Home |
Search |
Today's Posts |
#82
|
|||
|
|||
SSJVCmag wrote:
On 8/3/05 6:37 PM, in article , "William Sommerwerck" wrote: Let's stop talking about parrot-brained whatevers. Parrots -- especially the African gray -- are incredibly intelligent. You;re right of course. I was so caught up in pleasant conversation I forgot my manners. My apologies to avian folks everywhere. No slight intended. I don't know, I am sitting here watching an umbrella cockatoo trying to eat the cat. This is _not_ an intelligent thing to do. --scott I don't trust birds. -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
#83
|
|||
|
|||
|
#84
|
|||
|
|||
Now the champion ****wit champions parrot's brains !!
Summa-wank needs to go on the Letterman Show. Yes, and you can be my stupid-pet trick. (Note the placement of the hyphen.) |
#85
|
|||
|
|||
Scott Dorsey wrote:
my2cents wrote: Bruel & Kjaer have always referred to their 2615/2619/2639/etc as microphone preamplifiers, despite the fact that all have less than unity gain. The same is true for the manufacturers of the B&K look-alikes, such as ACO Pacific, Larson Davis, GRAS, etc. Are you sure? All of my B&K docs call them "Followers" rather than preamplifiers, presumably because they have voltage follower circuits inside. I don't know about the clones. Personally, I don't like _any_ of the words used. "Preamplifiers" is confusing, "followers" is not always accurate, "impedance converters" is accurate but incomplete, and "handles" is only correct for some styles of design. I think we should call them "bleem." --scott Bleem is fershlugginer. What about "capsule amplifiers"? Has ta be pronounced like Levon Helm did in "The Right Stuff", tho - cap-sooool. -- Les Cargill |
#86
|
|||
|
|||
|
#87
|
|||
|
|||
|
#88
|
|||
|
|||
(Mike Rivers) wrote in news:znr1123107061k@trad:
In article writes: Bruel & Kjaer have always referred to their 2615/2619/2639/etc as microphone preamplifiers, despite the fact that all have less than unity gain. The same is true for the manufacturers of the B&K look-alikes, such as ACO Pacific, Larson Davis, GRAS, etc. Can we say that "preamplifier" has two meanings, one to microphone manufacturers who don't care about anything beyond the output connector, and the other to people who buy studio equipment and need something to connect their microphones to? Oh, and a third meaning just for Phil Allison to start arguments about. Ignorance is bliss and many of the sudio people such as yourself appear to have both in abundance. The issue isn't about the meaning of the term "premaplifier" nor is about whether manufacturer's do or don't care about anything beyond the output connector. The issue is about the present correct and traditionally-correct meaning of the term "microphone preamplifier" which connects to a capacitive microphone capsule and has less than unity gain. |
#89
|
|||
|
|||
Scott Dorsey wrote: Personally, I don't like _any_ of the words used. "Preamplifiers" is confusing, "followers" is not always accurate, "impedance converters" is accurate but incomplete, and "handles" is only correct for some styles of design. I think we should call them "bleem." I'd call it a buffer amplifier to reflect its real function while discriminating it from what is usually meant by pre-amplifier: a variable gain amplifier used prior to a system input to bring a signal to the level expected by that input. "Buffer" has plenty of precedent in engineering for describing follower amplifiers. Bob -- "Things should be described as simply as possible, but no simpler." A. Einstein |
#90
|
|||
|
|||
William Sommerwerck wrote: The amp in a condenser mic does not amplify the capsule's power level -- it's a voltage amplifier. The capsule's capacitance is so small that it is essentially a hi-Z voltage source that must work into a high-impedance load. Other way around. Voltage gain on a KM84 is less than one (although a lot of that has to do with the output transformer). Voltage gain on the BLUE baby bottle is greater than one, though. But it's the current gain that is so important. Let's stop a moment. Are you telling me that a condenser capsule can produce an output of, oh, 1mV for an 80dB SPL? I don't believe it. The capacitance is so small, and the diaphragm moves so little, that dV = Q/dC isn't going to be a very large number. 'Fraid that's a pretty low sensitivity. 14 dB below 1mV/Pa which is already low for condensers. Bob -- "Things should be described as simply as possible, but no simpler." A. Einstein |
#91
|
|||
|
|||
|
#92
|
|||
|
|||
"Bob Cain" Bill Summa-wank Are you telling me that a condenser capsule can produce an output of, oh, 1mV for an 80dB SPL? I don't believe it. The capacitance is so small, and the diaphragm moves so little, that dV = Q/dC isn't going to be a very large number. 'Fraid that's a pretty low sensitivity. 14 dB below 1mV/Pa which is already low for condensers. ** Bad at thinking, bad at math too. A mic that delivers 1mV at 80dB SPL is 14 dB ABOVE one that delivers 1 mV/Pa. The Josephson C42 is speced at 8 mV/Pa, so gives 1.6 mV at 80 dB SPL. The capsule's output voltage is likely to be more again. ........... Phil |
#93
|
|||
|
|||
"Bob Cain" wrote in message ... Scott Dorsey wrote: Personally, I don't like _any_ of the words used. "Preamplifiers" is confusing, "followers" is not always accurate, "impedance converters" is accurate but incomplete, and "handles" is only correct for some styles of design. I think we should call them "bleem." I'd call it a buffer amplifier to reflect its real function while discriminating it from what is usually meant by pre-amplifier: a variable gain amplifier used prior to a system input to bring a signal to the level expected by that input. "Buffer" has plenty of precedent in engineering for describing follower amplifiers. Another term that has seen some use: "head amplifiers". Not as meaningful as "buffer amplifier", but at least there's precedent for it. Peace, Paul |
#94
|
|||
|
|||
SSJVCmag wrote: Let's stop a moment. Are you telling me that a condenser capsule can produce an output of, oh, 1mV for an 80dB SPL? I don't believe it. The capacitance is so small, and the diaphragm moves so little, that dV = Q/dC isn't going to be a very large number. 'Fraid that's a pretty low sensitivity. 14 dB below 1mV/Pa which is already low for condensers. Output of a 'condensor microphone' Vs Output at the capsule... The buffer has less than unity gain, approaching 1 as transconductance of the device (tube/FET) increases, so that the buffer output will be less than the capsule output. Bob -- "Things should be described as simply as possible, but no simpler." A. Einstein |
#95
|
|||
|
|||
Phil Allison wrote: "Bob Cain" Bill Summa-wank Are you telling me that a condenser capsule can produce an output of, oh, 1mV for an 80dB SPL? I don't believe it. The capacitance is so small, and the diaphragm moves so little, that dV = Q/dC isn't going to be a very large number. 'Fraid that's a pretty low sensitivity. 14 dB below 1mV/Pa which is already low for condensers. ** Bad at thinking, bad at math too. More like bad reading. ****ing cataracts suddenly under way and filling in missing detail with the wrong **** when I read. Haven't yet learned to take that into account. Bob -- "Things should be described as simply as possible, but no simpler." A. Einstein |
#96
|
|||
|
|||
"Scott Dorsey" wrote:
I am sitting here watching an umbrella cockatoo trying to eat the cat. Undoubtedly, you are also *listening* to the cockatoo trying to eat the cat. Kill the ****er and eat it. Just tell Chak you snapped. Or just wait a few weeks and you really will. -- "It CAN'T be too loud... some of the red lights aren't even on yet!" - Lorin David Schultz in the control room making even bad news sound good (Remove spamblock to reply) |
#97
|
|||
|
|||
|
#98
|
|||
|
|||
Lorin David Schultz wrote:
"Scott Dorsey" wrote: I am sitting here watching an umbrella cockatoo trying to eat the cat. Undoubtedly, you are also *listening* to the cockatoo trying to eat the cat. Kill the ****er and eat it. Just tell Chak you snapped. As the result of poor translation, I ate a parrot at Wo Fat's restaurant in Honolulu back in the seventies. It was actually pretty good. Or just wait a few weeks and you really will. I have survived a remarkably long time already. The real problem is that I can't play choral music any more... something about all of these invisible people around him really seems to alarm the bird. Orchestral stuff and solo vocals are fine. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
#99
|
|||
|
|||
my2cents wrote:
It doesn't matter what you like. Words have meaning, especially when they have been used exclusively in a specific context for nearly four decades. If you are unaware of the terminology, then you are as ignorant as Bob Cain and that's your problem. Nonetheless, you are certainly free to use whatever incorrect/non-standard terminology you wish. The problem is, as I point out, that there is no real standard terminology. Different manufacturers have used different words to mean the same thing. This, I am sorry to say, is a very common failing in the audio industry. You are partially correct and I stand partially corrected. In their 1962 catalog Bruel & Kjaer do in fact refer to the tube-based 2615 as a cathode follower. However, in their 1968 catalog they refer to the 2615 as a cathode follower and to the 2619, which was the solid-state successor to the 1615, as a microphone preamplifier. Since that time, all solid state successors to the 2615 have been referred to as microphone preamplifiers, not only by Bruel & Kjaer but by all of the manufacturers who make B&K look-alike microphone capsules and accessories. If you want to verify this, all you need to do is to take a look at any Bruel & Kjaer catalog that was published in 1968 or later, and do a Google search for ACO Pacific, Larson Davis and GRAS. I'll take your word for it, because again it does seem like a perfectly reasonable use. The problem is that there have been a bunch of other uses as well. (This is made worse in the case of some manufacturers by translation problems). Is Norsonics still making a Type I mike? --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
#100
|
|||
|
|||
William Sommerwerck wrote:
Let's stop a moment. Are you telling me that a condenser capsule can produce an output of, oh, 1mV for an 80dB SPL? I don't believe it. The capacitance is so small, and the diaphragm moves so little, that dV = Q/dC isn't going to be a very large number. Yup. The capacitance change is still a few picofarads, and the polarization voltage is pretty large. In fact, the output of the U87 capsule is a good bit higher than that. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
#101
|
|||
|
|||
|
#102
|
|||
|
|||
|
#103
|
|||
|
|||
|
#104
|
|||
|
|||
(Scott Dorsey) wrote in
: my2cents wrote: It doesn't matter what you like. Words have meaning, especially when they have been used exclusively in a specific context for nearly four decades. If you are unaware of the terminology, then you are as ignorant as Bob Cain and that's your problem. Nonetheless, you are certainly free to use whatever incorrect/non-standard terminology you wish. The problem is, as I point out, that there is no real standard terminology. Different manufacturers have used different words to mean the same thing. This, I am sorry to say, is a very common failing in the audio industry. You are partially correct and I stand partially corrected. In their 1962 catalog Bruel & Kjaer do in fact refer to the tube-based 2615 as a cathode follower. However, in their 1968 catalog they refer to the 2615 as a cathode follower and to the 2619, which was the solid-state successor to the 1615, as a microphone preamplifier. Since that time, all solid state successors to the 2615 have been referred to as microphone preamplifiers, not only by Bruel & Kjaer but by all of the manufacturers who make B&K look-alike microphone capsules and accessories. If you want to verify this, all you need to do is to take a look at any Bruel & Kjaer catalog that was published in 1968 or later, and do a Google search for ACO Pacific, Larson Davis and GRAS. I'll take your word for it, because again it does seem like a perfectly reasonable use. The problem is that there have been a bunch of other uses as well. (This is made worse in the case of some manufacturers by translation problems). Is Norsonics still making a Type I mike? --scott That would seem to be the case, and they too refer to their NOR-1201 as a "microphone preamplifier" which you can bet has just a slight bit less than unity gain. http://www.scantekinc.com/mics.htm |
#106
|
|||
|
|||
Mike Rivers wrote: In article writes: The buffer has less than unity gain Since we've gone from a legitimate question (which I forgot already) to playing games, you should play safe and not just say "gain." Say "voltage gain" and then people can ask you about the current gain or power gain. :-) Bob -- "Things should be described as simply as possible, but no simpler." A. Einstein |
#107
|
|||
|
|||
|
#108
|
|||
|
|||
William Sommerwerck wrote: Phil, if you're going to jump down peoples' throats, at least get your technical act together. The amp in a condenser mic does not amplify the capsule's power level -- it's a voltage amplifier. It *may* be a voltage amplifier. It may also be a voltage follower ( no voltage amplification at all ). It certainly is a *current* amplifier ! All of these put together means that there is significant *power* gain in a condenser mic pre. Time for school ? The capsule's capacitance is so small that it is essentially a hi-Z voltage source that must work into a high-impedance load. Voltage gain is not properly measured in dB -- the dBs is, strictly speaking, a power ratio. No - no no ! That idiocy about dBs only being for power is a classic lie. Sure Bell Labs didn't use dBs for voltages initially but I guess you've heard of dBv - replaced by dBu and dBV ? What kind of dBs do you think your equipment is specced in ? The pro-audio industry hardly ever uses dBm anymore. No need or reason. You might care to consider also that the best known example in the general population of the use of dB is for acoustic levels which are *pressure* levels and therefore also use the 20*log10 method too ! Graham |
#109
|
|||
|
|||
"my2cents" (snip) But, the issue is not what is the common/correct meaning and usage of the term "preamplifier," the issue is what is the common/correct meaning and usage of the term "microphone preamplifier." ** Have you forgotten the actual phrase that so *outraged* the brainless parrot ?? In relation to the Josephson C42 condenser mic, I posted this rhetorical question to Scott Dorsey: " Since when does the pre-amp in a condenser mic have a clipping level that varies with an audio frequency ???? " Please note: 1. It specifically refers to the electronics hidden *inside* a mic's handle !!! 2. That electronics has several functions - polarising the capsule with a suitable DC voltage, providing it with an ultra high impedance load, generating a low impedance balanced output from the resulting signal and deriving its own DC power from the same output wires. So, as long as you read the whole post, no possible confusion exists with other audio electronic items that might share the generic title "pre-amp" . BTW There has been no answer to my rhetorical question from Dorsey. The Brainless Parrot created his blatant "red herring" to hide his colleague's dumb error. .......... Phil |
#111
|
|||
|
|||
William Sommerwerck wrote:
Phil, if you're going to jump down peoples' throats, at least get your technical act together. The amp in a condenser mic does not amplify the capsule's power level -- it's a voltage amplifier. It *may* be a voltage amplifier. It may also be a voltage follower ( no voltage amplification at all ). It certainly is a *current* amplifier ! All of these put together means that there is significant *power* gain in a condenser mic pre. Time for school ? No. Shall I wave my EE degree in your face? To argue that the buffer stage in the mic amplifies the current output of the capsule -- which, in a strict, narrow sense, it does do -- is to twist the meaning of "current amplfication". The buffer is _designed_ as a voltage-gain stage which has a low output impedance. Voltage gain is not properly measured in dB -- the dBs is, strictly speaking, a power ratio. No - no no ! That idiocy about dBs only being for power is a classic lie. It's not a lie. dB means power ration and absolutely nothing else. If you want it to mean something else, you have to change the designation. |
#112
|
|||
|
|||
William Sommerwerck wrote:
William Sommerwerck wrote: Phil, if you're going to jump down peoples' throats, at least get your technical act together. The amp in a condenser mic does not amplify the capsule's power level -- it's a voltage amplifier. It *may* be a voltage amplifier. It may also be a voltage follower ( no voltage amplification at all ). It certainly is a *current* amplifier ! All of these put together means that there is significant *power* gain in a condenser mic pre. Time for school ? No. Shall I wave my EE degree in your face? One that must have been given away by the sound of it ! At least mine is actually in Audio. One of the first courses ever to specialise in the area of sound engineering. To argue that the buffer stage in the mic amplifies the current output of the capsule -- which, in a strict, narrow sense, it does do -- is to twist the meaning of "current amplfication". The buffer is _designed_ as a voltage-gain stage which has a low output impedance. Which involves *current gain* ! Voltage gain is not properly measured in dB -- the dBs is, strictly speaking, a power ratio. No - no no ! That idiocy about dBs only being for power is a classic lie. It's not a lie. dB means power ration and absolutely nothing else. If you want it to mean something else, you have to change the designation. You're a staggeringly stupid cretin. The diabolical lie about dBs being power only has been overturned. dBs are simple a ratiometric method of measure. Bell labs were idiotic to assert ( and that's all it ever was - simply an assertion ) that you could only use dBs for power ratios. They are mainly used for voltage and pressure ratios now. Or maybe you've missed out on that ? Do you still source and terminate everything in 600 ohms ? If you don't you'd better retract what you just said. Do you really know so little ? Are you really so badly informed? I'm staggered. Graham |
#113
|
|||
|
|||
"Pooh Bear" The diabolical lie about dBs being power only has been overturned. ** It is no lie and no amount of brainless posturing by Graham Stevenon has overturned anything. dBs are simple a ratiometric method of measure. ** With the provision that what is being quantified is a power level. Bell labs were idiotic to assert ( and that's all it ever was - simply an assertion ) that you could only use dBs for power ratios. ** That assertion is correct - a 3dB increase in level at a point is always a doubling of power. They are mainly used for voltage and pressure ratios now. ** To increase the voltage into a load by 3dB - you must double the power into that load. To increase the sound pressure created by a speaker at some point by 3dB - the power input has to double. Or maybe you've missed out on that ? ** "Parrot Brained ****wit" applies just as accurately to Graham Stevenon as it does the Rivers cretin. ........... Phil |
#114
|
|||
|
|||
Phil Allison wrote: "Pooh Bear" The diabolical lie about dBs being power only has been overturned. ** It is no lie and no amount of brainless posturing by Graham Stevenon has overturned anything. dBs are simple a ratiometric method of measure. ** With the provision that what is being quantified is a power level. ********** SPL ( sound pressure level ) has *never* been measured as a power level ! dB(spl) is *always* a pressure derived measure. It can be nothing else. Let's face it. Some suit at Bell Labs had a pole up his arse back in 1929/30 and succeeded in making a clot of himself for history to laugh at. I'm staggered that you could even remotely associate yourself with such an oudated view. The fact is that the audio world has gone on to use voltage derived measures to it's eternal credit. So - go on - why don't you 'diss' the dBu since you apparently think that only power dBs are valid ? You want the return of the dBm with all the confusion it caused ? Graham |
#115
|
|||
|
|||
"Pooh Bear" Phil Allison wrote: The diabolical lie about dBs being power only has been overturned. ** It is no lie and no amount of brainless posturing by Graham Stevenon has overturned anything. dBs are simple a ratiometric method of measure. ** With the provision that what is being quantified is a power level. ********** SPL ( sound pressure level ) has *never* been measured as a power level ! ** Sound pressure in air is strictly related to acoustic power flow at that point. Double the acoustic power flow and the SPL goes up by 3 dB. So you never realised that sound contains energy and thereby has power ??? Let's face it. ** You are nothing but a ****ing nut case - Graham Stevenon. I'm staggered that you could even remotely associate yourself with such an oudated view. ** The laws of physics on this matter are not outdated. I note that you snipped out the relevant points on this: " To increase the voltage into a load by 3dB - you must double the power into that load. To increase the sound pressure created by a speaker at some point by 3dB - the power input has to double. " The fact is that the audio world has gone on to use voltage derived measures to it's eternal credit. ** Power in a load is proportional to the applied voltage squared. Similarly, power in a sound wave at any point is proportional to pressure squared. That is why there is an additional factor of 2 ( ie 20 times log) in the calculation of dB ratios where voltage or pressure are the measured parameters. The one out of step and out of mind is ** YOU ** Graham Stevenon = bachelor of BULL**** !! ............ Phil |
#116
|
|||
|
|||
Phil Allison wrote: "Pooh Bear" Phil Allison wrote: The diabolical lie about dBs being power only has been overturned. ** It is no lie and no amount of brainless posturing by Graham Stevenon has overturned anything. dBs are simple a ratiometric method of measure. ** With the provision that what is being quantified is a power level. ********** SPL ( sound pressure level ) has *never* been measured as a power level ! ** Sound pressure in air is strictly related to acoustic power flow at that point. Double the acoustic power flow and the SPL goes up by 3 dB. So you never realised that sound contains energy and thereby has power ??? *of course* I'm aware of that. SPL is *SOUND PRESSURE LEVEL* however - not sound power level ! SPL increments of 20dB are a x10 or x1/10 step in pressure. Please re-adjust your attitude. Graham |
#117
|
|||
|
|||
"Pooh Bear" ... Please re-adjust your attitude. I think it's time to consider the source as trolling and stop the feeding. |
#118
|
|||
|
|||
"Pooh Bear" Phil Allison wrote: The diabolical lie about dBs being power only has been overturned. ** It is no lie and no amount of brainless posturing by Graham Stevenon has overturned anything. dBs are simple a ratiometric method of measure. ** With the provision that what is being quantified is a power level. ********** SPL ( sound pressure level ) has *never* been measured as a power level ! ** Sound pressure in air is strictly related to acoustic power flow at that point. Double the acoustic power flow and the SPL goes up by 3 dB. So you never realised that sound contains energy and thereby has power ??? *of course* I'm aware of that. ** Time for you to believe it too. SPL is *SOUND PRESSURE LEVEL* however - not sound power level ! SPL increments of 20dB are a x10 or x1/10 step in pressure. ** Which correspond to ** 100 times increase ** in sound power flow at the point of measurement. Which corresponds to *100 times increase* in the acoustic power radiated by the same source. So the term "dB" is being correctly used as a measure of relative power. Please re-adjust your attitude. ** You have not and cannot answer any of my points. You have no case and are making no sense whatever. As per ****ing usual. The heading is an insult to canaries. .......... Phil |
#119
|
|||
|
|||
"David Morgan (MAMS)" ** This asinine "Morgon" cretin makes even dead canaries look like geniuses. .......... Phil |
#120
|
|||
|
|||
"David Morgan (MAMS)" wrote: "Pooh Bear" ... Please re-adjust your attitude. I think it's time to consider the source as trolling and stop the feeding. Actually, I kept out of this particular one until Will Sommerwreck made a dumb**** assertion about dBs and how they can *ONLY* be used for power ratios as per Bell Labs 'pole up the arse' blinkered 1930s thinking !!!! PA as usual loves to climb aboard and simply make a merry nuisance of himself. For heavens sake, the AES sorted out the whole idiocy of the dBm and its then misuse / abuse due to the practical requirements of 'voltage matching' way back in the 1970s ! I'm staggered that the issue should even remotely re-appear. If anyone today was presented with the same issues I'm sure they'd run a mile ( or more ). Graham |
Reply |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
The drum-mic question, yet again | Pro Audio | |||
Some Recording Techniques | Pro Audio | |||
Some Mixing Techniques | Pro Audio | |||
recording drums (my way) | Pro Audio | |||
Recording Drums | Pro Audio |