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A/D question


MikeDV1
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Logic tells me the answer, but I'be been thinking about this lately.  Especially given all the ongoing discussion of which is "better sounding", digital vs. analog.  Every time I read one of these arguments, I rarely see this mentioned.

 

If one uses the Helix with any analog unit - stomps, preamps, 4CM - once their signal goes into the Helix (or any digital unit, any place in the signal chain for that matter) and the A/D back to D/A process (if running into a power amp, for instance), there's no more "true" analog signal once it's all gone through this process.  It's been digitized, is affected by any digital changes (EQ, effects, compressors), and is no longer "actually" analog other than the total signal that's pushed into a power amp and/or powered speakers - correct?  I've done all these combinations.  I find I like some of my stomp pedals, some the preamp sounds in rack units or amps, but once it goes into the digital realm, it's all digitally controlled and affected - making the whole "which is better" argument kind of moot when combining these units.

 

Crazy talk, or just something already considered but unsaid - duh!

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I'm pretty sure the folks that are still hung up on analog versus digital in this day and age are only hung up on it so they can have something to argue about.

Consider this fine example:  You send your analog signal from the standard guitar output to the Helix where it's immediately converted to a digital signal.  It's converted back to analog to be sent out of the XLR outputs to a digital mixer where it's immediately converted back to digital and processed through the mixing process.  It's then converted back to analog so it can be transmitted via an XLR signal out to a modern speaker cabinet such as a QSC K12.2 where it's immediately converted back to digital so it can be adjusted by the DSP processors and digital amplifiers in the speaker cabinet based on the configuration you set into the speaker's parameters and then eventually converted back to analog when it's sent to the speakers in the cabinet.  If that performance gets recorded on someone's phone...guess what?  Yet another cycle through the digital to analog conversion washing machine.  And yet some people would still argue they can tell the difference between an analog and digital signal in a double blind test.  Maybe it's true if they are half human and half bat.....

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Thousands of guitarists use digital delays/reverbs and have for many years. Nothing new.

 

Here's an interesting video on the subject. Watch the whole thing. The demonstration of what the bit depth does is especially interesting:

 

 

 

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Back in the 80s/90s when CDs first came around, we had similar discussions (and then again when MP3 came around). 

 

As far as CDs go, I always found AAD to sound better than DDD. 

And today's bland mainstream music, I don't blame the digital. I blame all of the uber processed recordings - every auto-tuned note synchronized to a computerized timing clock. All while compressors/limiters make the volume for each note exactly the same. No amount of - "let's put it on vinyl" will make it sound any better. 

 

So, while not completely related, it is not unrelated to your question. 

You just have to look at all the factors, not just one. Because they all have a role in the final output. 
Even the L6 stuff, some people say they get better tone using it with a tube amp (but then they go and record on a computer). So, in that instance, it is the last stage of tone that brings out the 'warmth' for them. Change the speaker to get a little 'extra'. Everything else is that same bland digital that they hate, but the tube amp they like. How do they capture the tube amp warmth on a computerized recorder, is anyone's guess. 

 

Using myself as an example, I never used a tube amp.  Once I 'completed' building my [previous/old] rig, it was all microchips. Nothing like today's digital experiences, but certainly not analog. But no one ever told me I was too digital/processed. No one ever told me my tone was lacking. They either liked what they heard or they didn't.  

*specifically a Peavey Bandit 65, two ART SGE Mach II, and a Rocktron Pro GAP (the black and red model).

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As rd2rk said, thousands - including me - have used digital delays and other transistor and digital effects for years.  I always thought the continued controversy about digital vs. analog had a little bit of silliness to it because of this.  The controversy wasn't so loud because there were still tube preamps and power amps to use, so the A/D D/A part was pretty much ignored by most (there were some "purists" who would make mention of it), but it still was relevant to my point above:  if something is turned into digital at some point, it's at least partially a digital signal.  Those of us who have played for years played plenty of tube amps (those were definitely most prevalent), solid state amps, and nowadays digital amps know they all have their perceived character, and some actual physics related reasons for one characteristic or another.  Saying one  "sounds better" than the other is just pissing in the wind, as far as I'm concerned.  Vibrating strings, turned into electrical impulses, moving through wires into tubes, transistors, digital devices, somehow making another thing move in some fashion to make sound waves.  Seems at the end of the day, it's still all in the fingers.  Turns out it's all an adventure for our minds.  This isn't a dig on the beautifully (and some not so beautifully) made, hand wired tube amps made with care and love.  The Mesa Road King head is still my favorite of all, and if I could afford another, I'd keep it in my basement - who could carry, set up, keep up that monster?  Not me, anyway.  I also had an Ampeg VH-150 solid state head I loved and gigged with for years that floated my boat as well.   But I can get the goods (my goods) through my Helix and a solid state power amp too.  Thanks for all the replies.

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On 4/30/2022 at 5:06 PM, MikeDV1 said:

there's no more "true" analog signal once it's all gone through this process.

 

There is no "untrue" analog signal.

 

What you have wanted to express is probably something along the line that an analog signal that was previously going through a digital stage via A/D and D/A wandlers possibly isn't exactly the same signal as at the beginning of that signal chain.

 

Well, yes. That would be true.

 

The same is also true for the original analog signal after it has flown through a 20 m long thin unshielded speaker cable, as opposed to the very same signal that has only flown through a 1 m long shielded instrument cable.

Both are analog so they both should be "true", right? Or not? :D

 

The main annoying thing you may experience via several A/D D/A stages these days is the increase of latency.

 

But then again, get yourself a quality 20 m instrument cable, plug it directly into your analog amp, walk 20 m away from your amp, and by the sheer laws of physics you will experience an analog latency of whopping 59 ms.

 

On 5/1/2022 at 2:03 PM, silverhead said:

Or, wait …. Is it the other way around?

 

No, you're right.

But my late dad would have strongly disagreed.

Heck, even my wife would! ;)

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It's definitely an interesting video ... but .... he refers to 1 KHz as being midrange when in actuality it is the beginning of the highs on a guitar.  That may not make sense to you if you don't understand how logarithms work but it is still true nevertheless.  1 KHz is roughly a 1st string at the 20th or 21st fret.  An open 6th string (E) is roughly 80 Hz.  Then he keeps jumping up the frequencies higher and higher and for some reason implying things should get worse as they get higher when in fact they naturally get better, not worse due to the time interval being so minuscule as to be unnoticeable to the human ear.  It's the lower frequencies where the stair steps should be most noticeable but he skips those frequencies altogether and that is unfortunate because those are the frequencies we need to know about.  In reality, he's addressing the harmonics of a typical guitar and those get better as they get higher despite his alluding to the contrary.  The fundamentals on a guitar are at or below 1 KHz.

Open E (6th) - 82.4 Hz

Open A (5th) -  110.0 Hz

Open D (4th) - 146.8 Hz

Open G (3rd) - 196.0 Hz

Open B (2nd) - 246.9 Hz

Open E (1st) - 329.3 Hz

 

20th fret, E (1st) - 987.8 Hz - still ever so slightly below 1KHz.

 

His conclusions are interesting but he did not apply them to the fundamentals of a guitar.  I'm no mad scientist but I do know the difference between fundamentals and harmonics.  

 

Also, the reality is ... if you've been playing in a rock band for a number of years you very likely have permanent hearing loss and you are probably legally deaf at frequencies over 10 or 12 KHz so 20 KHz really has little to no meaning for a working guitarist.

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On 5/1/2022 at 3:12 PM, MGW-Alberta said:

It's definitely an interesting video ... but .... he refers to 1 KHz as being midrange when in actuality it is the beginning of the highs on a guitar.  That may not make sense to you if you don't understand how logarithms work but it is still true nevertheless.  1 KHz is roughly a 1st string at the 20th or 21st fret.  An open 6th string (E) is roughly 80 Hz.  Then he keeps jumping up the frequencies higher and higher and for some reason implying things should get worse as they get higher when in fact they naturally get better, not worse due to the time interval being so minuscule as to be unnoticeable to the human ear.  It's the lower frequencies where the stair steps should be most noticeable but he skips those frequencies altogether and that is unfortunate because those are the frequencies we need to know about.  In reality, he's addressing the harmonics of a typical guitar and those get better as they get higher despite his alluding to the contrary.  The fundamentals on a guitar are at or below 1 KHz.

Open E (6th) - 82.4 Hz

Open A (5th) -  110.0 Hz

Open D (4th) - 146.8 Hz

Open G (3rd) - 196.0 Hz

Open B (2nd) - 246.9 Hz

Open E (1st) - 329.3 Hz

 

20th fret, E (1st) - 987.8 Hz - still ever so slightly below 1KHz.

 

His conclusions are interesting but he did not apply them to the fundamentals of a guitar.  I'm no mad scientist but I do know the difference between fundamentals and harmonics.  

 

Also, the reality is ... if you've been playing in a rock band for a number of years you very likely have permanent hearing loss and you are probably legally deaf at frequencies over 10 or 12 KHz so 20 KHz really has little to no meaning for a working guitarist.

 

Whether or not he knows the difference between guitar frequency ranges has little to do with the points he was DEMONSTRATING.

His point was not so much about what's perceptible (people imagine that they can perceive all sorts of things) so much as what's real and OBJECTIVELY DEMONSTRABLE.

Please do post a link to a video that DIS-proves anything he said, vs implying that he left something out that would disprove his main point.

 

I'd honestly be interested and would happily re-post that link whenever I post this one.

 

 

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As I said in my post, he left us out of his demonstration and that it is unfortunate because we need to know about those frequencies more than any others.   

He did in fact leave something out; everything below 1 KHz.

I too would like to know about frequencies from 80 Hz to 1 KHz or for that matter, as low as 40 Hz, which is the low open E on a 4 string bass tuned to standard pitch.

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On 4/30/2022 at 10:06 AM, MikeDV1 said:

Especially given all the ongoing discussion of which is "better sounding", digital vs. analog.  

 

I find the ongoing discussion more laughable as the years go on. I can't tell you how many times I've listened to a guitar player talk about how he won't use any digital crap, nothing but a trusty pedal board into a tube amp. When I look at their board it often has 2 or 3 Strymon's on it. I love breaking the news to them :)  

 

On 4/30/2022 at 12:50 PM, pianoguyy said:

As far as CDs go, I always found AAD to sound better than DDD. 

 

It certainly took mixing & mastering engineers many years to come to grip with the change. The transition was painful but (IMO) once people caught up to the technology I find I do prefer a "well produced/engineered" DDD recording.

 

On 4/30/2022 at 12:50 PM, pianoguyy said:

I don't blame the digital. I blame all of the uber processed recordings - every auto-tuned note synchronized to a computerized timing clock. All while compressors/limiters make the volume for each note exactly the same. No amount of - "let's put it on vinyl" will make it sound any better. 

 

Yes... yes... yes! The technology is fine, it's the abuse of the technology that is to blame. Guitar players are not immune to this.... for some reason guitar players intuitively know that they can't turn every effect on their monster pedal board on at the same time, yet with a modeler many lose all control then often claim modelling doesn't sound good. 

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On 5/2/2022 at 9:12 AM, MGW-Alberta said:

It's definitely an interesting video ... but .... he refers to 1 KHz as being midrange when in actuality it is the beginning of the highs on a guitar.  That may not make sense to you if you don't understand how logarithms work but it is still true nevertheless.  1 KHz is roughly a 1st string at the 20th or 21st fret.  An open 6th string (E) is roughly 80 Hz.  Then he keeps jumping up the frequencies higher and higher and for some reason implying things should get worse as they get higher when in fact they naturally get better, not worse due to the time interval being so minuscule as to be unnoticeable to the human ear.  It's the lower frequencies where the stair steps should be most noticeable but he skips those frequencies altogether and that is unfortunate because those are the frequencies we need to know about.  In reality, he's addressing the harmonics of a typical guitar and those get better as they get higher despite his alluding to the contrary.  The fundamentals on a guitar are at or below 1 KHz.

Open E (6th) - 82.4 Hz

Open A (5th) -  110.0 Hz

Open D (4th) - 146.8 Hz

Open G (3rd) - 196.0 Hz

Open B (2nd) - 246.9 Hz

Open E (1st) - 329.3 Hz

 

20th fret, E (1st) - 987.8 Hz - still ever so slightly below 1KHz.

 

His conclusions are interesting but he did not apply them to the fundamentals of a guitar.  I'm no mad scientist but I do know the difference between fundamentals and harmonics.  

 

Also, the reality is ... if you've been playing in a rock band for a number of years you very likely have permanent hearing loss and you are probably legally deaf at frequencies over 10 or 12 KHz so 20 KHz really has little to no meaning for a working guitarist.

So you are missing key info here.

 

To reproduce any frequency accurately you need a sample rate twice the frequency.  So, to reprocuce a 80Hz low E fundamental you only need a sample rate of 160Hz.  

Of course the TONE of your Low E string is defined by the harmonic series above the fundamental, so:(rounding the figure for simplicity)

80Hz, 160Hz, 240Hz, 320Hz, 400Hz, 480 Hz 560Hz....by this point the level of the harmonics is pretty low but not non-existent.

If we do this to an E at the 12 fret of the high string we have a fundamental at around 680, so the harmonic series is:

680 Hz, 1260 Hz, 2040 Hz,2720 Hz, 3400 Hz, 4080 Hz, 4760 Hz. Again - very quiet at this point. (note this is why most guitar speakers drop of sharply over 4 K)

It is the relative volume of each harmonic in the series that gives TONE.  There is an argument that the sample rate needed for guitar might be as low as 12K...and many of the early reverbs had this and professionals were very happy with them. The early Analog (as a BBD) delays topped out at 4K frequency range which fits with this well.

 

Modern digital devices sample at 44.1K or higher...which means a frequency of 22K can be accurately converted.

 

Now we cantr forget Bit Rate...and this is where those very low volume upper harmonics can get lost....the 12K sample rate reverbs of the eighties were originally 8 bit.  CDs are 16....modern devices can be 24 or 32....recording tech as high as 196.

Bottom line...early digital had limitations we could hear.   Modern digital - no way.

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You guys are missing my point.
Yes, I understand everything you're saying and I get your points exactly.

All I said was the video did not address the fundamental frequencies of guitars.
I did not say digital is crap.
I did not imply digital is crap.
I did not even hint vaguely that digital is crap.

I own a Helix myself and I love it.

 

All I did was point out that the frequencies the guy demonstrated were not within the fundamentals of a guitar.

I made no assertions beyond that fact.

 

Try not to be so obviously desperate to start a debate over it.

Contrary to popular belief, it is actually possible to make an observation without an evil agenda.

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On 5/5/2022 at 6:47 PM, MGW-Alberta said:

All I said was the video did not address the fundamental frequencies of guitars.

 

Point taken and addressed by @lawrence_Arps.

 

On 5/5/2022 at 6:47 PM, MGW-Alberta said:

I did not say digital is crap.
I did not imply digital is crap.
I did not even hint vaguely that digital is crap.

 

No, you didn't, and nobody stated or implied that you did.

 

On 5/5/2022 at 6:47 PM, MGW-Alberta said:

Try not to be so obviously desperate to start a debate over it.

Contrary to popular belief, it is actually possible to make an observation without an evil agenda.

 

You need to take your own advice!

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They were mastering records through digital delay units as far back as the 70s, so most who argue the toss don't even realise they're quoting "analogue" examples that were digitised, anyway.

FWIW, the process was the mastering engineer had to EQ the master on the fly, so a delay was introduced to allow him to make realtime adjustments. He listened 'live', made adjustments, the delayed signal was  sent to the master.

 

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On 5/11/2022 at 9:19 PM, soundog said:

I'm going to bed.

 

Nighty night!

Sleep tight!

Don't let the digital bed bugs bite!

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