Wes Lambert

MUSIC PRODUCTION - AUDIO ENGINEERING - GEAR TECH

Acoustic Research AR-2ax Speaker Rebuild

I was lucky enough to come across a pair of vintage AR-2ax (late 60's) loudspeakers a little while ago.  The only catch: blown tweeters, and these son of a bitches are sealed up good.  But after a little research, I decided that it would be a worth-while project to resurrect them.  I knew they were little golden nuggets the second I gave the cabinets a knock and a subsequent lift.  Nice and solid!

Below are some images from the re-build.  I replaced the tweeter and crossover section.  I reused the original midrange and low end drivers.  

Most of the information I used for the rebuild I found on The Speaker Pages and AudioKarma forums.  Thanks to all of the contributors on those forums.  You were very helpful in my research efforts.  

 


Overnight Sensation speaker build

I just finished building a pair of Paul Carmody's Overnight Sensations bookshelf speakers for my brother.  His old computer speakers crapped out on him and I managed to convince him to let me build him a pair!  I used the Parts-Express kit and at $130 a pair, these little guys kick ass!  They are well designed, utilize quality parts, and produce more than reasonable sound quality for the price point.  

Here are some pics of the build below.  There are more on my flickr!

 

 

 

 

 

The finished pair.  Time to enjoy some music!

Knock-down cabinets

Clamping the cabinets together

Building the crossovers

Assembling

Oh, hello in there

The corners came out pretty well! (birch laminate)

The backs

Building an 1176 compressor

A buddy of mine and I decided that we needed some 1176 compressors in our gear arsenals.  We decided to take matters into our own hands.  We purchased a few Hairball Audio kits along with some mnats Revision D boards and I put them together myself.  We decided to go with the Rev D circuits because they offer integrated LN (low noise) circuitry while still utilizing output transformers (later revisions feature an op-amp output).  Here's a link that explains the revision history.  Revision D is considered one of the more favorable versions of the 1176 circuit.  Hairball does a fantastic job with the kits and supplies high-quality parts.  They went together so smoothly.  So, how do they sound?  Like 1176 compressors!  There's no more difference in sound between these clones and an original 1176 than there is between two original 1176's from different eras.  I decided to use 2N5088 transistors, which are the same ones used in the Purple Audio MC77.  These are a bit more transparent and 'quicker' sounding than the typical 2N3708's found in the circuit.  The 5088's arguably give a more modern sound to the unit.  Either way, these compressors undeniably sound like 1176's.  These things are so versatile because they can be used favorably on anything from lead vocals to drums.  If anyone is interested in me building them a clone please contact me.  I will be putting up sound samples very soon.

More pics here on my flickr

Hairball Audio 

mnats page

The MNATS pcb's

Just a bunch of parts

Pots

The main PCB

Wiring the power section

A work in progress

XLR in/out and the output transformer

All buttoned up

It's alive!

I even installed the sexy red light above the meter like the original blue stripes