Recently I studied the "small things" that makes a difference. For example, someone here pointed the importance the nearness of resistor ends to transistor's base lead in the input of the differential pair (for high impedance node in general). Gainclone sounds better with components soldered as near as possible to the pins. JCarr makes audio gear using pin to pin connection, advoiding PCB. In classD, if the tracks are not right, they become "micro strip/transmission line". All of these have audible effect, but very hard to see on scope.
Lummanuaw,
the can type device sounded better to your ears because . . . . it looked better.
To be a bit serious, I don't know how long ago you did your experiment, but modern plastic packages are pretty damn good so I would be surprised if there any electrical effects on a typical bipolar type IC.
The packaging guys go to a lot of trouble to deliver (plastic) packages that dont stress the chip, allow minimum moisture in, or have any impurities in the plastic that can migrate into the chip.
the can type device sounded better to your ears because . . . . it looked better.
To be a bit serious, I don't know how long ago you did your experiment, but modern plastic packages are pretty damn good so I would be surprised if there any electrical effects on a typical bipolar type IC.
The packaging guys go to a lot of trouble to deliver (plastic) packages that dont stress the chip, allow minimum moisture in, or have any impurities in the plastic that can migrate into the chip.
When I have a problem with handphone signal entering audio system, I realize how diifficult it is to design a handphone. From the CCT, PCB track, and handphone IC's. In a small box, you put quite powerfull transmitter and audio+loudspeaker together, and the sound reproduction is not audibly distorted.
Can these guys find out what causes audible difference between feedback and non feedback in audio reproduction (from the non-feedback view)?
Can these guys find out what causes audible difference between feedback and non feedback in audio reproduction (from the non-feedback view)?
ShinOBIWAN said:
Hi John and Bob
Can you take your dispute offline please.
The theme seen in this thread seems to spill over from thread to thread on occasion. I suspect that by not publicly airing all these alleged wrongs the value of and the motivation for doing so would be infinitely less. Your both gents, please act like it.
Pre-emptive warning; If this thread continues down the path its started on then the moderation team will close it. We have little time and nor do we take any pleasure in having to watch a 'hot' thread making sure everything stays civil. This is something we can do without.
As I said earlier, John's introduction of the 25-year-old thing was an unfortunate distraction to this thread. I also suggested that if that discussion was to be continued, it was more appropriate that it be done in the permanent feedback thread. If fine with no more references to the distant past in this thread.
Cheers,
Bob
lumanauw said:
I believe that the 2N5566 and the NPD5566 are rather different parts, made by different manufacturers. So if one was a 2N5566 and the other was an NPD5566, that could account for a difference. I could be wrong, but I believe that most 2N5566 devices may have been implemented with two separate JFET die, while the NPD5566 was truly monolithic.
Cheers,
Bob
Charles Hansen said:
Charles,
For the record, you said and insinuated a whole lot more than those two points in your letter, and that is what I took issue with.
I don't stronly take issue with your point (a).
Your point (b) is a completely unsubstantiated generalization. I did not agree with it as a generalization, although I allowed that it was true in certain cases.
Your mis-characterizatrion of the Halcro review by taking it out of context to make your point about negative feedback was unforgivable.
Cheers,
Bob
rdf said:
Maybe, maybe not. At the risk of being accused of "competitor bashing", please look more closely at the whole Halcro thing. The DIY community does not usually stay in close contact with the world of commercial high-end audio. But here are a few facts:
a) Stereophile has never "recanted" on their overall positive opinion of the Halcro, but other magazines have. I can't remember if it was Soundstage (online) or The Absolute Sound, but the guy who gave the Halcro a rave review one month back-pedaled significantly in a review of another expensive amp literally one month later.
b) The Halcro amp is fairly controversial in the world of high-end, including reviewers, dealers, and end users. For example, in the first thread on this topic, I quoted an (unnamed) Stereophile reviewer who said he couldn't stand to listen to the Halcros (presumably for the reason I pointed out), and instead ended up using them as amp stands for the John Curl-designed JC-1 monoblocks, which he felt were infinitely better sounding.
The Halcros never caught on with dealers. A few dealers took them on as a replacement for Levinson when Levinson stopped production for 18 months. But they never had any success selling them to customers. There are a lot of potential reasons for this, but based on many conversations I've had, the biggest factor was that the customers are more discerning of sound quality than the reviewers and they just didn't like the way they sounded. The original Halcro importer no longer carries the brand, I would assume because either the manufacturer or the importer was disappointed with the lack of sales.
Basically the Halcros have people that love the way they sound, but at least as many people that hate the way they sound. But the same cannot be said for other equally expensive high-end products. For instance, take a look at any of the top-of-the line products released by Audio Research in the last two years. These have uniformly generated nothing but positive comments from reviewers, dealers, and customers. I have yet to see a single negative review or hear a single negative comment from a dealer or customer regarding the Ref 3 preamp or Ref 7 CD player or Refs 110, 210, or 610 power amps.
Of course and as always, the best thing to do is to listen for yourself. Find a Halcro dealer and give them a listen. Let us know what you think -- are the wonderful or are they not so wonderful? It would also be instructive to get a chance to compare them with the current Audio Research products.j
Edit: Just as the Halcro amp (with its high feedback) is controversial, so are the new IC's developed by National. If you peruse some of the DIY and other audiophile forums, you will find that there are a lot of people that love the way they sound, but also a significant number of people that don't care for their sound.
mightydub said:
The advantages you noted for monolithic designs are valid. However there are also disadvantages, particularly for high-performance analog applications. My reasons were outlined in my letter that was published in Stereophile. Basically, there are two major problems:
a) The resistors and capacitors in an integrated circuit do no sound as good as the best discrete resistors and capacitors.
b) In my experience, fine-tuning of circuit values by ear is mandatory to reach the full sonic potential of any given circuit. Changing resistor values, bias currents, and so forth can make significant changes to the sound of a circuit. This is obviously a difficult proposition with monolithic circuits, and furthermore to date it has never even been attempted. (National has recently hired Mark Brasfield to develop and/or promote their audio products. But the new National parts were developed before his arrival there. It remains to be seen what impact his tenure there will actually have.)
mightydub said:
I have no doubt that I would be able to design ICs with improved sound quality over existing products. One important question is whether the optimized values from a discrete circuit could be directly transferred to an integrated circuit, or whether the optimization must occur with the IC itself. In the latter case it would require dozens of masks (if that is the proper term) to be made. I would assume that this would never happen as it would drive development costs through the roof and make the resulting product quite unprofitable.
As to whether or not the final product would exceed the performance of a discrete circuit, we can only guess. My guess is that we couldn't, but that the gap could be closed considerably, perhaps to the point where it would only matter to only the most extreme audiophiles.
I went to the Stereophile site and pulled up that Halcro review. I was sooo not surprised to see the reviewer saying that the treble and midrange were forward. Over and over again, he returned to that same point. Likewise, I was rather underwhelmed by his immediate assumption that the recordings were to blame and that the amplifier was perfect--only revealing the flaws in the recordings.
After all, isn't this word for word what proponents of early digital claimed? The aggressive highs, the forward upper midrange. Oh no, it couldn't be digital!!! How could it be? Look at the distortion specs!!! Clearly it's the fault of the recordings, not digital!!! It's the mics, it's the mixing board, it's the master tape, it's...on and on and on...blaming every possible link in the chain except the digital recording and reproduction process.
Only...it was the fault of digital, wasn't it?
High feedback amps sound much the same as mid-period digital. Note how closely the reviewer's description matches the description I gave of high feedback amps in another thread recently...right down to the unnatural silence surrounding the images. Real images have more reflection, more air, more sense of space around them. Tubes do this damned well. Solid state not as well, unfortunately. (Trust me--I regret leaving the world of tubes, but it was just getting too expensive and difficult.) There's no need to undermine what solid state can achieve by hosing the signal down with excessive feedback.
And, as I've said elsewhere, the sound is initially exciting but in the long run the warts begin to show. A similar point to the one Charles makes in his post. Harry Pearson (to give one example) liked the Halcro at first, but backed away rather quickly. Back when I was in retail, customers generally reacted pretty much the same way. Sell them something with high feedback and you were pretty sure to see them in a year or two once the honeymoon was over.
Proof? You want proof?
Listen. Compare the sound to real music. It isn't right.
I don't mind people pursuing low distortion as a technical exercise. None whatsoever. As Nelson Pass observes, audio is a part of the entertainment industry, and I have no quarrel with people deriving their enjoyment from audio in ways other than listening. My annoyance begins when they proclaim that it sounds better...only they claim they you can't trust your ears because your ears are too easily fooled by listener bias. Huh? I must have missed something--how do you know it sounds better if you can't trust your ears?
Grey
P.S.: I may be wrong (if so, I'm certain that someone will say so very quickly, indeed), but it seems to me that I recall Bob Cordell having said that he hasn't heard the Halcro. Assuming that to be the case, how can he legitimately say anything about the "very high sonic quality achievable through the proper use of negative feedback" regarding the Halcro? Bias? You want bias? There it is. In black and white. He assumes that because the circuit in question uses feedback and has low THD figures that it sounds good. Now that's bias, folks.
After all, isn't this word for word what proponents of early digital claimed? The aggressive highs, the forward upper midrange. Oh no, it couldn't be digital!!! How could it be? Look at the distortion specs!!! Clearly it's the fault of the recordings, not digital!!! It's the mics, it's the mixing board, it's the master tape, it's...on and on and on...blaming every possible link in the chain except the digital recording and reproduction process.
Only...it was the fault of digital, wasn't it?
High feedback amps sound much the same as mid-period digital. Note how closely the reviewer's description matches the description I gave of high feedback amps in another thread recently...right down to the unnatural silence surrounding the images. Real images have more reflection, more air, more sense of space around them. Tubes do this damned well. Solid state not as well, unfortunately. (Trust me--I regret leaving the world of tubes, but it was just getting too expensive and difficult.) There's no need to undermine what solid state can achieve by hosing the signal down with excessive feedback.
And, as I've said elsewhere, the sound is initially exciting but in the long run the warts begin to show. A similar point to the one Charles makes in his post. Harry Pearson (to give one example) liked the Halcro at first, but backed away rather quickly. Back when I was in retail, customers generally reacted pretty much the same way. Sell them something with high feedback and you were pretty sure to see them in a year or two once the honeymoon was over.
Proof? You want proof?
Listen. Compare the sound to real music. It isn't right.
I don't mind people pursuing low distortion as a technical exercise. None whatsoever. As Nelson Pass observes, audio is a part of the entertainment industry, and I have no quarrel with people deriving their enjoyment from audio in ways other than listening. My annoyance begins when they proclaim that it sounds better...only they claim they you can't trust your ears because your ears are too easily fooled by listener bias. Huh? I must have missed something--how do you know it sounds better if you can't trust your ears?
Grey
P.S.: I may be wrong (if so, I'm certain that someone will say so very quickly, indeed), but it seems to me that I recall Bob Cordell having said that he hasn't heard the Halcro. Assuming that to be the case, how can he legitimately say anything about the "very high sonic quality achievable through the proper use of negative feedback" regarding the Halcro? Bias? You want bias? There it is. In black and white. He assumes that because the circuit in question uses feedback and has low THD figures that it sounds good. Now that's bias, folks.
By and large, no. It was mostly the fault of "engineers" (I use scare quotes to distinguish mixing board jockeys from trained EEs) who didn't know how to use the medium. I remember visiting a studio in the mid '80s where, despite having a brand new digital recording system, they were routinely running the VU needles into the red. And didn't back off the EQ or compressors one bit. I won't go into the use of peaky large diaphragm condenser mikes...
Funny how the horrors of the early digital systems were totally lost on people who understood them, like Gordon Holt. You DO remember his enthusiasm for the Sony F1, right?
Grey,
which of these reviews:
http://stereophile.com/solidpoweramps/1004halcro
http://stereophile.com/solidpoweramps/683
http://stereophile.com/solidpoweramps/806halcro
http://stereophile.com/solidpoweramps/406halcro
are you speaking about?
which of these reviews:
http://stereophile.com/solidpoweramps/1004halcro
http://stereophile.com/solidpoweramps/683
http://stereophile.com/solidpoweramps/806halcro
http://stereophile.com/solidpoweramps/406halcro
are you speaking about?
GRollins said:
Well, I do trust my ears. And I regularly visit concerts of classical music. These amps that "have more reflection, more air, more sense of space around them", especially when playing very simple music, fail completely when trying to reproduce great orchestra, and they produce agressive or muddy mismatch. The exaggerated air and space you admire so is a product of distortion.
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