Steve Eddy, are we still talking about polarity invert switch or did you drifted away and talking about input select switches now?
I don't choose materials based on how it smells. If I did, I'd never be using any ebonite which when you machine it smells like rotten eggs.
Godfrey's perversion of what I said was based on a statement I'd made that the cables I ended up with, in addition to sounding good to me, also looked good, felt good, and smelled good. I wasn't designing based on smell, only that the cables also smelling good was a nice side benefit.
It also relates to what I've said in the past about not caring why something might "sound" better to me. In other words, it didn't matter to me whether it was something that was actually audible, or due to purely psychological effects. If something sounded better to me simply because it looked good, felt good and smelled good, then give me good looks, good feel and good smell.
se
I am still very happy with my divorce, which brings me to the point that there are many roads to hapiness, as many ways as sound waves can take through the air.
This then leads to the following. I was reading Lipshitz's 1985 AES-paper "stereo microphone techniques: are the purists wrong". At the end he mentions as a fundamental flaw of stereo that:
-quo-
Consider equal in-phase signals at the loudspeakers, as would
be produced by a center-front source. At the listener's head the sound
pressure is up by a factor of two (6 dB) by scalar addition but the
sound velocity is up by only 3 dB (a factor of_sqrt(2)=1/sqrt(2)+1/sqrt(2)) by
vector addition if the loudspeakers subtend a 90 ° angle at the listener.
There is thus a 3 dB deficit.
-unquo-
Which leads me to two nagging questions:
1) in what sense will that influence our perception of sound, since we are sensitive to pressure variations,
and
2) this is only true if sound waves pass through each other like electromagnetic waves, or ripples on a point. To some extend this is probably the case, but wouldn't sound waves also combine to create new virtual sound sources, combining their momentums? Instinctively I would think that because of the propagation mechanism is different, the way momentum combines might also be different (in EM-waves the oscillation is perpendicular to the direction of movement, and with waves on a pond it is the same thing; with air waves the oscillation is in the same direction as the direction of movement).
I hope this learned gathering has clues.
This then leads to the following. I was reading Lipshitz's 1985 AES-paper "stereo microphone techniques: are the purists wrong". At the end he mentions as a fundamental flaw of stereo that:
-quo-
Consider equal in-phase signals at the loudspeakers, as would
be produced by a center-front source. At the listener's head the sound
pressure is up by a factor of two (6 dB) by scalar addition but the
sound velocity is up by only 3 dB (a factor of_sqrt(2)=1/sqrt(2)+1/sqrt(2)) by
vector addition if the loudspeakers subtend a 90 ° angle at the listener.
There is thus a 3 dB deficit.
-unquo-
Which leads me to two nagging questions:
1) in what sense will that influence our perception of sound, since we are sensitive to pressure variations,
and
2) this is only true if sound waves pass through each other like electromagnetic waves, or ripples on a point. To some extend this is probably the case, but wouldn't sound waves also combine to create new virtual sound sources, combining their momentums? Instinctively I would think that because of the propagation mechanism is different, the way momentum combines might also be different (in EM-waves the oscillation is perpendicular to the direction of movement, and with waves on a pond it is the same thing; with air waves the oscillation is in the same direction as the direction of movement).
I hope this learned gathering has clues.
I was referring to BOTH switches.
According to John, depending on whether the inputs were balanced or the outputs were balanced, the input switch and/or the polarity switch would use either two decks or four decks. With balanced, they were using a single deck for each of the left and right channel's inverting and non-inverting leads, which would require four decks for two channels.
Since they wouldn't know whether a customer wanted balanced or unbalanced ins and outs, they had to keep stock on four different switches, i.e. two different input switches and two different polarity switches.
I'm saying that without the bizarre requirement that the inverting and non-inverting leads each have their own deck, they could accommodate both unbalanced and balanced configurations using just two switches, i.e. one for input switching and one for polarity switching.
se
John, please read the posts slower. He asked you if he could post it, and was hoping for everybody's input on substitutes. Here's the question again..
My air guitar never sounded better..
Good to keep in mind.. Course, I sand purpleheart, so who am I to speak.
Ah, ok..I made the assumption that since he attributed it to you, it must have been an accurate depiction.
Oh well..egg on my face..
jn
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JNeutron, Do you know the specific differences between Vfets, lateral mosfets, vertical mosfets, Hitachi pinout, Harris IR equivalent mosfets, IR mosfets, and SUPERTEX T0-220 complementary mosfets (not made anymore)? IF not, then please withdraw from the controversy.
For everyone else: JUST the mention of the word: VFET shows that Scott is completely in the dark about the design parameters, as there are NO VFETS in a JC-80. Only, Supertex TO-220 mosfets that are difficult to substitute with anything else.
For everyone else: JUST the mention of the word: VFET shows that Scott is completely in the dark about the design parameters, as there are NO VFETS in a JC-80. Only, Supertex TO-220 mosfets that are difficult to substitute with anything else.
What an odd thing for him to say. Terribly incorrect, but really odd. The sound velocity is not higher. The waves pass in the night, so to speak, at levels which humans can survive.
I believe that requires non linearity in the medium..Isn't that how that two U/S wave virtual source thingy works?
That is an entirely different and somewhat off topic question..
I can only speak for myself.. I am clueless..
jn
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Great. And I've never criticized your choice of Shallco switches.
But it's not "extreme" in the sense of going the extra extra mile to achieve some greater performance benefit. It's utterly nonsensical and actually a step backwards in terms of performance benefits. I think Bob may have been laboring under the common mistaken "audiophile" notion that the "ideal" balanced configuration should have the inverting and non-inverting sides completely separate from one another as if they were separate channels like left and right.
I've seen this a number of times in the marketing literature for "high end" components. "Completely separate signal paths for balanced operation!"
Forcing you into a rats nest wiring job that can only diminish performance.
I liked Bob. He was quite a character. But the internal layout of the Blowtorch should have been left to someone else.
se
The schematic shows VN01/VP01 and you initialed it and sent it to me. I can only find that part number listed as Verticle DMOS FET.
You mean, other than working as an electrical test engineer for a manufacturer of V fets?? Or, having been in the position of taking every semiconductor type known to man at the time including ALL manufacturer's fets, performing a 200 to 400X visual inspection of the chips in a waffle pack, bonding the die to a gold plated TO-3 header, wirebonding via either U/S or T/C bonding using 1, 2, 5, 15, and 20 mil wirebond, and then subjecting the packaged device to testing to determine if the parts meet the manufacturer's specifications?
I know far more about the devices than you could ever hope to even understand, but I am willing to teach you if you were to ask questions. So I guess the answer is....YES, I do.
ALAS....that was not what Scott was talking about. The question was regarding the collective discussion about substitute parts.
So stop blathering. Instead of trying so desperately to find any opportunity to attack others, read more carefully please.
jn
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Oh well just another attempt to discuss an actual JC circuit.
sigh.. you tried.
jn
The TO220 parts are history but the dies live on in TO92 and SOT-89 packages http://www.supertex.com/pdf/misc/p_e_mode_mosfets_SG_device.pdf . Supertex was never very successful with high power parts. I always understood them to be vertical DMOS parts. I am still using them in new designs and current products e.g.: P-9 .
JN, a VFET is not necessarily a VERTICAL FET. It is an early power jfet that was made by NEC, Sony, and Yamaha, for example. It is a DEPLETION MODE device and it was discontinued, because it was too difficult to get a suitable yield. It is also sometimes called a Static Induction Transistor.
The power devices used in the JC-80 are called VMOS, because they are a vertical MOS structure, with ENHANCEMENT instead of DEPLETION as the fundamental property of the device. They cannot be easily interchanged.
The power devices used in the JC-80 are called VMOS, because they are a vertical MOS structure, with ENHANCEMENT instead of DEPLETION as the fundamental property of the device. They cannot be easily interchanged.
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Scott, your attempted insertion of this schematic at this time was inappropriate. It would have answered nothing and would not have contributed to further understanding of the questions recently posed. Secondly, you didn't appear to 'understand' the schematic details to do anything but confuse the situation, just like Demian just did by implying that a TO-92 part could easily replace a T0-220 part, even though the die inside are the same.
That is something that JN might do, Demain! After all, with a 45 degree spread angle of heat flow, anything should be possible! I maintain that only liquid Freon would do the job properly, and maybe not well enough, given the plastic thermal resistance. '-)
That is something that JN might do, Demain! After all, with a 45 degree spread angle of heat flow, anything should be possible! I maintain that only liquid Freon would do the job properly, and maybe not well enough, given the plastic thermal resistance. '-)
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