- WANTED: Obsolete Component LED Rectangular Light Bars - 1 Update
- Two Amps Fail Simultaneously, I Am Suspicious - 2 Updates
- High Z And Low Z Mics - 7 Updates
| Scotophor <a.j.franzman@verizon.net>: Feb 07 12:19AM -0800 > LED failure is generally defined as the point where the light output > has dropped by 50%. Selection of encapsulant can either accelerate or > retard this effect. Really? Then why do the online references seem to want to refer to dark current only in terms of photodiodes and other light-detecting (rather than emitting) components? I.E., dark current is the leakage current which flows when a light detector is detecting no light. Sure, an LED /can/ be used as a light detector, but for typical usage, the standard definition of dark current seems to be irrelevant. Can you cite references for your definition of "dark current"? > > Statistically speaking, I find it hard to believe that: upon identifying the LEDs, (A) I already had two of them, unused, among my supplies, (B) I already knew someone whom I believed might also have some, which I was able to verify in minutes by browsing his website. I later obtained more than a dozen of them from him, a mix of unused examples and pulls. (C) Within days I had found another person online who sent me three more, yet (D) In the 6+ months since, I have not been able to locate even a single additional example. What are the odds that I could locate and acquire the world's entire available supply of these in such a short time, and that I already knew the person who had most of them? It boggles my mind to think that I found as many as I did so quickly, yet there now don't appear to be any more to be had, anywhere. I believe there must be more out there; it's just going to take more time and effort to discover them. > Sooner or later, crap tends to get flushed. Are you making assumptions again, or do you have personal experience with the LEDs I'm seeking? Also, I can direct you to several collectors and sellers of some of the earliest commercially-made LEDs, which are IMO far more suited to be labeled as "crap", based purely upon light output and longevity, than those of my current quest. If people collect that junk, then why not some that are brighter and more unusual? |
| jurb6006@gmail.com: Feb 06 07:00PM -0800 >"** Probably had two leads going into the same cabinet - most cabs have dual >jack or Speakon sockets to allow chaining. >It's a dead sitter for dopey musicians to use both of them into each channel of >a stereo amp OR in this case two different amps. " I'd have to bet you're right. Remember these people have trouble with the concept of a LINE input versus a MIC input. Now I see that some of my (company) time is going to be spent on education. I wonder what they did before. Car dealers or something ? Actualy I know, they had an internet business selling musical instruments and the like. One guy there, I knew his Father when I was in business. He said he was fixing black and white TVs when he was like twelve. I am sure he would know better than to do that, but was he there at the time ? It is quite possible it was the counter guy and the boss, neither one of them ever claimed to know any electronics. Yeah, maybe not dopey per se, but unknowledgable. I know in the Allison vernaculr the word is "fucking stupid" but you know what I mean. I am not going to go in there and call them fucing stupuid. In fact when they blow shit up I make more money. Maybe I should just leep my trap shut. |
| Phil Allison <pallison49@gmail.com>: Feb 06 09:18PM -0800 > Actualy I know, they had an internet business selling musical instruments and the like. One guy there, I knew his Father when I was in business. He said he was fixing black and white TVs when he was like twelve. I am sure he would know better than to do that, but was he there at the time ? It is quite possible it was the counter guy and the boss, neither one of them ever claimed to know any electronics. > Yeah, maybe not dopey per se, but unknowledgable. > I know in the Allison vernaculr the word is "fucking stupid" but you know what I mean. I am not going to go in there and call them fucing stupuid. In fact when they blow shit up I make more money. Maybe I should just leep my trap shut. ** Just let them know the event was their own fault and IF anything of the sort happens again, there is NO warranty. I have repaired numerous mixers that had an amplifier leads plugged into an input and one where a Mackie 16:4:2 desk was a complete write off because the speaker lead from a 100W Marshall was *deliberately* plugged into a line input. The silliest one was with a stereo power amp accused of making the most horrible banging noise as soon as the volume control was turned up on one channel. The amp bench tested faultless. It was soon back with the same complaint, so this time I really quizzed the owner. The noise heard was a steady, very loud series of bangs, about twice per second, as soon as the control was advanced beyond about 33%. After puzzling for a time I tried a simple test - what happens if you plug the output of one channel back to the input and advance the volume ? Answer: It becomes a low frequency *square wave* generator with full rail to rail output. Same goes for most any amp that does not invert the signal. The dopey roadie was a adding an extra XLR lead to the back of the amp rack that was NOT needed !!! When I explained it to the owner - his come back was: " then how come you didn't think of that last time it was here ? " Astonished, I replied: " Well, I didn't think anyone would do something so stupid. ... Phil |
| rev.11d.meow@gmail.com: Feb 06 06:05PM -0800 On Friday, February 6, 2015 at 6:02:38 PM UTC-8, Phil Allison wrote: > - got a clue what that is ?? > > Besides that, OP needlessly and incorrectly modified the amp. > ** Bollocks he did. Technical Pro powered speakers have Mic input. OP doesn't need to modify the amp at all. D'OH ffs yourself |
| rev.11d.meow@gmail.com: Feb 06 06:28PM -0800 On Friday, February 6, 2015 at 5:47:32 PM UTC-8, Phil Allison wrote: > > The pictured unit, not the same as in the description, is bi-directional. > ** Not meant to be - the male XLR on one end makes it impossible to plug a mic or XLR mic lead into it. > .... Phil Didn't you say the XLR Male plug guzzinta the mixing board? I declare this thread a total troll on all of us here. Note missing XLR input information from original post. Note missing label info for this XLR jack. Note the manufacturer's website description of its powered speakers. Also note they have at least one model with a built-in mixer. With that I vote he goes with his mod and a microphone plugged into it. When it's too loud, they can adjust the Volume on a powered speaker with no volume control. Sounds like this whole plan is not only a troll, but a totally abysmal FAIL as well. Boy, did I ever fall for this one, yeesh. :( |
| jurb6006@gmail.com: Feb 06 06:28PM -0800 >"> Besides that, OP needlessly and incorrectly modified the amp. " Didn't that blown up picture depict an ATTENUATOR ? That's the last thing we needed. >"** Bollocks he did. " Don't tell me you are sticking up for me lol. But anyway, I will modify anything as long as it is a safe and reliabale design. I am goood enough to know when it is and when it isn't. I have done so quite a bit over the years and never got into a problem over it. In fact gained customers because of it. |
| jurb6006@gmail.com: Feb 06 06:35PM -0800 >"Technical Pro powered speakers have Mic input. OP doesn't need to modify the >amp at all. D'OH " There was ot enough gain. I connected line level to it and there was plenty of gain. The problem was the same on ¼" and XLR which feed separate OP AMPs. BOTH INPUTS SAY "LINE". So, are you really sure of that ? with a higher input to either the amp clips just fine, no distortion. If there was a fault in the amp it would have to be rtow separate identical faults causing the same reduction in gain in two separate OP AMPs. Is this what you're telling me ? |
| rev.11d.meow@gmail.com: Feb 06 06:35PM -0800 > >"** Bollocks he did. " > Don't tell me you are sticking up for me lol. But anyway, I will modify anything as long as it is a safe and reliabale design. I am goood enough to know when it is and when it isn't. I have done so quite a bit over the years and never got into a problem over it. > In fact gained customers because of it. Why doesn't your mod include a Volume control then? They should've purchased the model with the built-in mixer. If you want to add a mixer, feel free. You could always do your Gain adjustment mod, then test it that way with someone actually using the microphone... And see how good it all would be with a Volume control mod instead. Or use the built-in Mic input already on the thing. Yeesh |
| rev.11d.meow@gmail.com: Feb 06 06:41PM -0800 > BOTH INPUTS SAY "LINE". > So, are you really sure of that ? with a higher input to either the amp clips just fine, no distortion. If there was a fault in the amp it would have to be rtow separate identical faults causing the same reduction in gain in two separate OP AMPs. > Is this what you're telling me ? You still haven't said anything about the microphone in use, but this is the usual fix. http://www.audio-technica.com/cms/electronics/f4b735b4cabc30ea/ Audio-Technica CP8201 In-Line Transformer http://www.musiciansfriend.com/accessories/audio-technica-cp8201-in-line-transformer That answers your original question, which is in itself limiting the solution to Not include Volume control, which is essential for PA purposes. I never said you are wrong or incorrect in your approach, just time-wasting and too costly in the long run. $10 and you'd be done. minus Volume control, that is... :) |
| rev.11d.meow@gmail.com: Feb 06 06:50PM -0800 > >"> Besides that, OP needlessly and incorrectly modified the amp. " > Didn't that blown up picture depict an ATTENUATOR ? That's the last thing we needed. That red button is a locking mechanism, not a potentiometer. If you want to pay $20 more, use it plugged into the XLR Line IN, and your balanced microphone cable into it. But, you still don't have a Volume control. You could Manually PWM the mic's On/Off switch Really Fast to get a Volume control in there. :) Peace Out |
| You received this digest because you're subscribed to updates for this group. You can change your settings on the group membership page. To unsubscribe from this group and stop receiving emails from it send an email to sci.electronics.repair+unsubscribe@googlegroups.com. |
No Response to "Digest for sci.electronics.repair@googlegroups.com - 10 updates in 3 topics"
Post a Comment