Makes sense; evolving to fit the isolated environment. A mini-sort of Galapagos.
Jan
From what I understand we have more gut bacteria by quantity that all the other cells in our bodies, this is definitely a symbiotic relationship. We are covered from head to toe with skin bacteria, all those who insist on using strong disinfecting soaps seem to do that at their own risk of messing up the balance that actually keeps us healthy. And don't take antibiotics unless absolutely necessary, a modern mistake made for far to long.
On an audio related subject for those not following the thread what is wrong with opamps JC made some statements yesterday that I think others may want to comment on. He basically said that all opamps whether IC or discreet are an inferior method to develop an audio circuit. How can that be a truthful statement?
John has been saying that for 40 years now, so don't worry. What he means is that the 741 could be bettered by a discrete design.
As Scott pointed out (with some pride) Ligo tried discrete design and needed to turn to the AD797 to actually get things to work properly. But of course gravitational waves are easier to measure than playing a record.
As Scott pointed out (with some pride) Ligo tried discrete design and needed to turn to the AD797 to actually get things to work properly. But of course gravitational waves are easier to measure than playing a record.
I wouldn't lump everybody who might have some disagreements with you in one pot. Especially a pot characterized by the most extreme beliefs.
In any case, JC seems to be expressing his personal design philosophy, and not a scientific thesis. Maybe part of the problem is that he does not choose his words with enough care when writing about things than can be interpreted in a controversial way.
Mark,
I don't try to place people into neat little groups, just a reaction to some of the inflammatory comments JC can make that he doesn't seem to back up with substance. The reality is that you just can't produce many of John's designs today without a boatload of NOS devices, they are no longer available. So do we continue to say this is the best way to produce a product when it is no longer practical or even possible in many cases? Shouldn't we be trying to improve on class-d at this point as that seems to be the direction that amplifiers are going to take, I'm not sure there will be class ab amps in the not distant future.
Got to head out and meet a client, be back later to read the flame wars I probably just started.
I don't try to place people into neat little groups, just a reaction to some of the inflammatory comments JC can make that he doesn't seem to back up with substance. The reality is that you just can't produce many of John's designs today without a boatload of NOS devices, they are no longer available. So do we continue to say this is the best way to produce a product when it is no longer practical or even possible in many cases? Shouldn't we be trying to improve on class-d at this point as that seems to be the direction that amplifiers are going to take, I'm not sure there will be class ab amps in the not distant future.
Got to head out and meet a client, be back later to read the flame wars I probably just started.
JC does use opamps in some of his designs. His highest priced and most praised designs do not use them in the audio path.
In my stadium sized systems there are places where opamps cannot handle the dynamic range of what should be a low level signal adequately. I still have to resort to vacuum tube designs. One of these days I will get around to building a solid state version.
Contrary to the trolled opines JC pretty much so has standardized on what he wants to measure when he does a design and listening is really more of a final check. As far as I have seen he doesn't swap in one part for another and audition the change. Once he settles on what works he sticks to it until it becomes obsolete or better comes along. But that is my opinion of JC's methods based on a small bit of actual experience.
In my stadium sized systems there are places where opamps cannot handle the dynamic range of what should be a low level signal adequately. I still have to resort to vacuum tube designs. One of these days I will get around to building a solid state version.
Contrary to the trolled opines JC pretty much so has standardized on what he wants to measure when he does a design and listening is really more of a final check. As far as I have seen he doesn't swap in one part for another and audition the change. Once he settles on what works he sticks to it until it becomes obsolete or better comes along. But that is my opinion of JC's methods based on a small bit of actual experience.
In this perennial argument there are 3 or 4 schools of thought that cover the gamut from lets say 'commercial volume products' through to 'high end esoteric' on which the protagonists will never agree.
1. IC vs discrete (which would encapsulate somewhat the opamp discussion currently underway)
2. Feedback vs open loop
3. Solid State vs Tube
4. digital vs vinyl
5. JFET vs Bipolar
and combos of the above e.g. discrete JFET open loop must be better than IC opamp with feedback, or open loop IC opamp vs discrete. Or how about DAC's with open loop tube output buffers and no filters
We will never agree. However, if I look at the SOTA from 25 or 30 years ago and SOTA today, I can hear the progress and I can see it in measurements.
Now, as to which it is I am referring listed in my table above, I will leave that to you to decide.
1. IC vs discrete (which would encapsulate somewhat the opamp discussion currently underway)
2. Feedback vs open loop
3. Solid State vs Tube
4. digital vs vinyl
5. JFET vs Bipolar
and combos of the above e.g. discrete JFET open loop must be better than IC opamp with feedback, or open loop IC opamp vs discrete. Or how about DAC's with open loop tube output buffers and no filters
We will never agree. However, if I look at the SOTA from 25 or 30 years ago and SOTA today, I can hear the progress and I can see it in measurements.
Now, as to which it is I am referring listed in my table above, I will leave that to you to decide.
An IC opamp is just a circuit on a chip. The main differences I can see are the much tighter layout on the chip and (the biggie IMO) the caps and resistors on the chip are made out of parts of semiconductors.
FET curves look pretty much like tubes. But tubes have the capability to capture the micro-dynamics and vividness (there's that word again) in a way that no solid state quite can. What is the big, gross difference between SS and tubes? It's those little electrons that were thrown off the filament by heat. Once that electron is floating in space it sees almost no impedance to get to the other elements of the tube.
That's how I see it.
FET curves look pretty much like tubes. But tubes have the capability to capture the micro-dynamics and vividness (there's that word again) in a way that no solid state quite can. What is the big, gross difference between SS and tubes? It's those little electrons that were thrown off the filament by heat. Once that electron is floating in space it sees almost no impedance to get to the other elements of the tube.
That's how I see it.
Something said by an EL instructor years ago is that tubes sound different (better) because of the temperature they operate at. The ides was that they are less sensitive to ambient temperature changes by there immediate surroundings as compared to transistors.
I don't share the opinion one way or another but it is different.
I don't share the opinion one way or another but it is different.
Sometimes, the limited B+/- rails is a problem for opamp use. Though they can be used at higher voltage (typically 24v +/-) It isnt guarenteed. Otherwise a limitation that has to use added parts to overcome.
And, the OPS is often very basic and sub-par relying on a lot of GNFB to cover things it does. As long as we cannot get at the innards and make our own OPS, the opamp is limited there. Stuck.
Otherwise IPS are generally excellent on paper but are designed for small signal amplification apps. What happens to opamp input stages with audio levels like 1-2v rms as an input ? What happens to various recovery times with high fb? etc. Maybe look to the large signal performance/behaviour if not dealing just with phono cart output levels.
THx-RNMarsh
And, the OPS is often very basic and sub-par relying on a lot of GNFB to cover things it does. As long as we cannot get at the innards and make our own OPS, the opamp is limited there. Stuck.
Otherwise IPS are generally excellent on paper but are designed for small signal amplification apps. What happens to opamp input stages with audio levels like 1-2v rms as an input ? What happens to various recovery times with high fb? etc. Maybe look to the large signal performance/behaviour if not dealing just with phono cart output levels.
THx-RNMarsh
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