficiently good source material (256kbps AAC or better) is widely available. Most amplifiers are fine. Almost all wire/cable is perfectly good. High quality DACs are more abundant than you might think (e.g. the digital inputs of any half-decent AV receiver made in the past decade).
Good speakers.
Good placement.
Good acoustics.
Those are the ones to focus on. They're the ones to spend money on. If you wanted to add a fourth to that list, I'd add an honourable mention to in-room calibration systems like Audyssey and DIRAC. Depending on the sorts of imperfections in a given system the opportunity for improvements with DSP might be substantial and dramatic, or marginal to the point of being irrelevant. (For most systems it's somewhere in the middle.)
I agree completely, but emphasising that point tends to lead to flame-wars in most places on the internet. And it's such an imprecise subject to debate because everyone's room is different. Some rooms can be atrocious, while others can be unintentionally excellent. Some rooms can be easy to improve, some require knowledge and experience in order to improve. Some only require repositioning, some require treatment products that can cost a lot more than many enthusiasts realise.
My favourite video that demonstrates the effectiveness of acoustic treatment:
The best speakers i heard to date are from a german company called Backes & Müller. Active crossovers, each speaker has its own poweramp and a sensor attached to the membrane. The signal of the sensor is fed back into a comparator which calculates the difference to the music signal, this is then used to force the speaker to follow the music signal exactly.
>On the basis of physical factors all drivers make mistakes, which one must accept in passive and uncontrolled systems. In contrast, all BM drivers are a part of active error correction systems.
>Active loudspeakers know no conduction loss, no impedance issues; have faultless crossover performance, exact phasing, an optimal amplifier-chassis ratio, more actual output stage power at their disposal, quicker impulse processing and higher dynamics. All of this produces active regulatory intelligence. A sensor system continuously compares and corrects the membrane movements with the actual music signal.
>B&M uses two types of negative feedback: inductive and capacitive. Intelligent electronic fuses ensure that the entire system is reliably shut down in the case of an impending overload. The BM electronic crossover splits the music signal into individual paths of respective frequency ranges and allocates these to their individual output stage. Every individual output stage drives to its respective driver, optimised for its frequency range.
from http://www.backesmueller.de/en/b-m-technology.html
Pricey and not DIY friendly, but you can pick them up used on ebay for "peanuts". W0as thinking about buying an BM8 (3-way) refurbished for 2800 Euros, BM10 (4-way) refurbished costs 10000 Euros, got a BM12 (5-way) used for 1400 Euros.
The company is now owned by http://ksaudio.com
Every aspect of the room was built around the grand utopias and their placement. If you’re not familiar with them check them out here. https://www.focal.com/en/home-audio/high-fidelity-speakers/u...
The subwoofer drivers are unique in that they use an electromagnet instead of the usual strontium or neodymium permanent magnet.
I think what impressed me the most was that this guy was not annoying or in to the hand wavy audiophile hocus pocus. Just super passionate about getting everything done to get the absolute best sound even if the bang per buck was low. He had a wall of vinyl and was happy to let me pick several selections to play. From what I understand, this guy would open his home to anyone interested in a listening session. If anyone is in the DFW area and you can get plugged in to that community it seemed like a great group of folks.
In my limited experience, "clean power" (I know nil about this so I'm just repeating what I hear) was the most important difference people would "hear". My uncle used to have a Hi-Fi shop and I helped him sometimes. People hearing distortions in their existing setup used to make up for 90% of his customers. In those cases the number one step was to make sure that the power that comes to the system is clean. Being a certified electrician, he used to do his thing and you would almost always hear the "aaah" from the customers the moment you hit play. To me also the difference was generally night and day.
(Now of course that might be less true for some poorly made vinyl/phono level equipment but if you actually cared about audible distortions you wouldn't be listening to the sound of a needle scratching its way across a fragile plastic groove in the first place...)
If you spend most of your day wearing headphones, you might invest to them a bit.
Maybe in 50 years when it breaks I'll get a new one :)
That thread contains little to no evidentiary merit and a boatload of technical ignorance.
1. Decent monitor headphones or speakers sound the same. That’s under $500. Even some Sennheiser HD25’s are literally up there.
2. The equipment used to record such music cost less and was lower quality. Adding $500k doesn’t add anything because there isn’t anything there.
Then again I have no problem with people who spend $500k on audio kit. That’s up to them. If it makes them feel good buying something in that range then fair play to them. It’s mostly just art.
What I object to is little bags of stones wrapped around cables, magic boxes which absorb non physical entities in the room and directional cables. Woo and such needs to be taken down.
Add exotic guitars, vintage synthesizers, and other esoterica, and the total hardware budget for a mainstream commercial hit album is comfortably high six/low seven figures.
Some genres - mostly electronica - are 100% "in the box", generated and mixed with software. But they're usually still mastered in a high end studio with a combination of digital and analog tools on reference-grade monitors.
But all of that equipment is used to produce recordings that "translate" - play well on everything from ear buds to high end systems. That requires processing of its own.
True hifi recordings that aim to be as transparent as possible are very rare.
There's no such thing as "transparent" in pop/rock because it's all artifice. But even in classical recordings the sound has usually been edited and significantly processed, so the abstract concept of fidelity doesn't really apply.
A decent audio grade opamp is $2 for example.
But regardless, even just the input transformer on most mixing consoles costs at least $100. And many extremely high-end consoles use discrete opamps which can get really expensive. There's also a lot of tube-based outboard gear in studios.
Sure, you could build a mixing desk with only $2 opamps and no transformers, no tubes, etc. But that would sound bad. Unlike the audiophile world, recording isn't about doing everything possible to prevent distortion - if it was, all recording would be done with calibrated measurement microphones and other various lab equipment.
So how can distortion be good in recording if it's bad in reproduction? A few reasons. IM distortion, for starters - distorting every channel individually is going to sound much different (and in most cases, better) than distorting the mix of all the channels.
But also, in recording, the distortion is finely tuned to the exact song, by someone who gets paid hundreds of dollars an hour because they are very good at it (and yes, good at getting it to sound even better on a variety of different systems). A recording engineer can use exactly whatever mic preamp they think will sound best for the song. Yes, audiophiles do tend to adjust tiny settings for each song, but not to the degree that recording engineers do - no audiophile is going to own 20 different amps and switch them out for different parts of different songs (or at least not on a regular basis).
Recording engineers can also do so on an individual channel basis - use one preamp for the vocals, a different one for the large-diaphragm condenser over the piano, another different one for a small-diaphragm condenser pointed right at the piano hammers, etc. Unless they're using Dolby Atmos or some other multichannel format, an audiophile doesn't even have that option, no matter how much they enjoy tweaking minor settings.
So no, the signal path is certainly not way less than $100 worth of components - and it wouldn't sound nearly as good if it was.
You have no idea what you are talking about regarding signal chain. Discrete opamps are inferior on every possible measurement. This is total nonsense. Utter rubbish.
Do you know what noise figure is?
Do you know what CMRR is?
Do you know what PSRR is?
An interesting aside on cables... I play electric guitar a lot, which is far more sensitive to cables than hi-fi gear, because guitar pickups are high impedance, low output devices - enough that capacitance can have audio-frequency passive filtering, and grounding is a huge problem. With passive pickups, I can easily hear differences in various cables I own. But some of my guitars have active electronics onboard (EMG pickups or other preamps), and produce a low-impedance signal. I can't hear the difference with those guitars.
When it gets down to it, I use the cables that are most reliable and comfortable to handle. Sound quality doesn't even enter into it, whether or not it's audible.
It usually starts with amplifiers, then speakers, then source equipment... and then they start rearranging furniture, tearing out drywall and putting absorbers everywhere, and then it starts all over again in a cycle.
I find it best to stick with a nice comfy pair of headphones and keep expectations low for everything else. If you're only managing the volume of air between your ear drums and the headphone cups-- that can be done to an obsessive level for vastly less cost (and without divorce) than if we're talking about a whole living room.
I knew customers who built the foundation of their homes around speaker placement, having separate foundations for their towers so that fewer resonant effects from the house would impact the speakers. Haha. Madness is right!
And that $500,000 number is easy when you’re dealing with those circles for sure.
While my setup is somewhat (cough) less impressive/over-the-top than the one referenced above, there's no denying listening to a proper 1812 is a physical experience.
I'm partial to Kunzel's recording with the Cincinnati Pops - those cannons are LOUD. (Better be careful not setting the volume too high or you're likely to find yourself a couple of woofers short afterwards.)
WOW! That's ~5% of a Ducati. That's ... insane for a sound system.
Link: https://www.aliexpress.com/item/Breeze-Audio-BA100-Class-D-P...
It's not the best amp I've had, it's not loud enough for parties, or even very loud music, and it doesn't drive my planar headphones well.
What it does do is easily fill my home/office room well above comfortable working & listening level, it drives my Sennheiser headphones pretty well, it's cheap & small and it just works.
For what it is, it's brilliant.
The TPA3250 from the article, and the TPA3251/TPA3255 that have higher power from the same range are in a different class to those IMO, with much less distortion, and are just ridiculous value for money.
Maybe I'll replace it with the amp you linked :)
[0] http://nwavguy.blogspot.com/2011/07/o2-headphone-amp.html
If I made one of these, I 'd be tempted to put an ODAC and O2 board in the same chassis to have a complete amplifier.
Such a product is available commercially:
> https://www.jdslabs.com/products/48/objective2-odac-combo-re...
I would start by taking look on some oss version[2] and order PCB from OSH Park[3]. I've built this version few years ago and it works well.
[1] https://tangentsoft.net/audio/cmoy/ [2] https://github.com/akafugu/cmoy [3] https://oshpark.com/shared_projects/dRKK4dgN
It's also based on Tubes, and the sound is very, very satisfying. Will be happy to share a detailed guide, if anyone's interested.
[1] https://www.instagram.com/p/Bpl71mUHLbm/?taken-by=discovery....
[2] https://www.instagram.com/p/BplhIIqHNhl/?taken-by=discovery....
Thank you :)
Nobody is having those arguments anymore."
Those arguments are still front and center when it comes to amplifier design, both on the manufacturer and consumer sides.
Will "computational photography" (as touted in the latest iPhones) that alters photos based on criterion of perceived quality end up bringing these kind of inane discussions there too?
Edit: Never mind, I didn't factor in all the arguments about Photoshop altering.
Last weekend, I was in DC, and snapping pictures of the Washington Monument on my phone. My sister was shocked at how good they were. It's not hard, really.
To do good work in mixing and mastering, it's important to study the human perceptual mechanism and its propensity for illusion, and it's also important to understand masking effects and how to amplify certain components long enough to tweak them before dialing them back to recede into the gestalt.
It's also important to understand that in sound reproduction the vast majority of the distortion on the analog side comes from transducers (microphones and speakers), not amplifiers. (I'm not even going to bother with the article, because amplifiers aren't an important problem: buy something decently engineered and overpowered, and you're basically all set. Then worry about your speakers and your room, because they're the hard part.)
But it's likewise crucial to grok that the distortion introduced by digital components is disproportionately disturbing because it is enharmonic. And that practically speaking a lot of the damage that gets done in practice happens because people don't handle gain staging right and often don't understand the fundamental principle of preserving high resolution throughout production and only exporting to lower resolution as a final step.
In summary, there are a whole lot of interesting conversations to have on the subject of audio and how perception relates to production. But it's basically impossible to find a community to discuss these subjects with. Either it will be overrun by audiophiles and their pseudoscience, or well-meaning but undereducated skeptics will dominate the discussion with plausible but misguided debunking.
So every once in a while I throw up a piece like this into the middle of a giant discussion, with about as much hope as tossing a message in a bottle into the ocean.
I'm also curious, what made you leave your job as a mastering engineer?
I left the field (back in about 2003) because although I felt that I was good enough to compete and survive, I didn't love it enough to grind out a life as a workaholic and just get by.
Most of my writings from that time were forum posts with the perspective of the well-meaning but undereducated skeptic and wouldn't be that interesting to read today. Also, what was probably my best writing happened in forums which don't have public archives which have survived 15-20 years later. (Which amuses me as a former mastering engineer because one of our primary objectives is long-term archival.)
PS: not "enharmonic", "non-harmonic" dammit. The point is that while analog distortion is mostly harmonically related, digital distortion is not and therefore is much more poisonous in small quantities. Mixing especially (though mastering is similar) is all about making changes near or below the threshold of perception which sum to a cumulative perceptible effect.
My pet example is that I put high-pass filters (12db slope) at 250-300hz on almost everything that isn't a drum or a bass instrument. I'm slaughtering the bottom two octaves of guitars! And if you solo a guitar track, you can hear it. But in the context of a mix, all those bottom two octaves do is make mud and confusion, distracting from the clarity that the kick and bass (guitar || synth) needs. And I need that clarity, because I'm not mixing for $500,000 audiophile systems. I'm mixing for car stereos, boom boxes, Alexas, cheap earbuds, and worse.
So all that matters for me with audiophile systems - and I love audiophile systems - is that they sound good. That doesn't mean they sound accurate.
Despite that, your hostility to the skeptics illustrates that you and I still aren't really on the same page (though I don't doubt you produce compelling art, don't question your techniques, and agree 100% about ensuring that aesthetic gestures survive the transition to imperfect end-user environments).
To me, "objective accuracy" is a worthy and desirable intermediate goal for sound artists, a tool which can be leveraged for creative ends the same as a baker understanding food chemistry or an animator understanding Newtonian physics or a modern origami folder understanding programming. However, chasing "objective accuracy" means understanding the wildly non-linear, even bizarre human perceptual mechanism -- which is more of a pattern recognition machine and definitely not a measurement device -- in addition to all the strangeness of acoustics.
The problem with audiophiles is that their approach to "accuracy" is unscientific and doomed from the start. The skeptics on the other hand, have the right idea -- but those who have not done deep study often fail to appreciate just how difficult the problem is and how far off their intuitions are.
I've had some wonderful conversations with individuals whose perspectives are similar to mine, but it still seems impossible to find a hospitable public forum.
When it comes to recording, my "objective" reality is the sound I hear in the room before it ever hits a microphone. But what comes out of the other end of the microphone is already deeply subjective. The objective ability of hi-fi systems to reproduce that subjective, colored microphone signal (plus whatever processing is involved downstream) is about as objective as they get. But the recording itself? Outside the world of purely electronic music, it's a subjective experience.
I play acoustic guitar every day, listen to unamplified singers/musicians (other than me) at least weekly, play electric guitar at least weekly, gig regularly. These direct, objective experiences of the natural sounds of instruments color my interpretation of both magical-thinking audiophiles and pseudo-scientific skeptics. I know intimately what the natural sound is, I know intimately what the recorded/reproduced sound is, and I know how the entire recording process works, from miking to mixing to mastering. Laws and sausages. The audiophiles and skeptics are both missing that perspective.
So, as a recording/mixing engineer, as a producer, I'm looking not to deliver audiophile accuracy, but rather to deliver the intended intellectual and emotional experience of the music. What feeling is the artist trying to convey? How do I manipulate the sonics to emphasize the musician's intent, as expressed through the lyrics, the composition/arrangement, and the natural tones of their instruments? That's the fun part, for me.
(As an aside, I'm currently working on a particular song of my own, destined for my long-delayed solo album. I wrote the song based on a nightmare I had in great distress. A few years back, I suffered an illness that left me nearly unable to speak, much less sing, and my voice is permanently damaged (I have surgery a few times a year on my vocal cords to keep speaking and not die of suffocation). I recorded the song right after writing it, just a couple of weeks before my first surgery, with a near-useless voice. "My broken voice won't fill the air / I know that you don't really care / You may not need my song but I need to sing it anyway". Fitting with the broken voice is the melody repeated on a piano that hasn't been tuned in over 50 years and has been flooded multiple times, so it's, um, colorful. To both the audiophile and objective mindset, neither the voice nor the piano were worth recording at all. But as an artist trying to communicate an emotional experience, they're vital.)
It's just someone being sold snake oil.
That said, many high end audio folks are straight up whack jobs.
Where it gets tricky, is the arguments for how things like tube amps sound. There is nothing that analog components add to a sound that can't be simulated with digital transforms, but the trick is figuring out how various analog components effect the signal. For instance, my friend found that certain tube amps would overdrive components and force them out of spec, and this caused a non linearity in the response of the signal coming from the component that gave the amp it's distinctive distortion effect. Once he figured that out he was able to reproduce the effect digitally. Incidently, he's found that some guitar amps can never be made today, because they were built around a specific batch of a given component, and newer batches didn't have the same out of bounds responses. But this seems to be why so many people are still so big into analog amps, because it takes considerable effort (and apparently engineering skill) to reproduce some of the classic sounds.
Mind you, I'm biased by one of the best engineers I've ever met, so I could be wrong about the general consensus with audio engineers. I'm also mostly using a sample size of 1, though I have corroborated some of his assertions with some of the blogging I've read on the topic. One of the best (I wish I'd bookmarked), was a good overview of encoding by a prolific codec writer, who pointed out that even though a digitized sine wave looks lossy at a low sample rate, it's trivial to rebuild that sine wave perfectly, with just the digitized version (so long as the sample rate was above some multiple of the Nyquist frequency?).
Amplifier designers have to sell to a market that is rife with misinformation and a very poor signal-to-noise ratio between technical quality, profit margins and overall market success. I wouldn't expect many of them—especially the ones who have any name recognition—to be concerning themselves with objective technical performance.
Whereas the guy who designed the amplifier circuits for a product where the customer isn't being placeboed by the spec sheet—like powered studio monitors, or consumer devices like the Apple HomePod—is far more likely to be focusing on objective measurement rather than faulty market perceptions.
"The term linearity derives from an amplifier's linear relationship of input power to output power which, in an ideal amplifier, would be precisely related by the gain of the amplifier."
I see it as matching my argument.
Could I ask you to give a definition which clashes? Thanks!
Class D (switching) amplifiers are _not_ linear, they trade linearity for efficiency. The article you linked to actually says this:
"Over the years, a number of different biasing schemes have been developed for amplifiers, from extremely linear Class A operation, in which the active devices essentially remain powered on through the full sinewave cycle of an input signal, to more power-efficient schemes, such as Class D, in which multiple transistors are switched on and off to conduct different portions of an input waveform."
I think what you are doing is confusing the linearity of the transistor with the linearity of the whole audio amplifier treated as a black box, which is why I suggested you rephrase your argument rather than say you are categorically wrong, however what you said was:
"The thing is that transistors’ behavior is more linear and controlled when fully on or off rather than when used as continuously variable."
... which I'm afraid is really just wrong.
When a transistor is off, it’s off. Then it takes a certain input voltage to get it going. Then there’s a varying curve to full output.
In contrast, fully switching on or off “gets rid of the curve” and tranforms the problem into one of timing, and one of a modulation scheme for a series of on or off states. In that respect I contend that it is an useful thought to consider transistors’ behavior (in an amp) as more linear and controlled if used in only the on or the off state. The output quality of Class-D amps in relation to price, size, complexity, and power, and cost suggests to me that the gains are not only in power efficiency.
Class D amps do leave the operation of transistors in their linear domain on the table, and do gain efficiency by that. Overall linearity as a control mechanism is something I stand by saying is increased. You may present an alternate take of course.
A class D amplifier uses a smaller amplifier internally (which can be a single transistor or more complicated) that is driven open loop so that it is either hard off or hard on but very fast and efficient. The hard on state is known as full compression because the output power will not change with input power. This is purely non-linear behavior and can be very easily verified by measuring the high IMD components it generates. Class D amplifiers employ significant filtering to suppress these non-linear terms and allow you to recover the signal. Mathematically, they violate the linearity condition of F(ax) = aF(x)
Also you should reread the article you learned from. It directly contradicts you.
We are simply and obviously applying the word “linear” a little differently. I am aware that it is a specific term for certain behavior / a certain operating mode of transistors. I’m referring to it in another wider context on purpose. As another example “linear” in “linear algebra” isn’t about saturation or gates. I’ve gone through this before in this thread and believe my perspective is now pretty complete and clear here and won’t engage further.
If the price of source gear is a quarter of the price of gear attempting to reproduce source, something is broken.
That could perhaps explain some of the price - plus I think we're at the point where many of the headphone companies have discovered that there is an ultra-high end market for some of these products.
You can see this in the prices of many top brand flagship headphones - the majority of the well regarded brands have been gradually putting out exceedingly expensive flagships in the past 2-3 years.
10 years ago - then the Sennheiser HD650 was seen as a flagship at $400, now look at the Sennheiser HD820 released earlier this year at $2200.
You aren't going to find too many people who will say that the sound improvements between the two justify an $1800 increase in MSRP.
However if you reframe the perspective to that of a luxury good, given the perception of headphones (regardless of use case) has changed somewhat in the interim and are seen as a fashion accessory and there's a larger enthusiast pool - you can see that manufacturers would be willing to push new boundaries when it comes to price.
However I think it's only the lunatics, or the conspicuous consumers who are ignorant to the law of diminishing returns when it comes to headphones and audio in general.
An amplifier's ability to reproduce a 1khz sine wave into a resistive load tells us nothing about how it behaves in the face of 8-10 octaves of frequency range and the real dynamic range and harmonic complexity of actual musical content, when hooked up to the absurdly complex and nonmusical behavior of real speakers. The 5% THD of single-ended tube amps that people who've never heard one tell us proves how "inaccurate" they are is inaudible, but the grimy, dull sound of cheap amps that have excellent THD specs is plain to hear.
It's frustrating, in part because this stuff is, so far, mostly impossible to measure. It's hard to get a sense of how an amplifier will sound from specs.
No idea how this guy wrote this article and didn't come across DIY Audio (or he just didn't mention it in the article). There is a tonne of information here: https://www.diyaudio.com/forums/class-d/
I don't quite get the aggressiveness of your second point: surely just leaving whatever your first association to a topic is out cannot warrant such outrage? It's not like they present this article as groundbreaking innovation. Not only do they cite other DIY efforts. The whole premise of the article is that the author himself already did this ten years ago,.
I imagine this guy must have found the components of a site similar to DIY Audio. It would have been a nice addition to steer people in the direction of more information if they are interested in the topic (which a lot of the comments here seem to be asking about).
Is the amp in this article the same kind of amp that you could plug an electric guitar into? I know nothing about music or instruments, but I do know about electronics so I was thinking it might be fun to build an amp with my son.
I went to the diyaudio link you suggested, but I didn't immediately see information like in the article (buy this, this, this and this to build the amp). Can you point to where I could find a similar purchase list and assembly instructions on diyaudio? Thanks!
But obviously a new player isn't going to want to drop $1500 on a rig like that.
I'm no expert, but as far as I understand, this is a power amp, which takes an input at line level (~1 volt) up to a level that can power a speaker. Guitar pickups produce a signal around 100 mV, and typically need a "pre-amp" stage before the power amp to amplify this signal to line level.
Now if you wanted to make a PA system, I don't see why you couldn't use an amplifier like this with some modifications.
Nowadays, there exist units that provide complete signal processing for guitar: simulating guitar pre-amplifiers, amplifiers and speaker cabinets digitally. You plug your guitar into this, and then it can go straight into a PA system, or your recording console. Something like that can be used with an amplifier like the one being built here.
My rig consists of a 6U portable rack case with a few pieces of gear. The guitar goes into an ADA MP-1 MIDI-programmable tube pre-amp (built in 1987, revamped by me). This goes into a splitter-mixer (called the SMF-1 that I built myself) which bifurcates the signal through a digital effect unit that provides reverb, and then mixes it again. The dry signal remains analog. Then it goes into a 31 band equalizer, and from there to the power amplifier, an Alesis RA-100, which feeds a guitar "4x12" speaker cabinet (four 12" speakers). I could take out the amplifier and drop-in replace it with any rack-mountable amp, provided it doesn't require more than 3U spaces. QSC, Yamaha, Yorkville, whatever.
There also exist dedicated rack-mounted power amplifiers intended for guitar, like the Rocktron Velocity or Marshall Valvestate 8008 (both of these examples are stereo). Many of these kinds of ampls have been produced. These are just power amps; they can't produce any overdrive tones and have only minimal tone control or none at all. The 8008 has a switch on the back for "tube like" behavior, which just means current feedback. That will give it more of a mid-scooped frequency response, induced by the reactive speaker load. I can do something like that with my equalizer.
The amplifier project we see here could be turned into a guitar amp by adding a preamp circuit board into the chassis, fed by a guitar input jack, and exposing some tone and gain controls. The stereo function of the amp could be useful if we add jacks for an external effect loop and make it stereo (mono out, stereo in). Then we need a stereo guitar cabinet: minimally a 2x10 or 2x12 wired for stereo.
Yes, this amp can work — experimental musicians run instruments through much weirder things — but it'll sound strange.
Whether you build an amp or not, you should definitely buy a standard guitar amp, so that he can focus on his guitar playing. A standard guitar amp (solid state or tube, to taste) will let him hear how his playing compares to other musicians (who also use standard guitar amps), helping him gain a critical ear. He'll learn what parts of the tone come from his fingers.
When he's ready to go experimental, then he can start playing with (say) ripping pickups out of guitars and wiring them up to headphones as portable EM detectors. When he gets to that phase, that's the time to start using line amplifiers like the one in this article instead of instrument amplifiers. And drilling hundreds of screws into his guitar.
* Get a standard amp/cab combo.
* DIY something, I'm sure there are guides and such you can follow, but this is only practical in so far as it's a fun project.
* Use your computer. You can get inexpensive cables that plug into your computer USB and there's a variety of software to emulate amps.
1. Preamp with hi-Z input from guitar to line level
2. Ability to drive into distortion
3. EQ of some sort
4. (Sometimes) reverb
5. Amplify line to speaker level (this article)
6. Midrangey speaker+cabinet that sounds nothing like a normal flat speaker cabinet used for HiFi/PA/keyboard/etc.
However, as others have said, you can use a guitar modeler which performs steps 1-4 outright and simulates step 6 leaving only a need for step 5 and a "normal" speaker.
It's extremely versatile and sounds great.
https://www.boss.info/us/products/katana-air/
I'm but an amateur guitarist. I can't detect any latency caused by the radio communication. But I have not been able to find pro muscicians trying out the Katana Air and complaining on the latency. It really works. Over quite long distances too.
The only thing I would have wanted in the Katana Air is rechargable batteries in the Amp itself (the transmitter is charged by the amp). But that is not a major issue.
I'm not a musician and this confused me for some time. I'd see electric guitars with their own amp & speakers then a microphone for the the PA system in front of said speaker. I couldn't understand why the electric guitar wasn't just plugged in, something I read a few years ago was a light-bulb moment.
Depending on your budget, I'd get a Vox Pathfinder, AC4, or AC10, and then take him to get a pedal or two after Christmas. You can usually find an AC4 used easily. Some of the digital amps are fun, but if he really gets into it, he's more likely to keep one of the amps I mentioned and buy pedals anyway. An AC4 (especially an AC10) will be something which usually sounds really good on it's own.
Maybe take him to a store so he can find out which guitar/amp combo he likes most.
3e Audio has a nice board using that as well.
Not quite. Frankly, Class A or AB still has the upper hand from a pure sound quality perspective, and class D struggles to output sufficiently at high levels with lower levels of distortion in my experience.
That said, there have been many small class-D Amps from Lepai and Dayton that are excellent choices for near-field and non-demanding applications. They definitely have their place. The tech is advancing rapidly but it has not supplanted A or AB.
If you want some background in why there is still debate, I highly suggest reading some of Nelson Pass’ interviews and writings:
https://www.google.com/amp/s/parttimeaudiophile.com/2018/02/... https://www.passlabs.com/press/single-ended-class https://www.passlabs.com/press/leaving-class
Being powerful and reliable is more important than being all that good, since the room always sounds bad anyway.
That's because these amplifiers are not digital. The control loop is generally analog. Though there are chips which do in fact use digital inputs and do most of the work via fixed-function DSP, but those are mostly bigger chips targeted at 5.1 or 7.1 systems.
So what's it called if it is time quantized? The simple open-loop design depicted on the Wikipedia page could have the analog comparator + triangle wave generator replaced with a digital delta-sigma modulator (1-bit DAC). Then the switching times of the power stage would be quantized to the sample rate multiplied by the oversampling ratio. (Although it seems this open-loop model is an oversimplification, and real class-D amplifiers have feedback, so it wouldn't be that simple in practice.)
Then make it wifi.
Just think, you could eliminate that awful rat's nest of cables. The sound quality would be better. You could locate components where-ever convenient. Each component could have a web browser interface.
It'd be awesome.
Also, if you plug your audio components into its own switch, it should not get interference from the rest of your LAN.
Edit: look for example at TI TAS5756M, TAS3251 or TAS5825M.
Are you asking for an amplifier that would deliver similar performance to this, because you don't have the time to build one, or that you suspect you'll come out ahead on build vs buy because of the price you value your time at?
For speakers, the cheapest option is to buy some second-hand ones on eBay/Gumtree/Craigslist. Just Google model names and look for ones with good reviews. I like British speakers, so I usually search for Tannoy, B&W, KEF etc.
I put my efforts into building speakers instead. I got a cheap kit (https://www.diysoundgroup.com/overnight-sensations.html) and spent my time learning how to apply a french polish finish. I really enjoyed learning french polishing. It's one of those things that when you finally get it, it becomes immensely satisfying. Yeah, shellac isn't the most durable finish, but it sure is pretty.
+1
They have a switch mode power supply instead of the toroidal in the IEEE article, so in theory more noise - in real life? probably doesn't matter. THD < 0.01% at 30W, frequency response is +- 1db, the days of having to spend any money for an amp seem gone, < $70
Vinnie Rossi, Red Wine Audio. It is still amazing. But his stuff is now quite out of my price range.
These amplifiers are great fun, though.
https://medium.com/@leolorieri/underground-bands-get-more-wa...
What if you use balanced input?
http://sound.whsites.net/project30a.htm
You can easily insert a volume control right after such a stage.
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It looks like this particular board has tiny SMT components, which make this sort of thing a pain in the but.
There is something very satisfying about building something yourself that you get use out of every day. Such an amplifier is likely to fall into that category for me.
And slightly OT, but does anybody know any ABX test of balanced input/output signal? I find it hard to believe that there is a single person who can hear the difference.
A good place to find DAC reviews is head-fi: https://www.head-fi.org/forums/dedicated-source-components.7...
I've heard of cases where you could receive AM radio stations from such a setup; I lean towards "urban legend" for that though. While it seems theoretically possible (since many amplifier topologies can have resonance when fed signals outside their expected operating range), it seems a bit farfetched to actually end up with intelligible audio.
According to that site, Schiit stuff measures really bad.
List of all reviews: https://www.audiosciencereview.com/forum/index.php?threads/m...
Not sure what this means. I had a group undergrad project in 2002 to build and characterise a class-D audio amp. The idea was well-established at the time.
Time well invested.
Not quite chipless but pretty close.
Of all disciplines of human interests and hobbies, Audiophiles are one of the most stubborn, misinformed, anecdotal and delusional bunch. Of course I am generalizing, but every time I engage in a discussion about audio quality, it is a losing battle. Not because of lack of data or supporting evidence, but because of the fundamental dissent for data driven arguments. You cannot argue reason when the first step is to be born with "audiophile ears".
Why is it hard to understand that we have sophisticated metrology and instrumentation that can analyze things better than human ears can? I can understand a separate discussion about personal opinions regarding how "warm" a particular sound is, but that should remain distinctly as - subjective and that's perfectly OK.
It feels like the entire audio industry is promoting pseudoscience barring a very few vendors that actually care. We have a $8500 mp3 player from Sony claiming all kinds of things to the overwhelming abundance of cheap Shenzhen exports. There is just so much noise.
I absolutely abhor audiophiles.
The technique worked just fine, but man, that guy was loony. He was trying to claim, with a straight face, that a GPS disciplined oscillator wasn't stable enough for his audiophile-grade Rube Goldberg machine.
I wish there was a separate term between audiophiles who just want to spend a lot of money on hocus pocus, and audiophiles who want the measurably best performance.
Then the audiophile forums would not be polluted with people who spend thousands on cables and other rubbish, when the room response/treatment and speaker selection has a million times more effect on the actual sound.
I own Records and like you, I enjoy the experience. There is something amazing about listening to the entire album without distractions and in the sequence that the artist intended. You could do this with mp3/CD, but Records get me in the right mood :-)
It is ironic that higher quality mastering is done on a vintage outdated (barring recent resurgence) and objectively lower fidelity medium. It'd be nice to see CD's having great mastering and may be some of them do?
It's because there is a very limited number of people whom care about accurate sound reproduction. The _vast_ majority of listeners use garbage sound reproduction systems (Beats headphones, bluetooth cannon speakers, almost everything Bose makes now, etc). The small segment that cares is also heavily dominated by the audiophile sub-segment, selling vinyl to them is icing on the cake. The segment that _really_ cares about audio quality, those that care but are not 'audiophiles', is _extremely_ small and not worth targeting at the consumer level.
And what I often crave is the less accurate vinyl sound, that coupled with different production values.
Not better, just resonant with me. Easiest way to explain it.
Those days are long gone, but the culture remains.
Getting good sound out of an old victrola--which were very expensive--truly is an art. Getting passable sound out of today's average off-the-shelf electronics doesn't take much at all. But many audiophiles act like are living in the late 1800s.
[citation needed]
State of the art distortion measuring techniques resolved something like 0.002 % in the 70s.
It's also easier to display a 12" sleeve as "art" than a CD or a FLAC download ;). Turntables are better decorative living room items than CD players or tape decks, but that's also subjective ;).
I _like_ vinyl, but I'm happy to admit its almost certainly due to non-audio non-hifi reasons. I like the "ceremony" associated with cleaning the disk, dropping the needle on the lead in track, and getting up to flip it over and do it again every 5 or 6 songs. I like the cover art - there is arguably a loss to the world of a beautiful art form due to the demise of the 12" record and it's large art-work ready packaging. And, as you'll hear on a lot of '90's CDs - I like the 33 1/3 rpm flaws, the clicks, scratches, and wow and flutter - when I hear the opening bars of Tear Drops from Massive Attack's Mezzanine, I get nostalgic, not for the late nineties when it was released, but for the early eighties - that scratched, fuzzy, played-too-much vinyl sound they used - that was the soundtrack to my late teens. Whatever the minor differences in the audio reproduction, those 33 1/3 and 45 rpm noises bring back some wonderful memories... Which is enough reason for me to keep the turntable set up and occasionally spin some discs...
Then, the "digital revolution" came to music, and you could buy it online. Which, for nearly every case, was better. Especially for people who weren't in driving distance of a major city.
However, once I started to get a digital collection going, the size was overwhelming. Especially in regards to dj'ing. With vinyl, your entire collection isn't always available. You make little stacks, shift things in and out, and it's much more organic. Digital misses that. Plus, I never really knew track names. I just remembered album or record artwork. It was easier to find things that way.
I recently tried the latest noise cancelling headphones by Sony (1000XM3). The noise cancelling was excellent, but the bass was +5db overblown, boomy and drowned out most of the mids, the treble was dark to hide the NC hiss. It was unlistenable for jazz and classical without EQ. But the mainstream tech press think they are wonderful, even "WhatHifi" gave them 5 stars. An Audiophile is simply someone that cares about sound quality, most people don't.
There are of course much better headphones, and I wouldn't call them audiophile headphones, but I haven't found other wireless ones that do noise-cancelling and isolation as well and still manage to sound acceptable.
It's the same for everything they sell at those shops. They are there to upsell shiny shit to people who don't know what they want. Try finding a decent laptop for a decent price at one of those stores.
I've been a bit of an audio enthusiast for about 30 years and back then the expensive stuff was definitely better (mostly). Now its the opposite, the more expensive the stuff is, the worse it is and the dialog surrounding it has become cargo cult mumbo jumbo. I find it disturbing.
In general for laptops performance/cost is still vaguely linear, even in consumer shops, with audio its just a lot of noise even from supposedly professional shops.
That is not my experience at all. Audio gear that is 'flat', in that it outputs as close a representation to the recording as possible is largely shunned in audiophile circles. They mostly want to listen to something that 'sounds good', with all the psychoacoustic baggage that comes with such a statement. As an example if the end goal is accurate reproduction then a tube amp is objectively worse than almost any other amp built in the last 30 years, yet they sell!
TL;DR the technology is so good and so cheap now that what you get from a $150 set-up today rivals stuff costing much more from a decade ago. I still recommend spending 90+% of your budget over a few hundred dollars on better actual reproduction equipment, be it speakers or headphones.
Not in my audiophile circle (which is mostly head-fi). There are all different price points, and different goals within those. Most reviews I've read in the past decade talk about if the headphones / IEMs are more targeting accuracy or a "fun" sound, but most of the reviews I've ever read on head-fi are very concerned with accuracy and true-to-recording representation. FWIW I'm very much not alone in my interest in things like super low distortion class D, solid-state headphone amps with digital volume control (so you don't introduce a potentiometer / stepped attenuator / LDR into the signal path), ear measuring mics (e.g. https://www.minidsp.com/products/acoustic-measurement/ears-h... ), digital parametric EQs to adjust for not-perfect frequency response, room correction, etc.
The technology in modern decent (decent = what most people would call "high-end", but I'm talking few-hundred-dollar Class D for amps and something along the lines of a properly-engineered ESS 9018-based DAC, maybe $100-200, OR a ~$200-300 headphone DAC+AMP combo, think Oppo HA2-SE level) equipment is so good IMO that headphones / speakers / IEMs make a MUCH MUCH bigger difference than jumping to equipment 10x the cost at the DAC or amp level does. $200 headphones are not bad, but $1000 headphones are damn amazing comparatively. I've owned a dozen pairs of IEMs, and while my gaming 'phones are Shure SE215s, they're not in the same league as my Westone ES60s. Even with that said, most people who have never owned any serious music gear would likely be blown away by just how good the SE215s are, coming out of something like a Fiio K1 or a smartphone / laptop / desktop with a decent DAC+AMP.
Tube amps are still fun to play with, but maybe aside from some 300B snobs, I don't think many people really believe that they're more accurate than modern solid state. Some people also still like vinyl, and will happily spend $10k+ on a record player.
There are also the high-sampling-frequency crowd and the high-bitrate geeks. It's fun to think about, but I personally can't hear a difference between 192kHz/24bit and Spotify "high quality" 44.1/16 with an RME ADI-2 Pro and HD 800S headphones or the ES60s (both balanced, which does sound slightly better to me in both cases). I actually showed up to a headphone meet in Tokyo and pulled out Spotify to demo some flagship IEMs with, and the guy was trying to explain to me how that was like ~eating caviar on a donut.
That one sounds suspect but the only way to correctly measure headphones is on a binaural head.
Yeah.. I vastly prefer a real concert. But some people prefer their home audio setup instead. Even my old aunt.. I heard a guy (self-certified audiophile) complaining about the "bass response" when (apparently for the first time) he went to a classical concert. According to him the orchestra's "bass response" (whatever that means) was sub-standard. I prefer the real concert though (although I mostly go to small avenues). I should add that I have a tiny hearing problem in my left ear - normally I'm not bothered about it at all, but that ear is extremely sensitive to harmonics and quickly turns it into distortion if there's anything not quite right (whatever that is. I have no idea. But I noticed at one time that I can listen at much louder levels with certain high-end speakers. Of the type I could never buy.) Real concerts are bliss though. My ear never complains.
Had pretty much the exact same experience with some noise-cancelling in-ear pair of Bose. I was actually amazed at how good the noise cancelling was, but sound reproduction even in absence of any outside noise was very sub-par. Now I can't imagine the engineers didn't measure this thing, so I'm assuming it was done on purpose, maybe aimed for pop music or so?
It would be like saying that something can’t work because it’s a placebo - even if all they’re getting is a sugar pill, if the symptoms went away, that’s not really something that you can argue with.
I put audiophiles on the same level as sommeliers. The best wine is the one that tastes best to the drinker. You can haul out your GCMS to test the wine and your ABX testing software to test the audio and tell someone their subjective experience is Wrong, but this misses the point. We’re not talking about medical efficacy here, we’re talking about artwork.
if only audiophiles see it this way themselves...
Instead what you have is not placebo effect, but perceived value effect.
After working in high-end audio for many years it became apparent that the (high) price tag was in fact the benefit.
Some people just want what there neighbor cannot afford.
I don't have a $10k system, or anything close to it, but yes, my system that I put together for about $1000 is way way way way better than what you're listening onm because I care enough to have a good external DAC, and feed that into a good amp paired with either a set of decent used speakers or one of a couple of sets of good headphones.
No "cable lifters" in sight.
My laptop emits different squeals when I scroll a window, for example.
I have AB tested my amp with newer models and while there was a difference, it was very minor and not worth upgrading IMO
Another example from audio production, adjusting signal processors while processing is bypassed, and being convinced the sound is changed.
Another one I’ve been noticing is how the resolution of the gain control affects perception of the “power” of the amp. If the resolution of the volume knob is high, meaning it takes more turning motion for the same level increase, the amp “feels” weaker to me, biasing my perception of sound.
The mother of all dilemmas when it comes to comparing audio gear is that the louder source always sounds “better.” This a very powerful perceptual distortion.
So while I think stereotypical audiophile practices are non-sensical, I have no doubt that they really make the systems sound better to the practitioners!
I've had professional recording artists tell me they won't use MIDI over USB because the volume is lower than the old 9-pin connectors.
(Also, I’ve never encountered a 9-pin MIDI connector. 5-pin maybe?)
if i had to guess, it sounds like you have poor hearing ;P
16 bits gives you 96dB SNR (and subjectively more with dithering), which is plenty at non-deafening listening volumes. It's more than even the highest quality vinyl ever had. High bit depth is mostly useful so you've got some headroom during editing.
I can believe that, but the standard was designed to tolerate high bit error rates. 25% of the bits are redundant, as part of a error correction code:
https://en.wikipedia.org/wiki/Cross-interleaved_Reed%E2%80%9...
This scheme works very well, as proved by people consistently ripping bit-for-bit identical copies of CDs pressed or burned with the same audio.
Not a problem for popular music that's consistently loud, but a real problem for classical music with wide dynamic range.
It's important for the room to be quiet, as the sound is very faint and easily masked, but it's there.
It's possible that Bluetooth headphones could lose it because of compression, or cheap DAC in the sound card simply ignores least-significant bits.
CDs are still 1000x better than records with all their hiss and distortion in my humble opinion.
Not saying you're one of these people, but I think lots of old-timers who complain about the quality of CD's or anything digital don't really understand how they work - Even though the bits are "limited", they do not actually output a staircase as shown in the explanations, the signal is interpolated between samples by analog filtering on the output. So it's actually outputting a smooth line that goes through the sample points.
Also lots of stuff is available in 96k and above FLAC now if the limited bits are a problem. I get any music I care about in that quality but it's often because the mastering is better on those releases than the actual quality of the reproduction.
Sometimes there's a SACD, Bluray or DVDA release if there's no hi-res digital download available.
Anecdotally I'm happy if I can get anything at 48k 24bit or more.
It's really the loudness war that has ruined music. That's the only thing about records that I consider better than digital - because of the limitations of the medium, they can't brickwall compress everything or the needle will physically jump off the record.
Genuine question: what was so good about music before that is missing in your opinion now?
Also, do you enjoy digital re-releases of records you previously enjoyed as much as before? Why or why not?
I suspect this is a classic case of "you think you want X, but what you actually want is your youth."
In any case, I've heard some great sound from Type II and Type IV cassette tapes in the past. The worst part was that tapes I made myself from CD sounded way better than a store-bought cassette of the same album. That's when I learned they really cheaped out on those cassettes (brown-colored Type I tapes)
Sort of like how SP (2 hour) on a VHS tape looks much better than LP (4 hour) or ELP (6 hour).
The real difference in quality is probably mostly in having a machine that's properly setup and calibrated, with a good transport to minimize flutter, etc.
This is like when people complain that FM always sounds so much better than the newfangled digital radio, without realising that the station signal was transferred to the transmission stations in digital form, often at lower bit-rate than the newfangled digital radio.
People like the nice familiar sound of low quality audio. Lots of audio equipment deliberately adulterates the sound to "make it sound better".