Yes, your last point make the N and P beta equal not Idss still valid. I did some sims last year that indicated that if the beta's are different there is an Idss ratio that is a sweet spot for distortion not equal Idss'.
Another point is that if you use the asymmetric differential to single ended take off (I see it a lot) you lose some of the THD benefits.
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At these mV levels all this is speculative. Instrumenting an in situ measurement at sub Hz frequencies would be difficult. Maybe Ed can repeat his measurements at 100mV or 10mV and go down as low as the AP permits. We tended not to use electrolytics in the lab for .1Hz noise filters because of leakage but when testing my mic circuits I used some 2 or 4Hz filters and never saw an issue. BTW a large number of mics go through two large electrolytics used for phantom power at very low to moderate levels also with lots of low frequency noise due to wind, etc.
I don't advocate them and in fact like to avoid them by using high impedance circuitry.
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Someone should model/test these common mic circuits:
https://www.eetimes.com/document.asp?doc_id=1272487
Or Rod's
48V Phantom Feed Supply for Microphones
Small, delicate signals fresh from the real world (no dozens of opamps, no dozens of electro coupling caps), perfect for testing what yer talking about.
Hmmm, how much of the music I listen to, have been recorded through these condenser mics? Typical instruments?
Cheers,
Jeff
PS An eager someone with the proper gear could post some hi res clips through the common circuit vs an optimized one for Foobar ABX comparison/signal analysis ...
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Small, delicate signals fresh from the real world (no dozens of opamps, no dozens of electro coupling caps), perfect for testing what yer talking about.
Hmmm, how much of the music I listen to, have been recorded through these condenser mics? Typical instruments?
Also note before it comes up the caps are there with or without the phantom power turned on.
Sure. I think Ed was referring to the line level and power amp sections when the signal source is vinyl.
The elephant in the room?
I can’t say I avoid them. Only in a Naim clone there is a number of 10uf MKTs
(luxurious times for a copycat)
George
Attachments
But any sub Hz content is long gone by then. I use PS caps and 1Meg in my pre-amp.
Condenser mic use in recordings
"
Choosing the Right Mic
To make the best choice, you should consider what you are doing with the mic.
If you're recording vocals at home, you'll want a large-diaphragm condenser microphone if you have phantom power; if not, you might want to consider a large-diaphragm dynamic microphone like the Shure SM7B.
If you're recording acoustic guitar, you'll be best served by good small-diaphragm condenser microphone. A good choice, if you're on a budget, is the Marshall MXL 603S, but if you’re looking for a much better upgrade, the Neumann KM184 does the trick.
For recording on cello/upright bass, the one to choose is a large-diaphragm condenser mic. This is because, while the strings resonate quickly, the slower transient response of the large-diaphragm microphone will make for better low-frequency reproduction on these instruments.
Concert taping works best with a pair of small-diaphragm condenser microphones for stereo recording. The small diaphragm allows for faster and more accurate transient replication and better low-end reproduction.
For drums, you'll want a combination of dynamic and condenser microphones. Here’s are some recommendations:
Shure Beta 98 (great for toms)
Shure SM57 (great for overhead mics, cymbals, and snare)
Heil PR-40 (great for overhead mics, cymbals and kick)
Shure Beta 52 (great for kick)
"
Condenser Vs. Dynamic Microphones
"
Typical microphone applications
Drums
For starters, you’ll normally want to stick with cardioid dynamic mics on the drums, a cardioid small diaphragm condenser on the hi-hat, and a matched pair of either large- or small-diaphragm condensers for the overheads. Note that condenser mics can certainly be used on the snare and toms (and for the more adventurous, even kick). It’s a case of, once you know the rules, feel free to break ’em. After all, you’re an artist, painting with sound…
...
Electric Guitar
No need to over-think this one. If you can spare just one mic, use a dynamic (the iconic Shure SM57, for example), positioned close on the speaker cabinet. If you have a large-diaphragm condenser, try placing it a few feet back (if the source is loud, engage the pad, if the mic has one). You can mix these mics together at the console, or record them to separate tracks, if tracks are not at a premium. If you’re overdubbing the guitar (or you can place the guitar cab in another room during tracking), you don’t have to be concerned with (drum) leakage. Assuming the cab’s in a decent-sounding room, experiment by backing up your condenser mic to soak up more room sound. If the mic has multiple polar patterns, try switching it to omnidirectional. You can, of course, use more than two mics – just watch your phase relationships.
Acoustic Guitar
A small-diaphragm cardioid condenser is preferable here. As a starting point, aim it down, looking at the 12th fret, from about 6-8 inches away. Large diaphragm condensers can also work nicely on acoustic guitars, as well as ribbon mics. Have fun experimenting with different mics and placements to find what works best for you.
Vocals
When it comes time to overdub vocals, you’ll want a large diaphragm condenser mic. For a lead vocal, you should match the mic to the vocalist – who may also have a personal mic preference. The best way to approach this is to set up three or four likely mics, and have the singer sing the same (critical) section of the song into each of them. Record each of these passes to individual tracks, then invite the singer into the control room for playback to decide which mic best matches his or her voice (and the song).
Acoustic Piano
Usually recorded in stereo. Use two large-diaphragm condenser mics, or a large diaphragm for the low strings, and a small diaphragm for the highs. Piano mic placement is highly variable, so a certain amount of experimentation is in order. There are also piano mic kits that take the guesswork out of mic choice and placement.
Strings
Violins, violas, cellos, double bass. Just about any high-quality condenser will do. Or, if you’re fortunate enough to have a ribbon mic, this may well be what you prefer.
Brass and Reeds
Ribbon mics are incredibly flattering on brass instruments. And for reeds and double reeds, ribbons will capture the tone and pick up less of the mechanical sound of the keys. Large or small diaphragm condensers work well too.
"
Studio Microphone Buying Guide - inSync | Sweetwater
"
Practical Microphone Applications in Music
Here we look at the main purpose each kind of microphone is typically used for. This is a good guide to get you started and once you gain experience with each mic type you'll find additional applications that work for you.
Vocals
For live vocal performances where stage volume can get loud and feedback suppression is important, the best choice is to use cardioid mics - see our guide to the best microphones for singing live. Recording vocals on the other hand is a different undertaking that requires more attention to the singer's nuances, as such large diaphragm condensers work best. If you are going for a more vintage sounding vocal recording, use ribbon mics or go for good old dynamic mics instead. In addition, small diaphragm omnidirectional mics and shotgun mics can be used for capturing choirs and singing groups, and are especially useful when choirs perform in venues with great acoustics, like churches.
Drums
Because acoustic drum kits are naturally loud and punchy, you'll want to go with dynamic cardioid mics for the snare, bass and toms. Small diaphragm microphones can then be used to capture the nuances of the hi-hat, ride and cymbals. For best results, there are specialized mics that are fine tuned to handle the different frequencies and SPLs of each part of a drum kit, you can either get them one by one or go for convenient drum kit mic bundles. In the studio, you can setup an Omnidirection or ribbon mic to blend in some ambience into your drum tracks.
Electric Guitar Amplifier
Close mic'd guitar amplifiers are as loud, sometimes louder than drum kits, and as such they require mics that can handle high SPL. Your best bet is a cardioid or hyper cardioid dynamic mic that is well positioned in front of the amp speaker. Again a second condenser mic or ribbon mic, set back at a distance, can be used in case you are using multiple amps or if you want a warmer more classic sounding output, or in combination with a close mic to capture some of the room ambiance.
Acoustic Guitar
Acoustic guitars when not amplified have a softer sound with immersive nuances. These type of instruments require the fidelity and quality of large diaphragm condenser mics. You can also go for a well placed Cardioid condenser mic or Figure-8 pattern ribbons depending on the situation and noise level. Finally, setting up an extra small diaphragm mic will work wonders in capturing the higher frequencies that sometimes get lost when acoustics are plugged in or miked directly up front.
"
The Different Types Of Mics And Their Uses | Gearank
...
Small, delicate signals fresh from the real world (no dozens of opamps, no dozens of electro coupling caps), perfect for testing what yer talking about.
Hmmm, how much of the music I listen to, have been recorded through these condenser mics? Typical instruments?
...
"
Choosing the Right Mic
To make the best choice, you should consider what you are doing with the mic.
If you're recording vocals at home, you'll want a large-diaphragm condenser microphone if you have phantom power; if not, you might want to consider a large-diaphragm dynamic microphone like the Shure SM7B.
If you're recording acoustic guitar, you'll be best served by good small-diaphragm condenser microphone. A good choice, if you're on a budget, is the Marshall MXL 603S, but if you’re looking for a much better upgrade, the Neumann KM184 does the trick.
For recording on cello/upright bass, the one to choose is a large-diaphragm condenser mic. This is because, while the strings resonate quickly, the slower transient response of the large-diaphragm microphone will make for better low-frequency reproduction on these instruments.
Concert taping works best with a pair of small-diaphragm condenser microphones for stereo recording. The small diaphragm allows for faster and more accurate transient replication and better low-end reproduction.
For drums, you'll want a combination of dynamic and condenser microphones. Here’s are some recommendations:
Shure Beta 98 (great for toms)
Shure SM57 (great for overhead mics, cymbals, and snare)
Heil PR-40 (great for overhead mics, cymbals and kick)
Shure Beta 52 (great for kick)
"
Condenser Vs. Dynamic Microphones
"
Typical microphone applications
Drums
For starters, you’ll normally want to stick with cardioid dynamic mics on the drums, a cardioid small diaphragm condenser on the hi-hat, and a matched pair of either large- or small-diaphragm condensers for the overheads. Note that condenser mics can certainly be used on the snare and toms (and for the more adventurous, even kick). It’s a case of, once you know the rules, feel free to break ’em. After all, you’re an artist, painting with sound…
...
Electric Guitar
No need to over-think this one. If you can spare just one mic, use a dynamic (the iconic Shure SM57, for example), positioned close on the speaker cabinet. If you have a large-diaphragm condenser, try placing it a few feet back (if the source is loud, engage the pad, if the mic has one). You can mix these mics together at the console, or record them to separate tracks, if tracks are not at a premium. If you’re overdubbing the guitar (or you can place the guitar cab in another room during tracking), you don’t have to be concerned with (drum) leakage. Assuming the cab’s in a decent-sounding room, experiment by backing up your condenser mic to soak up more room sound. If the mic has multiple polar patterns, try switching it to omnidirectional. You can, of course, use more than two mics – just watch your phase relationships.
Acoustic Guitar
A small-diaphragm cardioid condenser is preferable here. As a starting point, aim it down, looking at the 12th fret, from about 6-8 inches away. Large diaphragm condensers can also work nicely on acoustic guitars, as well as ribbon mics. Have fun experimenting with different mics and placements to find what works best for you.
Vocals
When it comes time to overdub vocals, you’ll want a large diaphragm condenser mic. For a lead vocal, you should match the mic to the vocalist – who may also have a personal mic preference. The best way to approach this is to set up three or four likely mics, and have the singer sing the same (critical) section of the song into each of them. Record each of these passes to individual tracks, then invite the singer into the control room for playback to decide which mic best matches his or her voice (and the song).
Acoustic Piano
Usually recorded in stereo. Use two large-diaphragm condenser mics, or a large diaphragm for the low strings, and a small diaphragm for the highs. Piano mic placement is highly variable, so a certain amount of experimentation is in order. There are also piano mic kits that take the guesswork out of mic choice and placement.
Strings
Violins, violas, cellos, double bass. Just about any high-quality condenser will do. Or, if you’re fortunate enough to have a ribbon mic, this may well be what you prefer.
Brass and Reeds
Ribbon mics are incredibly flattering on brass instruments. And for reeds and double reeds, ribbons will capture the tone and pick up less of the mechanical sound of the keys. Large or small diaphragm condensers work well too.
"
Studio Microphone Buying Guide - inSync | Sweetwater
"
Practical Microphone Applications in Music
Here we look at the main purpose each kind of microphone is typically used for. This is a good guide to get you started and once you gain experience with each mic type you'll find additional applications that work for you.
Vocals
For live vocal performances where stage volume can get loud and feedback suppression is important, the best choice is to use cardioid mics - see our guide to the best microphones for singing live. Recording vocals on the other hand is a different undertaking that requires more attention to the singer's nuances, as such large diaphragm condensers work best. If you are going for a more vintage sounding vocal recording, use ribbon mics or go for good old dynamic mics instead. In addition, small diaphragm omnidirectional mics and shotgun mics can be used for capturing choirs and singing groups, and are especially useful when choirs perform in venues with great acoustics, like churches.
Drums
Because acoustic drum kits are naturally loud and punchy, you'll want to go with dynamic cardioid mics for the snare, bass and toms. Small diaphragm microphones can then be used to capture the nuances of the hi-hat, ride and cymbals. For best results, there are specialized mics that are fine tuned to handle the different frequencies and SPLs of each part of a drum kit, you can either get them one by one or go for convenient drum kit mic bundles. In the studio, you can setup an Omnidirection or ribbon mic to blend in some ambience into your drum tracks.
Electric Guitar Amplifier
Close mic'd guitar amplifiers are as loud, sometimes louder than drum kits, and as such they require mics that can handle high SPL. Your best bet is a cardioid or hyper cardioid dynamic mic that is well positioned in front of the amp speaker. Again a second condenser mic or ribbon mic, set back at a distance, can be used in case you are using multiple amps or if you want a warmer more classic sounding output, or in combination with a close mic to capture some of the room ambiance.
Acoustic Guitar
Acoustic guitars when not amplified have a softer sound with immersive nuances. These type of instruments require the fidelity and quality of large diaphragm condenser mics. You can also go for a well placed Cardioid condenser mic or Figure-8 pattern ribbons depending on the situation and noise level. Finally, setting up an extra small diaphragm mic will work wonders in capturing the higher frequencies that sometimes get lost when acoustics are plugged in or miked directly up front.
"
The Different Types Of Mics And Their Uses | Gearank
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Current RIAA has a 20Hz hi-pass. Most people have a low cut somewhere to save their speakers.
Dimitri was kind enough to lend me an extra copy of his latest project, an LP low frequency noise simulator. It converts L/R to M/S modulates by 1/f noise and converts back to L/R. You get all the sidebands on the content. I wonder if this could be used in an experiment.
Thanks, Pavel. It's a good link and I appreciate it! At the same time, I will (hopefully) pursue the LTSpice thing soon, as I'm also using it as an excuse to get a bit better with some features of the software and gain some intuitive sense about circuit behavior. Nothing helps me learn quite like playing around in a space and seeing what small perturbances ultimately affect.
That, I suppose, depends on philosophy, as I really don't care what the recording/mastering process is, except whether or not I enjoy the sound. Can't control that part of the playback.
On the other hand, I can control the electronics/speaker/room on my side. Not that I'm opposed to using pretty large bipolar electrolytics in coupling, as it's pretty pragmatic for BJT-input circuits where you want to keep the feedback networks pretty low impedance. But as Scott points out, there's plenty of ways to skin a cat, and my needs don't include a phono preamp.
There's TI's freeware, but I used HSPICE in undergrad and then nothing for a long time, so I don't know what else is out there. Since LTSpice is the lingua franca here, I figured it best to adopt that. The UI is definitely not to my liking at all, and half the time I wish I'd just type up the netlist myself rather than use the drawing tools.
Yes. I have used several but started with MicroCap and still prefer it. D. Self also uses it. very popular. Stable. But not a freebee.
Spectrum Software - Micro-Cap 11. Analog simulation, mixed mode simulation, and digital simulation software. SPICE and PSpice(R) compatible circuit simulator.
THx-RNMarsh
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It's probably best to assume I'm fussy and would rather have a lot of the nitty gritty at my control all the time, so I'm probably not the best case user. I have similar rants about things like COMSOL, where I'll dive into the JAVA configuration files if I need to, as sometimes the workflow is a bit kooky.
When it gets down to it, I care much more that the engine and the results are reliable. Oh, and that I can get decent component models.
I have similar rants about things like COMSOL, where I'll dive into the JAVA configuration files if I need to, as sometimes the workflow is a bit kooky. When it gets down to it, I care much more that the engine and the results are reliable. Oh, and that I can get decent component models.
For a limited number of nodes and parts (30?) the student version is still usable. However, number of models is limited etc.
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