The Great Commission
“And he said unto them, ‘Go ye into all the world, and preach the gospel to every creature.’” This scripture should be our number one reason to broadcast church services on local cable TV. Why else should you go to all the trouble and expense? A “heart for the lost” is a great and noble cornerstone. Equally important is timing. If our heavenly Father is leading you to begin, then the rest of this process will be easy. His Timing, His Plan
I remember the first time we thought about getting on TV. Our efforts focused on taping prayer school. As it turned out, it was not the right time nor the right venue. I suppose it was good practice but in the end we never used the tapes for broadcast. One Sunday, after a guest speaker had finished with his message, I approached my Pastor and commented on how, “that was something our community needed to see and hear”. He agreed and we began to plan anew. We’ve been taping our Sunday morning services ever since. So in our case, December 2001 was God’s timing and our Sunday service (as opposed to a classroom setting) was the correct venue.
I can’t stress enough how important it is seek our Father in heaven and find out what He’d have your church do. What works for us, what He has us doing, may not be what He has planned for you. Don’t chase someone else’s success, chase after His will for your specific situation.
Get Me on Cable TV Quickly and for Under $500
I wanted to place this scenario in the beginning so that you wouldn’t have to read through everything if all you needed was a quick and cheap solution. Just remember you get what you pay for, but with that said, if you follow this outline, you’ll be assured the very best quality for your $500 investment.
We are going to assume your meeting space has decent lighting, that you have a sound system with a mixer and that the cable TV provider in your town has an opening on their weekly “public access” schedule.
To pull this off we are going to park a Mini DV Digital Camcorder on a tripod in the back of your meeting space next to the sound board. You will grab sound from the RCA tape out on the mixer (you may have to split this with the cassette and/or CD recorder if you audio tape your services). Your camera’s video out will be plugged into an S-VHS video tape recorder and a small color TV will be plugged into the video and audio out of the tape recorder. The aforementioned sound also plugs into the S-VHS deck. Before service starts you will record about 45 seconds of video from your camera with the lens cap on and no sound. Make sure the S-VHS deck is set to “input” and not the TV tuner.
Rewind the tape and play to 30 seconds. Stop the tape here. Take off the lens cap and hook all your RCA cables up, turn on your TV to confirm that the video output from your camera and the audio from the sound board is looping through your deck. If you see picture and hear audio on the TV everything is good to go. Mute the TV or turn the volume way down. Alternately, you can leave the TV sound up and use a set of headphones (if your TV has a headphone jack to monitor sound. When the sermon begins, press record. That’s it, your done.
So long as your pastor doesn’t wander too far left or right from the pulpit/lectern, you can zoom the camera back enough to cover the total range that he/she will travel during the message. If not, you will have to have someone pan the camera back and forth to follow the action.
Since “public access” programming is usually limited to half hour blocks, your tape is ready for broadcast as soon as the counter runs past 30 minutes. Pop out the write protect tab, label the box and cassette accordingly (make mention of the 30 seconds of black) and drop it off at your cable TV offices. I’d play the video back to assure that your machine and tape worked properly and then rewind it to the beginning so that is ready to play.
That’s a quick overview, let’s go shopping. I went to the web site of a national retail store and came up with the following items:
Mini DV Camcorder $229.94
Tripod $ 24.84
13" Color TV $ 59.62
Sub Total: $314.40
For the S-VHS deck and blank tapes I went to a professional camera & video retailer
S-VHS Recorder $109.00
10 x 30 minute blank tapes $ 59.90
Sub Total: $168.90
Your grand total is $483.30 with enough tape for 10 programs.
How It All Works
A few short years ago a $500 setup like this didn’t exist. The price of consumer digital video cameras has dropped below the cost of even the cheapest old school VHS camera. The quality and consistency of video you get from today’s Mini DV equipment is outstanding. Let’s take a closer look at the hookups and technology behind this setup.
The one drawback to inexpensive video cameras, even digital cameras, is the sound. The “on camera” microphone usually picks up noise from the tape transport and the zoom motor. Also, the camera has to be within a few feet to get acceptable clarity. These inexpensive Mini-DV cameras generally do not have a provision to hook up an external microphone. The other issue is the tape. Most cable providers only accept the older “legacy” analog tape cassettes for their “public access” programs. Reason: they are not about to spend money updating equipment that is not making them a profit. This means that you will have to provide an S-VHS or U-Matic tape anyway, so why not record directly to the tape you will be delivering.
As it turns out, the camera tape is not an issue because we will be taping to an analog master tape format. Since your DV camera will be providing picture only, your sound can be grabbed directly from the house mix into the S-VHS deck. Most audio mixers have a “tape out” that is appropriate for our purposes. If you have to share with the cassette/CD recorder, simply use a splitter and send one half to each. Alternately, most house mixes are mono so you can take the left side and send it to the cassette and the right to your S-VHS. Use a mono to stereo RCA adaptor so sound goes to both sides of your tape.
Your camera can be set to full auto since the lighting is not apt to change indoors. Also, if your camera has manual focus, set it and forget it so that the system isn’t hunting.
You will loop the video and sound out of the S-VHS to a color monitor so that you can see and hear exactly what the tape is recording. I’d set the volume half way to get a feel for what’s average. If the volume is too low, you should raise it up on the mixer’s tape out. The AGC (automatic gain control) on your S-VHS deck will put the audio levels where they should be but if your input is too low, even the auto system can’t make up enough gain for acceptable levels.
That pretty much covers all you need to know for an entry level production. As you read on further you may see other things that you can incorporate into this setup. For instance, someone in your church may have a computer with video editing software. All MACs made and sold since the introduction of OS-X have a fine entry level video editing package called iMovie. Using your Mini DV camera as the interface, you can create a generic opening segment that gets recorded onto each tape before you record a service.
Video Editing
Editing is an easy feature you can add to your production. In the 1950’s the very first video editing system mimicked traditional film editing in that you would physically cut the magnetic tape and then splice it back together. This is where we get the expression “cutting” a show and this style of editing would be considered “linear”. In the 1960’s and 1970’s, linear editing was performed machine to machine whereby you copied your selected scenes to another tape and assembled the program in sequential order from the beginning.
Today almost all editing is done on computers in a nonlinear, nondestructive system. With nonlinear you can skip around much the same way a CD can. Computer hard drives have a reader arm that swings from the center to the edge of spinning magnetic storage disks. Remember the tone are on a record player, computer hard drives and CD’s access data in the same fashion. This enables the user to access data from anywhere on the disk very fast. Had the same data been on a magnetic tape like a VHS, you would have to fast forward or rewind. Nondestructive means that the original video data that you load onto the computer is not altered as you edit. The program file that you create as you edit simply gives commands to your computer as to where to go within your video data file and assembles the video on the fly as you play it back or export it from the computer.
For a very small investment you can have a nonlinear video editing system on a laptop computer. The MAC that I’m typing on right now doubles as my portable video editing system. Since you only need about 12 GB per hour of DV video, my laptop computer hard drive can hold about 3 hours of video.
As mentioned previously, the currently available MAC’s come with a simple video editing program called iMovie. For about $300 you can by the “lite” version of Apple’s professional video editor. Most of the features left off of the full version of Final Cut Pro (FCP) you’ll probably never need, so this should be a great first editing program. Video captured on your DV camera can be digitally transferred via the “Firewire” serial port on your camera to the corresponding port on your computer. You tell the software program the in and out point on your tape that you would like transferred from the camera, hit the start button and go have a cup of coffee. When you return the video is on your computer hard drive ready to edit.
The wonderful thing about digital video is that all of the picture and sound information is represented on tape as binary (0’s & 1’s) digital data. Your video is essentially one huge computer file. Moving the video from the tape to the computer simply copies the data from the cassette to the hard drive. There are other things involved that you never have to worry about or even understand, but is important to know that you get a perfect copy of your tape on your computer when you use the serial digital (Firewire) method of capture.
As with all things, there are issues that crop up that can effect the aforementioned process of video capture. Sometimes the read/record head on your camera and/or tape deck gets clogged. When this happens you may not be able to play a tape or the tape plays but has digital errors that show up as blocks or stripes on screen. Generally, if you use a head cleaning tape on a regular basis, this won’t happen.
If you are on a tight budget, your camera can double as the video editing VCR. If you have a stand alone Mini-DV tape deck, there is the possibility that a tape from your camera may play poorly if the tape head alignment is not within specifications. The manufacturer of my DV VCR informed me that Mini-DV cameras are notoriously out of spec and that it is a good idea to have it checked out if you experience a problem with playback. With semipro and pro equipment there is sometimes a free one time clean/align and adjust service, check with the manufacturer.
DV Taping Using CD Audio
A step up from live taping to an S-VHS tape is using the on camera Mini DV tape. This may or may not add considerable costs when you make the original equipment purchase. Before going any further, run this simple test if you can. Video tape an hour of service, it can include worship and whatever announcements you have. The important thing is that you have to make an uninterrupted recording. For this test you’ll be using the on camera microphone. During this time, have your sound person also make an uninterrupted recording onto a CD-R. CD-R recorders are becoming more popular as folks transition away from audio cassettes. Operation is similar to tape decks in that you hit record, set levels and hit stop when you’re done. If your sound booth doesn’t have one you can skip this test. While it may be possible to run this test using an analog audio cassette, I can give you the test results ahead of time. The digital video tape and the analog audio cassette will drift apart over time. Also, when your audio cassette auto flips from the A side to the B side you’ll have a few frames of missing sound. You’ll also have to re-sync after the B side begins again. I’ve done it when my video tape audio was bad and needed a sound track. As a last option, you can use cassette sound on your video project but it is a lot of work.
Both the Mini-DV camera and the CD-R recorder do an amazing job at holding a steady speed throughout recording. This test will confirm that a spoken word at the head of the tape and one at the end of the tape will be in sync with the lips/mouth of your speaker. The video will be in perfect sync since the sound and picture get recorded to the same tape. The trick is to slide the CD audio forward and backward in time until they line up in one spot and then see if that sync holds at the end of the program. This part of the test is done on your computer with a nonlinear video editing program. The video tape is captured normally and then dragged into the time line. The CD audio is copied as a file(s) to your computer’s hard drive. CD audio is 16 Bit at 44.1 Hz so you have to convert it to the digital video standard 16 Bit 48 Hz. Depending on the speed of your processor, you may be able to drag the file(s) right in and they will play realtime. My setup can do this, but as a habit I always render and save CD audio at 48 Hz so I have (1.) a single file and (2.) the right sample rate. Why do I keep calling the CD audio file(s)? Depending on your CD recorder and the length of the program, the machine may break the audio stream into smaller sequential chunks. That way when you pop a CD into a player you can navigate quicker. When you drag sequential files into an editor’s timeline the files butt up against each other and no one is the wiser that the audio is made up of multiple files.
In an editor like Final Cut Pro the timeline can display an audio wave form for each track of audio. Once you find the similar audio cue on the DV and CD, sliding the CD to match is accomplished by lining up the waveform. I usually look and listen for something that is easy to find. The louder the better. When you hear the same cue on the CD, zoom in on the timeline and fine tune the sync by lining up the waveform. The shape and length of the waveform parts are the timeline visual cue for lining up the two audio tracks. Playing the timeline and listening will confirm that you have sync. Any echo can be removed by sliding the CD audio one frame at a time either way until it’s just right. This cue point should be as near to the beginning of the tape as possible so that when you check the end of the tape for sync there is the maximum distance between cue points.
Now go to the end of the tape in the timeline. The lengths of your DV and CD tracks won’t match but this isn’t a problem. Find a spot at the end of your timeline where both DV and CD tracks appear together and play it down. If you have no echo, the two machines are in perfect sync. Happy, happy, joy, joy! If there is a slight echo, all is not lost. Silence the DV audio and watch the video with only the CD audio. Look at the lip sync of your speaker. If you’re not sure what to look for, compare the lip sync at the beginning to the end. If the CD audio is off by a frame or two when the other end is perfect you may be able to leave everything as is. Most viewers can’t see the difference. For a two frame drift over the length of a program a simple fix is to slide the whole CD audio one frame so that your sync is one frame early at the beginning and one frame late at the end. Now your two frame difference is no more than one frame out at any given time.
Suppose your sync is way off, so far that you can’t even find the corresponding visual timeline cue in the waveform, what can you do? You may have dropped frames in the video capture or there may be a break in the time code. Sometimes watching the whole video on the computer is the only way to confirm this. Before you go to all that trouble, try changing the length of the CD audio. You’ll be doing this by either speeding up or slowing down the track. This changes the overall length of the CD audio. Think of it as holding your finger on the record to slow it down or playing an album at 45 rpm. Those of you too young to remember records, think of what a DJ does when he’s scratching vinyl or a CD. While the results of “time warping” can be very noticeable, our small change will go undetected. To achieve perfect sync, the change in length of the CD audio will probably be less than 1/2% of the original. This small a change does very little to the quality of your track.
To calculate the amount of change you will be applying to your CD audio, trim both tracks at the head so that they start at exactly the same frame. This will be important for your calculations. Now go to the end of the timeline and find a good visual timeline cue on the DV track and line up the CD track using the techniques described. Once you confirm sync at the end of the timeline, go back to the beginning and see how far off your two tracks are. Use your mark in/out feature and read the number off the screen or park the play head at the beginning of the DV track and advance or reverse one frame at a time to manually count. The number you get is the difference in length between the two tracks. If the CD track extends to before the beginning of the DV track, you subtract the frame count from the CD. If the CD track starts after the DV track (to the right in the timeline) then you will be adding those frames.
The next step is to change the length of the CD audio by either speeding it up or slowing down. Video editing software can calculate this by either a % value or an absolute frame count value. To be accurate, we’ll use the frame value. Consult the manual for your video editing software and look for the speed change function. You will want to enter a new value for the CD track based on your calculations. Be aware of drop frame time code. If the new length doesn’t look right, use a time code calculator (free downloads available on the web) with the DF mode enabled. Alternately, you can keep entering new values in the speed change field until it looks correct.
All things being equal, you now have a nice digital audio track from your sound board for use with your digital video. This technique can save you from having to purchase a more expensive pro-sumer Mini-DV camera that has professional audio inputs. While a home movie DV camera can provide outstanding digital video, the sound will never be broadcast quality with the on camera microphone. This work around, while time consuming, will yield very good results. The key is in the details, so be very methodical with your testing. Write your settings down and see if they can be duplicated consistently. Once you find a working formula, the process will work each time.
Laptop Audio Recording
If you have a laptop of recent vintage, you can record the sound board audio straight to a hard drive. Now you have a single audio file in the AIFF format that can be imported directly into your project. If this laptop is the same machine that you will be editing with, just drag the file into the project folder on your hard drive. If you are using a different machine you can either burn a CD or drag and drop the audio file to a USB pen drive. If your laptop does not have an audio input jack (line or mic), there are interface boxes that use either the USB or Firewire ports to convert incoming audio to something your computer can read. They start in price from $30 all the way into the thousands.
There is a free audio recording program available for PC, MAC and Linux. Audacity is an open source software that is free to download, modify and use. You can save some time rendering the audio in the video editing program by changing the preferences in Audacity so that it records in the DV 48 kHz format. Once you start to line up the two audio tracks, all of the timing issues still apply so refer to the previous CD audio section.
DVD’s
The object of using CD audio is to take production to the next level. Each time I recommend something, the goal is better quality with minimal investment. If you don’t have a CD recorder in your sound booth you may want to purchase one. It would be a dual purpose unit since you can also create CD’s and then make copies. If this isn’t possible, the following information may not apply to you.
With the previous test completed the next step would be creating DVD’s. The price of DVD recorders has dropped significantly. They operate similar to the CD recorder. Attaching the video/audio output from your DV camera to the DVD recorder input is very simple. You’ll be using the digital video and the CD audio to create a program on your computer.
A Quick Word About Computers
Why is a MAC a better choice than a PC for video editing? Unless your a UNIX person running one of the open source LINUX distributions, your PC is essentially a MicroSoft computer. Someone else, not MicroSoft, assembled the computer. I say assembled because most PC’s use off the shelf components, the manufacturer is not necessarily designing their own components. The editing software available for a PC is made by yet another party and the serial digital interface (Firewire) that connects your camera to the computer (invented by Apple by the way) is usually not included in your new computer purchase, so yet another vendor is involved. While this can all be made to work, and there is a community of video editors who successfully use PC’s in video production, I would not recommend taking this route.
In contrast to the PC, Apple makes their own computer, their own operating system, their own video editing software and as mentioned previously they hold the patent for the Firewire interface. An out of the box MAC computer is all you need to get up and running with video editing. Want to be really professional? Purchase FCP and you’ll be running with the big dogs. I promise, you will not be disappointed a MAC for video editing. |
Using the supplied iMovie software or a the FCP program, take the following steps:
1. Capture the DV video (with audio) to your computer
2. Copy the CD audio files (.aiff) to your hard drive
3. Import the .aiff files to the project
4. Line up the CD audio track with the DV audio track
5. Confirm sync at start and finish of timeline (re-clock CD speed as necessary)
6. Mute or delete DV audio from timeline
7. Trim beginning so message starts at timeline start
8. Add one frame of black at head before picture start
9. Trim end so total run time is per cable company spec (28:00, 28:30, 29:00 etc.)
10. Add one frame of black at end of timeline.
11. Play video from timeline, through camera and into DVD recorder
You can always export your finished movie to iDVD and burn a disk from the computer but there are a few drawbacks. The multiplexing process is software based so it will take longer. DVD recorders also use software but the software is burned onto hardware so DVD recorders run faster. iDVD can’t make an auto play disk, so depending on what equipment your cable provider has, they may not be able to use DVD’s with menus. DVD Recorders can generally auto play but best to check before you buy. Also, make sure you get a DVD-R and not a DVD+R. The -R disk is the most universal. I’ve yet to find a computer or player that can’t handle a DVD-R. The same is not true for the +R disks.
The frame of black at the beginning and end of the program has an important role. When you are ready to record, you need black while the DVD recorder starts up. Without a frame of black, you will get a freeze frame when you begin recording unless the video is already playing in the timeline. Better to park on the black frame, hit record on the DVD machine and play the timeline as soon as you see time code running in the display. The black frame at the end serves the same purpose, when the video in the timeline runs out it will park on the last frame and freeze. Unless you stop recording before video finishes, you will record the last frame as a still. If it’s black, that’s the last thing you see on the DVD.
Balanced Audio
The next logical upgrade is the ability to record picture and sound directly to tape at the same time. Remember, the entry level Mini-DV cameras will take beautiful video but the audio is limited to the on camera microphone. The difference in price between an entry level consumer Mini-DV camera with no “audio in” jack and a prosumer camera with a decent “audio in” feature is considerable. Fortunately, with this step, there are legitimate advantages in addition to audio.
Prosumer cameras (a hybrid word: professional and consumer) feature three light sensitive chips. One each for the red, green & blue light. Separating the primaries onto individual chips increases your video quality dramatically. Also, lens optics and optical zoom range are sharper and longer respectively.
Look for a prosumer 3-chip camera that has a full manual audio input level control. AVC is great for run and gun shooting and home movies but setting the levels for the peaks and letting everything else fall in naturally always sounds better. Some cameras have mini-plug inputs which are fragile at best, one step better are RCA inputs. The bests connector, the king of all audio connectors, is the XLR. Not many prosumer DV camcorders offer XLR connectors, but there are adaptors available so that your fragile mini-plug or RCA input are attached once with the adaptor slung under the camera body.
The best feature of an XLR audio connection is the balanced audio signal. Balance audio is an invention of the Bell Telephone system. Essentially, any interference picked up on the wire along it’s run is canceled out on the far side. The technique is pure genius and simplicity. When any interference is picked up it is distributed on both wires. At the end of the wire run the two audio signals are put back in phase, along with the interference. Since this bad voltage attaches to each wire, and each wire was 100% out of phase with the other, the undesirable noise gets canceled out.
Let’s assume that you have either a prosumer Mini-DV camera with an XLR in or an adaptor. You can now take the mix out from your sound board and patch directly into the camera. Set your camera input level for the the loudest spoken word from the stage and your done.
Splitting the Main Microphone
Once you’ve recorded your church services for a while, you may notice that the overall house mix is not steady when you listen to it on TV. Usually this is your sound board operator riding the levels. If your not sure, watch that person. If you see them constantly fiddling with the faders and gain controls, you found your source. The best fix, one that will guarantee this won’t happen, is to split the main microphone audio feed. Even if the sound person doesn’t fiddle at all once the service begins, it is still in your best interest to get an audio feed independent of the house sound. The podium mic, lavaliere or handheld mic for your speaker is using usually goes to #1 on the board. What you want to do is intercept that audio signal before it goes into that mixer, split it, raise the level if necessary and give it back to the house sound. Now when the sound person rides levels and tweaks things, it will be of no effect on video tape. A small sub mixer is all you need to accomplish this. A mixer with two XLR inputs can be had for less than $50. Set up correctly, this arrangement will be totally transparent to the camera and the house mix. An inline sub-mixer is transparent when no one hears the difference.
To achieve transparency, the sub-mixer levels and gain need to be test calibrated. The most accurate method to achieve this is to send a 1K tone through your setup. Cable testers will generate a steady 1K test tone in mic, consumer line level & pro line level. Your goal is to set the sub-mixer’s levels so that the incoming test tone comes out the other end the same level. To do this simply by-pass the sub-mixer by plugging the test tone directly into the house sound board. This input should always be the cable that corresponds to the microphone used by your speaker, usually occupying the #1 position. Now when you send your test tone, experiment with mic, consumer line level and pro line level. See which one moves the mixer VU meter to 0dB. For this test you don’t have have the house sound up in the speakers, you just need to read the VU meters. Adjust the board to achieve zero dB on the scale (or 12 if the highest level on the meter is zero). Don’t touch the house sound board for the rest of this test. Now you can put the sub-mixer in line with the house sound using the same input. The mains out on the sub-mixer will probably be 1/4” phone so you either have to use a 1/4” to XLR adaptor or better yet buy a cable with these already on. Be sure that it is labeled for balanced audio and that the 1/4” plug has three bands; tip, ring & sleeve.
The following is a good starting point for your test. The gain control on the input should be all the way off. Turn down all of the effects and/or aux pots on that row of controls. The level or volume for that input should be set for unity, usually aiming straight up at 12 o’clock on a rotary knob or at zero for a slider. The EQ controls should be at unity as well. The fader has to send the audio equally to the left and right. For your test you only need one side but for taping you will be sending right to house sound and left to the camera (or the other way around, it really doesn’t matter). The Master out should also be set for unity. If you have to tweak the sub mixer to line up your meters for the test tone, move the master up and down. Once you get it set, the signal coming into the sub-mixer should be at the same level as the output. If the VU meter on the board is the same, you’re done. If not, tweak the sub-mix board until you get the VU at the same setting as when you went with the tone directly in.
The thing you want to avoid is boosting the gain along the signal path any more than you have to in order to maintain the same levels at each stage. This whole process is know as “gain staging”. If a signal is too weak and you pump it up with a gain control you will pick up noise. If the signal is too strong and you cut by attenuating it, you get distortion. Best to keep all the levels at each point of the signal path at a consistent gain. The sub-mixer should be sonically transparent, as much as possible for the hardware. Gain staging everything properly will insure a clean pass through for your sound.
The difference between a level and a gain control is amplification. The nomenclature from manufacturer to manufacturer may not be consistent, but traditionally a gain control is adding volume level by means of boosting and/or amplifying it. A volume or level control by contrast is attenuating or cutting the signal passively. A passive unit in the signal path (not powered by battery or AC) can not boost or amplify a signal. The XLR to mini-plug/RCA adaptor mentioned previously can not make your audio signal any stronger. By design it’s function includes the ability to block any voltage on the balanced input (phantom power) and cut or attenuate the signal. Professional audio is usually too hot for a consumer microphone input so these adaptors match the audio by attenuating the signal. That and the camera may have a switch or menu choice that allows you to choose between mic level and line level. This would be your first selection before ever adjusting an adaptor.
A dynamic stage mic, one that simply plugs into an XLR cable and does not need power, will be the weakest audio signal you will see. A condenser microphone, one that needs 48v phantom power from the house sound board would be somewhere in the middle. The wireless mic has the greatest potential for a hot signal due in part to the built in gain control on the receiver and transmitter. Condenser mics are not as common with live sound because their added sensitivity can cause feedback in the stage monitor speakers. If your main mic is a condenser, you may have to send it power instead of the house sound because your sub-mixer may not pass the 48v phantom power backwards through the main out to the XLR in.
Another inexpensive investment that will add extra value to your sound production is a microphone pre-amp. For under $50 you can get a hybrid solid state/vacuum tube pre-amp that you’d place inline between the sub mixer and your camera.
If your camera has RCA audio inputs, you may even be able to go 1/4” out of the pre-amp directly into the camera. As with other equipment, there are multiple advantages to using a mic pre-amp. One feature that is lacking on most small mixers (your camera sub-mixer) is a good VU meter. Most only have 3 or 4 LED lights. A microphone pre-amp like the one pictured here has a more useful LED range, one where you see changes easier. The more lights the better. This doesn’t increase the sensitivity or range of the unit rather it allows you to see subtle changes. Think of a seconds hand on a clock. If you need to time 15 seconds, it would be very difficult to do so with a minute hand and almost impossible with an hour hand. With VU meters, the more LED’s the better. I’d stay away from any pre-amp that uses a dial meter. About the only thing their good for is lining up your 1K tone. Needle meters do not show changes over time as well as LED lights and you may have to pay many times more than the pre-amp itself to get one that has the correct ballistics.
Pre-amps have amplifiers as the name suggests that allow for a gain control. As mentioned previously, a gain control adds volume to your signal. On the flip side, most pre-amps have an overload button that gradually attenuates the signal as it approaches the limit of your system. This clipping avoids the nasty distortion you get when someone screams, coughs or raised their voice well beyond the normal conversation you have set your mixers for.
These hybrid pre-amps use solid state circuitry for most of the design except for the amplifier. Instead of a transistor, they use a vacuum tube. You can always here the difference between solid state and tube amplification. Vacuum tubes add a warmth and natural compression to music and voice. Digital is great, it is very reliable but it lacks the presence of a tube warmth. There are many ways to describe this phenomenon but it’s best left for your ears to experience.
This page is a work in progress with new material being added regularly. Check back for updates. |