What is the point of this? What do most of you really know about tubes, their real sound quality, or their good or bad points? So far as I can tell, nothing. Only SY and we professional audio designers have any idea of the tradeoffs between tubes and solid state. However, SY is way out of line when it comes to universal transformer application, although I agree that my video playback certainly needs a pair of transformers to remove the cable broadcast garbage/ ground loops, mixed with high speed internet transmission.
john curl said:
Other than safety issues, the moderators don't censor technical content. It's up to the smarter guys to correct the mistakes of us rookies.
snoopy, I'd agree. That's a ludicrous spectrum for a device that's purported to be an amplifier. $300k for an effects box combined with a room heater. Wow.
KBK, I think that Scott is implying that you are operating outside your area of expertise, and he is set to bite your ears off, when you demonstrate this. I think that Scott is right about this. There are experts here that can contribute on many topics, so let's let them input after you put forth your tentative solution, hopefully everyone will learn, but as so many here seem prone to do here, please refrain from stating a guess as a fact, or you may regret the reaction by others.
john curl said:
John, I'm confused by what you consider misinformation. If you mean reviews in audiophile magazines, I would generally agree that they contain much.
That preamp is interesting. I always wondered if any one would exploit the fact that JFET's have an enormous power gain at audio frequencies. He's playing in the same world that you are as are a surprising number of people. When I was in France I picked up a tiny magazine to read. I figure every year 5 or 6 muti-$1000 preamps come and go.
Also in Frankfurt something funny happend; I was eyeing (as were a couple of German guys) a display for the latest 3-way $30,000 horn speaker that looked way over the top. My wife came by and sort of made a "What the f***" comment and the two guys and I made eye contact and started laughing.
john curl said:
I fact I have a great deal of respect for KBK. From what I have read he sells a product of real merit that was probably intelligently engineerd. In fact when he describes things that he actually sits down and does, it sounds like good solid after market modding. The other stuff keeps life interesting, I've read Schauberger and Steiner, also the famous Jesuit Kircher (way ahead of Monty Python)
In 1680 Kircher is said to have correctly computed the ordinary ( vs. forced) flight of a swallow at 100 ft/sec - and this before the invention of stopwatches!
We did BTW have a basement researcher from Ohio call us and claim he can remove 1/f noise from packaged JFET op-amps. This was at least 15yr. ago. We had the usual IP issue that was discussed elsewhere and nothing came of it. My guess was that he lucked out and stuck a part in the microwave and healed a bad damage site.
In fact generation-reconbination noise with a vary high temperature coefficient is the worst culprit and it's not 1/f. Google for Hasslet and Kendal (sp?) you will find enough to kill a few evenings.
In fact generation-reconbination noise with a vary high temperature coefficient is the worst culprit and it's not 1/f. Google for Hasslet and Kendal (sp?) you will find enough to kill a few evenings.
Annealing is a useful process. I wish that it was done better and more often.
Klaus, Siemens made MY EL-34's that I like. Long gone, but Siemens made them for the German military, if nobody else. Apparently they were designed for class C use in German military RF transmitters before WW2. They sort of lucked out as good Class A-B devices. Telefunken developed them first, probably lifting ideas from the RCA 6L6 and 6V6 before WW2.
Klaus, Siemens made MY EL-34's that I like. Long gone, but Siemens made them for the German military, if nobody else. Apparently they were designed for class C use in German military RF transmitters before WW2. They sort of lucked out as good Class A-B devices. Telefunken developed them first, probably lifting ideas from the RCA 6L6 and 6V6 before WW2.
SY said:
Considering Kircher is considered the father of modern Egyptology that's a good question.
I made an earlier comment about the lack of activity of the moderators on this thread regarding technical inaccuracy. I just assumed this was one of their responsibilities, and their 'inaction' was due to their lack of understanding of the material, but I now presume that I was incorrect in this assumption, and I apologize, for not reading your 'moderators statement' first.
I try to communicate on this thread (I am continually reminded by moderators and members alike that I do NOT own this thread) and therefore it can be impugned by just about everyone with an opinion of some sort. Only overt thread hijacking seems to be not tolerated, but much input is unfortunately uninformed opinion or even outright prejudice about hi end audio and even overt attacks on my associates and me are tolerated, and apparently considered acceptable.
Now, my latest criticism was about the nature and noise properties of fets, which I am an expert in the field. To have someone opine complete, misleading nonsense disturbs me, as it misinforms others here, even though I can see quickly through it.
I tolerate and even respect subjective reviews of audio products. In fact, I revel in it, as that is the only real way there is to really judge an audio design, except for listening to it myself, and I don't have the resources to do so, much of the time.
We have some powerful designers here, and I hope we can continue on a number of related topics, perhaps each of us learning something new, and perhaps (I hope) some audio prejudices dispelled by better understanding of the real facts.
I try to communicate on this thread (I am continually reminded by moderators and members alike that I do NOT own this thread) and therefore it can be impugned by just about everyone with an opinion of some sort. Only overt thread hijacking seems to be not tolerated, but much input is unfortunately uninformed opinion or even outright prejudice about hi end audio and even overt attacks on my associates and me are tolerated, and apparently considered acceptable.
Now, my latest criticism was about the nature and noise properties of fets, which I am an expert in the field. To have someone opine complete, misleading nonsense disturbs me, as it misinforms others here, even though I can see quickly through it.
I tolerate and even respect subjective reviews of audio products. In fact, I revel in it, as that is the only real way there is to really judge an audio design, except for listening to it myself, and I don't have the resources to do so, much of the time.
We have some powerful designers here, and I hope we can continue on a number of related topics, perhaps each of us learning something new, and perhaps (I hope) some audio prejudices dispelled by better understanding of the real facts.
I appologize for my very basic question, but I plan to do more DIY after I retire in a few years and would like to know what recommended J-fets part numbers and what quantities I should order before they are gone.
By the way thanks for this thread. Although I cannot understand all that is said, I have learned to listen more and look at spec less.
John, thanks especially for the Levinson JC-2 which got me started into high end audio. Unfortunately the phono preamp on one channel became noisy so it is no longer in service.
By the way thanks for this thread. Although I cannot understand all that is said, I have learned to listen more and look at spec less.
John, thanks especially for the Levinson JC-2 which got me started into high end audio. Unfortunately the phono preamp on one channel became noisy so it is no longer in service.
Experts in a field usually know more than amateurs, just because they have put more time, education, and experience into their field of expertise, all else being equal, such as basic intelligence or common sense.
Experts in a related field sometimes think that they know a lot outside their specific field of expertise, and actually get into technical trouble, because they are overconfident in their understanding of something they have only dabbled in, or have been told by others about.
The is the basis of: 'The Experts Speak' a book of misunderstandings of every sort throughout the history of mankind. Good reading.
When I go outside MY field of experience and education, I get into trouble, also. For example, if I try to truly understand how electricity flows from a quantum physics level, I get confused and have found that any public statements, no matter how well meant, will be twisted by some in one direction, and taken in another direction by another, and nothing useful will come of it. Quantum physics seems to have the same problems as audio design, as there are true believers, nay-sayers, flat-earthers, and extraterrestrials.
Experts in a related field sometimes think that they know a lot outside their specific field of expertise, and actually get into technical trouble, because they are overconfident in their understanding of something they have only dabbled in, or have been told by others about.
The is the basis of: 'The Experts Speak' a book of misunderstandings of every sort throughout the history of mankind. Good reading.
When I go outside MY field of experience and education, I get into trouble, also. For example, if I try to truly understand how electricity flows from a quantum physics level, I get confused and have found that any public statements, no matter how well meant, will be twisted by some in one direction, and taken in another direction by another, and nothing useful will come of it. Quantum physics seems to have the same problems as audio design, as there are true believers, nay-sayers, flat-earthers, and extraterrestrials.
John, are you saying I should not bother to get J-fets because I will not be capable of using them intelligently?
I would not buy them to design my own circuit but to build a circuit that has been designed and has become available for DIY. It might be a total failure, but if I do not have the parts I cannot even try.
I would not buy them to design my own circuit but to build a circuit that has been designed and has become available for DIY. It might be a total failure, but if I do not have the parts I cannot even try.
LHM IF you can, you should get a stock of at least 50 each (100 is better) of Toshiba 2sk170 and 2sj74. Everything else is up for grabs at the moment.
For the record, LHM, my previous post had nothing whatsoever to do with you in any way. I have to account for others as well on this thread, and that post was for them.
For the record, LHM, my previous post had nothing whatsoever to do with you in any way. I have to account for others as well on this thread, and that post was for them.
Thanks John. I just placed an order for 100 each with MCM. They had one of the 2sk170 and none of the 2sj74 so I have them on backorder. I wonder if they will actually be able to fill the order?
Lindsay
Lindsay
2SK170/2SJ74
AmpsLAB offers them too (1$/pcs).
http://www.ampslab.com/trans_2sk170bl.htm
Does anyone know if that's a reliable source?
AmpsLAB offers them too (1$/pcs).
http://www.ampslab.com/trans_2sk170bl.htm
Does anyone know if that's a reliable source?
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