Hi Grey,
Sorry, I knew it was an industrial career, rather than an audio specific career like my past.
The very first thing you should do in future is read posts with an open mind. This would probably avoid some of the confusion you feel from time to time. Believe it or not, I don't have strong positive or negative feelings about you. As my daughters would say, "take a chill pill".
Another way of saying this would be to avoid reading more into a post than there actually is.
-Chris
Sorry, I knew it was an industrial career, rather than an audio specific career like my past.
The very first thing you should do in future is read posts with an open mind. This would probably avoid some of the confusion you feel from time to time. Believe it or not, I don't have strong positive or negative feelings about you. As my daughters would say, "take a chill pill".
Another way of saying this would be to avoid reading more into a post than there actually is.
-Chris
Please, fellow designers, I do not usually follow 'marketing decisions' except that the first CTC preamp had even BIGGER knobs than it has now. I called them: 'Dolly knobs' and I thought that they made the preamp look like it would tip over. They were reduced to 'MM knobs' in my preamp and all others. We are not unaware of marketing forces. 😉
Yeah, but what if I happen to like the big ones?
(A recent news article said Dolly Parton had to postpone her tour because she strained her back. When asked how it happened, she blamed her...er...knobs...)
Grey
P.S.: Chris: Oh, I get it...you're saying there's nothing to your posts!
(A recent news article said Dolly Parton had to postpone her tour because she strained her back. When asked how it happened, she blamed her...er...knobs...)
Grey
P.S.: Chris: Oh, I get it...you're saying there's nothing to your posts!
Hi John,
It's great to see you don't get compromised by marketing forces. That is a good thing. An attractive case design is timeless, and that's a very good thing.
Really, the only point I made with regard to marketing is that you can have the best thingy in the world. If it doesn't sell, it's useless and doesn't exist for all intents and purposes.
Grey,
Let's give it a break.
-Chris
It's great to see you don't get compromised by marketing forces. That is a good thing. An attractive case design is timeless, and that's a very good thing.
Really, the only point I made with regard to marketing is that you can have the best thingy in the world. If it doesn't sell, it's useless and doesn't exist for all intents and purposes.
Grey,
Nope. As far as you're concerned, there isn't. It's all way above you.
Let's give it a break.
-Chris
We're in a thread dedicated to a preamp that was made only in limited quantities (~40 units?) and yet quite a few people seem to be interested in the design thereof. The number of DIY variants that will come from this thread is anybody's guess, but if even one goes commercial at some point ten years hence and the designer can point to the Blowtorch as the antecedent then I'd say the Blowtorch made an impact far beyond its own modest per-unit sales.
Grey
Grey
I am surprised by various inputs. The Blowtorch was a practical experiment, just like any racing car. It was designed to WIN listening contests.
How many all-out race cars are made of one model? How much energy does it take to make and run one of those, even for one race? Shall we ban F1 racing, as being wasteful of needed resources?
Why does Honda do so well as far as engineering and reliability? Could it be partially because they learned important lessons from high end racing? Could they have not learned from their 'excessive design efforts' and this info. gets passed down to the Civics, Accords, Acuras, etc? Read up on Honda and see what I am talking about.
I also make a much cheaper preamp that is in the marketplace. The first complaint is the skinny top plate that is prone to vibration. That one got past me, especially as Bob Crump is deseased, and that was his area of interest. I hope that Parasound will do something about it, because now we are NOW metal-shy, rather than metal excessive. So it goes!
AND the new Parasound JC-2, I am told, is ALMOST as good sounding as the BLOWTORCH. Wow, what a concept!
How many all-out race cars are made of one model? How much energy does it take to make and run one of those, even for one race? Shall we ban F1 racing, as being wasteful of needed resources?
Why does Honda do so well as far as engineering and reliability? Could it be partially because they learned important lessons from high end racing? Could they have not learned from their 'excessive design efforts' and this info. gets passed down to the Civics, Accords, Acuras, etc? Read up on Honda and see what I am talking about.
I also make a much cheaper preamp that is in the marketplace. The first complaint is the skinny top plate that is prone to vibration. That one got past me, especially as Bob Crump is deseased, and that was his area of interest. I hope that Parasound will do something about it, because now we are NOW metal-shy, rather than metal excessive. So it goes!
AND the new Parasound JC-2, I am told, is ALMOST as good sounding as the BLOWTORCH. Wow, what a concept!
These car - audio analogies go lame. It was a space research and space industry from which profited commercial, entertainment electronics like audio.
Many people in the West, at least, understand car analogies, because they have worked on them at some time in their lives, or at least followed CAR magazines.
Actually, my background is most effected by Aerospace, because I lived most of my life in Silicon Valley, my cousins, girlfriend, wife, worked for Fairchild, National Semi, etc. We were part of it. I personally had worked at Lockheed, UL, and Friden (making military stuff) before I went to Ampex more than 40 years ago. Where does anyone think that this technology comes from, except from aerospace-military. I chose to do audio with it, but that was my choice. Several of my colleagues built H-bombs, or at least contributed to their manufacture.
Actually, my background is most effected by Aerospace, because I lived most of my life in Silicon Valley, my cousins, girlfriend, wife, worked for Fairchild, National Semi, etc. We were part of it. I personally had worked at Lockheed, UL, and Friden (making military stuff) before I went to Ampex more than 40 years ago. Where does anyone think that this technology comes from, except from aerospace-military. I chose to do audio with it, but that was my choice. Several of my colleagues built H-bombs, or at least contributed to their manufacture.
And people say that money spent on the space race didn't yield any benefits for those of us who are still ground-bound...
Charles,
Referring back to your post on no-feedback designs vs. DC offset--how much effort do you put into matching your devices?
I've been able to get pretty good results just by matching Vgs, though obviously matching at more than just the one point would be beneficial. I'm limited on time so I settled for Vgs only and was pleasantly surprised at how well things turned out.
A nod to John for suggesting the 1A Toshiba MOSFETs a while back, as they work very nicely. No, I haven't tried the Hitachi parts. One--I've pretty much bottomed out on money for the time being. Two--someone (I believe it was John) pointed out that the N and P devices aren't as well matched as we might wish and since I'm trying to do without feedback, it looked as though the Toshiba parts would give me less trouble in the THD department. Three--they're at least as big a pain in the butt to get hold of as the Toshiba parts, if not more.
John,
Any comments on your device matching strategies for either CTC or Parasound?
Grey
Charles,
Referring back to your post on no-feedback designs vs. DC offset--how much effort do you put into matching your devices?
I've been able to get pretty good results just by matching Vgs, though obviously matching at more than just the one point would be beneficial. I'm limited on time so I settled for Vgs only and was pleasantly surprised at how well things turned out.
A nod to John for suggesting the 1A Toshiba MOSFETs a while back, as they work very nicely. No, I haven't tried the Hitachi parts. One--I've pretty much bottomed out on money for the time being. Two--someone (I believe it was John) pointed out that the N and P devices aren't as well matched as we might wish and since I'm trying to do without feedback, it looked as though the Toshiba parts would give me less trouble in the THD department. Three--they're at least as big a pain in the butt to get hold of as the Toshiba parts, if not more.
John,
Any comments on your device matching strategies for either CTC or Parasound?
Grey
Hi Nelson,
An idea that can be constructed at no charge by many people counts as being sold. The retail price is zero, that's all. By that, the concept and principles become known to a larger number of people, and therefore known. The principles have impact. This you know well from your own work.
John's work is in the same league in so far that his concepts are brought forward. There were as many Blowtorch units sold as could be made I'm guessing. The Blowtorch builds upon Jon's earlier work (I didn't say it's the same!!). John has graciously talked about the circuit ideas and what he believes are important factors to consider.
Hi Grey,
If I keep all the fet cases in thermal contact through a heat sink, I get very tight matches by measuring vgs at set drain currents. Using devices from the same lot number ensures that they track very well across the current operating range. This is the only way to repair a Counterpoint using fets. Here, tight matching is extremely critical.
-Chris
Yes. By definition this is true.
An idea that can be constructed at no charge by many people counts as being sold. The retail price is zero, that's all. By that, the concept and principles become known to a larger number of people, and therefore known. The principles have impact. This you know well from your own work.
John's work is in the same league in so far that his concepts are brought forward. There were as many Blowtorch units sold as could be made I'm guessing. The Blowtorch builds upon Jon's earlier work (I didn't say it's the same!!). John has graciously talked about the circuit ideas and what he believes are important factors to consider.
Hi Grey,
If I keep all the fet cases in thermal contact through a heat sink, I get very tight matches by measuring vgs at set drain currents. Using devices from the same lot number ensures that they track very well across the current operating range. This is the only way to repair a Counterpoint using fets. Here, tight matching is extremely critical.
-Chris
anatech said:
I understand your point. Having said that, I have ideas which
are not in circulation which have high value to me.
Hi Nelson,
I don't disagree. I like to think I have some good ideas too.
However.
If we leave this earth without revealing our brilliance to anyone else, those ideas are worth zero. I'll count further work based on those ideas as revealing those ideas to the masses. 😀
-Chris 😉
Edit: to clarify what I meant.
I don't disagree. I like to think I have some good ideas too.
However.
If we leave this earth without revealing our brilliance to anyone else, those ideas are worth zero. I'll count further work based on those ideas as revealing those ideas to the masses. 😀
-Chris 😉
Edit: to clarify what I meant.
We stand at the precipice of another semantic argument:
Value to whom and how to judge such value?
Speaking only for myself, I would prefer that this thread not turn into a semantics thread.
I say this knowing full-well that I'm likely to end up with a mud fight once I start a thread on this amp I've been fiddling with. It has no global feedback--don't expect any argument on that--but is it "no feedback?" That will hinge on whether people define degeneration as feedback. This I do not relish.
So, really, can't we just sidestep this?
Grey
Value to whom and how to judge such value?
Speaking only for myself, I would prefer that this thread not turn into a semantics thread.
I say this knowing full-well that I'm likely to end up with a mud fight once I start a thread on this amp I've been fiddling with. It has no global feedback--don't expect any argument on that--but is it "no feedback?" That will hinge on whether people define degeneration as feedback. This I do not relish.
So, really, can't we just sidestep this?
Grey
Grey, let us separate local from global loop feedback. Black did NOT invent local feedback, they MUST have known about it for decades before he wrote his paper. When MOST engineers say negative feedback, they mean feedback over several stages. Technically, this is incomplete, but so what? It is shorthand to describe a technique. Almost everyone uses SOME local feedback, AND it has real potential problems also, BUT not as many as does GLOBAL negative feedback. That is what we have found.
Hi Grey,
I'm listening to a pair of Cyrus Mono X amplifiers at the moment. I was talking to the designer in England (2004) before they existed as a product and got the first pair into Canada. No feedback and based somewhat on diamond transistor topology. Impressive sounding amplifiers. No feedback can be done, and done well.
Personally, I think the entire question of feedback or no feedback may depend heavily on the execution of the design and construction. The better these products become (the more accurate), the more similar they will sound to each other.
-Chris
The parameters were specified. Re-read please.
Where? You brought that one up recently.
It's been defined that local degenerative feedback is not considered feedback in a system sense. My understanding of the negative effects of feedback occurs when that feedback loop encompasses two or more power gain stages. Note my careful choice of words here. 😉 So maybe I defined a working example, something close enough to run with for the time being.
Cool!
I'm listening to a pair of Cyrus Mono X amplifiers at the moment. I was talking to the designer in England (2004) before they existed as a product and got the first pair into Canada. No feedback and based somewhat on diamond transistor topology. Impressive sounding amplifiers. No feedback can be done, and done well.
Personally, I think the entire question of feedback or no feedback may depend heavily on the execution of the design and construction. The better these products become (the more accurate), the more similar they will sound to each other.
-Chris
john curl said:
John,
I don't expect that you, Charles, or Nelson will have any problem with the degeneration, but you and I both know that there are others who might choose to take offense if I call the amp "no feedback." Should that come to pass...oh, hell, I don't know what I'll do...go camping and talk to the owls for a while, maybe. (I actually do a pretty fair imitation of a screech owl and am able to 'talk' to them. They will literally fly to me [probably a territorial defense mechanism being triggered] to check things out. I also happen to do a very good imitation of a barred owl, but they're not as prone to 'talking.' Screech owls will hoot back and forth with me for up to five or ten minutes. One of them got so distracted during a fly-over one night that he flew straight into a maple sapling. The tree was young and flexible and I don't believe the bird was hurt, but I'm sure it was a blow to the poor fellow's dignity.)
Chris,
I didn't mean you. I'm not aware of any reason why you would be bothered by the circuit. I could, however, give you a list of six or eight members who might be disposed to kick up a fuss about what is/is not feedback. I have no earthly idea what will happen if the simulation folks start in on it, but at least I don't anticipate a lot of hoo-rah about DC stability. They'll have to find something else to carp about.
Grey
1.5 kg Big Knob
I once had a 1.5kg (appr 3lb) heavy solid brass knob made to my spec, and it feells great to turn this "Dolly knob" on my stepped ELMA rotary switch. Steps are not really "steps" anymore but more like a normal pot.
The 70mm diam knob you can see in the attached photo.
Sigurd
I once had a 1.5kg (appr 3lb) heavy solid brass knob made to my spec, and it feells great to turn this "Dolly knob" on my stepped ELMA rotary switch. Steps are not really "steps" anymore but more like a normal pot.
The 70mm diam knob you can see in the attached photo.
Sigurd
john curl said:
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