Category Archives: Bargain Gear

Pro audio solutions from unexpected (and usually cheaper) sources

iphone as Master Clock?

I was shooting recently with Knoxville soundie Scott Minor. He told me about an iphone app that he and a friend developed that seems like it could be pretty useful. It’s called JumpStartLTC. It’s a a timecode generator that uses the processor cycles of the phone’s computer as a timing reference. It outputs the result to the iphone’s headphone jack.

Since the app is only $20, I figured it was worth a try. It’s not the same as a lockbox, since it can’t receive timecode… it can only output. But it’s reported to be very accurate… Scott says that he saw virtually no drift after leaving it running for two days.

It’s a simple app that has four buttons. One sets the hour (in 1-hour increments), another button resets to zero, the third button starts and stops, and the fourth button starts the clock at the time of day. There’s also a volume control, and of course, a timecode display.

The JumpStartLTC screen is pretty simple.

The JumpStartLTC screen is pretty simple.

Let’s consider a DSLR shoot, I do quite a few of these. While Canon says the latest 5d has timecode, there’s no way to jam the camera that I’m aware of. So the 5d may “have” timecode, but it’s really just a glorified counter. My 664, on the other hand, has a timecode generator with full timecode capabilities. It can jam to received timecode, or output a timecode signal (via BNC connectors) to act as a master clock.

So here’s a possible workflow for the 5d. With the iphone set to time of day, jam the 664 to the iphone using a 3.5mm-BNC cable. You can buy these for around $12… I made one for about three bucks. Now the iphone becomes a timecode display that you can flash at the 5d at the beginning of each take. Now in post, it’s just a matter of matching up the numbers. Most people just use PluralEyes for this, and that usually works fine, but this is just an extra layer of protection… if something happens to the scratch audio track on the 5d, PluralEyes won’t work, so this is another layer of safety. It isn’t a substitute for a lockbox (can’t imagine why anyone would expect a $20 app to replace a $600 device) but you might find it handy.

UPDATE: As an experiment, I used JumpStart on a 5D shoot yesterday (with country music artist Jerrod Niemann about his upcoming album release) to test how it would work. It pretty much works as advertised… though there were a few caveats. I learned that putting the phone to sleep freezes the timecode counter, so I had to restart the time of day and re-jam the recorder to the phone. This got old fairly quickly, so I left the counter running between takes to see how long it would last. I got a low battery warning after about 2 1/2 hours. I might try one of those iphone battery backs to see if I get more runtime. It also freezes if you remove the headphone jack, so it needs to stay connected as well. A useful addition to the program might be a “dim” button that would reduce the screen brightness and lower the volume on the audio TC output signal to save battery life.

I couldn’t tell, but it looked like there were a few frames of offset between the timecode on the iphone and the timecode in my recorder, but it would take a camera test to see for sure. It also appeared that pressing Time Of Day on JumpStart gives you a different offset each time, so once you start Jumpstart, it’s best to leave it running until lunchtime.

Taping my phone to my slate gave me a visual timecode readout for the camera... not essential, but it probably won't hurt to have it.

Taping my phone to my slate gave me a visual timecode readout for the camera… not essential, but it probably won’t hurt to have it.

About the only other downside was that I couldn’t use my phone for on-set photos, which I try to shoot whenever I’m on set, or check my messages (though it does briefly display incoming text messages). I always stay off my phone when I’m working, but there’s always downtime where you can fire off a quick note. But as a general rule, I never take calls when I’m on the set.

SECOND UPDATE: In the end, I abandoned this workflow. I just didn’t have the confidence that the iPhone could maintain sync. The only way I could come close is to re-sync the phone before every shot, and that took far too long. I finally ponied up the cash and bought a real timecode slate from Denecke. It wasn’t cheap, but it works great and I generally don’t have sync issues anymore, the slate matches the TC in my recorder within a frame or two per day. Cameras are a different story… most drift pretty badly in comparison… but the connector on the Denecke is bidirectional, meaning I can re-jam the cameras using the slate cable as an output, or I can connect the slate to the master clock (my 664) and by just switching it off and then back on again, the slate sees the cable as an input and re-jams itself. I love the thing!

Bargain Gear: The Crest Audio iPro One Preamp

As you probably know, I’ve been doing a bunch of ribbon mic experiments lately. The thing about ribbons is that, in general, their output level is fairly low, and the mics I’m building are no exception. As a result, you have to crank the input gain pretty high on a ribbon, and when I tested the Austin ribbon mic, it was pretty clear that my preamp department was lacking. And until I start making thousands of dollars in the studio, I won’t be able to buy a nice John Hardy M1 preamp like we had at OnLine Audio (list price, $2905 for four channels. It sounded REALLY good…)

So my alternative was to build one myself. A conversation with Les Watts told me he uses THAT chips for the pres that he’s built, and their performance equals or exceeds discrete mic preamps like those used in the M1. So I began looking at designs and collecting parts to build one or two myself.

The input side of the studio. The two interfaces are usually fed from these preamps, though I have direct outs on my mixer if I need more. I bought the Nady years ago. It works, but isn’t the best solution… I only use it when I’m looking for a quick signal input. It’s due for a complete overhaul soon. My other preamps are relatively new additions, a Presonus Bluetube, and on the bottom is the main subject of this review.

That’s when I came across the Crest iPro One. It uses THAT chips and has a very low EIN (Equivalent Input Noise) spec of -129dB. I found one on eBay for $140, including the shipping, so while I probably shouldn’t have, it was too cheap not to try one. They seem to be discontinued, I can only find them from a seller called Audiosavings. But they are brand-new units and arrived via FedEx just a few days after ordering.

It came in the other day, and I’ve set it in my rack and gave it a listen. Here’s my initial impressions.

About the only real beef I could find was that the name starts with an “I,” which has gotten really overused. The rest is pretty darn good… crazy good considering the price that I paid for it. It is indeed a low noise preamp, and my ribbon mic sounds way better when connected to this box.  In fact, it’s made the mic a viable option for a speaking voice signal, where before you really couldn’t use it for anything relatively quiet like spoken voice.

The Crest preamp and mic processor controls

And there are lots of other options available on this unit for coloring the signal to your liking. Going from left to right, first is a low-cut filter, which will be useful in several cases. It has a fairly gentle 12dB/octave slope, so it won’t be like a brickwall filter or anything like that, but it’ll help with low-frequency noises and resonances.

Next is a basic 2-band parametric EQ section that can be switched into or out of the circuit as needed. With the controls set flat and no mic connected, I noticed very little added noise when the section was switched in and out of the circuit, which was a good thing. It’ll probably be most useful as a notch filter to knock out an offending frequency, and has a greater cut range (24dB) than boost range (12dB). A very handy feature is a parametric to sidechain switch. With this, you can set up a de-esser easily by using the parametric to boost the frequencies that cause the compressor to to operate, causing it to clamp down on the highs. Or if the compressor is reacting too much to, say, a bass note or kick drum, the parametric-to-sidechain button can be used to doctor the compressor’s operation.

Next is a dynamic section which includes a basic expander (I prefer the term noise gate, though that isn’t exactly correct. A noise gate acts more like an on/off switch when a signal falls below a certain threshold, while an expander acts more like a fader that activates below a certain threshold). The release time is fixed, so this unit can seem abrupt on a signal like a voice, but you do have a ratio and a threshold control, so it has a pretty broad adjustment range. The compressor section has threshold, ratio, and make-up gain controls. It isn’t as adjustable as a standalone compressor, of course, but it’s easy to use and works well. There’s also a limiter with fixed attack and release times, I’d imagine this would be useful to prevent overloading your DAW input. The dynamics section also has an external sidechain input and an on-off switch, which are pro-level features.

The “SmarTube” feature adds high-frequency harmonics, which can “brighten up” a signal, according to the manual. I haven’t used it much yet. Personally, I believe that if you want “that tube sound,” you should use tubes. But then again, good tube gear can cost a fortune, so this may be an alternative. It could be especially useful when using the unit as an instrument interface, thanks to the inclusion of a line input and level control… another reason I bought the unit, it should work well as a bass direct in. I haven’t tested that yet, though.

The unit also has a headphone out, which is super handy to have. I love it when these options are available, as I can plug in and concentrate on a single function. It saves time since I don’t have to think about the signal flow.

There are two meters, gain reduction and output level. Sure, Crest could have saved a few bucks by using a single meter and a switch, but it’s great to have visual confirmation of the unit’s operation.

What I really appreciate are the little things, though. The fact that this has front panel connections AND rear panel connections, for example. It increases the cost to the manufacturer, and the suits would argue that the unit would still work with connectors on either the front or the back, but I really prefer both. Sometimes I’ll want to keep things clean in the front and use the back connectors, but when I want to plug in a mic or guitar cord, it’s great not to have to crawl around to the back of the rack, then realize I need my glasses, then go find a flashlight so I can see what the heck I’m connecting… you get the idea. And something as simple as putting the power switch on the front… somehow Nady seemed to think that on the PR8, the back was a good place for a switch, so on my other preamp, I have to reach around the backside of the rack to power it on and off… a stupid place to put a switch on a piece of rackmount gear, makes me cuss every time I do it. (Actually, the Nady is being scheduled for a full heart transplant. I’ll keep the connectors and the case, but replace the power supply and all the circuit boards with something that works better… probably a bunch of THAT circuits.)

Now, I haven’t put this unit through an exhaustive battery of tests, and I’ve only used it on a few actual sessions. A proper audio job is always much more telling than just going through the functions. But it really seems to be an affordable, very functional piece of gear. The overall weight seems lighter than you’d expect for a box of this size, and I’d imagine the switches and pots won’t last into the next century. But waddaya want for 140 bucks? For what it can do, I think it’s a terrific buy… if you’ve been wanting to try an external preamp, and you’re on a really tight budget, this would be a good choice.

Full Disclosure: I don’t have any connection to Crest. This unit was purchased at retail on ebay, and was done so for use in my own studio. I don’t receive any sort of benefit from this review. (though I’m not above that sort of thing at all. Feel free to send me your expensive gear, and I’ll publish an equally expensive opinion.) The post above is strictly my personal impressions, accuracy and correctness are not guaranteed, and your mileage will almost certainly vary- BG

The Austin Ribbon Mic

I recently received an Austin Ribbon mic kit from Rick Wilkinson (Rickshaw Records) out in California. Unfortunately, I can’t say I’m the proud owner… this mic is going to be built and given away as a door prize at the DIY panel at the Producers and Engineers Summit at Welcome To 1979 in November.

I haven’t finished the build yet, so I can’t give a complete review of the mic, but I can make some comments about the kit and the resources that come with it. Building a ribbon mic is not that complex- IN THEORY. It’s just a thin metal ribbon suspended between two magnets. There isn’t much electronic inside the mic, just a transformer. The design has been around since the 30’s.

The theory is simple. But like most things, it’s the Devil in the details. You can find articles and instruction on the web for free. And that’s what I started to do years ago. I got halfway through the project and shelved it… there wasn’t enough detail for me to be successful.

Or you can spend some money and increase your chances. Rick sells plans for ten bucks, or his ribbon kit for $275 with a Cinemag transformer. (There is a less expensive version with a stock transformer, and I understand the stock transformer is exceptionally high quality. It’s sold out right now, but should be available again shortly) Rick sent me a kit with a Cinemag transformer, so that’s the version I’m reviewing here.

The kit itself is extremely well done. The mic tube is powder coated brass, 1 1/2″ diameter, and exactly machined. All the holes are already drilled, so you don’t need a drill press. The motor frame (a critical part) is a machined piece of plastic. The fit was perfect. I especially liked his design… I designed my own once, and it was a cumbersome mess. Ricks is elegant, simple, strong, and works well. (some folks claim that metal frames are superior. Perhaps they are… I’m not sure… but I think that at least part of the reason behind this claim is that’s what is available from China.)

The greatest value for me, though, is Rick’s instructional materials. When you buy a kit (or his plans), he sends you a link where you can download  PDF instruction manual and several videos where he goes through the process of building a mic. These videos are really helpful, especially when it comes to corrugating and installing the ribbon.

Commercial mics use ribbons that are anywhere from 5 microns to 1.8 microns thick. The ribbon material that Rick supplies is about 0.8 microns. (Thinner ribbons increase high-freq sensitivity.) This is similar to “imitation silver” guilding leaf, it’s readily available on the internet. I’ve bought some from Hobby Lobby before and tried to cut a ribbon from it. I can say without hesitation that it ain’t easy. But that’s the beauty of these videos. Once you see someone doing it, you understand the method better… much better than just reading about it. And you can see that it is possible to make a well-functioning ribbon from scratch, but understand that it’ll take some practice. Even breathing can cause a cut ribbon to fly off your bench. So be ready to make several practice ribbons before you get one correctly made and mounted in your mic frame. And if you just can’t get it, there is an internet source for commercial ribbon foil now. A company called Lebow sells pure aluminum foil in a variety of thicknesses, including 1.8 and 2.5 microns. This would be vastly easier to handle, but it’s also vastly more expensive at $25/sheet. (There may be other sources as well, but this was the only one that I could find. I ordered two sheets to use in my own mics, but they aren’t in yet.)

Ribbon-making details is a big advantage of his instructions, but it isn’t the only one. For example, I learned that you can use a brass footrail cap on the bottom of your mic to hold the XLR connector. These things are nice, solid castings, and if you shop around, you can find them at about $5 apiece. (I wish I’d thought of that.) Circular Switchcraft connectors fit well in these caps.  This would be a good solution for any tubular-bodied homebuilt mic.

The videos do have a slight downside. You have to remember that Rick has built a lot of mics, so some of the things he does in the videos look easier than they will be to folks like you or I. It’s really difficult to explain the things that practice teaches you. But I’m pretty sure that I’ll have a working ribbon mic once the dust settles… I’ll keep you posted.

UPDATE: I finally got up the nerve to install the ribbon today. It worked on the second try, which really isn’t bad. I’m pretty sure that my success with this is pretty much due to Rick’s instruction. Like I said previously, I’ve tried this before and failed miserably. Seeing it done (in a video) makes all the difference.

A just-placed ribbon in the motor frame. This job requires lots of patience, but it can be done.

That is not to say, however, that it was easy. The foil is the definition of flimsy… if it were any thinner I think it’d fly off my bench because of the rotation of the earth. Using the more expensive 2.5 micron foil should be easier (though I expect still no picnic), and that’s what I’m planning for my own ribbon motor frames. (I figured this one should be made as a stock kit, in order to give a fair review.) There will be some slight differences, like slightly thicker magnets… I’m still in the design and prototype phase. But if they work, it’ll be fun to try some design variations like waffle plates (resonators) and silks.

Simple Broadband Absorbers

Here’s how I built a pair of simple broadband absorbers to cut down the room sound in my studio. These work as good as specialized acoustic treatments, but cost far less, and their absorption is good down to the 500Hz region, and it’s fairly flat across the spectrum. Note that absorbers don’t stop outside sounds from getting into the studio… they do shorten the reverb time of instruments as they are played in the room.

The absorber starts with a simple 1×3 wooden frame.

It’s really nothing more than a simple wooden frame with fiberglass fill, covered with cloth. Mine measured about 5’6″ by 30″. I used cheap 1×3 lumber (which is really about 5/8″ x 2 1/2″), but a true 1×4 would be better. If you use cheap wood, count on spending more time building them… I had to pre-drill all the nail holes to prevent the weak wood from splitting. I also used construction adhesive on all the joints.

The frame gets filled with plain R13 fiberglass. A few staples helps hold the fiberglass in place.

Once the frame is built and the fiberglass positioned, all you have to do is attach the cloth. I used a staple gun. They are fairly light, so they can hang on the wall with a simple screw. There may be times when I’ll want more room sound… then it’s a simple matter to move these somewhere else. Or stack them around a guitar amp, for example… they’re very handy to have around.

I turned the absorber over and stapled cloth to the backside, and it’s finished.

The finished absorber in place

How To Make Turtle Clips

I can hear you. You’re saying, “What the #%*& is a turtle clip?”… a reasonable response to the above headline, actually. I didn’t know about them myself until recently. A “turtle clip” is a mic clip with a little wire bail over it. The wire is there to keep fabric away from the mic, preventing clothing rustle.

A commercially available turtle clip for a Tram lav

If you’re flush with cash and short on time, you can buy these from B&H for $20 apiece. Or you could make them yourself. All you need are some bits of copper wire, something round (like a dowel or broom handle) to use as a former, a pair of needlenose pliers, and a pair of cutters. Optionally, you can use a soldering iron if you want to get fancy, but it isn’t required. The clips that I made require a bit of Topstik or Moleskin to secure the mic, but they work as well as the ones from B&H.

Any round object will do as a former. The size determines the diameter of the finished mic clip… about a half-inch or three-quarter-inch rod will do. Wrap the wire around the former as if you were winding a spring one and a half turns. It’s easiest to wind a little extra and then clip off the excess wire later.

Starting a turtle clip. Copper wire is wound around a round former, 1 1/2 turns

Now, using the needlenose pliers, bend a half turn of the wire up 90 degrees. Clip off any excess wire and you’re done, unless you want to solder the ends. Soldering only takes a second and does make the finished clips a tad stronger and smoother, but it isn’t required. If you haven’t done much soldering before, this step could be

Bend one of the loops 90 degrees. I used a vise, but pliers can work fine for this.

a little tricky, but it’s very easy with a little practice. (HINT: Heat the wires first, then apply the solder to the wires. Don’t apply solder to the soldering iron, except maybe to help transfer the heat to the wires.)

Once you’ve made a few of these, other variations and improvements will surely come to you…

Snipping off the excess wire. Having a little extra wire makes handling these a touch easier while you make them.

making clips with two bails, for example, or rectangular shapes rather than round. They will get rather bent out of shape with regular use, but they’re easily replaced and cost only a little time. And if you’re too busy to take the ten minutes it takes to make these, I’ll be happy to sell you some that I’ve made… only twenty dollars each!

My collection of homemade turtle clips. They didn't take long to make, and they get easier with a little practice.

Bargain Gear- Cowon iAudio transcription recorder

During a shoot for the PBS some years ago, the producer handed me a Cowon iAudio U2 MP3 player. This was to be used to record a copy of the audio sent to camera to send to the transcription

Cowon iAudio U2, 1mb model

service. These little things have two big things going for them… one, they’re pretty much dirt cheap (you can buy them used on eBay for $10-$20) and two, they’re TINY… about the size of a pack of gum.

The U2 has a provision for a line input via a 1/8″ jack, as well as an on-board mic. I bought one and added a small bit of velcro. I can stick it onto my bag or hide it on the set. The tiny little screen is a bit of a pain to use, and you have to navigate the menu maze to get it into record. But it can record WAV or MP3 file formats, and with 1gb of space, it holds a respectable amount of program.

I’ve just shipped mine back to Cowon to get the battery replaced, and they have yet to give me a quote. The battery on my unit is pretty much gone, and only operates the unit for about fifteen minutes before running out of power. Since there are so many options now for small MP3 recorders, the battery replacement cost will be the big factor for whether or not this unit will remain in service or retired. But it is a handy option to have in the bag.

UPDATE: Battery replacement for my unit is going to cost $27, which seems pretty reasonable. They’re working on it now, and it’ll be placed back in service as a basic standby recorder, giving me a similar capability as the Sound Devices mixer with the onboard recorder, but at a significantly lower cost. Until increased bookings allow the upgrade, this is a workable alternative. (My rule about expensive gear is get the business FIRST, THEN buy the hardware.)

UPDATE 2: I’ve received my iAudio back from Cowon. Their service department gets five stars… I’m not positive, but it looks like they’ve done more than just replaced the battery. The unit looks brand new. There’s not a scratch on it anywhere, and the little rubber cover for the USB connector seems new as well. I haven’t gotten around to doing battery life tests yet… i.e., how long it will record on a fully-charged battery… but I’ll post the results when I get them in.

Bargain Gear- the EV CO90

Most people can tell from my resume that I’ve been doing audio for a while. One of the advantages that I have over someone just out of school is in the gear department… I’ve used a lot of it. Some works great, others, not so much.

I first encountered Electro-Voice CO-90 lav mics at WCBD TV in Charleston, SC, nearly 25 years ago. These were wired lavs, and came with a transformer base to drive a balanced cable. While they weren’t particularly small or easy to hide, they are quite rugged… I’ve seen pissed-off news anchors slam them on a desk dozens of times, and they still work. They are omnis, which increases their usefulness in certain applications… even though I used to swear at them when we went to a tight 2-shot, since they would pick up the other anchor and phase cancel, especially when Jill Franco was wearing something busty and place the mic a long distance from her mouth.

The later version of this mic was the EV CO94, which had a TA3m connector on the mic head. This allowed them to be used with a wireless unit. The downside it that the 94s came with a slightly bulkier  rectangular “belt pack,” but it did work with 9v batteries which are easier to find. The head was the same size.

Here's a look at my latest eBay score… a CO90 complete kit. This one came with all paperwork, a battery (if you get one with a dead battery, please don't toss it in the trash for obvious reasons... save it for recycling), a single mic clip, a windscreen (easily broken and/or lost) and a second phantom power base... the only one I've seen.

So at the risk of driving the eBay price up, I can suggest buying a few of these as backups or extra mics. They are occasionally seen on eBay for about $25-35. Just a few things to be aware of before you buy:

1) The E625 batteries they used are no longer made, since they contained mercury. There are some substitutes that work (Z625PX, Energizer E625G). You might have to special order a few of these, since they aren’t commonly found at the pharmacy. But the current draw is miniscule– 150 microamps– and a battery will commonly last over 1000 hours.

2)Repairs. Electro-Voice was sold to Telex years ago, and the current company is a shell of its former self. Forget about factory service… I’ve called their parts department, and they have no replacement parts to speak of. There are two main failure points… the cable and the battery spring. The cable will often be just plain worn out, with cuts and breaks in the insulation. I’ve replaced the cables, but it’s quite a difficult task, as one end was soldered to a FET and potted in resin. If you buy one with a bad cable, then plan on quite a few hours at the bench to repair it, unless you get lucky. Sometimes a break in the insulation will be close to the base. In that case, the cable can be clipped ahead of the bad spot and re-soldered to the base, which is a good bit easier than re-soldering near the head. If you really want to change out the cable for new, you can buy replacement cable from Trew Audio’s repair department. It’s tiny and difficult to handle and solder, of course, so I wouldn’t recommend this as your first repair project.

A second place for these to go bad is the battery spring. These were special little dealies that EV made, kind of like a spring steel washer with three tiny leafs that press the battery against its negative contact and conducted current through the positive side. These little leafs are a weak point… I’ve had one with two of the three leafs broken off, so until I can come up with a suitable re-design, that mic will stay off-duty. You wouldn’t want to chance a dropout during operation because of a bad battery contact. A viable option in this case would be to skip the battery altogether… EV made a special phantom-powered only base, the CO90PM. These are gems if you can find them, but they’re extremely rare. It is possible to do your own conversion… details can be found here:

http://www.uneeda-audio.com/phantom/pl-76mod.htm

Another application for these mics that may be more useful is a plant mic, where the mic is hidden somewhere on the set. I’ve found a few EV model 370 Barrier Adapter Plates on eBay that just came in. These are simple glass-reinforced plastic plates, about 2-1/2 inches square, with a small recess and a clip to hold a CO90 head.

Electro Voice EV 370 boundary plate

The EV 370 boundary plate clipped to the CO90 head… an easy plant mic, surface mic, etc.

This will allow these mics to be used as a pseudo-boundary mic, though they will probably be improved by taping them down to a larger flat surface. The configuration isn’t a true boundary, like a PZM… a PZM(Pressure Zone Microphone) has the mic diaphragm parallel and very close to the boundary surface, 1/10-1/50″ away. A PCC configuration (Phase Coherent Cardioid) has the diaphragm set perpendicular to the boundary, except the CO90 isn’t a cardioid… so I guess that makes this a “PCO” mic, or Phase Coherent Omni. (To quote John Cleese, “He’s making it up as he goes along!)

Gear like this isn’t for everybody. To be honest, I rarely use these mics, and nearly always reach for my Countryman EMWs. But it’s good to have some hardwire choices in your kit in case the wireless situation gets buggy.