what do You think A.E. meant by his comment? Seems to mean pretty much just what he said.
-RNM
Well said. And I thought you could paint a similar picture about the knowledge and experience of the designers involved, but it would run backwards.
No more JC's and Bonzai's coming on line.
Jan
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I cannot but agree, Andrew, however don't forget that those horrible 2N3055 and its relative complements (e.g. BDX18, etc) did, for a time, make some of us happy. I remember when I bought my reVox A7X integrated amps, at the time ir was a pretty good unit, and Studer/Revox made sure they used only devices from RCA. A friend with the same model unortunately had to change his output stage and purchased the devices from SGS-Thomson (I think?) and his amp never sounded the same again. Everybody and their dog was making them and the varied as no other device I have ever heard of varied before. I also remember only too well some receivers from those times, mostly from Germany (and especially from Wega, then independent and later purchased by Sony) which made sounds better than most of today's similar fare.
Remember the legendary NAD 3020, or the first Lecson power amps, cylindrically shaped and designed by Bob Stuart? Or the never forgotten Armstrong receivers? Did you know that Arcam kept them in products until the late '80ies?
Now if someone would just break out from the theoretical limitations of magnetic materials we could make a new breakthrough in loudspeaker design, but alas we do have physical limitations to deal with. I'm still pushing to make something new and interesting outside the norm but there are few that I think are really working outside the known way of using commodity components.
I was getting my arms burned with some chips coming off my lathe today, needed to put on some long sleeves and gloves as I start to machine some 1010 steel for a new pole piece and cup for my Be dome tweeter. Wish I could get my hands on some small quantities of electric steel, that would be an improvement over low carbon steel. The cone driver is more interesting but until some higher powered Neo or other magnetic material with HT properties is found not much more I can do in that area besides some weird ideas I have for surround and spider.
Some of us are still looking for answers to problems nobody is talking about. It takes both theory and experimentation to move forward in all fields. With no new theory or ideas what is there to do but lower costs?
I was getting my arms burned with some chips coming off my lathe today, needed to put on some long sleeves and gloves as I start to machine some 1010 steel for a new pole piece and cup for my Be dome tweeter. Wish I could get my hands on some small quantities of electric steel, that would be an improvement over low carbon steel. The cone driver is more interesting but until some higher powered Neo or other magnetic material with HT properties is found not much more I can do in that area besides some weird ideas I have for surround and spider.
Some of us are still looking for answers to problems nobody is talking about. It takes both theory and experimentation to move forward in all fields. With no new theory or ideas what is there to do but lower costs?
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All 3055 were not equal, Motorola s alumnium cased were decent with 2.5MHz Ft and the usual PNP complementary BDX18 was as fast if not more, actually it was rather the front ends that were sub par, often a resistances loaded dfferential and a single transistor VAS, with a more adequate FE one can pull very good numbers from this old power pair.
The USA was behind the times. There was a ton of tube revival and DIY going on in Japan in the 1970s, and Europe slightly later. It wasn't all tubes, either. Plenty of solid state class-A as well as speaker building. When I fell into it in the mid 80s, it was already going strong. Of course it was not yet time for a vinyl revival. I didn't even hear a CD until 1985.
I do remember a friend, rather high placed in the European audio world, and now president of a large speaker company, lamenting the eminent demise of DIY. He claimed that the young guys just weren't interested because they could buy such good stuff off the shelf. Circa 1989. I think he was wrong about DIY.
The linked post is proof of that, zero awareness of the proceedings in the rest of the world.
(the early '80s was when Menno van der Veen started writing valve + transformer articles for Radio Bulletin in these parts. Pretty much the 1st audio related mag I was subscribed to)
very very late 80's after a few people noticed what the Japanese mags were saying and doing...
Did Glass Audio start that early??
Joe Robert's "Sound Practices" probably pushed this before Audio Amateur really got anything going...
My recollection is that SE was still very rare in the early 90s.
Even tubes (other than the commercial brands with PP pentodes) were rather 'exotic' and DHT was seen as an oddity with limited application (which to some extent it is).
_-_-
I suspect same.
Agreed. I designed, built, programmed and operate a motion control platform that used the most advanced operating system available at the time. Windows 95. It was created with an ME, an EE(moi), one theoretical physicist, one magfield/measurement physicist, one EE tech, and one mech tech.
It is currently beyond the state of the art as all of you know, 20 years later. That is a result of the strength of collaboration between theoretical and practical. (Btw, it still runs '95, we just broke network connections a long time ago as antivirus is unsupported now. I always get a laugh when I tell the high school tours about win '95, the kids go bug-eye.)
Three national labs and two commercial companies have been trying to duplicate our work for a decade now. I was told by the state department (through the chain of command of course) to answer every question they ask. In ten years, they have not asked the right questions. Again, that is because either theorists ask, or experimentals ask. The right group of talent is necessary.
CERN had this problem, theorists should NOT be trusted to design solder joints meant for a production environment, it cost them two years and about 50 million dollars in hardware.
I do not know who you refer to. Who is A. E.?
John
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Ah, thank you.
Richard,
There have been several instances where I came up with an insight that advanced the field beyond what was known or understood. However, it was my theoretical physicist colleagues who mathematically developed it to apply it to my hardware. To this day, there exists two blocks of code in my software that I cannot understand. I know the code, I understand what goes in and what comes out, but the math is far beyond me.
Our cross- understandings made that possible.
AE is correct, but he seems to downplay the math.
John
I'm trying develop DIY process for labeling panels using home made water slide laser printed decals.The decal is backed on the panel. I need to dissolve the film after baking. The film is made from dextrose corn sugar residue.
What common chemical can dissolve this film without attacking the baked on laser toner.
Sodium hydroxide maybe, spa chemical. What?
What common chemical can dissolve this film without attacking the baked on laser toner.
Sodium hydroxide maybe, spa chemical. What?
You mean baked on? Never thought of doing this but doesn't sodium hydroxide eat aluminum?
I worked with a colleague in my earlier days who came from Poland, and had managed to get out in the late 70's. He had a very good technical education (MSc) and was a good mathematician.
I was working on a SMPSU one day and wanted to know how I could determine the RMS current through the filter cap so I could specify the right part. He took a piece of A4 paper and right in front of me derived the formula. I spec'd the part accordingly and as far as I know, there were never any field failures (industrial instrumentation).
There were a lot of other things he helped solve as well. He was very complimentary about my 'minimalist' circuit designs - one of which I later published in EDN Design Ideas ('Low Cost Isolation Amplifier')
The point is, I think you need the theoretical guys and then you need practical people.
I was working on a SMPSU one day and wanted to know how I could determine the RMS current through the filter cap so I could specify the right part. He took a piece of A4 paper and right in front of me derived the formula. I spec'd the part accordingly and as far as I know, there were never any field failures (industrial instrumentation).
There were a lot of other things he helped solve as well. He was very complimentary about my 'minimalist' circuit designs - one of which I later published in EDN Design Ideas ('Low Cost Isolation Amplifier')
The point is, I think you need the theoretical guys and then you need practical people.
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