Jan Lohstroh
/OT on
Somewhere in this thread Jan Lohstroh came up, as the person who actually designed what later came tio be known as the 'Otala amp'. If you are interested in a bit of history, my interview with Jan Lohstroh is here:
http://www.audioamateurinc.com/digital/609/pageflip.html
Starts on page 5.
/OT off
jd
/OT on
Somewhere in this thread Jan Lohstroh came up, as the person who actually designed what later came tio be known as the 'Otala amp'. If you are interested in a bit of history, my interview with Jan Lohstroh is here:
http://www.audioamateurinc.com/digital/609/pageflip.html
Starts on page 5.
/OT off
jd
John and others,
Someone actually walked into my office with the complete original Quantec service manual with all schematics and their tutorial on making noise measurements. I remember a few people were interested in this, unfortunately is is a bit of work to scan-in parts of it especially the foldout schematics. Is there still any interest?
Be warned the parts are mostly obsolete and I would not build all the discrete op-amps like they had to anyway.
Someone actually walked into my office with the complete original Quantec service manual with all schematics and their tutorial on making noise measurements. I remember a few people were interested in this, unfortunately is is a bit of work to scan-in parts of it especially the foldout schematics. Is there still any interest?
Be warned the parts are mostly obsolete and I would not build all the discrete op-amps like they had to anyway.
I have the service manuals for most Quantech stuff. I think the tutorial would be of general interest since its still not well known here how to measure device noise.
What I'm looking for is the manual for the 315C (I have the 315B manual which has almost nothing in common with the c version) and drawings for the socket adaptors for the 5173. I have figured out, mostly, the adaptor wiring but I would like to see how they thought it should be done.
The later 5173 is mostly IC and only uses discrete devices where needed. The older units date from the late '60s when opamps would not have been adequate to the tasks.
I think a new design with a PC interface using a sound card could be very useful since Quantech is no more and there are no commercial equivalents I know of.
What I'm looking for is the manual for the 315C (I have the 315B manual which has almost nothing in common with the c version) and drawings for the socket adaptors for the 5173. I have figured out, mostly, the adaptor wiring but I would like to see how they thought it should be done.
The later 5173 is mostly IC and only uses discrete devices where needed. The older units date from the late '60s when opamps would not have been adequate to the tasks.
I think a new design with a PC interface using a sound card could be very useful since Quantech is no more and there are no commercial equivalents I know of.
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With a hammer??
What do you mean exactly??
It would be more productive if you gave some examples of your work, or of the work of others that you believe is superior. Then it would be useful to state how or why whatever it is is actually superior, or SOTA.
Or else perhaps, you are just 14 years old and/or are used to going to various forums and banging your drum for fun? Or should I say, acting like a troll?
Dunno.
_-_-bear
...ummm I would like to discuss this too... was the schematic of the JC-80 posted here.
Perhaps someone would post the link so that we can get back to this question??
Not sure what you mean, John, about that "adding DC gain" to minimize their difference. Might be clear looking at the skeezamatic??
_-_-bear
PS. "do not feed the trolls"
On second thought change my mind. Actually it is JC our subjectivist lord and savior who can't substantiate a single word in his claim about people with subpar systems not having valid opinions on hi resolution. He can't offer one tangible parameter that would make an expensive system better than a cheaper one except for the arbitrary price tag placed on these items. I'm afraid if you don't trust measurements then it is your side which hasn't a leg to stand on when claiming that one system is superior to the other.
If you want to come out and discredit people for the price they paid on there equipment then I think a perfectly fair counter argument is that these overly expensive systems simply do not benchmark as well as a great deal of there mid fi counter parts. They don't have half of the "synergy" because most of the time they are put together guided by superstitions and not any understanding of electronics.
If you want to come out and discredit people for the price they paid on there equipment then I think a perfectly fair counter argument is that these overly expensive systems simply do not benchmark as well as a great deal of there mid fi counter parts. They don't have half of the "synergy" because most of the time they are put together guided by superstitions and not any understanding of electronics.
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Attacking Mr. Curl is not a substantiation of your words, Key.
I do not think Mr. Curl has put forth the argument that you claim he has.
Price has not and is not a criterion of quality alone, never has been, never will be. Mr. Curl certainly has not claimed price as a criterion of quality.
You seem to have a problem with "expensive" things.
Suggest you deal with that in some other way.
You can build a very fine system based upon the information in this thread, and elsewhere in this forum, if you have the time, energy and mental accuity to discern what is appropriate to build, and how to build it.
In fact, if you bothered to read this thread, and the entire part that came before it, you would have actually learned something - quite a lot actually.
Btw, calling Mr. Curl a "subjectivist" is rather funny.
Btw, which equipment have you engineered, designed, or even marketed?
Don't bother responding. We can assume that answer.
Again, suggest you post elsewhere, Key.
Like in another forum perhaps? One where merely being contrary is de rigeur??
You are just throwing chum into the waters of an otherwise productive discussion.
_-_-
I do not think Mr. Curl has put forth the argument that you claim he has.
Price has not and is not a criterion of quality alone, never has been, never will be. Mr. Curl certainly has not claimed price as a criterion of quality.
You seem to have a problem with "expensive" things.
Suggest you deal with that in some other way.
You can build a very fine system based upon the information in this thread, and elsewhere in this forum, if you have the time, energy and mental accuity to discern what is appropriate to build, and how to build it.
In fact, if you bothered to read this thread, and the entire part that came before it, you would have actually learned something - quite a lot actually.
Btw, calling Mr. Curl a "subjectivist" is rather funny.
Btw, which equipment have you engineered, designed, or even marketed?
Don't bother responding. We can assume that answer.
Again, suggest you post elsewhere, Key.
Like in another forum perhaps? One where merely being contrary is de rigeur??
You are just throwing chum into the waters of an otherwise productive discussion.
_-_-
I just posted in here to comment on an overlooked flaw I saw in SACD and then got sidetracked. No doubt John has more experience and credibility than I do and I never said anything to the contrary. But he also makes a lot of unsubstantiated claims all over this forum and uses his credibility as a reason that he doesn't have to substantiate any of it. So I was merely jumping in an disagreeing with his argument which seemed to be pretty empty.
Basically all he said was that most of you think the only thing that is different from mid fi and expensive gear is the price tag. And his counter argument to that was that better parts cost more money. No explanation as to why the more expensive parts are better no substance. Just that he knows and we don't. It's a pretty common argument amongst audiophile types where the last straw they usually try to grasp at is your ability to hear - even though that may very well be measurably more accurate than the accusers.
I see his argument only as a way to cast doubt on people with perfectly valid opinions on audio. And I see the idea that great audio reproduction has to be expensive as a flat out myth at this point. Give me something substantial to argue against and maybe I wont seem like such a troll or whatever - I tend to think your problem with me is all in your own perception as I already said not to take me too seriously.
Basically all he said was that most of you think the only thing that is different from mid fi and expensive gear is the price tag. And his counter argument to that was that better parts cost more money. No explanation as to why the more expensive parts are better no substance. Just that he knows and we don't. It's a pretty common argument amongst audiophile types where the last straw they usually try to grasp at is your ability to hear - even though that may very well be measurably more accurate than the accusers.
I see his argument only as a way to cast doubt on people with perfectly valid opinions on audio. And I see the idea that great audio reproduction has to be expensive as a flat out myth at this point. Give me something substantial to argue against and maybe I wont seem like such a troll or whatever - I tend to think your problem with me is all in your own perception as I already said not to take me too seriously.
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I'm not some crazy objectivist that thinks nothing matters. It's just that his paragraph was way too vague for me to cosign. I'm sure the stuff that measures better is in fact better. But you also have to consider that you can do a lot of things like phase linear DSP crossovers for free now. So I can see where if you use your money wisely compared to the average joe audiophile that you could come up with a system which mercs some of the uber expensive gear out there for a fraction of the cost.
The problem with me trying something along the line of his pre-amp is that it would serve no purpose in my active system. It would only inject a layer of coloration no matter how good it is since I don't need it for any utility that I can see.
The problem with me trying something along the line of his pre-amp is that it would serve no purpose in my active system. It would only inject a layer of coloration no matter how good it is since I don't need it for any utility that I can see.
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Key, the topic, before you hijacked it was not SACD, but dual servos for DC control.
If you want to compare components, compare some bulk film resistors to your "other" types of resistors. If there was no reason for bulk film resistors to cost more, or for designers to use them, why would they even exist?? Get back to us on that, would you??
Now, if you want to talk about if they are audible, you are in the wrong thread perhaps - since this thread does have a title - have you read it??
Of course, if you had bothered to read the first part of this thread, that topic was rather beaten back and forth in specific on a number of levels... did you read the part about the chassis construction??
You keep coming back to the same thing: "if you use your money wisely compared to the average joe audiophile that you could come up with a system which mercs some of the uber expensive gear out there for a fraction of the cost". So what are you trying to say??
Are you saying you could build a Tesla electric car in your garage for less using stuff you buy from catalogs and scrounging the junkyards?
Obvously, your position is that the digital domain obviates the analog one. You've said that about a half a dozen times now.
We got it.
Stop repeating yourself, ok?
Again, if you really think this is so, why not start your own thread and hash it out there? Don't forget to suggest your own "dream system for less" so that someone might have an idea what you're talking about, ok??
As it is said, if you have nothing really to say, say nothing??
_-_-bear
If you want to compare components, compare some bulk film resistors to your "other" types of resistors. If there was no reason for bulk film resistors to cost more, or for designers to use them, why would they even exist?? Get back to us on that, would you??
Now, if you want to talk about if they are audible, you are in the wrong thread perhaps - since this thread does have a title - have you read it??
Of course, if you had bothered to read the first part of this thread, that topic was rather beaten back and forth in specific on a number of levels... did you read the part about the chassis construction??
You keep coming back to the same thing: "if you use your money wisely compared to the average joe audiophile that you could come up with a system which mercs some of the uber expensive gear out there for a fraction of the cost". So what are you trying to say??
Are you saying you could build a Tesla electric car in your garage for less using stuff you buy from catalogs and scrounging the junkyards?
Obvously, your position is that the digital domain obviates the analog one. You've said that about a half a dozen times now.
We got it.
Stop repeating yourself, ok?
Again, if you really think this is so, why not start your own thread and hash it out there? Don't forget to suggest your own "dream system for less" so that someone might have an idea what you're talking about, ok??
As it is said, if you have nothing really to say, say nothing??
_-_-bear
Damn someone needs to go out back and smoke a j or something. It's just audio man lol chill out. And for the record I think it was you that re-upped the post and urged me to continue so don't act like I am asking for attention here. I just saw one of John's comments as an extension of a totally unrelated thread. I probably misread it but frankly I didn't care and continued going back and forth because I was bored. Sorry to mess up your otherwise logical conversation.
Key, give it a break, will you? For some people, I can never give enough proof about half the things that I know and do, any more than 5 star chef could prove why he does things a certain way in every case. I go with the flow, you know, whatever works, BUT I do try to measure things like wire differences and I have personally invested thousands of dollars in test equipment just to try to find something useful about wire differences. I HAVE found differences, but most people here, who like to give me a hard time, don't accept my evidence, including SY. I just have to laugh it off.
Yet, to ignore what we have found to work is silly too, and a further waste of time and money. Many people, my direct competitors in many cases, miss important subtle factors that I hope to capitalize on in my next generation of designs. Also, in all fairness, the designs I have available are the best that I can do, within the constraints that I have to work in. I hold virtually nothing back, but I still learn to do things better, by relying on subjective feedback. For example, right now, I am told that 2 separate amps sound better in one location, than my JC-1 power amps. I now have to find out why. It will not be directly in the measurements, that's for sure. But I cannot ignore it, like so many would here, just because the measurements are OK. This is what creates, what we like to call, progress.
Yet, to ignore what we have found to work is silly too, and a further waste of time and money. Many people, my direct competitors in many cases, miss important subtle factors that I hope to capitalize on in my next generation of designs. Also, in all fairness, the designs I have available are the best that I can do, within the constraints that I have to work in. I hold virtually nothing back, but I still learn to do things better, by relying on subjective feedback. For example, right now, I am told that 2 separate amps sound better in one location, than my JC-1 power amps. I now have to find out why. It will not be directly in the measurements, that's for sure. But I cannot ignore it, like so many would here, just because the measurements are OK. This is what creates, what we like to call, progress.
Dear fellow - I did not ask you to continue.
I asked you to not continue as you were.
When or if you are bored, consider doing something (else) constructive next time?
_-_-bear
EDIT: I thought about this for a bit... what ur doing Kay is the equivalent of arguing with (for example) Eric Clapton about how he plays guitar - when you don't even really know how to play yourself to begin with... do you see how that comes off?? You get the privilege of getting the chance to communicate with and "hear" what people of that caliber (but in audio design) have to say by being part of this forum. Try to recognize who is who and who you are??
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