We were just learning about caps in 1973. I was an engineer, but we usually used ceramic or mica for small values. Mylar for medium values, tantalum for big values, and polystyrene, IF we needed a predictable tempco. At the time I only used a modified Heathkit tube based IM analyzer and I did quite well with it, at the time. My residual distortion was about .005% distortion, but that was low enough. There was a Crown IMA available that did .001% IM, but I could not afford it at the time.
At Ampex, in the 1960's we used HP oscillators (.035%) and HP wave-analyzers, a hetrodyne type, that had a measured residual at least as good as the oscillators.
About that time, in 1973, Mark Levinson used a HP THD meter that went below .01% or so.
I had not seen a HP339 or the Sound Technology until 1974. They just were not available to just anyone at the time.
For many years, THD was discouraged, because of the inherent problems with it, but HP and ST started a trend in that direction, when they could do .001% distortion, because of improved oscillators, and better auto-nulling.
In theory, we could have measured some harmonic distortion and even IM in many ceramic and tantalum caps, but we were just not looking for it at the time, and you have to load the cap so that it is actually rolling off the test frequency, in order for any significant nonlinear distortion can be generated.
At Ampex, in the 1960's we used HP oscillators (.035%) and HP wave-analyzers, a hetrodyne type, that had a measured residual at least as good as the oscillators.
About that time, in 1973, Mark Levinson used a HP THD meter that went below .01% or so.
I had not seen a HP339 or the Sound Technology until 1974. They just were not available to just anyone at the time.
For many years, THD was discouraged, because of the inherent problems with it, but HP and ST started a trend in that direction, when they could do .001% distortion, because of improved oscillators, and better auto-nulling.
In theory, we could have measured some harmonic distortion and even IM in many ceramic and tantalum caps, but we were just not looking for it at the time, and you have to load the cap so that it is actually rolling off the test frequency, in order for any significant nonlinear distortion can be generated.
John,
That is an interesting story. It makes one wonder whether the progress of audio reproduction over the last 30 years or so was maybe more a matter of better parts (active as well as passive) than better topology? Seems to me that the more successfull designs were not really radically new topologies.
Jan Didden
That is an interesting story. It makes one wonder whether the progress of audio reproduction over the last 30 years or so was maybe more a matter of better parts (active as well as passive) than better topology? Seems to me that the more successfull designs were not really radically new topologies.
Jan Didden
Hi Jan,
I've seen much of the same old thing year after year, but there are those who have come out with interesting developments. The Marantz 500 was very advanced for 1969 when it was released, as were things like the 240 and Nak 620. The Japanese really came out with some cool circuit configurations. Nelson Pass has brought out some innovations and of course Bob Carver. There is an imaginative guy.
John, you have your own contributions.
Interestingly, much of what was new was a rehash of things designed much earlier in the tube era, 20's and 30's were a hot time for development.
Yes, some components (especially op amps and capacitors) have gotten better. Simply learning how to implement the right part type is probably more important than the name on the thing. Resistors are another thing again. I don't miss carbon comps at all.
-Chris
I've seen much of the same old thing year after year, but there are those who have come out with interesting developments. The Marantz 500 was very advanced for 1969 when it was released, as were things like the 240 and Nak 620. The Japanese really came out with some cool circuit configurations. Nelson Pass has brought out some innovations and of course Bob Carver. There is an imaginative guy.
John, you have your own contributions.
Interestingly, much of what was new was a rehash of things designed much earlier in the tube era, 20's and 30's were a hot time for development.
Yes, some components (especially op amps and capacitors) have gotten better. Simply learning how to implement the right part type is probably more important than the name on the thing. Resistors are another thing again. I don't miss carbon comps at all.
So true.
-Chris
By listening with wisdom and experience to these warfare sagas
with that ever recurring "The older I grow The better I was" theme.
Let's face it: All these preamps are "mature" technology. There is
nothing groundbreaking new happening here today except say
a new voodoo teflon capacitor or silver wire or a milled enclosure.
In 10 years, the claim to fame will be sth. like "xyzzy built the first truly
excellent class D amplifier" and for sure xyzzy won't be one of those
guys begging for a Blowtorch blueprint. It will be someone who
sits in the lab now; simulating, soldering, measuring and listening.
Probably someone we would consider mortal today.
regards, Gerhard
Hi John,
There is nothing that one person can do that is not possible for another to do as well. All it takes is some time, knowledge and the willingness to go ahead with something.
You have build some very good preamplifiers and power amplifiers. There are other good ones out there too. I can't say which are better, and the creator is biased. It takes some non-partial people to have used both to comment.
I know a guy who is convinced he makes the best amps of any. They sound awful.
But they are his babies, so he is happy.
The only thing I know is that you build the best designs you can with the parts, ideas and manufacturing at your disposal. This doesn't mean that there can't be equals or better units somewhere.
Please keep in mind I have not passed judgment on anything here. I think your comments to Gerhart are a little harsh. Did you build a perfect CD player? I'm curious only because you brought it up.
-Chris
There is nothing that one person can do that is not possible for another to do as well. All it takes is some time, knowledge and the willingness to go ahead with something.
You have build some very good preamplifiers and power amplifiers. There are other good ones out there too. I can't say which are better, and the creator is biased. It takes some non-partial people to have used both to comment.
I know a guy who is convinced he makes the best amps of any. They sound awful.
But they are his babies, so he is happy.The only thing I know is that you build the best designs you can with the parts, ideas and manufacturing at your disposal. This doesn't mean that there can't be equals or better units somewhere.
Please keep in mind I have not passed judgment on anything here. I think your comments to Gerhart are a little harsh. Did you build a perfect CD player? I'm curious only because you brought it up.
-Chris
Anatech, it may be a language translation problem, but I get a little tired of being picked and poked at when I discuss audio design history. It is true that we developed most of the topologies that are discussed here in the late 1960's, when complementary silicon transistors first became affordable. There are only so many ways to put something together.
However, since then, we have speeded up amplifiers considerably, greatly improved their protection circuitry, and introduced complementary fets to lower distortion, especially higher order distortion.
Some designers, even people other than me, have found that high feedback, output coils, and bipolar transistors at the input are not optimum for best sound. It is more than just our personal opinion, and we would be fools to ignore what others have been successful in making, and only go our own way. We find that many audio designers do follow their own path exclusively, and that keeps us in business, as we do not usually have the resources of a Sony, Krell, or another major company, and we would be quickly edged out in the marketplace, IF we could not make something a cut above the average.
Keep on designing with those output coils, fellow designers.
However, since then, we have speeded up amplifiers considerably, greatly improved their protection circuitry, and introduced complementary fets to lower distortion, especially higher order distortion.
Some designers, even people other than me, have found that high feedback, output coils, and bipolar transistors at the input are not optimum for best sound. It is more than just our personal opinion, and we would be fools to ignore what others have been successful in making, and only go our own way. We find that many audio designers do follow their own path exclusively, and that keeps us in business, as we do not usually have the resources of a Sony, Krell, or another major company, and we would be quickly edged out in the marketplace, IF we could not make something a cut above the average.
Keep on designing with those output coils, fellow designers.
Hi John,
Please John, I have not criticized you or your designs, ever. I am among those who did not question the use of your style of chassis and have accepted all the information you have given out regarding your design philosophies.
I do not believe there is a language problem here, but I do think that you feel as if every move you make is questioned. A bit sensitive to comments and questions.
I have asked questions to learn mostly, or check my own knowledge. They seem to have been received as if they were an attack on yourself. This was never the intent on my part. You have to admit that a person that blindly accepts whatever they are told is not imaginative in the least. To question is to learn.
If you feel there is a problem between us, I'd be more than happy to deal with it directly via email. You are too far away to call directly on the telephone.
If I may quote you ...
-Chris
I agree with you on this. No complaint. I prefer J-Fets at the input also. Trying to get away from output coils on my own.
Please John, I have not criticized you or your designs, ever. I am among those who did not question the use of your style of chassis and have accepted all the information you have given out regarding your design philosophies.
I do not believe there is a language problem here, but I do think that you feel as if every move you make is questioned. A bit sensitive to comments and questions.
I have asked questions to learn mostly, or check my own knowledge. They seem to have been received as if they were an attack on yourself. This was never the intent on my part. You have to admit that a person that blindly accepts whatever they are told is not imaginative in the least. To question is to learn.
If you feel there is a problem between us, I'd be more than happy to deal with it directly via email. You are too far away to call directly on the telephone.
If I may quote you ...
I don't expect any one person to know everything. I sure as heck don't, not even close!
-Chris
anatech said:
You have the same sort of 1010xxx long distance services up there in Canuckistan that we have down here don't you? I use the 1010-987 service here to call several of my Canucklehead friends and it's only a couple cents per minute. Very economical. Hell, I even called South Korea and talked for about an hour or so and it was only something like $7.
se
Hi Steve,
a) Don't have John's number and ...
b) Don't know him well enough to simply call the man even if I did.
If a conversation were to take place, it would have to be at both our conveniences. The best place for that would be at "The Burning Amp Festival" which I am hoping to attend.
I honestly don't believe it's a big enough issue to warrant extraordinary steps from anyone really. That offer is open to anyone who feels there is a misunderstanding with me. I have much better things to do than troll around any web sites.
It is, however, a very small world and you never know who you might run into. It pays not to create enemies where there not not be any. Don't you agree?
-Chris
I think we do. I've never used one of those services to be honest with you. I also:
a) Don't have John's number and ...
b) Don't know him well enough to simply call the man even if I did.
If a conversation were to take place, it would have to be at both our conveniences. The best place for that would be at "The Burning Amp Festival" which I am hoping to attend.
I honestly don't believe it's a big enough issue to warrant extraordinary steps from anyone really. That offer is open to anyone who feels there is a misunderstanding with me. I have much better things to do than troll around any web sites.
It is, however, a very small world and you never know who you might run into. It pays not to create enemies where there not not be any. Don't you agree?
-Chris
Hi John,
I did. You reacted as if I were attacking you or your designs. I'd rather not have more misunderstandings John. It might help if you assume my posts are just what they are with no attempt at annoying you. Maybe I'm the one under the wrong impression. I just know that we are not communicating most of the time.
Since this is all badly O.T. and is not helping your thread, I'll clean these and related posts out tomorrow.
Sound okay?
-Chris
Edit: Any issues you feel we may have should probably be dealt with via email. No need for it to be in your thread.
I did. You reacted as if I were attacking you or your designs. I'd rather not have more misunderstandings John. It might help if you assume my posts are just what they are with no attempt at annoying you. Maybe I'm the one under the wrong impression. I just know that we are not communicating most of the time.
Since this is all badly O.T. and is not helping your thread, I'll clean these and related posts out tomorrow.
Sound okay?
-Chris
Edit: Any issues you feel we may have should probably be dealt with via email. No need for it to be in your thread.
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