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Keeley C4 Compressor

^# 6

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$65.00 Price Tier: High-end

4.5 (56)

12 Reviews

This product is Vintage or Discontinued

Newer option

Keeley Compressor Plus

$142.50 - $309.00

4.5 (62)

Find out who is using Keeley C4

10 community setups

Featured in

Best Compressor Pedals for Guitar

18 wishlisted

113 saved

Page last updated Jul 03, 2026

Pricing and availability

We compare 600+ stores and found this item at 1 store. Prices updated July 3, 2026.

Store

Reviews

Price

5.0 (48)

$65.00 29 available Used

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Average Price: $301

High-end/Boutique

$50

$201+

Price Tier

In the Compressor Effects Pedals category, Keeley C4 Compressor is priced in the High-end/Boutique range. This premium gear is built to very high standards and offers premium features.

Budget

Standard

High-end

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Description

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The Keeley C4 4-Knob Compressor is a perfect blend of precision and control, designed to elevate your sound to new heights. Crafted with the same high-quality metal film capacitors and precisely matched transistors as its two-knob counterpart, this pedal offers a higher level of customization with the addition of attack speed and input gain knobs. The added controls enable on-the-fly adjustments, allowing you to effortlessly transition from perfect, squishy funk tones to Gilmour-esque territory. The Keeley C4 is not just an effect pedal, it's a passport to uncharted sonic landscapes.

Key Features:

High-quality metal film capacitors and precisely matched transistors
Addition of attack speed and input gain knobs for enhanced customization
Allows for on-the-fly adjustments, perfect for mid-gig transitions
Capable of producing a wide range of tones, from squishy funk to Gilmour-esque sounds
Masterfully designed for controlled, precision compression

Product specs

Brand	Keeley
Model	C4 4-Knob Compressor
Finish	Custom, Silver
Year	2010s
Made In	United States
Categories	Compressor Pedals
Pedal Format	Standard

FAQs

What are the main controls on the Keeley C4 Compressor?: The Keeley C4 Compressor features four main controls: Sustain, Level, Attack, and Clipping. These allow for precise adjustments to compression characteristics, output level, and tonal shaping.
Is the Keeley C4 Compressor suitable for both guitar and bass?: Yes, the Keeley C4 Compressor is designed to work well with both electric guitars and basses, offering smooth compression and sustain enhancement for both instruments.
What kind of power supply does the Keeley C4 Compressor require?: The Keeley C4 Compressor requires a standard 9V DC power supply, which is common among guitar pedals, making it easy to integrate into most pedalboards.
How does the Keeley C4 Compressor differ from other Keeley compressor models?: The Keeley C4 Compressor offers a four-knob configuration for more detailed control over compression parameters, providing a more customizable compression experience compared to simpler models.
Does the Keeley C4 Compressor maintain tone transparency?: Yes, the Keeley C4 Compressor is known for its ability to provide compression without significantly altering the natural tone of your instrument, maintaining transparency and clarity.

Videos

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ProGuitarShopDemos

Keeley Compressor Pedal 4 Knob

ProGuitarShopDemos

Keeley 4 Knob Compressor Pedal Review by Sweetwater

Sweetwater

Keeley 4 Knob Compressor | Reverb Demo Video

Reverb

Keeley C4 Compressor in 100 Seconds

docSanchezFX

Keeley Electronics - C4 Compressor

Keeley Electronics

Keep or Sell? Keeley C4 Compressor (4 Knob)

Middle Aged Gear Junkie

Origin Effect Cali76 vs Keeley C4 Compressor

shnobel

Keeley Compressor C4 vs CMAT Mods Signa Comp

shnobel

Reviews

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PROS

Preserves original instrument's frequency spectrum while taming dynamics
Transparent sound, does not color tone
Four knobs allow detailed tone shaping
Solid build quality
Can be used like a preamp to even out high/lows
Works well with both guitar and bass
Enhances sustain without overly compressing tone
Low noise operation even on high settings
Complements overdrive pedals well
Adds clarity and warmth to tone

CONS

Controls may not be intuitive for all users
Possible reliability issues with older units (e.g., loose input/output jack screws, scratchy pots)
Clipping knob may darken tone for some setups

Owner Insights

We analyzed real musician discussions from forums and Reddit to find what players love, question, and tweak about Keeley C4 Compressor.

Features and functionality

0 0

The mislabeled "attack" knob actually controls the release time, affecting how quickly the compressor stops compressing after the initial note attack.
Source
0 0

The switch placement on the Keeley 4 Knob is noted as too close to the knobs, which can be inconvenient for some users.
Source

Comparisons

0 0

Unlike the Dyna Comp Mini and Deluxe, the C4's circuit design does not allow for true adjustable attack control due to its non-linear attack curve.
Source
0 0

Some users prefer the Joyo Scylla compressor over the Keeley C4 for bass due to concerns about the Keeley cutting low end frequencies.
Source
0 0

Some users prefer the Wampler compressor over the Keeley 4 Knob for better overall performance and satisfaction.
Source
0 0

The Barber Tone Press is favored by some for its ability to blend compressed and dry signals, offering more control over the compression effect.
Source

Use cases and applications

0 0

Users note that turning the knob towards "humbuckers" results in a more compressed, squashy sound, while "single coils" allows more pick attack to be retained.
Source
0 0

The Keeley C4 Compressor can be used with bass guitars, but may cause a slight roll-off in low frequencies, resulting in a more mid-forward sound.
Source

User experience

0 0

It's noted that while the Keeley C4 works with bass, it may not provide the transparency desired for all bass applications.
Source

Value and pricing

0 0

Used Keeley 4 Knob compressors typically run around $200, compared to the two-knob version at approximately $180.
Source

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4.5 out of 5

Based on 12 Reviews and 56 Ratings

5 star

4 star

3 star

2 star

1 star

alecani

2413

over 1 year ago

Great.

The compressor is one of those pedals that you shouldn't skimp on. This Keeley offers four pots for all sorts of adjustments. It is perfectly transparent and absolutely silent.

Roles:

Singer Guitarist Keyboardist

Genres:

Rock Blues Blues rock

From Gear Setup

guitarnerd

373

almost 9 years ago

Versatile compressor but not built like a tank (Updated on 13/11/17)

Primarily used with my active bass guitar. Love the transparency of this pedal. Versatile adjustments for fingerstyle and slap/pop. But the controls aren't intuitive. Finally got it to work after reading the user manual.

Revising this review to comment on the pedal's electronics build. I was disappointed to find this pedal suddenly dead in my rig. What happened was that the screws on the input/output jack was lose. After tightening the screws, the jack moved and i suspect the soldering joint got disconnected. My 2007 unit was having scratchy pots. You can take this review as a pinch of salt since mine is an old unit. Not sure whether improvements has been made to construction.

Roles:

Singer Guitarist Bassist

Genres:

Rock Pop Pop rock

blondguru

2065

over 8 years ago

First and Only Compressor

Needed a compressor, so I got the nicest one I could find. I don't use much compression, but when I do- this gets the job done well. With 4 knobs, it's not as simple as others on the market. Had to do a bit of experimenting before I could find what I liked.

Roles:

Guitarist Keyboardist Music Producer

Genres:

Rock Pop Alternative rock

From Gear Setup

ironmikenorton

127

about 9 years ago

Another great pedal...

I have been with Bob Keeley since he was just selling mods on Ebay. They take good care of me there. I only got this pedal because my gear was stolen outside of a show near Jacksonville, FL last year and my original 2 knob was taken. I'm still heartbroken over it

Anyway...I am a slide player, and for the way I use a compressor, this is simply the best one on the market.

Roles:

Singer Guitarist Music Producer

Genres:

Rock Folk, World, & Country Blues

jgalvanscp

153

about 10 years ago

Why didn't I get this sooner

This is my most recent pedal buy but Keeley made a great pedal here. It provides clear sustain that doesn't get in the way. I have it on all the time as a constant on my board now and it really gives my sound that freshly recorded clarity you would hear on your favorite tracks. GO GET THIS PEDAL

xaqary

5455

about 9 years ago

Killer pedal

I'm just gonna second the other reviews here. Only thing I'd add is I LOVE using the Keeley w/ an overdrive. Common set up here is the Keeley & the Electro-Harmonix Crayon overdrive.