Archive for the ‘touring equipment’ Category

this new panel is looking kind of old-school star trek

Now that I’ve had good test results from the Class-T amp I’m using to make those old stage monitors into self-powered stage monitors, it’s time to whip up a new plug panel for the new connectors needed – power, line-level input, and so on. This process is raising more questions than I expected, so this post is partly me thinking out loud, and partly taking suggestions.

When I got these speakers, they had unbalanced XLR in, and unbalanced XLR daisy-chain, and that’s all. That’s kind of weird these days, so I added a 1/4″ unbalanced (“phono”) connector. That looked like this:

But unbalanced 1/4″ phono plug is not really optimal for powered speakers, because the signal going to the speakers is line level, which is a lot lower, and therefore a lot more subject to interference. So I need some sort of balanced input, I think. Also, I still want to be able to use the speakers in their original intended mode – as passive devices driven by external amps, so I kind of need two connectors. Plus the soon-to-be-built-in amplifier needs a power lead, and it’d be nice to have a couple of status indicators, and so on and so forth.

So that all fits together in the existing amount of space like this:



Without and with labels

So does the drill pattern for all the holes I need in this new panel. I had been thinking of adding a second panel or something, but since I was able to make it fit, I think I’m better off not bodging more exceptions into the cases.

My initial thought was 1/4″ plywood – I have that, it’s easy to work with. But now I’m looking at the number of connectors which are involved here, and the number of resulting holes, and I’m thinking, should this be metal? Or would a particularly sturdy plastic work?

The original was metal, and I’m pretty sure I mean steel. It’s sure as hell not aluminium – adding one jack to it was a huge pain in the ass, and aluminium isn’t that hard to drill out.

So, yeah. Plastic would be a lot easier, but would it be sturdy enough? Serious question, I don’t know. Aluminium would be easier to drill and file than steel, and is still pretty strong. But that’s still a lot of work.

Maybe I could/should get someone with a cutting system to cut it out for me. I know that’s a thing you can hire out, but I don’t know anything about it. I have a scale drawing and that’s all.

I guess I can ask Fishy that when he gets back from Tokyo. But I hate waiting once I have all the parts for something. Anybody got experience with hiring out metal cutting in Seattle, and know things like how much that cost? ‘Cause I have no idea.
 


This post is part of a series on restoring infamous vintage stage monitors. Spoiler: they made good, in the end.

give this board a proper power supply

Give this little Class-T amplifier a proper power supply, which I’ve finally done, and suddenly it’s MADE OF LOUD.

Yes, these are the monster stage monitors that I blogged about rebuilding before. But they’re still “passive” mains, which is to say, they need external amplification – like essentially all concert gear before about 15 years ago.

What I’m doing here is spending $23 (holy crow $23?!) each on bare-board Class T amplifiers, and $26 each on high-quality 24 volt power supplies, and making them into active monitors. This will let them be useful with modern mixers, which tend to not include amplification, expecting that to be bundled into the speakers themselves.

Being me, of course, I’ll leave the old-style functionality exposed. So they’ll be usable with both old and new-style gear.

Funny thing is, these monitors… they were famously terrible, but at this point, they’ve become actively pleasant to listen to. I’m doing an extended power test of the amp and power supply right now, and I’m staying in the room and listening to it on purpose, because hey, why wouldn’t I?

I know where the beat is at,
‘cos I know what time it is
fishin’ in the rivers of life

 


This post is part of a series on restoring infamous vintage stage monitors. Spoiler: they made good, in the end.

to vancouver! also, a build follow-up

Off to Vancouver for a show! Not one of mine tho’, we’re seeing Le Vent du Nord tonight at the Rogue.

I mentioned that the instrument pickup I built last week sounded really good if I used my finger, but terrible using their standard attachment methods. I tried attaching it using a plastic clamp, but at first, that didn’t seem to help, so I rebuilt the piezo portion of the device, without the double-sided tape which had confused me the first time around.

That’s had an interesting effect. Held on by hand, the sound is definitely different – lots more low-end – but I think I like it less. But at the same time, using the clamp now works – it sounds the same with the plastic clamp as it does held on with finger, which is a huge improvement, and makes it usable on stage.

This is definitely something which requires more tinkering, but I’ve got it far enough along to try using during Friday’s show. Because SURE UNTESTED GEAR WHY NOT right? Well, you have to test it sometime. XD

Time to fly. See you at the Rogue?

making a backdrop

I’m making a backdrop! Not for the big show Friday evening, but for Conflikt opening ceremonies a few hours beforehand. What it’s specifically for will have to wait until then, of course – but I can say it’s Vaudeville-style, for foreground-style action. Which is part of why it’s so painterly. Those backdrops tended towards that sort of treatement.

Oh, and here’s a short follow-up to that pickup build report from last week: I’m going to have to redo the piezo disc. I wasn’t able to make a clamping solution work, and I’m hoping that a clean disc will pickup the low-end frequencies without so much fiddling. Fingers crossed!

build report: Zeppelin Labs Cortado

Since I’m starting to play Anna’s octave mandolin in concert occasionally, I want to get a pickup of some sort attached. Yeah, I can play into an instrument microphone, and I’ve been doing so, but wow I hate that. I hate being tied down into a single place on stage.

A couple of months ago I ordered a Zeppelin Labs “Cortado” pickup kit. I’d planned to try making it into a boundary microphone/PZM – and I probably will order another kit to do that – but since hey, I need a pickup, I have a kit, let’s see how this works when built as actually designed!

I started working on it during yesterday’s DIY Music Chat on Twitter, mostly because it seemed fitting. It’s a small kit, and one of the easier builds I’ve made. Here are all the parts except for a missing ground wire. I don’t know what happened to it, but I have lots of wire so it was no big deal:

Populating the circuit board was very trivial. They did warn you about the transistors, which is good – I have a grounding strap so I used it. But it really was just insert-into-holes-solder-on-backside work. The instructions do walk you through technique, so if you’re new to this, the detail they provide is nice.

The only surprise was that my serial number was in the series that needed a small mod to the circuit – instructions were in a service bulletin. This was only an issue with some of the units in my run, so this may’ve been optional, but I went ahead and did it. It just consists of adding a second resistor in parallel to the included one.

Assembling the piezo pickup is probably the closest part of any of this to being difficult. First – and I’m a little confused about this – you attach the double-sided tape to the back of the disc, and trim it. This doesn’t seem to have any function and I’m not 100% convinced this isn’t an error in the instructions.

Then the red wires which come already attached have to be removed, and replaced with leads from the shielded cable they provide with the kit. That involves stripping the end of the multi-lead cable, bundling the shield together into a connector, and stripping the ends of the other two wires.

The two central wires get attached to the piezo disc, exactly where these are attached:

Then you put a layer of electric tape on either side of the discs (for electrical isolation, which makes the double-sided tape redundant, which, again – instruction error?), then wrap the whole thing in the provided copper tape. It’s important to make sure the bottom side – which is how it attaches to instruments – stays very flat:

Then that aforementioned shield ground is soldered to the copper tape. Also, you should make sure the joins on the copper tape are nice and conductive, which means lots of weird-looking not-actually-random solder spots.

Shielding is pretty important in applications like this, because you’re dealing with small signals at the pickup, no matter what. So it’s important to get that right, and right throughout. Which is why the circuit board gets mounted inside the tin which is provided with the kit.

Drilling that tin was the biggest problem I had, honestly. You need a 3/8″ drill bit, and I didn’t have one of those, so I had to go buy one. And I bought a nice one that was supposed to be super-good at drilling smooth holes in metal. That did not go well, but since that’s not the kit’s fault, I’ll not dwell on it. Anyway, I managed to hide the damage.

The next step is connecting a ground connection on the board to the tin itself. Again, not difficult, but important – what you’re doing is grounding the entire circuit and pickup, to block radio frequency noise. That connection is in the upper right, here:

Once you’ve done that you bring in the wires from the XLR connector, to attach to the circuit board. Those wires are also shown in the picture above. Then on the other side of the board, you do the same thing with the leads from the piezo pickup, just like that:

…and screw the board down inside the tin. There’s a spacer to keep the board from touching the metal case, which is now a shield housing.

And that’s literally all there is to it. Throw in a couple of tight zip ties to keep cable stress off the circuit board, and you’re done with construction.

Now, use is another matter. For long-term attachments, they say to use the included double-side sticky tape – it’s permanent, though, so be sure you know where you want it before applying. But, as above, they already told us to use that sticky-tape. So… I’m not sure what’s up with that.

For temporary attachments, they suggest things like holding the pickup down with painter’s tape, or poster tack. I don’t have any poster tack, but I tried the painter’s tape, and that didn’t work very well at all. It collected sound, but it sounded really midrange-heavy, really tinny – it didn’t pick up any of the low end at all.

So then I tried poster-weight “command adhesive” strips, the removable ones 3M makes. I didn’t expect that to work well, and it didn’t – though I did pick up some more of the octave mandolin’s low end that way, so it was a step in the right direction.

I was starting to get worried that I’d done something wrong in the pickup at that point, so I tried just holding the pickup against the octave mandolin’s face. That worked just fine (10 second mp3, open strumming) so I think it’s just issues with making a good attachment.

Since the user instructions say that you can try plastic clamps to attach the pickup, and those are cheap, I’ll be buying one to try that. I’ll have to space the clamp off the pickup itself with a layer of foam or something, because of wires, fragile pickup disc, etc., but I hope it works – I really don’t want to be playing into an instrument mic even for one song at Conflikt. And held in place by hand, the pickup really sounds good.

Also, the noise level on this thing is hilariously low – they promise a low noise floor and they really overdeliver. VAST TRACTS OF SIGNALtiny noise floor! Well done there.

I am still wondering if the difficulty I’m having is caused in any way by the double-sided tape being inside the pickup bundle. I know I didn’t get that wrong – there are photos of how to do it in the instructions. But I’m wondering if you’re supposed to skip the electric tape on that side if you use the double-sided tape, and they forgot to mention that.

I’ll drop Zeppelin a support note it. If I was supposed to leave it out, well, I have more copper tape. I could re-do this pretty easily if that’d help. I’ll report on that, too.

Anyway, if the plastic clamp test goes well, this will definitely turn into a recommendation. I’ll try that this Friday, and report back. Given that this kit only costs like $25, it’d be a good addition for very little money, so I hope I can end up recommending it.


 


This post is part of The DIY Studio Buildout Series, on building out a home recording studio and other DIY audio projects.

found gear

Sometimes you buy gear, sometimes you make gear (particularly if you’re a DIYer like me), sometimes you just find gear.

Leannan Sidhe’s lead singer had an old black leather purse she didn’t use anymore because somebody got paint on it. It was passably renfaireish before that – at least after she’d put on a metal decoration on the front to distract from the modern clasp – but since the paint accident she’d put it aside. And that’s how I found it at a rehearsal.


paint not shown.
(it was mostly on the strap)

Now, at renfaires – her band does a lot of renfaire gigs, and these days that includes me – you can sell CDs and stuff. But you want to keep them and your sales gear out of sight, since those are obviously very much not period. Talk about it at your show, of course, but don’t carry a big cardboard box from Memphis around. The illusion is tenuous enough as it is.

So when I looked in this old purse and saw it had CD-width dividers built-in, I said, “Oh, is this what you used to carry CDs in before you got that awesome wooden box you use now?” And she looked at me and said, “…I never even thought of that.” And so she gave it to me.

The paint was just latex. It came off with a mild orange-oil-based adhesive residue remover (De-Solv-It) that doesn’t even need gloves to use. And so now I have a renfaire sales box – one compartment for CDs, one for download codes (and an extra CD, because it fits), one for money and Square for charge cards and a pen and there’s even room left over. Keep the big stock in your tent, refill between shows as needed, carry 10 or so CDs to a set, everybody wins.

I didn’t even have to make this thing. It already even had correctly-sized dividers inside! I just had to recognise what it was, and clean it up. So yeah, sometimes… you just find gear.

anybody know where I can get spares of these beads?

A piece of costuming that I use for some gigs – mostly Leannan Sidhe gigs – threw one of the ring-type beads that are used in tying up the front. It’s just flat gone – no sign of it – so I need a replacement.

I think they’re shell. I’ve been a few places trying to match them with no joy and with the stores not having anywhere to suggest. So… any crafters or beaders out there seen these recently?

Failing that, anybody have a similar? I was thinking maybe niobium – but I’d rather keep what’s there now if I can. (Also, I haven’t seen any that would work.)

also this weekend

Some months ago, I discovered “Class T” amplifiers, and also discovered that they have pretty good reputations and can be had for astonishingly low prices direct from manufacturer. They’re mostly used in automotive audio, but I’ve had some thoughts on converting my passive main speakers to active main speakers, so I acquired one.

I finally built a test harness for one of these boards on Saturday night.


Damn right I know how to party

Result: it’s worth building a better harness, and, most particularly, use a more suitable power supply. I basically grabbed a 15v DC adaptor out of my I ♥ You Power Supplies box of random salvage, and really, that’s a pretty shitty test transformer.

But even with that, it worked, as in, it functioned and sound good enough to give it a proper go. I didn’t get the low end out of it I’d’ve liked to, but, again, radically underpowered supply voltage, and one of the places that shows up is in lack of low end oomph. I’m hoping that’s it, because if it is, I’d be able to upgrade a lot of old kit on the seriously cheap.

And that’s not a bad thing at all.

How was your weekend?
 


This post is part of a series on restoring infamous vintage stage monitors. Spoiler: they made good, in the end.

emergency compartment

Raptor emergency supplies compartment is all sorted:


A Well-Stocked Raptor is a Secure Raptor

Tho’ honestly, it’s good to have an emergency kit if you’re going out on long trips – for me, road trips for shows – and this vehicle has a place for a rather substantial one in back, as long as you don’t mind many shallow boxes. It’s hard to see in this photo but all this is in recessed divided sections, underneath the cargo floor, which is really nice. Nothing slides around or gets in the way.

The red box is a basic first aid kit, to which I’ve added a few extra supplies; the other boxes are as labelled. Under this layer there’s another separate compartment, with a toolkit, basic repair supplies (fuses, tubing, etc), spare tire and tire repair kit, as well as flashlight, things like that.

If you like putting things away in neat little boxes (even if the supplier changed their labels mid-stock and you ended up with two different labels, aheh), this is a pretty good vehicle to have. XD

anybody got experience with little electric coolers?

Anybody got experience with those little 12V electrical in-vehicle 12V coolers? I can get this one with credit union rewards points. The maker has a smaller model (really tiny) which has a small number of reviews that are highly mixed, and a larger model (substantially larger)which has a large number of reviews and is thought well of overall.

This model, though, lacks reviews. It’s 14L (a little over 3.5 gallons?) and… um… well, it looks like this:


Cooler than … what, exactly?

I don’t expect miracles, but it’d be nice to keep things cool in the Raptor without hauling around ice and/or burning uselessly through cold-packs. Mostly because let’s face it, after day one, all of those things are dead, while this thing would in theory keep going.

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