I did not find you being rude, courage.
You express probably what many of us think .. but do not say.
Sometimes other people can find those that honestly speak their mind,
even in a normal or respectable tone of voice,
as being hostile.
It often tells much more about the reader, than about the writer 😀
We see what we want to see.
And close our eyes for anything not confirming our own thought and opinions.
Note, that John does not even specify, quote what was 'rude', in his view.
This is a sign as good as any 😉
thinks
Lineup - has been told many times saying bad things,
but when asking them to give a quote what was bad
.. Lineup never got a good satifying explaination
You express probably what many of us think .. but do not say.
Sometimes other people can find those that honestly speak their mind,
even in a normal or respectable tone of voice,
as being hostile.
It often tells much more about the reader, than about the writer 😀
We see what we want to see.
And close our eyes for anything not confirming our own thought and opinions.
Note, that John does not even specify, quote what was 'rude', in his view.
This is a sign as good as any 😉
thinks
Lineup - has been told many times saying bad things,
but when asking them to give a quote what was bad
.. Lineup never got a good satifying explaination
As far as the JC-2 schematic is concerned, it is here, and it is now easier to discuss it.
The point was to compare the JC-2 with the CTC Blowtorch as designs, and there are subtle differences, even if the essence of these designs were both designed the CTC design team.
I might make some obvious comparisons:
Global feedback vs local feedback
Open loop bandwidth
Silver switches vs relays
Gain stage count
Circuit board material
Solder
Wire
Etc, etc
The point was to compare the JC-2 with the CTC Blowtorch as designs, and there are subtle differences, even if the essence of these designs were both designed the CTC design team.
I might make some obvious comparisons:
Global feedback vs local feedback
Open loop bandwidth
Silver switches vs relays
Gain stage count
Circuit board material
Solder
Wire
Etc, etc
When it comes to the 2N3819, I started using it 40 years ago, along with the 2N4416 (selected for 100Hz noise) that the Ampex video department used. It is like the 40 year old Pirelli tire that I used on my SAAB Sonnet sports car, it worked pretty well back then, but I would not recommend it for every application.
Actually, I don't know what you specifically want in a fet. Most of the fets that I use have much higher Gm, more Idss, but also higher input capacitance. If I were making a condensor microphone input, I might, (and I actually have done this) the 2N3819 with some success. However, if I were trying to make a voltage variable resistor, I would try to find an even lower Gm device.
However, normally I would use a 2SK170 for most anything else.
You might try a Toshiba 2SK246.
Actually, I don't know what you specifically want in a fet. Most of the fets that I use have much higher Gm, more Idss, but also higher input capacitance. If I were making a condensor microphone input, I might, (and I actually have done this) the 2N3819 with some success. However, if I were trying to make a voltage variable resistor, I would try to find an even lower Gm device.
However, normally I would use a 2SK170 for most anything else.
You might try a Toshiba 2SK246.
I am still very surprised that my inputs on this thread are so often 'second-guessed' by people who apparently know a lot less about the subject and often appear to harbor prejudices about what audio designers do, and why.
I am trying to teach everyone here something from my experience, which has been verified by the acceptance of certain of my designs in a favorable way by reviewers across the world. These are general concepts, not specific schematics, and I hardly think that most who are wary of my input could duplicate my efforts in any case, being without the resources or experience.
The very notion that I would deliberately mislead anyone here by deliberately modifying a schematic is an insult to me. Therefore, I consider such accusations, rude.
I am trying to teach everyone here something from my experience, which has been verified by the acceptance of certain of my designs in a favorable way by reviewers across the world. These are general concepts, not specific schematics, and I hardly think that most who are wary of my input could duplicate my efforts in any case, being without the resources or experience.
The very notion that I would deliberately mislead anyone here by deliberately modifying a schematic is an insult to me. Therefore, I consider such accusations, rude.
One of my friends has recently bought Parasound Halo JC-2 preamplifier. We also made a listening test, described in another thread.
The schematic shown corresponds to real JC-2, as far as I have seen of this preamplifier. We also have made some recommendation, as John knows. Again, it was same in schematics and in the real preamp.
The schematic shown corresponds to real JC-2, as far as I have seen of this preamplifier. We also have made some recommendation, as John knows. Again, it was same in schematics and in the real preamp.
John, the remark I made was not meant personal. It refers to the schematic of the JC2 in which not only I found discrepancies.
It seems like it has become a general rule in this thread that only statements in favour of John and his designs are allowed. The basis for fruitfull discussion is taken away if we all can only agree and accept the knowledge of one or two without being allowed to question what is being presented.
Having the courage to stand alone, takes far more then echoing what others say. In that regard some may experience me as different, strange or even annoying and not within the framework of their thinking.
It seems like it has become a general rule in this thread that only statements in favour of John and his designs are allowed. The basis for fruitfull discussion is taken away if we all can only agree and accept the knowledge of one or two without being allowed to question what is being presented.
Having the courage to stand alone, takes far more then echoing what others say. In that regard some may experience me as different, strange or even annoying and not within the framework of their thinking.
Mr. Curl, we are reading and learning alot from your posts. You're still here posting, while offending posters come and go. It will be the same way in the future too. All of us can see who has the determination and passion for this matter.
I wonder if anyone had done any listening comparisons between the Blowtorch and JC-2? How close did the JC-2 come to it?
courage said:
Your not alone really. Think about the number of enthusiasts that belong to this site, relative to the few that speak up. There must be some with different ideas and experience that just listen for bits that fill out pieces or their personal puzzle. Speaking out when posts contradict your experience is important. IMHO...
Attention to the details is how I've continued to educated myself over the years.
Mike.
Badge said:
I do not think it is very fair to compare the simple JC 2
against the state of the art (SOA) Blowtorch.
Because Parasound Halo JC 2 Line Preamplifier
was manfactured in Taiwan and the price was only $4000 US-dollars.
I would rather compare Blowtorch against some real interesting high end amp.
Like the new Ayre KX-R line preamplifier, US $18,500
Weight: 18.2kg (40 lbs) = more the most Power Amplifiers 😉
..zero global feedback and fully balanced operation..
Using carefully matched JFET as main devices.
In my opinion, this is the one most interesting design.
Charles Hansen as being a diyaudio member could surely
give us some more details about this great piece of amplifier.
Lineup
I might now comment as to why the JC-2 is not comparable to the Ayre, but the Blowtorch is.
Both are expensive, no compromise preamps for what they are designed to do.
Both operate open loop, and have very high open loop bandwidths.
Both use extra high quality volume controls, beyond Alps Blue Velvet.
Etc, etc.
It does make a sonic difference, but a relatively subtle one.
Is it worth it? It depends on your financial resources. Some people are fairly rich, and an investment in a Blowtorch or Ayre is fairly typical for them. There are even more expensive products out there.
Both are expensive, no compromise preamps for what they are designed to do.
Both operate open loop, and have very high open loop bandwidths.
Both use extra high quality volume controls, beyond Alps Blue Velvet.
Etc, etc.
It does make a sonic difference, but a relatively subtle one.
Is it worth it? It depends on your financial resources. Some people are fairly rich, and an investment in a Blowtorch or Ayre is fairly typical for them. There are even more expensive products out there.
Not expecting a cookbook, but perhaps some relative scaling of the differences between the JC designs, or where those differences manifest themselves (soundstage, dynamics, ???).
We have switching, wiring, PWB materials, attenuator, and chassis construction all before we enter the active topology. I am interested as well in discussion of power supplies and regulation.
We have switching, wiring, PWB materials, attenuator, and chassis construction all before we enter the active topology. I am interested as well in discussion of power supplies and regulation.
Ken, we discussed power supply regulation several years ago on this thread. Just look around the earlier threads.
I would say that the VERY BEST efforts just sound more NATURAL and effortless. The next best are very good sounding, and NOT offensive, sonically.
Often, serious mistakes are made in layout and grounding that merges the channels more than absolutely necessary. This is caused, for example, by NOT keeping the stereo separation very high even to 20KHz. Most designs start to merge the stereo signal long before the audible bandwidth is reached.
I would say that the VERY BEST efforts just sound more NATURAL and effortless. The next best are very good sounding, and NOT offensive, sonically.
Often, serious mistakes are made in layout and grounding that merges the channels more than absolutely necessary. This is caused, for example, by NOT keeping the stereo separation very high even to 20KHz. Most designs start to merge the stereo signal long before the audible bandwidth is reached.
Hi Ken,
I agree with you; power supply is of a great importance.
Regards, Pavel
As far as this discussion, it would be nice to rate relative importance of topology, PSU, active components, passive components, switches, realys and wires.
To a less experienced reader, it might seem that all of the discussed items are of the same importance, which is not the case, and sometimes some of the changes is barely audible. It would be fair to rate the achievable real sound improvement, IMHO.
I agree with you; power supply is of a great importance.
Regards, Pavel
As far as this discussion, it would be nice to rate relative importance of topology, PSU, active components, passive components, switches, realys and wires.
To a less experienced reader, it might seem that all of the discussed items are of the same importance, which is not the case, and sometimes some of the changes is barely audible. It would be fair to rate the achievable real sound improvement, IMHO.
Let me try, Pavel.
I surely rate the importance of active components above passives.
Topology is of importance, maybe above components, but if you have this great topology with lousy parts you'll miss.
Then PSU is of importance. And filtering of mains. With a more and more RF polluted worlds, this becomes more and more important. And to this one must add the enclosure and that it gives proper shielding.
RK
I surely rate the importance of active components above passives.
Topology is of importance, maybe above components, but if you have this great topology with lousy parts you'll miss.
Then PSU is of importance. And filtering of mains. With a more and more RF polluted worlds, this becomes more and more important. And to this one must add the enclosure and that it gives proper shielding.
RK
Unfortunately, I see in the BEST audio design that attention to details is so important that it is almost like 'links in a chain', rather than most important to little importance.
When I first started making my own designs, circuit topology was 'everything' to me. It should be obvious from the photo of me holding up the 40 year old power amp design to other designers on this website at the Burning Amp Festival. That is something that I soldered up on a kitchen table on a weekend and subsequently used for 5 years as my main power amp. It's only claim to fame was the complementary symmetry input stage, and .5A operating bias. I am always slightly embarrassed when I show it around, as my understanding, experience, and appreciation for quality construction was minimal, at the time, at best.
Many of the subtle factors that I have tried to point out on this thread have been learned over 4 decades of trial and error. For example, the first significant 'improvement' in the original amp, besides changing part values and devices, was the JC-3 power amp design about 6 years later, initially built by Swiss Technicians, so a lot better looking. It also performed somewhat better, as well. Still the largest change was adding complementary Darlington output stage, and a jfet input complementary differential input stage, rather than using matched bipolar input devices.
Each 'improvement' over the years has been from cut and try experience, or looking over the shoulder of others, including the Japanese engineers who often tried various approaches and wrote about them in papers given at the AES.
Now, what happens IF I started to ignore all the subtle aspects, because I just handed the 'simplified schematic' to another group of engineers and let them built it?
Failure in the marketplace, that's what.
Both the Parasound JC-1 and JC-2 are based almost entirely on product 'failures' that I revived, along with my associates, to PROVE that attention to details counts.
Yes, the JC-1 is essentially the HCA-3500 on steroids.
The JC-2 is essentially the PLD-2000, with attention to details, such as wiring, layout, connectors, etc.
Superficially, there is hardly any difference in the products, BUT look at the response from the hi fi magazines! It is completely different, YET we did not advertise in any consistent way in these same magazines since the introduction of the 'improved' designs. It makes just that much difference to pay attention to wire, connector quality, layout, etc.
So, taking the JC-2 schematic recently put up on this thread, EVEN WITH VALUES, fixing certain oversights that includes removing 3 resistors, one in the servo an two 100 ohm resistors in the input switching (thanks PMA) will NOT guarantee a really great sounding preamp, that independent listeners will rave about. That is the problem that has to be addressed equally to the elegance of schematic.
When I first started making my own designs, circuit topology was 'everything' to me. It should be obvious from the photo of me holding up the 40 year old power amp design to other designers on this website at the Burning Amp Festival. That is something that I soldered up on a kitchen table on a weekend and subsequently used for 5 years as my main power amp. It's only claim to fame was the complementary symmetry input stage, and .5A operating bias. I am always slightly embarrassed when I show it around, as my understanding, experience, and appreciation for quality construction was minimal, at the time, at best.
Many of the subtle factors that I have tried to point out on this thread have been learned over 4 decades of trial and error. For example, the first significant 'improvement' in the original amp, besides changing part values and devices, was the JC-3 power amp design about 6 years later, initially built by Swiss Technicians, so a lot better looking. It also performed somewhat better, as well. Still the largest change was adding complementary Darlington output stage, and a jfet input complementary differential input stage, rather than using matched bipolar input devices.
Each 'improvement' over the years has been from cut and try experience, or looking over the shoulder of others, including the Japanese engineers who often tried various approaches and wrote about them in papers given at the AES.
Now, what happens IF I started to ignore all the subtle aspects, because I just handed the 'simplified schematic' to another group of engineers and let them built it?
Failure in the marketplace, that's what.
Both the Parasound JC-1 and JC-2 are based almost entirely on product 'failures' that I revived, along with my associates, to PROVE that attention to details counts.
Yes, the JC-1 is essentially the HCA-3500 on steroids.
The JC-2 is essentially the PLD-2000, with attention to details, such as wiring, layout, connectors, etc.
Superficially, there is hardly any difference in the products, BUT look at the response from the hi fi magazines! It is completely different, YET we did not advertise in any consistent way in these same magazines since the introduction of the 'improved' designs. It makes just that much difference to pay attention to wire, connector quality, layout, etc.
So, taking the JC-2 schematic recently put up on this thread, EVEN WITH VALUES, fixing certain oversights that includes removing 3 resistors, one in the servo an two 100 ohm resistors in the input switching (thanks PMA) will NOT guarantee a really great sounding preamp, that independent listeners will rave about. That is the problem that has to be addressed equally to the elegance of schematic.
Not an easy question, and I am not sure that I could make a top-down list of stuff that are the most important stuff.
But let's say we have the amplifier basics, and we want to design a high-end or ultra-end amplifier,
I would say that components (active, passive, mechanical, PCB) parts are at the top of the list.
Also on he top is power supply issues from AC mains to regulated PS units.
Topology comes further down the list as I think that one can achieve very good sonics with many different toplogies.
Sigurd
But let's say we have the amplifier basics, and we want to design a high-end or ultra-end amplifier,
I would say that components (active, passive, mechanical, PCB) parts are at the top of the list.
Also on he top is power supply issues from AC mains to regulated PS units.
Topology comes further down the list as I think that one can achieve very good sonics with many different toplogies.
Sigurd
PMA said:
I agree that component knowledge is essential for amplifier making.
Especially actives like transistors.
It takes a lot of use and trials to know how to make the best out of one transistor.
And what device to use in a certain circuit context.
And what levels of currents and assisting resistors to add.
Experienced designers have this know how by heart.
Like for example John Curl has regarding JFETs and the optimal use of them.
He can tell you much more than the datasheets show.
Especially actives like transistors.
It takes a lot of use and trials to know how to make the best out of one transistor.
And what device to use in a certain circuit context.
And what levels of currents and assisting resistors to add.
Experienced designers have this know how by heart.
Like for example John Curl has regarding JFETs and the optimal use of them.
He can tell you much more than the datasheets show.
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