Jeff Wexler

Hey, Philip, I think I can set it so that you can add to the gallery, if what you are referring to is the Web Gallery, not the images posted at my website. I will look and see if this can be done --- I know I set it so that people can download the images from the Web Gallery. Regards, Jeff Wexler

For those unable to get the Web Gallery link working, you can now go to my regular website, photo page and then to the View Sound Cart Gallery. This will work (although I posted images which display smaller than I intended... sorry). My site: < jwsound.net > - Jeff Wexler

Sorry about that. I will look into why that happens. The Web Gallery, slideshow routines that Apple uses (this particular gallery is up on my .Mac account) may have some browser incompatibilities. I will see what I can sort out. - Jeff Wexler

Here are some pictures of the CartPower supply boxes that I have been building. This is the latest version I am currently using. Rack ears are on the back (since I mount the box from the back of my cart) and the face faces me so I can see the LCD readout and get to the switch. I have also made a companion box, the same dimensions, that sits on top of this one and has batteries only in it. These 2 boxes are then connected and I have longer running capacity (for those days when I think we will be without AC for a longer period of time). Regards, Jeff Wexler

Quite awhile ago Bob Marts gave me a huge collection of images of sound carts which we wanted to put up somewhere for people to be able to browse and get ideas. These are from sound mixers all over the world and there is quite as variety of carts and approaches, and quite an interesting array of equipment in use. I was somewhat reluctant to post these because neither Bob nor I have been able to identify many of the carts and their owners. I decided to put it up anyway and the easiest place to put them was on my Web Gallery. Here is the link: < http://gallery.mac.com/jwsound#100100 > Regards, Jeff Wexler (and special thanks to Bob for gathering all these images)

Excellent question. In real world working experience if I have been on battery alone for any length of time and it gets down to 10.5 to 10.0 vdc, I stop using that battery (because the equipment will be at the bottom of its voltage range and might quit at any moment). So that battery might be put on a conventional external charger with no load on the battery, OR, I have just powered up the cart power supply (with its regulated DC power supply) and let that supply "charge" the battery. In those instances I might be reluctant to also ask the cart power supply to operate the equipment (the load). The scenario that I referred to really was the situation where the battery is seriously discharged, maybe down to 4 or 5 volts (wouldn't power any equipment anyway) from just sitting --- then I would definitely use a charger to bring it up to full before letting the regulated DC supply float across. Regards, Jeff Wexler

What Mick describes here accomplishes approximately what my supplies do but uses a product, from PSC, that one needs to purchase (but you are relieved of the duty of building something yourself). Also, Mick's setup has way more battery capacity than I need (with the accompanying weight to the cart as well) so I stick with basically 1 30 aH battery. I don't have the need for multiple voltages so my regulated power supply (10 to 15 vdc adjustable) works just fine. I will post some pictures of the cart power supply box I am using now. Regards, Jeff Wexler

While I was there they did the drawing and lots of people did win lots of really good stuff. Most of the vendors I think had been very generous in donating things to be given away. As I was leaving, they were giving away a brand new iPhone donated by Lectrosonics. Also, I shopped at Audio Services when they first opened up an office (and it was just that, an office) in 1976. It was in an office building on Sunset in Hollywood, right around Cahuenga or Vine maybe? I believe it was on the 9th floor and was essentially an unfurnished office with maybe a desk or two and some tables with some products laid out. Dick Topham was the main guy and I think he was having to do everything himself... always gracious and helpful and interested in whatever it was we were doing in production. Long, long time ago, that's for sure

Yes, exactly. The regulated DC power supply (I can also post some links to the ones I have used, both linear - heavy! and switching) is connected to the battery terminals and the also the distribution to the cart to the same terminals. So, in essence when the regulated DC supply is "on" the equipment (the load) AND the battery are being fed 13.8 vdc. This works out to not be exactly like powering the equipment directly off the power supply because the battery is connected also and serves as a big buffer lessening any AC ripple that could come through. I did do one supply where I put a diode between the battery and the power supply so that when not in use DC would not flow back into the power supply. I don't do that anymore but I do have a breaker/fuse/switch so that when cart sits for weeks and weeks not working I can disconnect the power supply from the battery. Regards, Jeff Wexler

The simplest way to describe the cart power supplies I have been building for the last 10 years or so is to let you know the main components: sealed lead acid batteries and regulated DC power supply --- it's that simple. No charge circuit, no standby UPS stuff, no inverters, etc. I use either linear power supplies (with transformers and available new or through surplus) or switching power supplies (more on the type later) that when plugged into AC (usually 90 volts to 240 volts) put out 13.8 volts DC at around 10 amps. This is connected to the battery and then the equipment, the load, is also connected to the battery. When plugged into AC, the DC from the power supply floats across the battery keeping a fully charged battery, fully charged. When the equipment is powered up and drawing considerably less than 10 amps, the battery stays charged and everything is happy. If there is no AC or the AC gets pulled accidentally (does that every happen?) the equipment is still getting DC but now off of only the battery. There is no noise, no charging circuit to introduce any trouble, the equipment is quite happy to be powered off the battery. When the AC returns, whatever has been drawn off the battery is replenished. It is an elegantly simple system that has been 100% reliable for the last 10 years or so. There are a few caveats: if you use switching power supplies you must purchase supplies that have a low noise and low AC ripple spec (but most of the medical grade supplies work very well in this respect) and they must have an amperage rating that is greater than the maximum current draw you have will all equipment powered up. Secondly, you must choose a battery type that is suitable for constant current across and this type is generally the sort that is used in backup lighting systems, alarm systems, any place where the battery is happy in a stand by mode. Then you choose how many amp hour capacity you want based on how long you want your equipment to run off the battery alone. In my case I have 35 amp hour battery which will run everything on my cart for 6 hours. Lastly, you must start out with fully charged battery so that means having a conventional battery charger available. The float system relies on having a fully charged battery so if the cart has been sitting around for a long time and the battery is discharged, it should be fully charged before using this system in production. All of this stuff is housed in some appropriate case or chassis box with everything fuse protected and multiple 4-pin XLR outputs as needed for distribution. On my cart there is one connection to this box and then my cart is internally wired with several DC connection points in the proper places for the equipment in use. I also made the wiring from all these connection points "home runs" meaning there is a continuous wire from each connection point back to the power supply. Rather than looping through each connection point this seems to cut down on interaction amongst the equipment. Regards, Jeff Wexler

Good looking cart and nicely outfitted. As everyone knows, I have built a few CASE based type carts in the past but have always found things that I don't like (even though all of these have been my own design so I have no one to blame). Seeing all of these new carts (and most seem to be built around a case) has given me renewed interest in looking into building another cart. Thanks for putting up the images and good luck working with your new cart. Regards, Jeff Wexler

Yes, congratulations all around, managing to complete anything regardless of scale is a real accomplishment. Hopefully we will all get to see it somehow in the near future. Hey Crew, nice picture of you showed up here along with your post. Regards, Jeff Wexler

I didn't ask Forrest if he was still doing any of those mods. I got the feeling that he has had to give up all of that "outside" work now that he has a full time position at Coffey Sound. I can't imagine he would even have the time. It might be nice if he made his schematics available to someone else who does have the time to do these things. Regards, Jeff Wexler

I could re-route things but I don't. Here is the setup (coming out of my Cooper 208): output A (main mix bus) goes to Input 1 to Track 1 on the Deva. This allows me to feed Track 1 the mix, post fader, of any of the 8 inputs on the Cooper. Output B (2nd mix bus - Cooper) goes to Input 2 to Track 2. This allows easy assignment of a Cooper input to the mix bus B with the pan pot. Inputs on the Cooper 1 through 4 are the 4 Zaxcom wireless (for talent or plant mics) and they go out pre-fader iso direct to Deva inputs 3,4,5, and 6. The 2 main boom mics go to Cooper input 7 and 8 (since I use input 8 as my main boom mic from Don --- usually the only mic we're using!). So, every mic that is plugged in, the wireless 1 through 4, the 2 boom mics 7 and 8, show up on the Deva meters pre-fader --- the Deva meters serve then like input meters which the Cooper does not have. Nothing will be showing on Deva track meters for track 1 & 2 until something is sent there subject to the input fader to the mix busses. You can see how it is very easy to have all mics available to go into the mix to track 1, as always, and then if any or all of those elements are needed as iso tracks I just arm the corresponding track. I may be using up to 3 mics but they are all being mixed to track 1 and I don't feel any need to split them out and record all 3 also as isos. It is really much simpler than it is to describe, but that is the short answer as to why I don't reassign anything either via software or hardware during a typical day. Regards, Jeff Wexler

48 v. phantom power is NOT supplied through the 6-pin LEMO connector --- 2 pins on the connector access the 9v. supply (the battery) that's all. The way you can power a 48 v. mic from the xmtr is to use the vDb powering cable (an accessory that most people who have used the Audio, Ltd's have --- I have 2). This cable which has a LEMO on one end and a 3-pin XLR female on the other, has a bulge in the middle which houses a DC to DC converter to step up the 9v. supply to 48 volts. Regards, Jeff Wexler

nvt said: "The 824 allows 1, 2, 4, 5, 6, and 8 track counts -- as it's only an 8 input machine, that only precludes recording 3 and 7 track poly files. It does seem a bit arbitrary, although in practice it's never come up as an issue." It is probably a function of how I work and the jobs that I am on, I find that if I am recording anything more than 1 track (1 track only is what I do about 80% of the time) it turns out that I need to record 3 tracks. Also, these 3 tracks are never track 1, 2, and 3, it is almost always track 1 and then track 3 and 4 possibly. I think now that we have changed the topic thread, we probably have nothing else to talk about! If someone more knowledgeable than me can chime in with the relative value of mono files vs. poly files (although I think I do know the answer and it isn't that poly files are silly) that would be good. Regards, Jeff Wexler

At the last big announcement event there was very little attention paid to the Mac Mini but it was in fact upgraded with faster dual core processors and higher capacity hard drives in the standard configuration. I think the ultimate destiny for the Mac Mini will be that it will be E-O-L (end of life) at some point in the fairly near future. It is an excellent machine but it may have trouble finding a real following with the general computing public. The Mac Mini's greatest value came from its small size and low price --- aimed particularly at those people who already had a keyboard, mouse and monitor. Now, with the incredible prices for the new full featured iMacs (with 20" and 24" displays) the overall cost of a new Mac Mini, a new monitor, keyboard and mouse, it just doesn't make sense. For us, the Mac Mini is still a really useful computer because of its size and the possibility of reasonable DC powering and the use of smaller keyboards and monitors for cart use. The Mac Mini is quite an attractive option for those who do not wish to use a full laptop on their sound carts. The Mac Mini allows for more flexible placement of monitor display, keyboard and mouse, than the laptops. On the other hand, the laptop, with built in keyboard, trackpad and screen, there is nothing else to add (and the DC powering is already possible usually with a simple car adapter). As for Mac software for cart based recording, there really is only 2 main choices that are in general use these days. That would be Metacorder from Gallery Software and Boom Recorder from Vos Games (Take Vos). Both are in fairly wide usage on many sound carts, either running off a Mac Mini or a laptop. Both of these software recording applications require the use of some hardware interface unit and there are several popular units in use (the MOTU Traveler being one of the most common). Regards, Jeff Wexler

I don't think that will happen but I am working on doing some more of these things and also working on getting the video of the previous one available. All of these things were done by our Education Committee at the Union so there are some obstacles to making these available to everyone. I know Don would like it to be available for everyone, maybe even as a DVD or a download, so we are exploring those things. Regards, Jeff Wexler

I am curious if this link to my website works. Anyone interested, click on the link and let me know if it takes you directly to a slideshow (Quicktime movie) that we showed at Don's class last year. This is images only, no content from class, sorry. http://jwsound.net/Site/dcboomshow.html Thanks, Jeff Wexler

Thank you Brian for posting that. I knew someone had done this with the Mag-Safe connector. From the looks of it, this is the way to go for anyone wishing to power a MacBook or MacBook Pro from a 12 vdc source. Regards, Jeff Wexler

Remember this description only applies to the old style connector (round with a center pin) and does not address the Mag-Safe connector. All current Mac laptops have the Mag-Safe connector. I don't remember if the original question stated whether this was a powering solution for a current model (MacBook and MacBook Pro) or the older ones. Regards, Jeff Wexler

I am hoping Courtney will chime in here (or on r.a.m.p.s.) since we have been discussing this for awhile now since I gave him a spec sheet from SONY for their approved HD workflow. I believe the problem is the project frame rate for the Avid having already been established to accommodate something different than what you're doing. I am not an expert on ANY of this, I just listen a lot and try and ask relevant questions. Let's see what somebody else comes up with on this one. Regards, Jeff Wexler

I shouldn't think it would be necessary to build a special 24 volt block (movie-style) battery to run a Mac laptop. Except for the Mag-Safe connector problem (the new MacBook and MacBook Pro --- more later) there are lots of so-called auto adapters that are designed to connect a laptop to a standard 12 vdc source. So, any standard 12 vdc block type battery would then serve your need. When Apple introduced the Mag-Safe power connector (a really good idea but not compatible with anything else out there) all the companies that had produced all the accessory power connections (for airline hookup, car adapters, etc.) were S-O-L. I am not up on the current state of affairs in this area although I know that Apple has made available an airline adapter with the new Mag-Safe connector on it --- this is a standard Apple accessory now and possibly that could be adapted in some way. I did see that some company is again making power adapters (auto, airline, etc.) that uses the Mag-Safe connector, but I don't remember what company is doing that. Regards, Jeff Wexler

I spoke with Forrest the other day, he is at Coffey Sound now heading up their service department, and he said that he is NOT doing the Yamaha DC conversion anymore. Regards, Jeff Wexler

Interesting item that could be the simplest way to hook up a microphone directly to the computer (Mac and Windows) http://centrance.com/products/mp/ "At home or on the road, MicPort's compact, USB-powered design offers maximum audio fidelity and minimal system configuration. Protected by a rugged chassis, MicPort's low-noise circuitry preserves high-quality audio. The onboard headphone jack delivers zero-latency monitoring via direct circuit. Mic gain and headphone volume adjustment couldn't be easier with MicPort's two conveniently located rotary controls." Regards, Jeff Wexler