Tag Archives: amplifier

Bose 1800 Amplifier aka Carver pm1400

22 Aug

The arena I work out of, the Brick Breeden Field House, has a fairly sizeable Bose (yes, I know) sound system.  I’m not going to get into specifics of the install, because it’s really nothing special.  However, one aspect that did impress me was the amp rack–a stack of ten Bose 1800s.

Image From what I can tell, this amp rack has rarely been powered down since installation.  These babies have been running for a solid 15 years and still function as designed.  Mentioned in previous posts, I’ve been cleaning out our tech storage areas and continue to find all sorts of goodies from previous installs.  In my findings have been several Carver professional amplifiers, including a pair of Carver pm1400s.


Now look at the above pictures and tell me the Bose 1800 and Carver pm1400 aren’t the same amp with different branding.  Turns out Bose subcontracted their amplifier production out to Carver for their professional systems at the time.  It seems the only real difference is the Bose version has an EQ module installed for use with their Panaray speaker systems, which can allegedly be bypassed for use with other systems.

At 450 watts per channel into 8 ohms, these are not wimpy units, and workhorses to boot.  For this post, I suppose the moral of the story is don’t judge a book by its cover, or in this case hold a prejudice against gear just because of a brand stigma.  Side note: such a prejudice getting lifted can be seen in the case of the Behrigner X32, with so many former haters now finding themselves behind one.

That’s all for now. Maybe I should go clean the fans in those amps.

QSC 1400 overheating at the new gig.

15 Jul

Hey there, trusty followers.  I’m sure you’ve been on the edge of your seat since my last post in…. uh… well, too long.  A lot has happened.

I’ve relocated to Bozeman, Montana to take a gig as Technical Director of Sports Facilities at Montana State University.  Yes, that’s a bit of a mouthful, but I’m excited for what the future holds.  I can’t say I could have predicted this move, but what the hell, sometimes you feel like getting a little crazy.  I’ll give you the rundown on this in a future post.  I promise it will be soon-ish.


Looking out my front door.

Anyhow, the second day on the job, a set of speakers in our arena, aimed directly at the court, purposed primarily for our basketball team (go Bobcats!) to crank their warm up jams(z) through, was cutting in and out.  We were listening to the radio at the time, so someone suggested perhaps our tuner was just losing signal.  However, only the one zone was being affected, so I greatly doubted that was cause.  I nodded my head and tried to keep an open mind, but kept thinking in the back of my head, “we’ve got an amp overheating.”

Sure, it could have been lots of things, but the overheating hypothesis just felt right.  Music would play through the speakers for a few minutes, then shut down for about 1/3 less time than it had played.  So a minute and a half-ish of playback, 30 seconds-ish of death. Give or take an ish.

Upon a visit to the amp rack, what else did we (my comrade Tom and I) find but a little QSC 1400 that was hot as Hell.  We were in the middle of something, so we shut down the amp, put a fan on it and went back to taking down some soft goods, figuring we’d troubleshoot when we had the time.

I used to have a QSC 1400, or rather “borrowed” one from my dad, and I was fairly positive they were forced-air cooled.  Today I had an extra hour to squeeze behind the amp rack and point my flashlight at the back of the amp.  Yep, there’s a fan.  And yep, upon powering up the unit, the fan didn’t budge.

I really love fixing broken audio gear, so I ripped that baby out of the rack faster than you can say “thermal meltdown” and pulled off the top.  HOLY CRAP–the fan was absolutely covered in black, super-dust gunk.  Of course, I was so excited to clean the thing at this point I forgot to take a picture.  I immediately removed the fan and started to flush the motor with WD-40.  The fan was still quite difficult to turn by hand, and wasn’t even close to moving on its own accord.

It took a full disassembly of the fan motor to clean out all the crap.  I reassembled the fan, put the fan back in the amp, the amp back in the rack, and got the jams(z) once again pumping.

While I completely understand how such a task can be overlooked in a fast-paced, event-driven environment, try and make a point to clean your amplifiers’ cooling systems, at least once every, oh, decade at least.  And if you’ve got amps fancy enough to have filters, don’t forget to clean those–I’ve seen a few too many filters full of “dryer lint.”  Great for campfires, bad for amplifiers.

I leave you with an interior shot of the QSC 1400, post fan cleaning.  These are great little workhorses.  When cared for, they can provide clean, reliable power for years and years.


By the time this needs cleaning again I’ll be mixing FOH for Peter Frampton.