Stewart world 2.1 digital?

[Wiremessiah]

Your 1" analog tape machine is a lot more complicated than a digital recorder... I used to service them back in the day

Just a black box for me. I just push record. Not all the tracks are calibrated equally, but thats what makes it so compelling. Perhaps a digital multitrack with no editor might be more simple, but not protools or any editing software.

 

[seamonkey]

class d could be considered "non analog" or "non continuous"

Look at your computer screen, it's refreshing 60 or 120 times a second. That's pretty darn slow, and yet it looks continuous. It too is analog. Eye's are analog, computer screens are analog out.

Modern Class-D is working at least 250,000 times per second, there's no way for humans to hear that.

Look close at magnetic tape under a microscope and you'll see it's made of magnetic particles. It's not continuous in that sense.

Nerve impulses are sent from your ears to your brain. It's not continuous - it's pulses.

I think the way things are going it's going to be harder and harder to worry about what kind of signal it is, than what we perceive. Human perception is nothing like reality. As long as we perceive an continuous signal with our analog senses, it is "continuous".

 

[beans-on-toast]

I have thought about the convenience of digital and have a full 16 track logic and protools setup with a bunch of softsynths i acquired, but it was all too much with all of the instruments i already play. I found just pressing record on my 1" 8 track tape machine and just playing with no editing is the easiest simples and best sounding experience for me.

I'd love to get a clasp box. The signal goes to tape and loops right back to the DAW. The advantages of the sound of tape and heads without the disadvantages.

Home « Endless Analog

 

[Wiremessiah]

Look at your computer screen, it's refreshing 60 or 120 times a second. That's pretty darn slow, and yet it looks continuous. It too is analog. Eye's are analog, computer screens are analog out.

Modern Class-D is working at least 250,000 times per second, there's no way for humans to hear that.

Look close at magnetic tape under a microscope and you'll see it's made of magnetic particles. It's not continuous in that sense.

Nerve impulses are sent from your ears to your brain. It's not continuous - it's pulses.

I think the way things are going it's going to be harder and harder to worry about what kind of signal it is, than what we perceive. Human perception is nothing like reality. As long as we perceive an continuous signal with our analog senses, it is "continuous".

Well thats just getting deep into semantics. Film is only 24 frames per second yet looks continuous, but we wouldnt call it digital. All matter is made of discrete particlans so in your sense of the world everything is digital. I just want to know more about how signals work, and digital and analog are decent terms to categorize them into, taking for example the continuity of a vinyl groove vs.the discrete nature of an a/d converter as a jumping off point.

 

[BassmanPaul]

Well thats just getting deep into semantics. Film is only 24 frames per second yet looks continuous, but we wouldnt call it digital.

WE wouldn’t call Class D digital. You are!

Personally I don’t like how tape sounds. I much prefer a direct feed to the cutting lathe for pristine recordings!

 

[Wiremessiah]

I'd love to get a clasp box. The signal goes to tape and loops right back to the DAW. The advantages of the sound of tape and heads without the disadvantages.

Home « Endless Analog

Those are cool if you got old tube or colored machines like a studer j37 or an ampex, but for a machine like mine (otari mx70) that is called "vanilla" its not really helpful. I guess it could be with some low output tape slammed into saturation but thats not really my thing. I just love the simplicity of it and the actual transparency. Digital is often called transparent because of the clarity and brightness of it, but if you heard my minimoog played back through my machine, youd hear that its just like a time delayed straight wire. With acoustic sources especially piano and acoustic guitar, digital does a better job at transparency, but with electric instruments clean wide track tape is more real and live sounding.

In fact the reason i fell in love with tape is when i went to engineering school i brought my newly acquired vintage beatle bass into one of the studios with a studer a827 24 track. None of us, including the teacher could believe how great it sounded coming back off tape.

 

[seamonkey]

so in your sense of the world everything is digital.

No, it's all analog

 

[agedhorse]

Those are cool if you got old tube or colored machines like a studer j37 or an ampex, but for a machine like mine (otari mx70) that is called "vanilla" its not really helpful. I guess it could be with some low output tape slammed into saturation but thats not really my thing. I just love the simplicity of it and the actual transparency. Digital is often called transparent because of the clarity and brightness of it, but if you heard my minimoog played back through my machine, youd hear that its just like a time delayed straight wire. With acoustic sources especially piano and acoustic guitar, digital does a better job at transparency, but with electric instruments clean wide track tape is more real and live sounding.

In fact the reason i fell in love with tape is when i went to engineering school i brought my newly acquired vintage beatle bass into one of the studios with a studer a827 24 track. None of us, including the teacher could believe how great it sounded coming back off tape.

The ear is an easy thing to fool. I used to service Otari, while you may feel that it is transparent the fact that the channels are not all calibrated identically and also have individual amplitude & phase curves means that they are all different even if you can't hear the difference. Same goes for digital, except that the channels will all sound identical, and it will be even closer to the sound of the source even if you don't appreciate all the signal degradation that happens via an analog tape machine. There is a difference between accurate and what you feel that you prefer.

I've worked extensively in both worlds (analog and digital), but am much more of an analog guy. It does pain me to say that digital can be just as good or better than the analog circuits that I have designed, but I don't claim that analog is always going to sound better even if I designed in the analog domain. It's all about the intent and skill of the designer more than the actual technology. I do agree that often the digital user interface pretty much sucks compared with the analog interface, but that's what's being accepted these days.

 

[beans-on-toast]

Those are cool if you got old tube or colored machines like a studer j37 or an ampex, but for a machine like mine (otari mx70) that is called "vanilla" its not really helpful. I guess it could be with some low output tape slammed into saturation but thats not really my thing. I just love the simplicity of it and the actual transparency. Digital is often called transparent because of the clarity and brightness of it, but if you heard my minimoog played back through my machine, youd hear that its just like a time delayed straight wire. With acoustic sources especially piano and acoustic guitar, digital does a better job at transparency, but with electric instruments clean wide track tape is more real and live sounding.

In fact the reason i fell in love with tape is when i went to engineering school i brought my newly acquired vintage beatle bass into one of the studios with a studer a827 24 track. None of us, including the teacher could believe how great it sounded coming back off tape.

I demo'd a clasp with an A827, it worked very well. The advantage is time saving, you don't go to tape and then play back the tape to load it into protools. But the Studer machine adds a nice quality to the sound. It also reduces the project tape cost. The same tape is used over and over because the tracks are not being stored on tape. Recording is as fast as just using protools. Multiple takes can be done one after the next, no delays rolling back for each retake.

All digital, without tape, sounds even better with the right converters. For that, I like BURL Audio.

 

[HolmeBass]

Okay that makes sense. I have a digitally generated control voltage pedal i use to control parameters on analog synths, and i wouldnt call the synths digital. However, even if class d amps were created with tubes, "digital" CAN also mean non continuous, so in that sense it seems to me at the very least class d could be considered "non analog" or "non continuous" disregarding my stewart.

Not that it matters, just trying to get a handle on what class d is. I have read several articles on it, but am still out of my depth.

At the risk of possibly duplicating a response of someone with more experience than I, I felt like chiming in on what I see here as an inaccuracy.

Digital does not mean non-continuous. So PCM/PWM modulation schemes are not themselves automatically digital. Digital implies a sampling of one or more analog parameters and a conversion to a pur data state of "just numbers". Those numbers would then be operated on by a program, usually embedded firmware, as "just numbers". The resulting processed signal, whether your bass' signal or just a control signal, would then have to be converted from digital back to analog, usually a voltage of some sort, that then operates in the circuit.

Digital implies analog-to-digital conversion, or beginning with digital data. Pulse code/pulse width modulation, like FM, do not require the A/D conversion. Sometimes the controller for PCM is digital, but I don't think the actual modulation ever is.

Unless Agedhorse or some of the other honchos disagree, in which case I am wrong and they are right.

 

[bobcruz]

Another way to counteract the unfortunate association of the word "digital" with any sort of amplification is to imagine how such an amplifier could operate--would it somehow make the zeroes and ones bigger? Louder? But zeroes and ones don't sound like anything...hence the need for conversion to an analog signal that actually can be amplified. There could be all kinds of digital conversion and manipulation of the signal going on in the preamp, but the amplification isn't going to be part of it. This is just how a totally ignorant lay person (me) thinks about it and I could be very, very mistaken. Someone will probably come along and show us how digits can be amplified....

 

[HolmeBass]

Another way to counteract the unfortunate association of the word "digital" with any sort of amplification is to imagine how such an amplifier could operate--would it somehow make the zeroes and ones bigger? Louder? But zeroes and ones don't sound like anything...hence the need for conversion to an analog signal that actually can be amplified. There could be all kinds of digital conversion and manipulation of the signal going on in the preamp, but the amplification isn't going to be part of it. This is just how a totally ignorant lay person (me) thinks about it and I could be very, very mistaken. Someone will probably come along and show us how digits can be amplified....

Well, easy to "amplify" a signal in the digital domain, DAWs do it all the time. You just increase the bit depth value. Your bit depth determines the dynamic range on incoming A/D, so once converted, you just up the "volume" number. Super easy to do in the digital domain.

 

[R Baer]

I have an old stewart power amp that has never failed me, but i never did any research on it until now, 5 years later. I looked up threads on this forum and several times it was mentioned as a digital amp. Obviously thats not a cut and dry term, but its specs state it is a class H amp, which from what i read is just a class a/b with modifications.

The only reason i ask is that i am an analog snob and all of my instruments, amps, effects, processors amd recorders are all, in some cases painstakinly, analog, and i feel slightly cheated for buying a digital amp. Please give me peace of mind. Nothing against digital, its just that like skittles i do my best to avoid it.

I still use a World 2.1 and really love the way it sounds for bass. If yours is still chugging along, I would hold on to it, it's a great amp.

 

[bobcruz]

Well, easy to "amplify" a signal in the digital domain, DAWs do it all the time. You just increase the bit depth value. Your bit depth determines the dynamic range on incoming A/D, so once converted, you just up the "volume" number. Super easy to do in the digital domain.

Kind of like this?

Musical input signal converted to digits: 01100110001110101111000111000010

Bit depth manipulated like so: 01100110001110101111000111000010

For some reason that second string still sounds the same to me as the first string. I'm just hopeless with technology.

Sorry, just messing with the idea--obviously when that second string does actually get converted and amplified, it will be louder I'm sure.

 

[HolmeBass]

Kind of like this?

Musical input signal converted to digits: 01100110001110101111000111000010

Bit depth manipulated like so: 01100110001110101111000111000010

For some reason that second string still sounds the same to me as the first string. I'm just hopeless with technology.

Sorry, just messing with the idea--obviously when that second string does actually get converted and amplified, it will be louder I'm sure.

While the data are recorded as a "string of 1's and 0's" it is not like each sample is represented just by a single 1 or 0. (Except in 1-bit recording, which I frankly don't understand.)

In a 16-bit sample each sample is represented by 16 numbers, either 1 or 0 each. A 24-bit sample is represented by 3 bytes. Digital recording is always done at a certain sample rate and bit-depth. Each channel of CD audio is comprised of signed 16-bit values at a 44.1 kHz sample rate.

So increasing the volume digitally involves changing the values of some of the 1's and 0's in each sample.

 

[Wiremessiah]

The ear is an easy thing to fool. I used to service Otari, while you may feel that it is transparent the fact that the channels are not all calibrated identically and also have individual amplitude & phase curves means that they are all different even if you can't hear the difference. Same goes for digital, except that the channels will all sound identical, and it will be even closer to the sound of the source even if you don't appreciate all the signal degradation that happens via an analog tape machine. There is a difference between accurate and what you feel that you prefer.

I've worked extensively in both worlds (analog and digital), but am much more of an analog guy. It does pain me to say that digital can be just as good or better than the analog circuits that I have designed, but I don't claim that analog is always going to sound better even if I designed in the analog domain. It's all about the intent and skill of the designer more than the actual technology. I do agree that often the digital user interface pretty much sucks compared with the analog interface, but that's what's being accepted these days.

The ear is an easy thing to fool, but not as easy as the mind. If you or i or the "golden ears" of audio cant tell an audible difference, then there is no practical difference or any difference worth talking about. Case in point: for a long time DSD was considered the holy grail of digital, and in fact sadly many high end experienced and accompished engineers sti think it is. However, AES did comprehensive blind tests and scientifically proved it was completely and utterly indistinguishable from PCM. I cant and wont fault anyone for thinking that dsd sound better to THEM, because i know the extreme power of placebo effect and that one can and does hear differences that are not there. I know what you are saying about being pained by the high quality of digital, and trust me i know the feeling. I have a $5000 tube eq that has been shown to be indistinguishable from the high end modeled plug in version. How do you think the million dollar stradivarius owners felt when it came out they were no better than modern instruments in blind tests? Its far easier to bury your head in the sand and continue to believe myths that have been proven false.

So my ears and mind are not easily fooled. I do blind tests all the time ( though obviously not double blind) and I actually came up with a psychological distinction in audio engineering which i call absolute vs relative listening. It involves the difference between comparing two audio signals vs evaluating them on their own. Its kind of like the "pepsi challenge" of the 80s where pepsi exploited a human psychological phenomenon to sell soda. They gave people two small samples of coke and pepsi, and pepsi would win almost every time because it is sweeter. But it was later proven that the perceived superiority was negated when people were asked to evaluate the two by themselves or by drinking larger amounts, which is analagous to absolute listening.
The idea is that when comparing two signals in the standard a/b test the signal that is louder or brighter even by a fraction of a db will sound better, and this is also scientifically proven. But that doesnt mean that perceived quality difference will translate to a whole mix or that the sacrifices in dynamic range for loudness will make a listening experience better in the absolute.

But anyway back to tape, not all machines are created equal, but clean (not artificially colored by analog front ends which is what companies are doing now to distinguish themselves) digital converters of the modern era are almost completely homogeneous.

My particular machine is very transparent, disregarding any small level or eq changes due to drifting alignment (which i check every month or so, and sometimes adjust if it goes out by more than a db) which are not audible. My machine was sort of an anomaly in that it was one of the last machines designed before digital took over and is extremely precise. I have done lots of blind a/b tests between sources, and digitally and tape recorded sources, and digital does better at certain sources and my machine does better accuracy with, generally speaking, electric instruments like bass,guitar, clavinet, and analog synths.

The term "transparent" can mean different things,and digital seems to capture acoustic environments and instruments better meaning digital is transparent in that way, while my particular machine capture the liveness and realness of electric instruments. This is not just in my mind, i have had engineer friends say the same.

But again it doesnt really matter. Any self respecting engineer can make a good album with just stock pro tools and stock plug ins. But we pick the gear that is most inspiring and best fit for us.

 

[Wiremessiah]

I still use a World 2.1 and really love the way it sounds for bass. If yours is still chugging along, I would hold on to it, it's a great amp.

I never considered getting rid of it. I just saw some people on this forum calling it digital and wanted to know why. I understand more now. But my analog snobbery and ignorance about class d amps convinced people i was trying to say analog is superior. Its not, i just happen to like vintage gear which is analog and went for all analog just as an arbitrary philosophy. It forces me to be in the moment when recording and to keep small mistakes which make my recordings more live sounding, rather than perfect, which often takes the life out of music. I have noticed a lot of high quality live versions of songs i hear are much better sounding to me that the overproduced studio versions. The imperfections, particularly subtle tempo changes even from bar to bar make music richer IMO. The grid and perfect tempo unnatural to me.

 

[agedhorse]

I agree whole-heartedly about inspiring... I am more inspired designing analog circuitry but understand that there are things that can be more accurately done with lower noise in the digital domain.

 

[Wiremessiah]

I agree whole-heartedly about inspiring... I am more inspired designing analog circuitry but understand that there are things that can be more accurately done with lower noise in the digital domain.

But accuracy is a false ideal IMO. Its a vestige of when people in the recent past had to worry about noise and transparency, and even crappy semi pro gear was out of reach of most musicians and engineers. Now everything is near perfect, so much so that now everyone is making "colored" gear even converters which is absurdity. We idealize the sounds of the past when the people back then would killed for a garageband setup.

Accuracy is good for classical and such, but for instruments like bass (a magnetic pickup is the least accurate transducer there is) euphony is a better ideal.

 

[megafiddle]

Wait, class d does mean digital. Regardless of nomenclature, thats what i meant by digital. But the stewart is not class d. Or does "switching" mean the same thing?

But the transistor wasnt invented until 1947, and from everything i read class d is made from mosfets. Not trying to argue, i am just ignorant on the subject and only know what i read from different sources.

Okay that makes sense. I have a digitally generated control voltage pedal i use to control parameters on analog synths, and i wouldnt call the synths digital. However, even if class d amps were created with tubes, "digital" CAN also mean non continuous, so in that sense it seems to me at the very least class d could be considered "non analog" or "non continuous" disregarding my stewart.

Not that it matters, just trying to get a handle on what class d is. I have read several articles on it, but am still out of my depth.

"Digital" is often used quite loosely, to describe logic and switching circuits. This is likely the result of assuming that a circuit which only has two levels must be representing either a "0" or a "1".

"0" and "1" are only interpretations. Depending on the application, the two levels (or states) could mean true or false, on or off, yes or no, or red or green. In the case of a class D amp, the two levels represent a certain positive and negative voltage, not numerical quantities.

In a digital system, the levels do represent numerical quantities, with the levels usually organized in groups of a fixed size. For example, CD audio consists of 16 bit groups; each bit represents a 0 or 1, and the 16 bit group can represent any value between -32768 and 32767. This is a true digital system, where some analog value (the instantaneous voltage of an audio signal) is represented as a numerical quantity.

The class D amp is not a digital system, as the high and low states of the switched voltage do not represent numerical values of the audio signal. Instead, these represent another analog quantity: time. In this case the analog signal voltage is converted to an analog pulse width.

Analog signals are continuous, at least in our macroscopic experience with them. Digital signals are discrete because of practical and technical limitations. The analog quantity must be sampled and "frozen" at a fixed level so a conversion to a numerical quantity can be performed. This conversion takes time, and so there is a limit as to how frequently (at which rate) it can be performed.


The technology has nothing to do with whether a sytem is analog or digital. Digital computers have been built with vacuum tubes (ENIAC). Analog computers have been built with solid state op amps.

-