I have a very wise friend who talks about the various ways in which people make sense of the world, in their eyes. For example, one person uses religion and intuition to make sense of much of the world around him, while another might use the scientific method and hard data to make sense of things to her.
In my experience, this is a divide that an adult cannot cross. A young child might be influenced one way or the other by her surroundings, but as adults, we're too firmly stuck in one way of thinking to be able to make the transition.
In the world of hard scientific data, human senses are well known to be fallible and easily tricked (just Google "optical illusions" to see hundreds of examples.) Our other senses - touch, hearing, taste - call also be equally easily, and equally completely, fooled.
So if one op-amp sounds better than another, there are two possible explanations: One, the op-amp really does perform differently, in which case there will be no trouble at all collecting hard data to show this effect is real. Hard data such as oscilloscope traces and spectrograms.
Two, the op-amps actually perform virtually identically (indistinguishable to the human ear), but the nature of our fallible human minds lets us be tricked into hearing one sounding better than the other.
This failing of the human psyche (prejudice, in effect) has been very well documented in thousands of ways for at least the past couple of centuries. For example, classical orchestras used to hire a vast majority of male musicians (whose auditions sounded audibly superior to the hiring committee). Then a legal challenge resulted in new legal requirements that altered the auditioning process in one tiny detail: a thin black cloth was placed between hiring committee and musician so they could not see each other, and other gender cues (perfume, the sound of high heels) eliminated.
After which point, surprise, surprise, suddenly the winning musician at orchestral auditions turned out to have about a 50/50 chance of being male or female. With the "good old boys" unable to engage their prejudices because they did not know the gender of the performer, the hiring process took a huge jump towards objectivity - and everyone benefited as a result. Women musicians didn't lose out to discrimination, orchestras now had the most talented musicians regardless of gender, and audiences enjoyed better music.
To nobody's surprise, I mostly end up on the "scientific method, real data" side of the gulf whenever possible. I find the entirely subjective / intuitive world view terribly limiting, confusing as heck, and seriously damaging to the pocket-book.
Just one sub-forum over, today's typical audiophile falls into the "science is bunk, my senses are infallible, mpingo discs work ( Shun Mook Mpingo Disc | highend-electronics, inc. ) category.
So the question is, which side of the gulf does avtech23 fall on? The side that believes we can hear things we can't measure, or the side that has a century of data showing the opposite?
For now, only avtech23 knows the answer to that conundrum.
I will add that for all of us, some decisions are entirely subjective (such as my preferring my wife to every other woman I've met, or my preference for one guitar amp over another). That's an inevitable part of being human.
But when it comes to technical decisions like op-amp choices, I try my best to follow the scientific method and use hard data, logic, mathematics, and reason to make my conclusions, and to leave subjectivity out of the equation as much as possible.
-Gnobuddy
My goodness, they also do $149 stickers..sorry I meant "Holographic amp tuning chips". Wonder if the dolphins are acoustically superior?
Albat Amplifier Tuning Chips | highend-electronics, inc.
So the question is, which side of the gulf does avtech23 fall on? The side that believes we can hear things we can't measure, or the side that has a century of data showing the opposite?
For now, only avtech23 knows the answer to that conundrum.
As an engineer, I have to side with the logical and measurable. Most of the time.
The hard part of this hobby is trying to make informed decisions though. It takes a lot of time to go wading through the internet to find solid truth regarding the performance of audio, and cutting through the swathes of snake oil. Sometimes a world class chip will sound terrible depending on implementation, but finding a reliable technical source that confirms that is not possible. That's why I asked the question - other than youtube videos, I've not heard the difference between 'old school' spring reverb and '21st Century' digital faux reverb. I knew it would be subjective, but sometimes subjective is all that is available and experience matters.
Another challenge I find is when I find items with identical specs but real-world experiences differ. And not possessing any decent analysis equipment (other than an oscilloscope), I have no way of telling what the technical differences are. Hobby time (and $$) would get sucked away by running comparisons that then get picked apart by the subjectivists and looked at skeptically by the scientists.
And economy. In Oz, the OPA2134 is 12 times more expensive than the RC4558. Does the OPA2134 sound 12 times better? Probably not. But here is the thing - E-Guitar is not Hi-Fi. I don't need to be chasing the thousandths. In this particular implementation, we are sending the signal to be distorted and then sending it back to be distorted some more by the 6v6. I can't see why the cheaper option would sound considerably worse when it is only acting as a side-line to the 12ax7, rather than being the main preamp, and comfortably within specs.
That is assuming that there is a way to MEASURE every aspect of hearing differences. I don't believe this is the case. I agree that differences detected by some CAN be just prejudice; but not EVERY difference. I don't think that our measurement methods have gotten to the point of being infallible. Just as there are subtle changes you can measure but not hear, there are differences you can hear but not measure.
Sadly, I agree with both of you. The Internet has given us thousands of new sources of information, but most are not curated for quality, so there is a whole lot of nonsense mixed in with a few nuggets of gold.
If by "audio" you mean what used to be called Hi-Fi, I myself take an extremely pragmatic approach. By 1960, there was already several decades of high-quality research into human hearing, amplifier performance, the stereophonic illusion, et cetera. Back then, this was real scientific research, conducted by smart, educated, qualified people, like the world-class engineers and scientists who worked for Bell Labs.
By 1980, audio amplifiers routinely exceeded the capabilities of the human ear. By 1990, anyone could walk into a chain store and walk out with an audibly perfect amplifier under their arm, for not much money.
This isn't just me pulling stuff out of thin air. The evidence from carefully conducted listening trials is that we can't hear THD below about 0.5%. Even cheap amplifiers routinely beat that performance by a factor of ten nowadays.
The clincher is a super-simple experiment that Peter Walker (audio engineer and creater of the British firm QUAD) developed and conducted many decades ago: run actual music into an audio power amp, driving actual loudspeakers. Tap off a wee bit of the output signal adjusted to match the size of the input signal; subtract one signal from the other, and look at the residual.
If the amp is mathematically perfect, there will be no residual at all. This is impossible in practice, but Walker found that his QUAD amps of the 1960s and 70s already had residuals below the threshold of human hearing - and in some cases, below the actual thermal noise of air molecules at room temperature bouncing off the human ear-drum!
So audibly perfect amps have been around since before I was born. They were incredibly expensive and rare at first, but the evolution of technology has changed that drastically. Audio amps turned into big discrete op-amps, then into integrated "chip" amps, and suddenly you could get audibly perfect performance for a few bucks.
That being the case, I completely lost interest in Hi-Fi audio amplifier design and construction. There was nothing new to be learned there. Now I buy my audio amps from thrift stores - often a couple of decades old, always with audibly perfect audio performance (i.e. remaining distortions and imperfections are below the ability of the human ear to detect), unless actually damaged and malfunctioning.
When the CD and later DVD audio and WAV and FLAC files arrived, most of the remaining audible imperfections in the record chain also disappeared. No more hiss, no more wow, no more flutter, no more 20% THD from record-player stylus tracing distortion at high frequencies near the centre of the record (where groove velocities are lowest.)
From my point of view, there is only one component of the audio reproduction chain that is still audibly imperfect: the loudspeaker (and the room it's in.) No two sound identical in my experience, which means they all have errors above the threshold of human detection - they all have audible flaws.
A bad PCB layout can turn a modern chip into an oscillating disaster. Something like that should show up fairly easily with a little measurement equipment.
This is one reason why chip manufacturers usually provide a reference PCB design nowadays. They've already prototyped and tested that design, and know it works. Mess with their expertise and time at your peril - it's unlikely the typical DIY hobbyist at home will do any better, and usually, they will do much worse.
But I don't believe in mysterious reasons why the same chip, operating properly, should sound good in one application and bad in another. By definition, a good chip has no sound of its own at all - all distortions are below audibility - and this will be the case for every properly designed, implemented, and constructed application.
A few years ago I still used to hear very bad-sounding digital reverbs. Turn up the reverb level, and it didn't sound anything like actual reverb in an actual large room - it sounded like a cheesy 1980s guitar effects pedal.
Nowadays, not so much. I have real spring reverb in both my Fender amps, and a digital reverb pedal on the pedal-board I use when I play guitar through my little P.A. system. For guitar, I can't tell the difference. For vocals, I only use digital reverb, and as long as you have a halfway-decent implementation, it works fine.
If you're lucky, you stumble across someone else who happens to share your own subjective tastes, and then you can share information with him/her.
But there is such a wide variety of subjective tastes out there. Some are incomprehensible to me (such as the people who like Slayer songs and guitar tone.)
So, like Voltwide, I often find myself having to rely on my own subjective assessment much of the time.
I agree with you, both in the specific case, and in the underlying philosophy.
One way to hedge your bets is to breadboard the circuit first, and listen to it. Sounds okay? On to the PCB design (or Veroboard, or whatever you plan to use.)
Doesn't sound okay? It takes seconds to pull out the 4558 and plug in a 5532 in its place.
Solderless breadboards are wonderful things...I wish they had been around when I was starting out, at eight years old! I wouldn't have inhaled nearly as much solder smoke, or burned myself nearly as often if they had.
-Gnobuddy
Agreed. And when there is an actual difference (not just prejudice), our instruments and measurements will show that the difference really does exist.
Agreed. But our senses are incredibly fallible; our measurement methods may not be infallible, but they are far less fallible than our senses. A fifty-cent electret microphone has a far flatter frequency response curve than our ears do, for example.
If we put, say, a 2 dB, quarter-octave-wide notch in the frequency response of an amp, a good pair of ears might just barely be able to hear it - but even the crudest frequency response measurement with a 1960-era audio function generator and VTVM would immediately reveal it, and not only reveal it, but quantify it: centre frequency, exact depth, exact shape. Stuff our own ears could never even begin to do.
Here's where we don't agree - I do not believe this to be true.
Which is fine. It's a big world, there's plenty of room for differing opinions. It just means you and I won't always see things the same way. (Which is a good thing, as it's actually dangerous to only hear one's own beliefs echoed back by everyone around us. That's how cults with bizarre beliefs start.)
-Gnobuddy
At their time reverberations springs were the best available - simply because no alternatives were available. Nonetheless the sound always was a poor approximation of reverberation and BBDs were even worse. During that era I designed spring reverberation, BBD delays and a digital delay unit as well. It was 1982 that I participated at a demo of the then new Quantec Reverberation System, invented by Wolfgang Schwartz. Since that moment I knew there are far better options to produce natural sounding reverberation the digital way.
Certainly I understand your preference of "vintage" sound, but I think this can be achieved with modern technique as well.
Personnally I prefer the digital reverb delivered by spinsemi F-V1. Nice sound, low noise and affordable price.
Certainly I understand your preference of "vintage" sound, but I think this can be achieved with modern technique as well.
Personnally I prefer the digital reverb delivered by spinsemi F-V1. Nice sound, low noise and affordable price.
Digital spring reverbs can be very convincing but the one thing they can't do is make the sound of kicking the spring tank.
Spring King Reverb | Danelectro Guitars
Spring King Reverb | Danelectro Guitars
Certainly another good point for the digital variantDigital spring reverbs can be very convincing but the one thing they can't do is make the sound of kicking the spring tank.
Spring King Reverb | Danelectro Guitars
Please remember that the Belton brick, which is being discussed in this thread.
a) is NOT a Digital anything, period, so bringing digital reverbs into the discussion is irrelevant
b) it has a "defect" built-in in on purpose, to make it better simulate a coiled steel wire *spring*, and does it quite well.
If given the choice, I would use a real spring, but my Plan B would be a Belton Brick.
a) is NOT a Digital anything, period, so bringing digital reverbs into the discussion is irrelevant
b) it has a "defect" built-in in on purpose, to make it better simulate a coiled steel wire *spring*, and does it quite well.
If given the choice, I would use a real spring, but my Plan B would be a Belton Brick.
I briefly owned a solid-state Fender Frontman 25. The ad copy said it had "Real spring reverb". This was technically true, however the reverb "tank" was a masterpiece of Walmart-style cost reduction.Digital spring reverbs can be very convincing but the one thing they can't do is make the sound of kicking the spring tank.
The single spring was maybe two inches (5 cm) long, there was no metal enclosure, the spring was just suspended in a scrap of moulded plastic. It actually sounded reasonable at low reverb levels, but if you turned up too far, you got this weird sound like a demented metallic woodpecker sliding down the inside of a drainpipe. Every stroke of the guitar pick would start the woodpecker pecking again.
So there's another thing that real spring reverbs can do, and digital ones can't.
-Gnobuddy
The recording studio at Hitsville USA (Motown's original Chicago location) supposedly used a hole in the ceiling, and an actual echo chamber above it, for their "reverb".
Using an actual reverberation chamber or room, typically with hard tiles on all surfaces, was not unusual in that era: The History of Echo (Echo) Chambers (Chambers) – Audio Geek Zine
The old tradition continues today when someone does a home recording in their bathroom, just to get the natural echo / reverb of that small, hard-surfaced space on the track.
-Gnobuddy
There's nothing like a touch of the chance/unknown or barely controlled chaos, sort of like John Cage.
Thanks for the link.
On the MOD FAQ, they refer to this page which has some videos of comparisons between MOD, Accutronics and Belton (spring) reverb tanks: Accutronics Products and Specifications | Amplified Parts
I feel that the MOD sounds like it has a stronger sound to it over the accutronics.
Wow talk about marketing on a technicality.
I've heard of 'hybrid tube amps' where the tube heaters are the only thing connected to the circuit (authentic 'tube glow') but also cases where they don't even bother with that - a simple LED underneath the tube is more efficient
I'd love to hear the sound of a demented, drainpipe bound woodpecker!
Here is the brick patent. It does sound good with the intentional dither.
I just personally prefer the spring.
https://patentimages.storage.googleapis.com/b6/4a/1a/3cbfa35d17ebe6/US8204240.pdf
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I just personally prefer the spring.
https://patentimages.storage.googleapis.com/b6/4a/1a/3cbfa35d17ebe6/US8204240.pdf
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Attachments
While looking for information on the price of the Beltron reverb module in Canada, I stumbled across this little write-up on the history of the Accutronics spring reverb: https://www.sweetwater.com/insync/accutronics-reverb/
Sadly, there is no mention at all of the demented metallic woodpecker effect.
-Gnobuddy
Sadly, there is no mention at all of the demented metallic woodpecker effect.
-Gnobuddy
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