Jim, I have just browsed this thread and had quite a giggle at some of the responses.
For what it is worth, I have been participating in this forum for quite a few years. In that time I have come to recognise that there are quite a few contributors who's advice is worth listening to. Sy is right up there on that list. When someone offers advice after saying they are 'a newb at this' and their only qualification is 'their ears' and they start talking about tubes for hundreds of dollars - my advice is just smile and walk away.
Unfortunately in this era of easy communication equal time/space devoted to an argument might appear to imply equal credibility. Not true.
For what it is worth, I have been participating in this forum for quite a few years. In that time I have come to recognise that there are quite a few contributors who's advice is worth listening to. Sy is right up there on that list. When someone offers advice after saying they are 'a newb at this' and their only qualification is 'their ears' and they start talking about tubes for hundreds of dollars - my advice is just smile and walk away.
Unfortunately in this era of easy communication equal time/space devoted to an argument might appear to imply equal credibility. Not true.
No shortage of fairy tales on the netI once believed that the 12AX7 simply had to be a great candidate for a phono-stage, after all they were ubiquitous in early phono-stages. as DIY builds on the net and even among the so-called boutique phono-stages one finds lining the shelves of Audiophile? outlets.
Luckily, the DIY gang here dissuaded me of the notion that the 12AX7 was the best way to go based on some pretty irrefutable evidence (tube characteristics) and years of experience building their own phono stages.
Old Harman Hosner, Avery Fisher and company, knew what they were doing in this regard. When they specified a 12AT7, 12AY7, 12AU7 or 12AX7 for a particular stage they weren't being cavalier..in every case where I substituted a variant for the intended tube in pre-amps, power amps and tuners...the performance of the equipment took a steep nose dive.
DF96 is correct in saying "The 12AT7 and 12AX7 are so different that only in a guitar amp could they possibly be considered as candidates for a swap."
Guitarists have a set of sonic objectivesthat are generally in-congruent with Hi-Fi audio objectives.
In hi-fi, sound is the only objective. I am not trying to convince everyone using 12ax7's to throw them away and replace them with 12at7's. But what do you tell someone who was bold enough to try it and liked what he heard? Are you going to say he is wrong because the designer of circuit says it should work better with a 12ax7 ?
My point, my only point, is if you like the sound better, why not?
What higher criteria is there?
I have enjoyed all the advice given here. Surely, some of it is more relevant than the rest. But advice given in any situation is based on your experience. No one here, apparently, owns the unit in question (ART eq). So no one apparently has experience with it. No one yet knows the circuitry in the unit, so no could know what it is best suited for. I have tried to get the schematic, but to no avail thus far.
While it can be characterized as such, this isnt about how equal the responses are as to one side or another. You underestimate me greatly if you think my actions to follow are based on this.
It is my plan to hear what 12at7, 12ax7 and 5751 tubes sound like in my unit. In the end, the winner will be what sounds best.
General advice is merely that. Even given years of experience and practice, anything said in general has its exceptions. My unit may or may not be one. I intend to find out. If there is a appearance that I am ignoring good advice, then lets just say that no one but me knows what advice ive decided to take, and what advice ive decided to politely ignore. But there is more to this thread than just my aims. Hopefully, everyone who reads it will gain something. Everyones contributions lead to that. All of them.
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Well I look forward to hearing what you discover with tube substitutions for your particular piece of equipment...if you like what you hear fine...
I have a friend who thinks his little Minimus 7s are the cats pajamas...I don't argue or poo-pah his enthusiasm...but if he were to ask me can I do better? or worse? by embarking on a particular modification or turning them backwards I would feel compelled to provide some advice and observation based on my experience.
That's what many of the more experienced (I exclude myself ) DIYAudio types have been providing.
But hey, I'm all for experimentin' so have at it, by all means! Just let us know what you discover!
I have a friend who thinks his little Minimus 7s are the cats pajamas...I don't argue or poo-pah his enthusiasm...but if he were to ask me can I do better? or worse? by embarking on a particular modification or turning them backwards I would feel compelled to provide some advice and observation based on my experience.
That's what many of the more experienced (I exclude myself ) DIYAudio types have been providing.
But hey, I'm all for experimentin' so have at it, by all means! Just let us know what you discover!
Well I look forward to hearing what you discover with tube substitutions for your particular piece of equipment...if you like what you hear fine...
I have a friend who thinks his little Minimus 7s are the cats pajamas...I don't argue or poo-pah his enthusiasm...but if he were to ask me can I do better? or worse? by embarking on a particular modification or turning them backwards I would feel compelled to provide some advice and observation based on my experience.
That's what many of the more experienced (I exclude myself ) DIYAudio types have been providing.
But hey, I'm all for experimentin' so have at it, by all means! Just let us know what you discover!
I too hear people trying things that in my own mind, i am fairly certain wont work or sound good. 2010-11 were humbling years for me. Some old held beliefs were shattered utterly. I am not beyond being wrong.
Perhaps I need to remind people that I was not the one who put 12at7's in my unit. And until I hear a 12ax7 in their place, i wont know if that was for the better or worse.
To this point, my total investment has been $11. If there are those of you thinking I may be contemplating spending hundreds, your wrong.
I do indeed intend to share my findings. Evidence in the form of listening is not to be trusted entirely by some here though, so i dont know if it will have any impact.
With any online site like this, you get lots of folks making all sorts of claims where its hard to sort out the experienced trusted listener from the inexperienced untrustworthy ones. I suppose people must make up their own minds on what information and claims are to be trusted, and which not. I suppose if I had time enough, I could describe all my previous blunders and misconceptions, and what I learned from them. It might make some of you laugh, and it might remind some of you of your own past experiences.
In any case, I am new here. Nobody really knows me or trusts me. Well, thats ok. These things take time. I dont design or even understand all but the most simple circuitry. Its just not my field or interest to know that part. But I enjoy listening and improving my listening experience. So hopefully, common ground can be found there.
Jim, I have to ask you what that means. I don't understand.
In electric music, where you make sound with amplifiers and what-not, sound is also the objective. Accuracy of reproduction is not, though. When you're making music, you are producing sounds, making sounds that please you (and hopefully others) from whatever it is you want to work with. Taking a pre-existing sound and intentionally distorting it can be part of the fun.
In "hi-fi" the "fidelity" is supposed to be to the original musical event (however that was made). Hi-fi is supposed to be a faithful sonic copy of the original musical sounds. Accuracy (uh oh, there's that word) in audio reproduction is the objective. Nothing creative about it -- other than the creation of faithful reproducing machines. (oooohhhh, that'll start some controversy...)
I'm going to assume that your ART EQ is meant to be a clean, well-damped sort of EQ, as opposed to the type that has lots of colorations that are meant to enrich the sound (which are in reality pleasant distortions). Let's say you take that nice, clean EQ and you change tube types. That will certainly change the way the circuit acts, and assuming that the original designers knew how to make the EQ non-resonant and "clean", that change of tube type will probably degrade the cleanliness of the circuit. It will now distort more.
Now, you may like the sound. I may like the sound. Half the world may like the sound. And that is absolutely fine, because we're talking about an effects box here.
So in my opinion, since this is an effects box, try anything you like that isn't going to break the unit. Try a 12AY7 if you like. 12AT7? Sure. And of course, try all the flavors of 12AX7/ECC83 you care to sample. Whatever gets the sound you're after, use it to make music.
But if you're worried about some sort of fidelity to some sort of original sound, then that's a different story.
I guess you just have to say what it is you want from this EQ. If you're looking for a certain sound you like, I don't think anybody's going to be able to tell you what that is. You'll have to find it. If you want the most faithful reproduction of the original sound but with a carefully tailored change of frequency response to shape that sound, then I don't know if this relatively inexpensive ART EQ is going to give you that. Maybe one of those Manley all-inductive parametric EQ's would be better. Expensive, though. I heard one at an AES in NYC years ago. Darned impressive.
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ART Pro Audio
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I should clarify, because I said that really badly. What I mean is that the creation of faithful reproducing machines is something of a scientific pursuit, or engineering. It's the making of a machine. That takes a lot of creativity, but of a different kind than making a musical performance.
I didn't mean to sound chauvinistic about musical creativity vs. creativity in other fields, but it certainly came off that way. My bad.
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I/we are getting out of the context of the thread a bit, but this is an important point.
You ask some very valid questions. I say sound is the only objective. For me, that generally means, what sounds good. But that is a oversimplification. And my situation is more complex than I have led on. But thats not important. So here is my take.
Accurate reproduction. Well, that would seem the audiophile goal, but its really a masquerade. An Illusion. One would have to know what the original sounded like in order to know whether what is being reproduced is an accurate rendition of it wouldn't we? Unless your a mastering engineer that has access to the origin masterings, we dont know what its supposed to sound like. So, in the end, what the vast majority of us has to do is listen to the end result and evaluate what we are hearing. Does the drum sound like a drum? Does the Sax sound like a Sax? Are the vocals believable and moving? ect.....Even this method has its short comings unless your privy to hearing these instruments regularly and know what they are supposed to sound like. Adding complexity to it all, many recordings intentionally alter the sounds of basic instruments and purposely make them sound like something different. So again, your only left with what sounds good to you.
Faithful sonic reproduction starts with the mastering, not your source component. If you have ever sat down and listened to several different masterings or media of the same release, you know how greatly different the same thing can sound. So before it even gets to your source device (turntable, CD Player, Digital file on your computer), there is not one standard to compare to. They all have their strengths and weaknesses, but none of them are faithful in an absolute sense.
In short, we sometimes assume that the CD (or other media) we put into our player has the right sound to start with, and so every component must emulate that sound without changing it any more than necessary. For some Cd's(any media), this is absolutely true. You dont want to change a thing. I dont want every component tinkering with it. But I do have one (EQ) that can. It has bypass controls if I dont want it, but gives me flexibility for when I do.
I dont regard an EQ as an effects box. I guess it can be used that way, but I do not. It has specific purposes.
1) Frequency response deficiencies / colorations as a result of the room environment (bass peaks for example) that room treatments havent/cant address
2) Poor mastering (smiley faced EQ given to the recording as a result of over use of compression, noise reduction and elevated high frequencies)
3) Or sometimes, I just dont agree with a mastering engineers eq choices (too bright, ect) and have to fiddle with things to make it listenable
Your right about Manley. If I could afford Manley, id have one (or something like it)
Now we're getting somewhere, it's all about what is the preferable "sound" which includes all the instruments,vocals etc.. the way we individually think it sounds the most pleasurable (which doesn't always mean a faithful reproduction of what has actually been recorded) seeing that many recordings aren't so great.
Trying to find a middle ground on a bad recording can be a bummer. On the other hand a good recording can be tuned in (
Andrew.
Trying to find a middle ground on a bad recording can be a bummer. On the other hand a good recording can be tuned in (
start new thread) to sound very good indeed.
Andrew.
If you drop the wrong tube in it, the distortion goes up. Period. You may like that sound, but it's indeed an effects box. You can like whatever you want, after all, it's your system. But don't pretend that your electronics is faithfully passing on the signal, it's not- besides changes in frequency response (that, after all, is what an EQ is supposed to do), as a distortion generator, it's adding stuff that wasn't present in the original signal. Whether that's good or bad is your choice.
I'll see if I can change your mind with my next project.
If a hi-fi circuit apparently designed for a 12AT7 sounds better with a 12AX7 in (or vice versa) then it is extremely likely that at least one of the following two statements is true:
1. the designer was incompetent,
2. the listener likes distortion and/or skewed frequency response.
There is a small possibility that some circuits might work equally well with either, but that would probably mean that the circuit has not been properly optimised. A circuit designed to get the best out of one of them would not work so well with the alternative. These are inconvenient facts.
1. the designer was incompetent,
2. the listener likes distortion and/or skewed frequency response.
There is a small possibility that some circuits might work equally well with either, but that would probably mean that the circuit has not been properly optimised. A circuit designed to get the best out of one of them would not work so well with the alternative. These are inconvenient facts.
Surely adding audible distortion would be undesirable. I hear none from this unit. Even when I push a EQ band to +12db I hear none.
As it turns out SY, you only live 2 hours from me. Maybe you should come listen some time when I get my speakers finished. By then, I should have some 12ax7's on hand, and you can help me sort this out.
OK, here's the problem. It's a philosophical one, I guess. What is "distortion"?
If you push an EQ band +12dB, you want to hear the result of that. And you have added a form of intentional distortion, by boosting that band by +12dB. Then there are the artifacts of that boost, which would also be distortions.
Not that all that is necessarily "bad." If you're making a CD, and the intentional distortions sound good, print it. But doesn't that define your intentional distortion adding device as an effects box? And what's wrong with that, if that's what it is?
By "distortion" do you mean audible "nasty" sounds that you don't like? I'd say that is not an accurate definition. You might call them "undesirable distortions" as opposed to "effects" or "sound processing." I don't see anything confusing about that.
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PS - I've recorded some jazz, rock 'n roll and chamber music and mastered a couple of CDs professionally. Not big-time, but I know what you mean about CD mastering, etc. I was also a professional musician for the younger half of my adult life, back in the days of Neve consoles and all that good stuff.
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Distortion:
Measured vs Audible
I think all active circuitry adds measurable distortion. Generally, tubes add more than their transistor counterparts. Yet, many prefer the sound of tubes. I among them, to a point.
So higher distortion levels dont necessarily translate to something sounding bad. I believe I have read that the threshold for audible distortion is somewhere in the 0.5 - 1.0% range. Of course this is an oversimplification cause you have different orders of it, different types, ect...but lets keep it simple.
I remember in the late 70's early 80's, there was a craze on the market to advertize super low distortion figures for receivers /power amps. You went from advertised total harmonic figures of 0.1 - 0.5% to .01 and .008% and such. I heard these units and I wouldnt say this made them sound better. Some sounded good, and some not so. Just like before. So imo, while audible distortion has no place in hi-fi audio, inaudible distortion seems to play little to no role at all when determining and evaluating good sound.
Over the years, products have come along time and time again using some published specification which tries to demonstrate their products superiority.
Others include slew rates, signal to noise ratios, ability to drive super low impedances, current capability, class "a" operation and so on. None of these tactics in of themselves made for a product that was consensually superior to designs that preceded it, yet each has its place.
There has always been a bit of a chasm between the measured performance of an audio device and its perceived quality of sound. By this I mean that sometimes you have a device that measures very well, but doesnt sound very musical. Then you have something that sounds great, but its specifications are not superior to its rivals in any way.
Obviously, if there was one approach, one measurement that defined great sound on a technical level, everyone would strive to incorporate it. But I havent yet seen that great technical performance derives directly to great sound necessarily.
Its a bit like theoretical physics in a way. A great new theory with elegant looking math is promising. Its looks like it should work and prove true. But despite its beauty in math, often times experiment proves it to be untrue.
Don't be so sure.
Aphex, for example, has made a business out of selling distortion boxes. And there are a lot of high distortion amps which very audibly alter the signal but are favored by some. Likewise, open invite to my place if you want to take a listen. And if you're at LSAF this weekend in Dallas, I'll be sharing a room with Pete Millett- a chance to hear the Engineer's Amp and the Red Light District side by side.
An externally hosted image should be here but it was not working when we last tested it.
Here is the schemeatic. Have at it.
It seems 12AT7 was its design after all
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