Chris Reitz dot Com

OK, so I’ve been putting this off for WAY too long. I promised a tutorial on how to make old acoustic foam pretty, so here’s Part 1. (You’ll have to wait for the glue to dry for Part 2.) I should add that, although good acoustic foam is rated at least Class B for fire safety, chances are, my trick here is NOT Class B, so don’t try this in a commercial studio. This will also change the sound absorption qualities of the foam a bit (that disclaimer is just for the audiophiles). However, the stuff still works, just not as well as it could in an ideal world.

So we're going from this.....

....to this.

The materials you’ll need are some ok-quality 8′-long 1x2s (they don’t have to be perfect, but builder-grade furring strips don’t quite cut it — you also need them to be exactly 2″ wide which furring strips are not), the foam (duh), some 1/8″-thick particle board, and some nice-looking, thin fabric. Add to that some tools and glue, but I don’t want to list all of that, down to how many nails you need. That’s not the point.

1'x1' foam tile

OK, first, cut the foam into manageable sizes. I made my tiles 1′x1′, 2′x2′, and 1′x2′. That way, there’s a nice variety. Makes things prettier in the end.

Now, you’ll want to cut the 1×2 into whatever lengths you’ll need…four 2-footers, two 2-footers and two 1-footers, or four 1-footers. The closer you get to perfect measurements, the better, but remember it’s all going to get covered up by the cloth, so don’t spend hours trying to get these cuts perfect.

Marking off the lap joint

Now, we’ll cut lap joints on either side. Quick math lesson, but if you want a lap joint using a 2″x3/4″ board, you’ll need to cut a notch in each board that’s 3/4″x1″. Here’s the setup, and the finished product(s). As you can see, I’m making more than one tile, not one weird octagonal one.

The cut lap joints. Next step: glue!

As you can also see, I like using Titebond II glue.  It dries fast, is pretty strong, and doesn’t do weird stuff to the wood.

Note that all of the boards look the same, and that they have the lap joints on the same side. It is SO easy to put the lap joints on the wrong side, and then you have to buy new wood. Not fun.

OK, now, using plenty of clamps, glue it up, and then measure the diagonals of your tile, to make sure it’s square. Both diagonals should be the same length. If not, bend/twist/torque the tile until they are.  Then let dry.

Clamping hte frame

And I’ll see you again when the glue’s dry.

Actually, one thing to note. I mentioned it before, but you don’t need to make the frame look like it’s made by a master cabinetmaker. It’s going to be covered by fabric. Make sure things aren’t too far out of whack, but if they’re off by up to 1/16″, it’s not the end of the world. The fabric will hide it.

OK, gotta run some errands and wait for the glue to dry. Peace out!

The TC-PDT's Krone head

ok, so I got my punchdown tool yesterday, and spent a little while (2 hours – HA!) punching some audio cable down. I think I gave the thing a pretty decent workout.

First of all, I’ll say it’s waaaay better than the screwdriver I was using before. It punches wires down very nicely, with a lot less effort and problems than the screwdriver approach.

That having been said, there’s good reason why the TC-PDT cost $16 and the one from Full Compass that I’d mentioned before cost $170. it’s a little tough to tell in the photo (sorry about the bad focus—cell phone pic), but it’s got a little chisel blade on the side of it, that’s supposed to cut off the wire, so it’s flush with the side of the punch block. It doesn’t work all that well. It sort of cuts off the wire, but kind of leaves it hanging, and if you punch the wire down at the wrong angle, you can shave plastic off the punch block itself. Whoopsie.

From what I’ve seen, the $170 tool has a little wire cutter at the end that snips off the wire, like a pair of scissors. That seems to me to be a better design. That having been said, $170 for a tool that I’m going to use probably another ten times ever would be just a wee bit impractical.

All said, I’d say the tool is really good for the money.

A Punch Block

OK, so my radio station moved, and they didn’t need a couple extra Krone punch blocks and a really nice big (3′x6′!) desk.  So, I took the punch blocks, and my brother helped me grab the desk. And then, because our band’s studio has been in pieces for about a year, we figured it might be cool to redo it using the desk as an editing desk, and, of course, using the punch blocks.

First of all, note that some of this stuff (in particular using a screwdriver to punch wires down) only works on Krone punch blocks.

Second, note that you’re probably going to get a better punch down if you use a punch down tool. Same way cutting wood works a lot better with a saw than with a hammer.

Third, (and this is partly why I used the screwdriver approach) I had trouble locating a nice cheap punch tool. Full Compass sold one for $70 (tip not included, and about $100 extra). I talked to my rep at Full Compass and he told me that they’d only ever sold one of those, so he suspected they weren’t the way to go. After a bit of googling, he suggested this from Newegg, for $16. Obviously, it’s more cheaply made, but theoretically, if you’re not a broadcast engineer, punching stuff down every day, you should be able to get along with the cheap tool. When it arrives in the mail, I’ll try it out and see.

So basically, what I wanted to run is balanced audio from the board to the blocks, and then balanced audio from the blocks back out to other stuff like an EQ, DAW, and a bunch of ports where you can plug instruments in.

A TRS Plug

First step, make the plugs. Sorry, I didn’t get a shot of how I made an XLR plug. They aren’t hard to make. My biggest issue with making any kind of connectors is I’m not good at working with tiny stuff, so it takes me a while. But after about 5-6 TRS plugs, I was pretty much clipping along. No pun intended.

Once I had the tip made, I threaded it through the table, to the punch blocks, and punched it down. For those of you who haven’t punched stuff down before, you don’t have to strip the wires.

Tinning the ground wire

I found that, because the ground wire was bare and stranded,  it was a lot easier to punch down if I tinned it with a little bit of solder first. Then using a 1/8″ Craftsman flat blade screwdriver, I just forced each wire into a slot, bare, black, red, bare, black, red (aka ground, cold, hot).

Punching down with a screwdriver

The reason why I mention that it’s a 1/8″ Craftsman screwdriver is because, as I said before, some screwdrivers won’t work. I tried two other screwdrivers before I found that the Craftsman worked. I think it was a combination of slot width, and the fact that the sides of that particular screwdriver’s blade were grooved, which seemed to help keep the screwdriver from slipping out of the slot I was trying to punch the wire into.

I haven’t had the opportunity to run audio through the setup yet and see how it sounds, but so far, I’m really impressed. For about $65 worth of cable and connectors and two free punch blocks, looks like I’ll be able to make a whole studio. Pretty legit.

Totally different note, I need to write up how I’m making some old disgusting studio foam look schnazzy again. Next time I’m making some, I’ll try to remember to take pictures.

Top view of cable routing

Pretty, ain’t she, at least so far?

So I bought this really awesome Phonic MM1805X board off one of my buddies about a year and a half ago, and then moved three times. Well, somewhere during one of the moves, the main volume slider got bent up, and completely screwed up the volume control, so that it didn’t work half the time, and the other half of the time, it crackled when you moved the pot around.

For those who can't read really fuzzy cell phone photography, the model number is RS60112A600N.

I just ended up getting another board, but my band kind of needed a good studio board, so I figured I’d try fixing the volume slider. The worst that could happen is that I’d fry the already unusable board. The best that could happen is that I’d have a fully-functional board at the end of it.

The red box is where the new pot is (on the other side of the board). It's a little scuffed up from so many solderings and desolderings, but it works perfectly fine!

Well first I tried sticking two 10kΩ potentiometers in the corner, up by the main outs, and seeing if I could wire them up so they’d work. No such luck.

A few months later, I got my hands on an old Behringer board that had been hit by lighting, and I thought I’d pull one of the main sliders out of that (it had two, for left and right) and stick it in the Phonic. That sort of worked. Now I had the right channel of my board working. Better than nothing, but still, my band needed a full stereo main out. I mean, a rock band in mono would be kind of lame…

The new slider is the one on the far right. It's a slightly different color too.

finally (and this is almost a year later), I broke down and bought a new slider from Mouser for $4 (plus $7 shipping — OW!) and tore my board apart for the third time.  Just for the record, it’s an A-taper 10kΩ dual 60mm slider, made by Alps.

And then, with a couple screwdrivers, pliers, some patience, and a whole bunch of desoldering braid, I stuck the new pot in.

And of course, the last thing to do is to test the thing, then assemble.

Just a test of the board. Worked great through both left and right channels. Perfect.

And that about took care of it! It worked like a charm. Now to finish that relay rack….my buddy Tim wants to see that with some ‘Kahn Industries’ decals on it….I’ll have to see what I can arrange.

And one more. How to record on a tight budget. I had another one about mastering, but it didn’t really have anything good in there. I might eventually write something up about it.

Your band wants to record a hit, but how? You’ve tried your parents’ tape deck and it didn’t work. How do the pros do it? Bad news. The pros do it with a lot of money. But there is a way to do it without having a multi-million dollar budget.

These days, most recording is done digitally, or on a computer. So, if you have a desktop computer, or a laptop with a bit of space on the hard drive, you are in luck. Otherwise, you can build a computer for a very reasonable price. My band built one for $385. It had a 40GB hard drive, 1.56GHz AMD Athlon XP processor, and 512MB of RAM. We found a monitor that was being thrown out, and used that. You don’t need a fancy computer to record audio. The only thing I’d change if I were building a new computer is I’d get a much bigger hard drive. But if you’re willing to store most of what you do as CD backups, a 40GB drive is just fine. [It's hard to find a 40GB drive anymore...just shows you when I wrote this!! HA!]

if you have a laptop, you’ll probably want to look into getting a PCMCIA sound card like the DigiMark Pocket VX 220. Most laptop sound cards aren’t good enough to record with, so you need either a USB card (ok) or a PCMCIA card (better). [Firewire is even better, but Firewire cards can get very expensive.]

Next, you will need a small mixer. It only needs enough inputs for one person’s instrument and one microphone. My band uses a Behringer Eurorack UB1002FX. It has two mono inputs (one mic and one guitar), and four stereo imputs for things like keyboards. We got it for about $75.

Get a good microphone. Usually, the more expensive you can afford, the more expensive you should buy. My band uses a Shure Beta58 that we got for about $150, but if you can afford a $600 multi-pattern large-diaphragm condenser, get one. It will help your sound. [I also recently bought an Audio-Technica AT2020 for about $80. I HIGHLY recommend it if you're looking for a cheap, nice-sounding condenser.]

Buy a set of good speakers. Decent studio monitors cost about a thousand dollars but I have gotten away with using a Phillips minisystem ($150) and some $20 Sony headphones [which later broke and now I'm using $40 Sennheiser EH150s].

Recording software can be the most expensive item on your list, if you let it be. Or you can let it be the cheapest. My band uses a package called Audacity which is free. We got it from Stanford’s PlanetCCRMA website, which offers a comprehensive group of Linux audio packages for recording. We also got a bunch of free effects plugins from PlanetCCRMA. Audacity also runs on Windows for those who prefer. Otherwise, you are looking at $500 to thousands of dollars for multi track recording software [Adobe Audition is a great broadcast editing suite, and runs about $350].

Set up your studio where you can (where you won’t get too much noise or complaints of noise) and record one track at a time. My band usually does drums first, then main [rhythm] instrument, then other instruments, then vocals. Make sure your ‘vocal booth’ is reasonably quiet. We use my (small) room with some winter blankets over the doors to the outside and to the bathroom [this will be changing soon---we're building a real studio!!]. Try to get rid of any reverb in it, and also try to get rid of any resonant frequencies (notes that sound louder than others when sung for more than a couple seconds). You can usually do this with blankets and pillows, but if you can afford it, you might be interested in special acoustical foam and bass traps. [I got some for free when a broadcast school got gutted for a new tenant to move in.]

When you’re in the studio, take time to listen to tracks and see if you really want to keep them. You are not a pro, so it will take you some time to produce professional sounding audio. It took my band several years of studio experience to be able to throw a track together in a couple hours. Our first recording took a day for a 5-minute song. At the end, we didn’t like it and we re-recorded it. Several times. I’d estimate that it took close to 40 hours of studio time to record our first 5-minute song.

ok…that about covers it for my re-posts. I’ve got a couple other things that I might eventually post up, and yes, I know, I still need to finish my relay rack. I’m procrastinating, which those of you who know me know I can be very good at.

This is the first in a series of short articles I’d written while I was still back in school. When I graduated, I lost my web space, so I’m just re-posting them here. So here goes: How to perform music on a tight budget.

Who cares about recording? Your band wants to perform! You have seen the setups that big bands use, but there is no way you could ever afford them. Is there any way to perform without spending thousands of dollars?

The technically correct answer is no. My band managed to pull off a performance setup for about $2000. Which technically is thousands. But hey! it’s not $20 000.

The first thing to ask is how many instruments do you have and how many vocalists do you have? In my band, we have three instruments (plus an acoustic instrument) and two vocalists. So we need three mics (one for each vocalist plus one for the acoustic instrument), two guitar (mono) inputs and one keyboard (stereo) input. We also use a CD player for extra tracks that we can’t perform (like extra harmonies). That brings the total up to 3 mics, 2 stereo, and 2 mono. Mics usually run off XLR cable, and guitars and keyboards run off 1/4″ phone (or TRS) cable. CD players sometimes run TRS and sometimes run RCA. So, we needed 3 XLRs, 4 TRS and 1 stereo RCA. Go to your local audio dealer with these numbers and they will show you a mixer which might work for you.

Ask yourself (realistically) how large your typical audience would be. For us, we didn’t see catering to a crowd any bigger than 500 people. And that was an overestimate. We ended up needing two 15″ speakers. Tell your dealer this number too. They’ll show you a speaker/amp setup which will work.

Just a side note, there are two ways to amp your speakers. One is to buy an amplifier and run the output of your mixer into that. The other is to buy a power mixer, one with an amp built in. We used a power mixer. It works, but if you see your band ever needing to expand a bit, I’d suggest getting the amp separately. Either that or get active speakers (speakers with a built-in amp). These options cost more, but they are more expandable. If you’re planning for the day when you play the Astrodome, don’t get a power mixer.

What if you are in the situation my band is in? 2 vocalists and 6-part harmony? How the heck do you perform your music? What my band did is to burn a “Performance CD” which has all the tracks that you won’t perform. That way, you can’t be accused of lip-syncing, but you won’t have to figure out how to sing more than one note at once.

Get a good sound guy. This can be the toughest thing to do on this page. You have two options. 1) get a guy who is familiar with your music and knows what kind of sound you’re interested in, or 2) YOU do sound and write down all your settings and teach someone how to set up the mixer for your settings and how to fight feedback if it occurs. My band did #2. It works reasonably well, although, I suppose #1 is a bit better.

OK, so I promised pictures. here they are. Yup, got my computer fixed, so now I should be able to post a little more regularly.

Fig 1 - The layout I'll be using. The ciircuit board will go where the ribbon cables are.

This next one made me mad, because it means I’ll probably have to buy about $12 more worth of switches, and spend another hour soldering them all up.

Fig 2 - The broken switch

Fig. 3 - Most of the TRS jacks in place. Still need to paint the back plate.

Well, sorry, I know that this is a pretty lame post, but I didn’t really have time to do more. Hopefully the pictures make up for the lack of new info. Part of it is that I’m waiting for a nice day, so I could paint my back plate black, and part of it (ok…ok…I admit it) is laziness. I’ll have more next time.

Pictures coming soon…

I got set back on this a little, because I needed to shell out for a new suspension and a 60,000-mile checkup on my car. In the meantime, some good things and some bad things have happened to the project since.

The Good

I got some more TRS connectors! I’m almost ready to put the whole thing together! I only need one more connector.

The Bad

One of my switches broke. Yes, that’s right, broke. The ones I got were made of plastic, and apparently I bumped a switch and the threads broke, so I can’t bolt it down anymore. I’ll have to decide whether to buy another switch, and just hope it won’t happen again, or whether I should replace all the switches with better quality ones. That’d take a lot of desoldering, and resoldering though…we’ll see.

I’m probably also going to need to get some pretty long, pretty skinny bolts from somewhere. Again, we’ll see

The Obligatory Rant

Some pretty smart people have worked at Radio Shack, but unfortunately, usually the ones who make a career of working there seem to be complete morons. I went into the Shack today to buy my TRS jacks, and I had to tell the guy five times that I didn’t want any batteries, cell phone accessories, batteries, batteries for my smoke alarm because Daylight Savings Time is coming up, batteries, or anything else (including batteries). Maybe next time I’ll just tell him, “if you keep going with your litany, I’m going to put my connectors back, and get them from Full Compass.” That ought to shut him up. I guess at least he’s not like the guy who used to work there. You’d ask that one for a resistor and he’d take you to the remote control cars.

Anyway, I’ve been having computer problems, so as soon as those are done being fixed, I’ll post pictures.

Fig. 1 - Circuit Diagram for the Relay Rack

So I’m building a relay rack for my home studio.

First, for those who don’t know, a relay rack is just that; a rack of relays. The relays are used to switch between audio stuff. Most often, you’ll see relay systems built into higher-end mixer boards in radio stations or production studios. Usually, the relays are set up so that, if you turn on a microphone, it kills the speakers. That way, it is impossible to get any feedback while you’re recording. You can also wire up a relay so that if you turn the microphone on, an ‘on-air’ light would light up.

So anyway, I’m building a 4-channel relay rack. Four mono microphone channels, which switch a set of stereo speakers on and off.

Q: Why don’t you just put switches between the amp and the speakers?

A: Two reasons.

1) (and this doesn’t answer the question), I have active monitors, so I’d need to tear my monitors apart to do that.

2) (and this does answer the question) assuming that I had an external amp running to a couple of speakers, I still wouldn’t run switches between the speakers and the amp. I wouldn’t do it for the same reason why you never ever run an 6Ω speaker to an amp that’s designed for a 8Ω load.  Electronics nerds will be able to tell you that the smaller the load you’re running, the larger the current you’ll be running. So if you attach a 6Ω speaker to an 8Ω amp, you’ll be making the amp run higher currents than it is designed to do.

Q: OK, so what do speakers have to do with switches?

A: Well, a switch is the same as attaching a 0Ω speaker to your amp. The amp will end up supplying WAAAAY higher currents than the amp is designed for. So if you want to be replacing your amp all the time, you can run switches between the amp and the speakers, but a relay rack saves the expense of buying a new amp every couple of months.

I first got the idea to build the relay rack when a friend of mine gave me his old homemade relay rack as payment for driving a mixer board from Madison to Milwaukee for him. He had just a single channel, running to two RCA cables that go between your mixer and your speakers. The switch was a DPDT (middle-off) toggle on a 1RU plate, and the relays were screw-terminalled and zip tied to a 4RU plate. It worked, but I thought I might be able to make it slicker.

I took my friend’s relay rack, and drew out the circuit diagram, and then expanded it to a two-channel version (See Fig. 1). Four channels is cooler than two (and most radio stations would need four channels anyway), so I’m building a 4-channel, 1-RU version of the relay rack.

Fig. 2 - A front view of the relay rack

So here’s the front view. There isn’t a split in the rack plate; that was my cheesy attempt at panoramic photography with my cell phone, and the two halves of the plate ended up different colors. The way the rack works is if the main power (big switch on the right) is off, all microphones are off and audio passes straight through from the board to the amp. If you turn on power, same thing happens, but if you turn any of the mikes on (the little switches on the left), the speakers turn off, and the mic turns on.

Fig. 3 - Wiring the switches and status LEDs

OK, so first off, I drilled holes in the rack plate and mounted the switches and status LEDs. Easy enough. I’m a little bummed that I got Channel 3 a little off where it should be, so it doesn’t look completely professional, but I’ve seen (and done) worse. I just used a center punch and a drill press.

Now the fun begins. Wiring. Between the LEDs and the switches, there were a total of 24 connections, so I decided to use some ribbon cable I had lying around. Two cables, with 12 conductors each. I could have done a lot of the wiring at the switches, but somehow, I wasn’t that smart. If I ever build another one of these, I’ll do more wiring at the switches, so I don’t have to run so much cable.  That having been said, the ribbon cable does give it a kind of a hot-roddish look!

Fig. 4 - The switches wired up

I also used a couple cable clips from Radio Shack to route the cables. It makes them lie more nicely, and fit better in the small 1RU space. Anyway, neatness is good.

Next, I soldered the relays to a little circuit board (Fig. 6). The blue ones are for the microphone channels (Normally Open), and the black ones are for left and right audio (Normally Closed). The switches will be connected to the board via a Parallel-style connector. I bought a 25-pin one, thinking I’d need all of the inputs, but all I needed was 6 (See Figs. 5 and 7). That’s ok. I’ll probably still use the 25-pin one.

Fig. 6 - The brains of the relay rack.

Fig. 5 - Wiring the ribbon cables

Fig. 7 - Wiring the ribbon cables

If you’re curious about what’s under all the blue tape in Figs. 6-7, Fig. 8 is a circuit diagram of all of the connections. All that ribbon cable for six connections. No use crying over spilled milk, but next time I’m going to wire up 90% of this right at the switches.

Fig. 8 - Circuit Diagram of the LEDs and switches

Well, that’s how far I’ve gotten for now. A quick look at what I’ve still got to do (and therefore, a sneak preview of future posts), I need to figure out how to mount the 25-pin connector to my little circuit board, wire it (and the corresponding one on the ribbon cable) up, figure out how to mount the circuit board in my rack, make a back plate for the rack, where audio I/O will happen, and wire up the audio I/O jacks. Wish me luck; I’ll need it!