I believe that 'objectionists' should withhold their opinions from this thread. Aren't there enough threads on this website to 'contibute' without having any new idea tossed out without examination? Maybe, just maybe, some hi end designers here, like Martin, Charles, and me, have just a little more experience than many engineers and physicists in other fields. I go by what works, not what fits in 'The Standard Model'. I have been very successful with this approach. Just look at my latest reviews, if you don't have a clue about this.
Joshua_G said:
Joshua please re-read one more time. I did not state that which you quote. Be more careful with what you state in this way, so as to avoid libel.
If you read the original entries in this thread you will see that it all started with requests for informatioin on the pre-amp, and that is all and exactly what I asked for. I have no desire ever to make such a pre-amp whether reverse engineered or not. You nee to be more careful with understanding the words used.
john curl said:
Not sure if this is technically possible, but it would be really interesting to create a thread and let everybody read while letting JC manage as of who qualifies as a high end designer and is therefore allowed to post there. Call it e.g. "High End designers thread". I am sure it would be a very successfull and enjoyable topic, although from wildly different perspectives
.
PMA, I am a pretty open minded guy. I wouldn't care IF the power of prayer worked to make better audio equipment. I would certainly consider it, at least, and not reject it.
At CES there was a strange metal ball that was placed between the speakers. Talk about a 'graven image' BUT it did something right, at least in that demonstration setup. I am not going to 'condemn' it just because I would not accept what it did, and could not afford it in any case.
At CES there was a strange metal ball that was placed between the speakers. Talk about a 'graven image' BUT it did something right, at least in that demonstration setup. I am not going to 'condemn' it just because I would not accept what it did, and could not afford it in any case.
janneman said:
No, but I'm beginning to be annoyed in this thread by the occasional posts that make sense. They spoil the whole fun, that's why I would like a thread of pure High End Audio entertainment, driven by recognized High End Masters.
I would then also have a much clearer view on who's considered an aspiring High End designer (being allowed to post) and who's considered a pitchfork wielding villager that can't tell his *** from a hole in the ground.
Others may find such a thread extremely educational, though.
john curl said:
I care more in how it sounds, or how it may impact the sound – I care less in how it works.
I DO know that there are things I neither know nor understand and I'm fine with it.
Concerning my audio system, I have it to enjoy music, rather than increase my knowledge.
john curl said:
Thanks.
I bought recently 100 of them on eBay from a fellow from China.
I might comment on low noise design. There are several facets to low noise design.
When I started out, 40 years ago, the real problem was the actual sources of the sound, whether it was the microphone element, the tape head, or the phono cartridge.
In even earlier years, when tubes were the only game in town, input transformers and high inductance pickup heads were the norm.
For example 1 Henry coils on either phono pickups or reproduce tape heads were expected. This limited the absolute bandwidth, but it could be tweaked to 20KHz and beyond.
For microphones with long runs, input transformers were added with gains of 10,20, and maybe even 30 to bring up the signal up to normal.
These input transformers, like many quality transformers today, were expensive, and usually commercial companies compromised the transformer quality just to save money. We all lived with transformers that bloated the bass and maybe even rang at high frequencies.
By 1968, progress was made in solid state, that tubes actually became obsolete for new design. As we switched to solid state, a rethink was possible that showed that we didn't really need those input transformers anymore, in many cases. In 1968, the PNP 2n4403 was introduced that was the first LOW COST example of a low Rbb' part. It was not the quietest device, the 2n4405 was even quieter, BUT much more expensive, and the 4403 had an NPN compliment, the 2n4401 that made design topology more flexible.
By 1966, E.A Faulkner had already shown that paralleling devices could lower voltage noise in transistors by effectively lowering effective Rbb' that was very high in most 'low noise' devices at the time.
It was now time to try paralleling and removing step-up tranformers. I did my first paralleled bipolar design in 1968, in order to remove an added sel-sync transformer attached to the record head, that had to have 10mH or so input inductance.
This led the way to replace the transformers used with MC cartridges at the time. Why not?
Until the 2n4403 came into being, this just was not practical.
Today we can get parts that have 10 or 20 times LESS Rbb' without any other obvious compromise. We don't have to parallel bipolar parts, anymore, if we don't want to.
Unfortunately, jfets are slightly different.
Back in 1968 we had access to factory noise preselected 2n4416 jfets. Using one of these devices in place of the typical npn 'low noise' part found it comparable in noise, but the transformer was still necessary.
By 1973, Siliconix came up with a series of analog switches, that were really quiet, and somewhat affordable. We settled for the j110, for the first Levinson JC-2 phono stage, and it worked successfully for several years, BUT they changed the process and lost the low noise. What to do? Some went for the j113, not too bad, but then in 1979, Toshiba jfets came on the scene and blew everything else away. NOW, Toshiba jfets rule the scene, except that they are disappearing from existence.
The next manufacturer who will mostly fill in for Toshiba is Linear Systems, and they will probably be what we will have available in future, in jfets. They will be more expensive, but they should do for most applications.
When I started out, 40 years ago, the real problem was the actual sources of the sound, whether it was the microphone element, the tape head, or the phono cartridge.
In even earlier years, when tubes were the only game in town, input transformers and high inductance pickup heads were the norm.
For example 1 Henry coils on either phono pickups or reproduce tape heads were expected. This limited the absolute bandwidth, but it could be tweaked to 20KHz and beyond.
For microphones with long runs, input transformers were added with gains of 10,20, and maybe even 30 to bring up the signal up to normal.
These input transformers, like many quality transformers today, were expensive, and usually commercial companies compromised the transformer quality just to save money. We all lived with transformers that bloated the bass and maybe even rang at high frequencies.
By 1968, progress was made in solid state, that tubes actually became obsolete for new design. As we switched to solid state, a rethink was possible that showed that we didn't really need those input transformers anymore, in many cases. In 1968, the PNP 2n4403 was introduced that was the first LOW COST example of a low Rbb' part. It was not the quietest device, the 2n4405 was even quieter, BUT much more expensive, and the 4403 had an NPN compliment, the 2n4401 that made design topology more flexible.
By 1966, E.A Faulkner had already shown that paralleling devices could lower voltage noise in transistors by effectively lowering effective Rbb' that was very high in most 'low noise' devices at the time.
It was now time to try paralleling and removing step-up tranformers. I did my first paralleled bipolar design in 1968, in order to remove an added sel-sync transformer attached to the record head, that had to have 10mH or so input inductance.
This led the way to replace the transformers used with MC cartridges at the time. Why not?
Until the 2n4403 came into being, this just was not practical.
Today we can get parts that have 10 or 20 times LESS Rbb' without any other obvious compromise. We don't have to parallel bipolar parts, anymore, if we don't want to.
Unfortunately, jfets are slightly different.
Back in 1968 we had access to factory noise preselected 2n4416 jfets. Using one of these devices in place of the typical npn 'low noise' part found it comparable in noise, but the transformer was still necessary.
By 1973, Siliconix came up with a series of analog switches, that were really quiet, and somewhat affordable. We settled for the j110, for the first Levinson JC-2 phono stage, and it worked successfully for several years, BUT they changed the process and lost the low noise. What to do? Some went for the j113, not too bad, but then in 1979, Toshiba jfets came on the scene and blew everything else away. NOW, Toshiba jfets rule the scene, except that they are disappearing from existence.
The next manufacturer who will mostly fill in for Toshiba is Linear Systems, and they will probably be what we will have available in future, in jfets. They will be more expensive, but they should do for most applications.
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