Thursday, December 09, 2010

Eugene Noise Fest transpired last Saturday. It was packed into a single day (taking place in a house that was no longer 100% tenant friendly) which turned out to be a long haul. Always happy it happens, and I'm always happy when it's over.

I actually brought my camera, mainly to take a gear porn shot of my set-up in front of my sound system, but by the time I went on (over four hours behind schedule) I was in a no bullshit frame of mind and didn't take a pause for sightseeing.

The PA system is described as follows: (I'll get around to taking set-up pics, eventually)

Fender MX-5200 mixing desk feeding a Rane AC23 crossover with points set at 120 hz and 1K4 hz.
Low end fed to a Mackie M1400i high passed at ~38 hz feeding a McCauley 6242 and a Carvin HE15 (rebranded Eminence as far as I can tell) in the folded bass horns as described previously.
Middle range fed a Crown Power Base 1 driving a pair of JBL D130 loaded in Altec 828 cabinets.
High range fed the EICO HF87 driving Altec 288 compression drivers bolted to JBL 2395 horns.

At least, that was what was hooked up at the beginning. From the get go the left HF driver was hanging out in the realm of the non-existent. I chased a red herring around the speaker assembly (involving disassembly on the stage) because I had done a little work on that driver earlier that day only to conclude that the trouble was stemming from the amplifier (to be accurate, the channel of the amp I'd worked on previous as well). I begrudgingly swapped that channel out for one side of the Heil 400 which was my supporting backup amp. This entailed moving from a transformer coupled 35 watt tube amp to a direct coupled 400 watt solid state amp without speaker protection. Nervousness did ensue. But having no back-up HF drivers, the early (1950s I think) Altecs had to go in. To be fair, the 16 ohm load of the compression driver really damped the power output of the sand amp, and in the end everything played nice there.

Sound was still off on the left side. This was narrowed down to a non-functional main (middle range). I had, in preparing and packing up for the show, considered pulling some spare JBL drivers for just such a contingency. Of course, considering and doing are not the same thing. So, in order to have full range response on I hauled ass to the practice space, pulled a pair of JBL K130 from a 2x15, and set about climbing behind the stacks upon return.

This is when I reaffirmed my deep seated hatred toward slot head screws (22 of them were holding the back panel on) while working in a small dark corner. This entire process took about 45 minutes, from leaving to fetch a replacement driver to having it installed, during which the longest set of the evening transpired. Oh, and I became reminded to plug the speaker cable back in after it didn't work right the first time.

And thus, sound was delivered in full and the speaker side of things gave no further problems and sounded good (though I plan on setting the low-mid crossover point a touch lower next time as the bass drivers got a little shouty at 120 hz).

But wait, what's that smell?

Redplating tubes are the easiest thing in the world to spot under these circumstances, and it only took a glance into the amp cabinet to source the origin of the burning odor. Of course, at this point I am morally obligated to NOT shut the sound system down. We're fully running behind and I've done enough damage as it is. The pair of output tubes in runaway are in the problematic channel I've already bypassed, so without further ado I knock a few volts off at the variac, borrow a glove (happened to be a left hander, which was of no concern at the time) and set about pulling the tubes hot. The gloves, which had those rubber grip bumps, immediately began to emit smoke. I do hope this offered entertainment value to everyone observing the events. Gloves saved my skin, absolutely, but they did not make handling the tubes comfortable by any stretch of the imagination, so with a smoking hand I made the snap decision to lay the tube atop my TOA mixer to cool. Repeat for the other, and the rest of the evening my side went okay.

I made a single rule to follow this year at ENF: "If it requires soldering to fix, it is broken and we're going to live without it". I'm happy to say I held fast to that rule and everything came together, unlike 2008:

Photo credit: Matt Brislawn

Huge round of thanks to Doug Theirault, for use of DI boxes which eliminated the ground loop hum, and to BLOODSON DRIFTER for use of a glove, without which would have caused me much continuing grief.

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