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#61
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Amp Design Concept -- Preliminary
On 22 Sep 2006 04:55:24 -0700, "Telstar Electronics"
wrote in .com: Frank Gilliland wrote: As far as "matching problems", if you are referring to mismatched gain in transistor pairs, that only causes harmonics. If the mismatch is great enough to cause one transistor to run hotter than the other, that would be due either to component failure or ****-poor quality control. No, I'm talking about impedance matching problems. On the input is not a big issue... only reducing the available drive... but a mismatch on the output is critical... and causes big problems with excessive transistor heating... leading to premature failure. Ok. So what does that have to do with the difference between a PCB mounted amp and a chassis-wired amp? |
#62
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Amp Design Concept -- Preliminary
Frank Gilliland wrote:
Ok. So what does that have to do with the difference between a PCB mounted amp and a chassis-wired amp? I think the problem here is always one of repeatability. Anyone can fiddle around for a time impedance matching and make one amp work... but when you plan to make a number of units... having wires running all around, and putting components in different physical locations unit-to-unit makes performance unpredictable. There is another problem that shouldn't be overlooked about the wiring method... that is the problem of manufacturability. The PCB version is usually much easier and faster to build... not a insignificant advantage when building numerous units. www.telstar-electronics.com |
#64
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Amp Design Concept -- Preliminary
On 22 Sep 2006 05:31:06 -0700, "Telstar Electronics"
wrote in .com: Frank Gilliland wrote: Ok. So what does that have to do with the difference between a PCB mounted amp and a chassis-wired amp? I think the problem here is always one of repeatability. Anyone can fiddle around for a time impedance matching and make one amp work... but when you plan to make a number of units... having wires running all around, and putting components in different physical locations unit-to-unit makes performance unpredictable. Well, you think wrong. I tried to explain this before but I guess it didn't sink in the first two times, so let me make this -really- simple: http://bama.sbc.edu/ Many of those radios were (and still are) considered by many to be some of the best ever built. If you really think their chassis wiring construction made their performance "unpredictable" then there are only three possible conclusions: One, that your experience is severely limited; two, that your sanity is in doubt; and three, that you are digging for the lamest of excuses to discredit me at the expense of your own credibility. I'm guessing the prize is behind door number three. There is another problem that shouldn't be overlooked about the wiring method... that is the problem of manufacturability. The PCB version is usually much easier and faster to build... not a insignificant advantage when building numerous units. Haste makes waste. |
#65
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Amp Design Concept -- Preliminary
On Fri, 22 Sep 2006 15:14:43 -0400, wrote in
: On Fri, 22 Sep 2006 02:31:44 -0700, Frank Gilliland wrote: On Fri, 22 Sep 2006 04:49:01 -0400, wrote in : snip Your belief that a properly soldered connection is more likely to fail than a connector tells us a lot about the success of your amp. This amp symbolizes your life and is doomed from the start because of your false beliefs. Your long stream of failures continue. Actually the solder joint doesn't fail. The wire itself fails because of frequent motion and repeated bending of the wire at the weakest point -- where the wire is bare of insulation just above the solder joint. Anybody who has ever owned a portable radio (or anything else) with a 9V battery clip knows exactly what I'm talking about, and I'm sure you do too. The best connectors are the ones that clamp both the wire and the insulation. Connectors such as IDC, SMA/B/C, BNC, Molex pin & socket, and even common crimp-type ring/fork/spade/hook connectors are all superior to just soldering the wire to the board. But nice try. It sounds like your amp can't be soldered because it's unstable. (physically) If that's the way it sounds to you then maybe it's time for you to think about getting a hearing aid. Are you sure that the reason automobile manufacturers use connectors is because they believe a connector is more reliable than a properly done solder joint? No, it also has to do with servicability, which is another reason -not- to solder the modules together. Now.... do you have an LEGITIMATE concerns or are you just trolling? |
#66
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Amp Design Concept -- Preliminary
Are you sure that the reason automobile manufacturers use connectors is because they believe a connector is more reliable than a properly done solder joint? No, it also has to do with servicability, which is another reason -not- to solder the modules together. Now.... do you have an LEGITIMATE concerns or are you just trolling? You actually suggested that for reliability reasons a connector is preferred over a proper solder joint. A quote from you: " Interconnection wires that are soldered have a high rate of failure in abusive environments. That's why auto manufacturers use connectors, even under the hood" Give us a break. When practical a properly done solder joint is always more reliable than a connector. |
#67
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Amp Design Concept -- Preliminary
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#68
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Amp Design Concept -- Preliminary
Many connectors are these days just pressed on (ethernet, phone, etc) and just as or more reliable then soldered connectors. Over thirty years? You can slow down but you can't stop galvanic action, oxidation or migration of foreign materials. If practical use a proper soldered connection to eliminate most of this. |
#69
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Amp Design Concept -- Preliminary
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#70
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Amp Design Concept -- Preliminary
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