Belden ICONOCLAST XLR Cable Review

[srkbear]

But it is contentious to say (absent evidence) that different brands or vintages of tubes will have distinctive sounds when driven into clipping characteristic of that brand or vintage. Different tubes, sure, but two different (say) Amperex ECC83 from 1957 with square getters and L70F factory markings will also sound different from one another. In any population of tubes, there's a spread of grid leakage current, plate resistance, and input voltage to take the tube to clipping. The shape of the ink on the glass envelope is not relevant to that.

I’m not sure it’s contentious to say anything in the absence of evidence, if scientific evidence has yet to be attained. Observations are what beget hypotheses that can be subjected to scientific rigor. And although I do build guitar amps as a hobby and work as a research scientist professionally, I’m not certain what data exists on this subject—it’s something I’ve planned to look into this weekend.

If you glance a few posts up, I was the one who brought up the subject of valves being driven outside of normal operating ranges in guitar amps, and I acknowledged that there is quite a bit of lore about tubes and their various levels of esteem in this industry. I also acknowledged Amir’s compelling conclusion of negligible differences among tube brands, in Hi-Fi applications, that he demonstrated via measurements. I do not discredit this evidence, but I don’t agree that it is generalizable to overdriven tubes in guitar amp scenarios—and as I said earlier I’m unsure of how such an experiential, nebulous endpoint, such as the subjective qualities to which guitarists aspire, could be scientifically qualified and properly controlled in the first place.

Nevertheless, given how much this lore has influenced the reverence of certain sought-after tubes amongst decades of esteemed musicians, recording engineers, producers and manufacturers, I think it’s a subject looking into, and I shall. It’s possible that these accepted truths have never been subjected to scrutiny at all, and I have no doubt that there is quite a bit of snake oil pervading the NOS guitar amplifier tube industry either way.

Until then, although I recognize that you are a technical expert in audiophile applications of amplifier engineering and design, to my knowledge there has been no data put forth on here that settles this question either way. And thus I’m going reaffirm that until either you or I return to this forum with new information gleaned from the literature that says otherwise, it is perfectly reasonable, and not a bit contentious, to hypothesize that two different tubes, driven out of their rated operating ranges, might sound different.

 

[SIY]

Until then, although I recognize that you are a technical expert in audiophile applications of amplifier engineering and design, to my knowledge that expertise does not extend to the realm of guitar amplifiers or overdriven tubes. And thus I’m going to call you on your ultracrepidarianism, assert that you are as clueless as the rest of us on this topic, and reaffirm that until either you or I return to this forum with new information gleaned from the literature that says otherwise, it is perfectly reasonable, and not a bit contentious, to hypothesize that two different tubes, driven out of their rated operating ranges, might sound different.

Having measured some thousands of tubes, having spent particular time looking at clipping behavior and its causes, and having designed and built a few dozen guitar amps, I admittedly might not have your deep insight. However, with what scraps I do have, there's no evidence supporting any claims of brand dependence, and the spread of characteristics within brands makes the claim highly unlikely.

 

[srkbear]

Having measured some thousands of tubes, having spent particular time looking at clipping behavior and its causes, and having designed and built a few dozen guitar amps, I admittedly might not have your deep insight. However, with what scraps I do have, there's no evidence supporting any claims of brand dependence, and the spread of characteristics within brands makes the claim highly unlikely.

OK, I admit that I deserve your response for getting inappropriately defensive about what I made up as you dismissing the art behind tube amp guitar playing. I assumed your wheelhouse was specific to Hi-Fi amplifier construction—I stand corrected on your experience, and I’ll offer my sincere apologies for underestimating or disrespecting your expertise.

I don’t know you or the scope of your work personally, and I am indeed not an audio professional—I build Fender Tweed reproductions strictly as a hobby, and practice medicine as a scientist. Your profile carries the imprimatur of “technical expert”, and I trust Amir’s judgment in promoting that badge—so I will of course defer to your fund of knowledge on this subject. This discussion is risking going way off topic, but I do want to explain my position before wrapping this up.

I still maintain that in the absence of data we cannot say whether tubes in this context are equivocal, and although I’m aware that their science is well-established (I am not at your level but I own a Hickok and have measured many a tube), I know of no measurements standard that quantifies how tubes respond to the subtleties of guitar playing technique. I certainly won’t foolishly invoke my own anecdotal experience in sound differences among tubes, but I play the guitar and there is definitely an art to how tubes respond to nuances of performance in terms of sustain, compression, and harmonics. I can’t explain why, but some tubes respond beautifully to these techniques and some simply do not.

Tubes have an entirely different sound over transistors when driven to distortion, and the sound of limp tubes can be heard a mile away—and despite my aversion to anecdotes I’m not yet convinced that these effects are subtle enough to be written off to the hallucinations of cognitive bias without concrete evidence.

I do suspect that there are reasonable arguments to be made for tube build quality informing the preferences for certain manufacturers, such as Telefunken, Genalex and Mullard—and unlike the twerps at Head-Fi who fall for veils lifted by a $1,000 power cable, decades of artists have strongly preferred the sound of vintage amps and NOS tubes, and I think that phenomenon warrants rigorous scientific inquiry before being shrugged off, that’s all. Peace.

 

[SIY]

OK, I admit that I deserve your response for getting inappropriately defensive about what I made up as you dismissing the art behind tube amp guitar playing. I assumed your wheelhouse was specific to Hi-Fi amplifier construction—I stand corrected on your experience, and I’ll offer my sincere apologies for underestimating or disrespecting your expertise.

I don’t know you or the scope of your work personally, and I am indeed not an audio professional—I build Fender Tweed reproductions strictly as a hobby, and practice medicine as a scientist. Your profile carries the imprimatur of “technical expert”, and I trust Amir’s judgment in promoting that badge—so I will of course defer to your fund of knowledge on this subject. This discussion is risking going way off topic, but I do want to explain my position before wrapping this up.

I still maintain that in the absence of data we cannot say whether tubes in this context are equivocal, and although I’m aware that their science is well-established (I am not at your level but I own a Hickok and have measured many a tube), I know of no measurements standard that quantifies how tubes respond to the subtleties of guitar playing technique. I certainly won’t foolishly invoke my own anecdotal experience in sound differences among tubes, but I play the guitar and there is definitely an art to how tubes respond to nuances of performance in terms of sustain, compression, and harmonics. I can’t explain why, but some tubes respond beautifully to these techniques and some simply do not.

Tubes have an entirely different sound over transistors when driven to distortion, and the sound of limp tubes can be heard a mile away—and despite my aversion to anecdotes I’m not yet convinced that these effects are subtle enough to be written off to the hallucinations of cognitive bias without concrete evidence.

I do suspect that there are reasonable arguments to be made for tube build quality informing the preferences for certain manufacturers, such as Telefunken, Genalex and Mullard—and unlike the twerps at Head-Fi who fall for veils lifted by a $1,000 power cable, decades of artists have strongly preferred the sound of vintage amps and NOS tubes, and I think that phenomenon warrants rigorous scientific inquiry before being shrugged off, that’s all. Peace.

I play as well, and have marveled at some of the stuff that gets slung around seriously among the non-technical players.

We've gone far afield of the topic here, but briefly, the greatest determinant of overload characteristics is the circuit itself. This is especially true of the biasing arrangements for signal tubes and the amount of sag under load from the rectifier.

The chief differences among signal tubes is in microphonics (generally not brand dependent), grid current (ditto), and Vgk for the operating point. The last is particularly important- let's say I have a 12AX7 voltage amp with (nominally) a 1mA idle current. I might achieve this by biasing the cathode to be 1V positive of the grid, or equivalently, biasing the grid to be -1V with respect to the cathode. Now... if I run a population of a couple dozen tubes, I'll see that the voltage I need to get that 1mA idle will have a spread from (say) 0.75 to 1.25V. And if I grab a tube from the lower end of that population and one from the upper end, yep, they will act very differently under overdriven conditions and go into overload at very different points. An unbypassed cathode resistor will smooth those differences somewhat but not eliminate them. But here's the key: that spread is almost entirely unrelated to brand! There is a mild (very mild) correlation of microphonics to brand, but again, the population overlap is very high.

If someone wants to demonstrate that they can distinguish between Brand A and Brand B of tubes in this service, there's some relatively straightforward ways to do that, and it would be interesting. But of course, that's less fun than telling stories about Groove Tubes versus NOS Mullards or whatever. My amps have tended to use tubes outside of the common ones, so the brand stuff is far less relevant, but even so, I still went through the process of plugging and unplugging tubes until I got the sound I wanted. Difference is, the tubes I used were cheap and easy to find, so I could buy a dozen to get one that did what I wanted it to do.

Side note: don't let my honorary title have any meaning to you. Argument from authority is a poor way to do things, and I try very hard to avoid it.

Edit: I really should have mentioned that for anyone seriously interested in the technology end of tube guitar amp design, a must-read are Merlin Blencoe's books, most notably "Designing Tube Preamps for Guitar and Bass."

 

[DonH56]

I probably "argue from authority" all too much as I am too lazy and/or have not the time to dig up all the old references, let alone post enough background material to cover years of college and decades of experience to explain my position. I do tend to look up a little info on posters presenting themselves as knowledgeable before assuming they are "clueless". That is a much harder task on the trumpet forum I help moderate, since I have a decent understanding of electrical engineering from working at it for decades, but am not a professional trumpet player (not for years, and only briefly then). Most pro players do not understand the physics of the horn, but I am certainly hesitant to correct them on an open forum. They play better than me no matter their knowledge of flow dynamics. But we have kid players, grade school through college, who "know it all" and they are sometimes hard to pick out immediately. Here at ASR it is actually easier to recognize "the good guys" as many of the principals know each other, by reputation if not personally, and Amir (@amirm) vets folk before giving them the "Technical Expert" label. Much more credible than going by post count or "likes"

Feel free to like this post, however.

I had to look up "ultracrepidarianism" -- nice word, but not applicable to @SIY, and I am pretty sure the engineers and scientists I know don't know that word either. Probably all as clueless as me. Have to remember it the next time I want to call somebody a liar in a public forum.

Out of curiosity, how did we move from high-priced cables to tubes? Not complaining, I think tube characteristics are much more interesting, especially for audio frequencies...

 

[mattanderson]

Out of curiosity, how did we move from high-priced cables to tubes?

There's only so much to discuss.

 

[DonH56]

There's only so much to discuss.

Well, yeah, and tubes are a lot more fun to discuss IMO!

 

[Doodski]

There's only so much to discuss.

It's the off topic diversions that keep me reading sometimes and even marking threads as to be , "Watched." It kills the doldrums.

 

[srkbear]

I play as well, and have marveled at some of the stuff that gets slung around seriously among the non-technical players.

We've gone far afield of the topic here, but briefly, the greatest determinant of overload characteristics is the circuit itself. This is especially true of the biasing arrangements for signal tubes and the amount of sag under load from the rectifier.

The chief differences among signal tubes is in microphonics (generally not brand dependent), grid current (ditto), and Vgk for the operating point. The last is particularly important- let's say I have a 12AX7 voltage amp with (nominally) a 1mA idle current. I might achieve this by biasing the cathode to be 1V positive of the grid, or equivalently, biasing the grid to be -1V with respect to the cathode. Now... if I run a population of a couple dozen tubes, I'll see that the voltage I need to get that 1mA idle will have a spread from (say) 0.75 to 1.25V. And if I grab a tube from the lower end of that population and one from the upper end, yep, they will act very differently under overdriven conditions and go into overload at very different points. An unbypassed cathode resistor will smooth those differences somewhat but not eliminate them. But here's the key: that spread is almost entirely unrelated to brand! There is a mild (very mild) correlation of microphonics to brand, but again, the population overlap is very high.

If someone wants to demonstrate that they can distinguish between Brand A and Brand B of tubes in this service, there's some relatively straightforward ways to do that, and it would be interesting. But of course, that's less fun than telling stories about Groove Tubes versus NOS Mullards or whatever. My amps have tended to use tubes outside of the common ones, so the brand stuff is far less relevant, but even so, I still went through the process of plugging and unplugging tubes until I got the sound I wanted. Difference is, the tubes I used were cheap and easy to find, so I could buy a dozen to get one that did what I wanted it to do.

Side note: don't let my honorary title have any meaning to you. Argument from authority is a poor way to do things, and I try very hard to avoid it.

Edit: I really should have mentioned that for anyone seriously interested in the technology end of tube guitar amp design, a must-read are Merlin Blencoe's books, most notably "Designing Tube Preamps for Guitar and Bass."

Now you’re speaking my language! More technically than I can when it comes to the math, but I’ve read Blencoe, to the extent that I can without an EE degree. Thankfully I dove into it before I grabbed for any undischarged filter caps.

When I first joined this forum I was a complete novice in applying any of the principles I had been taught about evidence-based science to my audiophile hobby, and I had to get sternly confronted a few times on here about marketing-born myths I had bought into and cash I had wasted on nonsense before I got deprogrammed. Until this topic came up I foolishly thought I had sorted all this out.

My insistence on data to settle this comes from decades of dogma I have accrued about the tubes that were employed by so many of my musical heroes, going all the way back to Chet Atkins and the Beatles. I’ve spent years researching and hunting down rare tubes everywhere from antique shows to dusty small town Woolworth stores, and the process of building a collection, twiddling with my Hickok and swapping them in and out of various amps has brought me some of my fondest, most joyous memories.

Being confronted on here with the possibility that it was all a ruse is a bit of a crisis of cognitive dissonance for me, especially since it suggests that countless eminent artists I admire have been bamboozled themselves for eons (and by emulating their choices I may have wasted an alarming amount of money).

So I’m still looking for evidence. I may have to maintain a fixed delusion about this one if I can’t find any. My mission in building these amp reproductions has been to be so faithful to the originals that they’re indistinguishable—so in that sense I can at at least hang on to the belief that my handmade ‘53 Tweed Bassman looks a hell of a lot cooler with RCA black plate 12ax7s, than it would with a new pair of crappy Russian versions instead…

 

[srkbear]

I probably "argue from authority" all too much as I am too lazy and/or have not the time to dig up all the old references, let alone post enough background material to cover years of college and decades of experience to explain my position. I do tend to look up a little info on posters presenting themselves as knowledgeable before assuming they are "clueless". That is a much harder task on the trumpet forum I help moderate, since I have a decent understanding of electrical engineering from working at it for decades, but am not a professional trumpet player (not for years, and only briefly then). Most pro players do not understand the physics of the horn, but I am certainly hesitant to correct them on an open forum. They play better than me no matter their knowledge of flow dynamics. But we have kid players, grade school through college, who "know it all" and they are sometimes hard to pick out immediately. Here at ASR it is actually easier to recognize "the good guys" as many of the principals know each other, by reputation if not personally, and Amir (@amirm) vets folk before giving them the "Technical Expert" label. Much more credible than going by post count or "likes"

Feel free to like this post, however.

I had to look up "ultracrepidarianism" -- nice word, but not applicable to @SIY, and I am pretty sure the engineers and scientists I know don't know that word either. Probably all as clueless as me. Have to remember it the next time I want to call somebody a liar in a public forum.

Out of curiosity, how did we move from high-priced cables to tubes? Not complaining, I think tube characteristics are much more interesting, especially for audio frequencies...

To be fair I apologized for that and removed the contentious and condescending language from my original post awhile ago. We all have character defects and get carried away with ourselves sometimes, right? Perhaps it’s something I need to take a look at.

Anyway, the message that I was very ineffectively trying to communicate was that if there is no data on a particular subject, then arguably nobody’s an expert. Those with greater expertise may be able to form more educated hypotheses, but I wasn’t proclaiming myself more educated. I was deferring to the legions of artists who have spoken and written about preferred tubes for decades, right or wrong.

I thought the matter called for concrete evidence to the contrary before generalizing results born out of Hi-Fi tube performance towards tubes driven out of their rated operating ranges.

But dammit I’m digging myself deeper into a hole and over explaining because I made a fool out of myself, make me stop!

 

[DonH56]

To be fair I apologized for that and removed the contentious and condescending language from my original post awhile ago. We all have character defects and get carried away with ourselves sometimes, right? Perhaps it’s something I need to take a look at.

Anyway, the message that I was very ineffectively trying to communicate that if there is no data on a particular subject, then arguably nobody’s an expert. Those with greater expertise may be able to form more educated hypotheses, but I wasn’t proclaiming myself more educated. I was deferring to the legions of artists who have spoken and written about preferred tubes for decades, right or wrong.

I thought the matter called for concrete evidence to the contrary before generalizing results born out of Hi-Fi tube performance towards tubes driven out of their rated operating ranges.

But dammit I’m digging myself deeper into a hole and over explaining because I made a fool out of myself, make me stop!

Stop.

 

[srkbear]

Stop.

Thanks, I’m relieved. If you ever do decide to use the term “ultracrepidarianism” (which is merely an extension of the Dunning-Kruger Effect), here’s one of my favorite cartoons ever, courtesy of RationalWiki:

 

[DonH56]

Thanks, I’m relieved. If you ever do decide to use the term “ultracrepidarianism” (which is merely an extension of the Dunning-Kruger Effect), here’s one of my favorite cartoons ever, courtesy of RationalWiki:

View attachment 210838

xkcd (https://xkcd.com/) is definitely the comic for geeks... After Dilbert, of course!

 

[srkbear]

xkcd (https://xkcd.com/) is definitely the comic for geeks... After Dilbert, of course!

Perhaps you defy ultracrepidarianism via omniscience. You knew where my favorite comic came from too? How are you with macrame? Elevator mechanics?

 

[DonH56]

Perhaps you defy ultracrepidarianism via omniscience. How are you with macrame? Elevator mechanics?

Still with the insults? I am a generalist but certainly do not claim omniscience. Hardly. Macrame? I managed to pass the knots badge in Scouts long ago. And tie the halter on my horse. The elevator in our building had to be repaired recently (not by me) and a bunch of us very non-omniscient EEs gathered around to watch. It is hydraulic, not the usual motors and cables, so it was a treat to see the "guts" of the system. Mechanical engineers are amazing folk...

Anyway, knowing little about tubes, almost nothing about macrame, and practically zero about elevator mechanics, I am out of here.

 

[Blumlein 88]

Still with the insults? I am a generalist but certainly do not claim omniscience. Hardly. Macrame? I managed to pass the knots badge in Scouts long ago. And tie the halter on my horse. The elevator in our building had to be repaired recently (not by me) and a bunch of us very non-omniscient EEs gathered around to watch. It is hydraulic, not the usual motors and cables, so it was a treat to see the "guts" of the system. Mechanical engineers are amazing folk...

Anyway, knowing little about tubes, almost nothing about macrame, and practically zero about elevator mechanics, I am out of here.

I don't understand srkbear's replies here either. Rather strange.

 

[srkbear]

Still with the insults? I am a generalist but certainly do not claim omniscience. Hardly. Macrame? I managed to pass the knots badge in Scouts long ago. And tie the halter on my horse. The elevator in our building had to be repaired recently (not by me) and a bunch of us very non-omniscient EEs gathered around to watch. It is hydraulic, not the usual motors and cables, so it was a treat to see the "guts" of the system. Mechanical engineers are amazing folk...

Anyway, knowing little about tubes, almost nothing about macrame, and practically zero about elevator mechanics, I am out of here.

Dude, I was kidding! I was impressed that you knew the source of my favorite comic! I am really not some pompous ass, if you knew some of my prior posts I do have a sense of humor, there was no insult implied here at ALL. The exact opposite. I thought my post before that clarified that I was trying to lighten things up, please let me reboot and walk across the burning bridge, help!

Edit: I fixed the post. Now does it make more sense I hope? That’s how I meant it, promise…

 

[srkbear]

I don't understand srkbear's replies here either. Rather strange.

He knew where my favorite comic came from. I was kidding around with him in a worshipful, “how do you know all this stuff?” way. Poe’s Law, please!

 

[srkbear]

OK here’s me, name is Steve, not srkbear or Socrates. Human being here, 99% of the time goofy, not professorial, not even at work. Reset!

 

[Blumlein 88]

OK here’s me, name is Steve, not srkbear or Socrates. Human being here, 99% of the time goofy, not professorial, not even at work. Reset!
View attachment 210867

Are you the top face or the bottom face??