First of all, I would like to direct you to a comprehensive discussion of Compression/Limiting located on the Harmony Central Web site at: http://www.harmony-central.com/Effects/Articles/Compression/.
It does a great job of explaining the purpose and mechanics of compressors, and will be a good primer for exploring the Keeley unit described here.

More info from Robert Keeley can be found by clicking here.
 
 

Like many things these days, I first became aware of Robert Keeley and his products through the Internet and some message forums.  I had been hearing good things about a compressor pedal he makes based on the old-style Ross Compressor.  The Internet is a source for a lot of great knowledge, but the advantages of giving everyone such easy access to having a published voice can also be perilous to those seeking reliable information.  It's very common to find "Pedal of the Day" ravings by guitarists thinking they've found the next big thing.  One person says "You've gotta try this, it's the greatest pedal ever made" and it starts a chain reaction of people blindly flocking to buy more "toys."

I always try to keep this in mind before I succumb to my own impulsive urges to find the holy grail of gear that will bring me total musical bliss (as if that's even possible).  The preliminary reviews I saw on the Keeley Compressor were excellent and it was hard to find anyone who was disappointed with the pedal.  After directing a friend of mine to Robert's Web site, I was pleased to find that he ordered and received a unit that I could audition first-hand before actually buying one myself.
 
 

To be honest, I don't normally use compression on my guitar signal unless perhaps I'm in a recording studio and want to get a little more sustain and "cluck" out of it.  My most common application for a compressor pedal is when I'm trying to play what I refer to as the "Nashville/Bakersfield Telecaster Twang" style of guitar or what others commonly call "chicken-pickin'."  Compressors are ideal for getting a clipped type of tone commonly used in funk and other percussive styles.  A good compressor pedal can help add definition to the tone, while improving the feel conducive to nailing lightning-fast runs with even dynamics.  I sometimes use a compressor in conjunction with an overdrive or distortion; but compressors tend to be so noisy that they are even louder with a gain box involved.

My friend brought his Keeley Compressor over one night with his mid-60's Fender Vibrolux Reverb amps (one of the finest examples I've played) and gave me a great opportunity to get some initial impressions of the box.  I was immediately struck by how much quieter the Keeley was than my MXR Dyna-Comp .  The compact nature of the Keeley was also right in line with the MXR, so that was a good thing as far as pedalboard space was concerned.

I was suitably inspired to get one from Robert and received it exactly four weeks to the day after placing my order.  Not bad, considering that he forewarned of a 6 to 8 week turnaround time on his site at the time I ordered it.

Now that I've had some time to spend with my own Keeley Compressor, let's take a better look at the unit.....

Here are some convenient links to points in this article or you may view everything in order by simply scrolling down the page:
 
 

Here is the owner's manual in Robert Keeley's own words...

Thanks for your purchase of the finest hand built compressor on the market today.  I truly believe every attempt was made to improve upon the design of the famous Ross while keeping the structure of the design identical.  The Keeley Compressor uses precision resistors to keep the sound quality as close as possible to the original engineer's intent.  It also uses film capacitors where harsh sounding ceramic capacitors were used in the original for cost cutting measures.  Film capacitors are used in the audio circuits of many high-end components because of their ability to recreate the fine details of music.  Tantalum capacitors are used for filtering and stabilizing as they were in the gray model.  Your Keeley Compressor has two significant features over the Ross.  First, it has a true bypass switch, the Fulltone 3PDT.  This expensive choice was made to ensure that you had no tone loss when the effect is off.  The original had a problem with weakening your signal even when the effect was off.  Not true with the Keeley Compressor.  You will still be able to use it in the bypass mode even when the battery goes dead.  Try that with any of your other effects!  Second, there is an effect LED that lets you know when it is on or off.  The original design did not have that.  I hope you enjoy the features and the thought put into your new compressor.

IN-     This is the standard location for your guitar cord.  It is possible to connect this pedal to the output of your overdrive/distortion pedal.  I think it sounds best if you go from your guitar into a tube-sounding distortion and then into the compressor.  Experiment and find out what variation gives you the tone or effect your are looking for.  Make sure to unplug this jack when not in use.  The circuit and battery are active until your cord is unplugged from this jack.

OUT-     Connect this to the input of your amplifier.  It is also possible to send this output to a variety of other effects.  It is generally accepted that an overdrive/distortion unit goes after a compressor.  Please experiment with effect placement in your signal chain to find the sound that defines your playing.  Again, I like the compressor after the overdrive.
 

S. = Sustain-     This is the most important feature of this pedal.  You can use this control to give a sustain effect with almost no increase in noise or high frequency loss.  This is true with the control in the 9 o'clock position.  This is a great place to start experimenting if you want to run the compressor all of the time as a tone shaper.  You can get a nice, full effect if you run this control in the 12 o'clock position.  I like this position for lead playing.  It brings out the note detail.  It is also great for country or funk style playing.  It compresses the notes you may play too loud and expands the notes you play too softly.  If you run the control to the 3 o'clock position or greater, you can get a radical sustain effect.  Although this position does have some slight increased noise, it allows you to get feedback on demand.  It is truly impressive to get a nice, singing feedback at low playing levels.  Again, this setting is great for lead playing.  Noise you may hear at the far extreme of the control is not a dirty control, but rather, the ability for the Keeley Compressor to amplify all the way down to DC level signals!
 

L. =  Level-     Use this control to match the bypass mode signal with the effected signal.  You can also use this as a volume boost during solos.  It provides the ability to overdrive your amp if you choose.
 

Warranty-     Your pedal is warranteed against defects for one year.  Parts and labor to repair the unit will be covered during the warranty period.  Parts that the warranty covers include transistors, IC's, and other electronic components that may become defective.  Shipping is the responsibility of the owner.  The warranty does not cover knobs that are broken or other parts that are abused.  Please take the time to make sure the jacks are tight.  Don't forget, pedals need maintenance too.  If your pedal ever becomes defective after the warranty period, please send it back for proper repair.

Robert Keeley BSEE
http://www.robertkeeley.com
 

The first thing I noticed about the Keeley Compressor was its compact size.  You won't find too many boxes with a smaller footprint, yet it is large enough to easily make positive contact with on the floor.  You can see from the pictures above and below that it is considerably smaller than a BOSS pedal.  BOSS pedals are fairly compact themselves.  The other thing I like about the Keeley is the simple yet professional looking cosmetics.  No silly graphics or crazy logos:  just a classy industrial look that gets to the point quickly.  Other pedal manufacturers should take a cue from the easy-to-read layout.
 
 

Keeley offers a few upcharge options on the Compressor.  The buyer can choose a standard red LED status light or upgrade to a brilliant blue LED.  A jack for an external power supply (compatible w/ BOSS and Ibanez units) is also available, though Keeley says the unit should run for an amazing 4-6 months with heavy usage from a 9-volt battery.
 
 

Build-quality on the pedal is superb.  Following the trend of several modern boutique amp manufacturers, Keeley has seemingly "over-built" this unit, which should result in very reliable and toneful performance.  The heavy-duty aluminum chassis feels as if it could take a beating.  Robert says he tests the units under fairly hard conditions before they leave for shipment.  The wiring and circuit board are extremely clean and clutter-free.
 
 

I must confess that it is pretty hard for me to get excited about a compressor pedal.  Don't mistake me for someone who doesn't find utility in them, because I have used different ones on numerous occasions with desired results.  Of all the effects available to guitarists, compressors tend to be less dramatic unless they are being used to heavily squash and clip the signal.  The traditional curse of compressors has been their noisy nature and most units are only happy when placed before an overdrive circuit, that is if a distorted sound is desired.

If I had to pick two words to describe the Keeley Compressor, they would be "sweet" and "transparent".  This pedal "gets out of the way" of the player and that is a good thing.  While I do think transparency is sometimes given too much emphasis in the world of effects (after all, an effect is supposed to affect the signal), the ideal compressor should be transparent and relatively quiet.  The Keeley excels in these areas.  While the guitarist can tell if the pedal is on  (there is an ever-so-slight "sweetening" of the sound and an increase in warmth when engaged), the Keeley Comp still lets the true tone of the instrument shine through with clarity.  It is also one of, if not the quietest compressor pedals I've ever played when the sustain is set for maximum squash.  Compressors are notorious for the amount of noise they inject into the signal chain (this is why "threshold" controls or noise gates are found in some models...usually rack units)  The Keeley is a standard bearer for quiet operation.

As you will note on the audio files below, there are some settings on the unit where the listener might have a hard time telling if the effect is even engaged.  Rather, the player is the one who might be able to notice the greatest difference with the compressor on.  The notes sustain and "bloom" according to the guitarist's attack.  The lower sustain settings on the Keeley are great examples of an effect that is more easily felt than heard.  When the unit is on, it helps me to play things a bit differently than when it's off.  Certain riffs, especially faster ones, are executed with more consistency in attack and level.  The sound is so unobtrusive that it helps the pedal's ability to be used as a clean boost.  Simply keep the sustain knob between 9:00 and 12:00, then set the level knob for the desired amount of volume boost.

The sustain knob provides a very moderate and nice reduction (compression) of notes that are struck hard while lifting those with less attack up until settings are dialed as high as 3:00.  Chords seem to sound richer and ring out with more detail.  Once the sustain control is dialed above 3:00, the famous squashing effect native to compressors begins to become more pronounced and thankfully retains excellent musicality.  I find the most usable settings for maximum compression with minimal noise are turning the sustain knob between 3:00 and 5:00.  Unity gain is achieved at these settings with the level control around 11:00.  Moving the sustain any higher will result in more noise, though Robert says:  "Noise you may hear at the far extreme of the control is not a dirty control, but rather, the ability for the Keeley Compressor to amplify all the way down to DC level signals!"

One interesting note is that Keeley recommends placing overdrives and distortion boxes before this compressor.  Most manufacturers recommend the opposite for their products.  While the difference is subtle, I was pleasantly surprised to find that I did indeed prefer the Keeley post-distortion.  It seemed as if there was more clarity to the tone and slightly less harshness compared to running the compressor first in the chain.

Robert Keeley is currently offering a modification to the BOSS Blues Driver (BD-2) pedal.  Having been a dedicated user of the BD-2 since its introduction, I was very pleased to learn that someone was turning their attention to refining what I think is an overlooked gem among overdrive boxes.  In my opinion, the Keeley-modified BD-2 has a smoother top-end and more focused bottom-end than my stock Blues Drivers.  For the sound files demonstrating compression with overdrive, I was able to use the modified BD-2.

I did encounter a noticeable "click" during activation of the compressor pedal, however this seems to be a normal attribute of this type of switch and is in no way unmanageable.  It is very high-quality, nonetheless, and the unit is true-bypass, which many tone aficionados seem to require these days.
 

The following sound samples were recorded by Jason Barker using a Don Grosh Electratone guitar w/ 2 Kent Armstrong P-90 pickups through a Keeley-modified BOSS Blues Driver & Keeley Compressor straight into a Carr Rambler amp.  They were recorded with a close-miked Shure SM-57 and fed to an Alesis ADAT XT-20.  There is no noise gating or suppression of any kind on these files, nor are there any other effects involved except for a little amp reverb.

SETTINGS	MP3 SOUND FILES
---	Introductory Comments
Sustain-    9:00       Level-    11:00	noise test single note sustain test single chord sustain test improvised playing comparison
Sustain-    9:00       Level-      3:00	improvised playing comparison
Sustain-  12:00    Level-    12:00	improvised playing comparison
Sustain-  12:00    Level-      3:00	improvised playing comparison
---	Comments on Transparency & Feel
Sustain-    3:00       Level-    11:00	comments & improvised comparison
Sustain-   5:00    Level-    11:00	noise test pedal steel riff comparison funky compressed improvisation BOSS Blues Driver demo w/ compressor
Sustain-  12:00   Level-    12:00	BOSS Blues Driver w/ compressor noise test BOSS Blues Driver w/ compressor improvisation

 

As I look back on what I've typed here, I am thinking "Man, I sure wrote a lot about a simple little compressor box."  The fact is that the Keeley Compressor is such a wonderfully-executed unit that you would be hard-pressed to find a simpler or quieter pedal compressor.  It doesn't seem to favor one type of guitar or pickup over another.  While the Keeley is fairly expensive, keep in mind that you are getting exceptional quality and outstanding customer service.  From my dealings with Robert Keeley, I have found him to be very personable and responsive to e-mails.

I believe that he did not expect the demand for his compressor that currently exists, therefore you can expect a bit of a wait to receive one.  He is very concerned about maintaining quality control standards, which bodes well for the consistency of his products.

I have not played every boutique compressor currently available, so I cannot authoritatively comment on them at the present time.  However, I just can't envision anyone being able to surpass the Keeley.  How can you top quiet operation in a hand-crafted compact unit with warm, clear and sweet tones?  The Keeley is absolutely elite and a pure joy to use!
 

For purchasing information contact Robert Keeley at:  audio6L6@aol.com

or

Visit his Web site at:  www.robertkeeley.com