Tube-Tech CL1B

The TUBE-TECH CL 1B is an all-tube optical mono compressor. 

It delivers a very musical and smooth compression, preserving the clarity of the source even at extreme settings, and this is where CL 1B really stands out compared to other compressors. Furthermore, the operation is very intuitive, enabling you to achieve your goal achieve your goal quickly and easily. 

The TUBE-TECH CL 1B Compressor features a gain-reduction element, positioned immediately after the input transformer. It is controlled by the sidechain amplifier, which also contain the two time control circuits - one for fixed and one for variable Attack/Release. 

The two time-controllers can either be used separately or combined. This circuit contains semiconductor OP-amps for the entire control. 

The gain-reduction element is followed by a tube-based push-pull amplifier with variable gain up to 30 dB. 

A dedicated Bus selector with three positions (Off, Bus 1, Bus 2) is used whenever you want to link several compressors together. Input and output transformers have a static-screen between the primary and secondary wirings. Both Input and Output are balanced as well as fully floating.

Urei 1176 "BlueStripe"

While the 1176 has seen a huge number of revisions in its history, the most significant revision to the 1176 circuit was designed by UREI engineer Brad Plunkett in an effort to reduce noise —
hence the birth of the 1176LN (LN stands for low noise) at revision C.
Numerous design changes followed, resulting in at least 13 revisions and variations on the 1176. Most units include the revision letter with the serial number. Revisions C, D and E (the first three with the LN circuit) are all very similar, and are historically the most beloved.

Revision A (AKA “Bluestripe”) 

Design Date: 6/20/67 

Serial Numbers: 101-125 

Faceplate is brushed aluminum with blue paint and red power light 

Original 1176 designed by Bill Putnam for broadcast use, class A design 

Signal Preamp: Used FET (field effect transistor) in a voltage divider configuration for gain reduction, a technological first 

Used FET as voltage variable resistor to control the gain 

Used ‘T-pad’ resistive attenuator to drop the input voltage 

Input Stage used a 600 ohm input transformer 

Used FET followed by bipolar transistor as preamp 

Output amp used essentially the same circuit as in the preamp, but followed with a 2N3053 operating in class A 

Output transformer was the UA-5002; this transformer has split secondary, tertiary winding for negative feedback, emitter winding; the design was basically that of the 1108 preamp 

A Weston meter is used

Gates Sta-Level Compressor

The Sta-Level dominated the sound of hit radio in the 1960’s.
The original 6386 compressor developed by G.E.,utilized a novel program controlled release circuit. 
The Sta-Level implementation creates density and consistency while minimizing typical compressor side-effects at up to 40dB of gain reduction! 
The program path is transformer balanced throughout to cancel control-induced distortion. Push pull circuitry with 6V6 output stage provides wide voltage swing for gain control and line output. The result is that the Sta-Level brings a uniquely familiar intimacy, air and warmth to your tracks.

Urei 1178

The Model 1178 is a two channel version of the very successful 1176LN Peak Limiter used in many recording studios, broadcast stations, sound reinforcement installations, etc. The Dual Peak Limiter was designed for those applications where two channels of program material are processed, and the balance of these audio channels must be maintained. The two limiters inside the Model 1178 are matched to assure the high degree of tracking necessary for critical stereo applications.

Single adjustments of attack and release time affect both channels simultaneously, while the input and output level controls are adjusted independently. In the stereo mode, a front panel switch allows the two limiters gain reduction amplifiers to be linked together such that the audio signal with the larger peak-to-peak amplitude causes the same amount of gain reduction in both channels. On the other hand, when switched to single mode operation, the two limiters process the signals independently. This provides the user with exceptional flexibility in operation.

The Model 1178 was designed to have performance characteristics similar to the single channel 1176LN. Limiting is accomplished by utilizing FET´s as voltage variable resistors. Unique circuitry permits severe limiting without added distortion and the compression ratio may be optimized for various program materials. The gain structure throughout the Model 1178 maintains an excellent signal-to-noise ratio at normally used control setting.

Dual, backlighted front panel meters may be switched to read either the amount of gain reduction, or the output signal level referenced to +4 dBm or +8 dBm. Also switch selectable are the meter reading characteristics: either indicating average signal (VU ballistics) or peak.

Altec 436

The 436 series of compressors were all-valve, vari-mu designs, meaning that the amount of compression taking place depends on the level of the signal that is fed in.
Early Altecs were inexpensive and basic; the original 436A model had fixed parameters and no user controls whatsoever. 1958 saw the release of the 436B, which featured an input gain control, then, a few years later, the 436C included threshold and release-time controls. These modifications came about as a result of Altec’s engineers discovering that the cheap 436s were being modified by studio engineers to make them more suitable for processing pop music in recording studios. 

The Altec 436Bs that EMI bought in 1959 (three years before The Beatles’ first sessions) were heavily modified to include an output attenuator and ‘recovery’ switch, which controlled the compression release-time. 
A unique feature of EMI’s six-position recovery switch was the Hold setting, which prevented a compressed signal from returning to its original level when in use.

SSL G Series Bus Compressor

Engineers have come to rely on this master compressor to "glue together" mixes like nothing else, as well as patching into it for wonderful results on drums, pianos and more. 

The G-Series Bus Compressor has a host of plugin emulations, some of them officially sanctioned, including one by Universal Audio, one by Waves and SSL’s own version.

1. Threshold sets the operating level for the knee of the compressor. 

Threshold is continuously adjustable from -15 dB to +15 dB. 

2. Make up Gain compensates for a change in signal level due to compressor activity. 

Make up is continuously variable from -5 dB to +15 dB. 

3. Attack controls the quickness of the compressor’s response to changes. 

Six switchable attack rates: 0.1; 0.3; 1; 3; 10 and 30 ms. 

4. The Release time of the master compressor is switchable between 0.1, 0.3, 0.6 and 

1.2 seconds, or to automatic. If Auto is selected, the release time is dependent 

upon the duration of the program peak. 

5. Ratio sets the ratio of signal level to signal gain, i.e., the compression ratio. 

Ratio can be switched between 2:1, 4:1 and 10:1.

Neve 32264

The 2264 and 32264 were derived from the 2262 which was Neve's attempt at competing with the Pye Compressor and would slot into a Pye slot in a rack.  

The first 2264 used the same steel metalwork as the 1073 but was changed to the familiar extruded top and bottom panels soon after.  

The difference between the 2264 and the 32264 is the paint colour, knobs and lower case lettering instead of upper case.  

"3" means new appearance design.

Neve 2264

Originally designed in 1974, the 2264 mono Limiter/Compressor quickly became a legend. 

Delivering similar facilities and performance as the earlier 2254 Limiter/Compressor type, it did so despite being packaged in a more compact form-factor. 

Discreet, Class A/B design and transformer-coupled circuits ­used in the input, innovative bridge-driver design, side-chain and output stages ensured a totally unique sound. 

The original 2264 units are still sought after, decades after production stopped, and they remain one of the milestone pieces of studio equipment.

dbx 160

The dbx 160 is a single-channel compressor/limiter. 

Circuit design such as true rms level-detection and feed-forward gain reduction places the 160 in a different class from the conventional compressor/limiter. 

"VU” is the common nickname for this highly regarded studio staple, famous for its simple control set and firm, distinct compression characteristics. 

The dbx 160 also has unique nonlinearities not found in other VCA compressors, giving it a sonic distinction from later models.

LA - 3A

The LA-3A Classic Audio Leveler made its debut at the 1969 NY AES show, and marked the departure from the tube design of the Teletronix LA-2A. The LA-3A incorporated components and design concepts from the Putnam-designed 1176LN Limiting Amplifier, giving the LA-3A its own distinctive sound.

The LA-3A became one of the signature sounds of 1970s rock and roll, adding just the right edge on electric guitars and handling vocals beautifully.

Neve 33609 / Metal Knobs

Derived from the original Neve 2254 compressor, circa 1969, the 33609 stereo bus compressor/limiter utilizes a bridged-diode gain reduction circuit and many custom transformers. 

The uniquely musical character of this circuit has made the 33609 a studio standard since its release.

The completely stepped-controlled 33609 is made up of separate compression and limiter sections, each with their own threshold, recovery and bypass controls. Two of the recovery selections for each section are dedicated to a program dependent auto release. The compressor section also offers five ratio selections and 20 dB make-up gain, while the limiter offers a fast or slow attack. The mono/stereo switch couples and decouples the left and right gain reduction elements.

NEVE 2254

The 2254 was designed in 1969, the original Neve 2254 mono Limiter/Compressor unit quickly became a legend.

Discrete, Class A design and transformer-coupled circuits – used in the input, innovative bridge-driver design, sidechain and output stages ensured a totally unique sound. 

The original 2254 units are still sought after, decades after production stopped, and they remain one of the milestone pieces of studio equipment.

LA-2A

The LA-2A Leveling Amplifier is an audio compressor invented by James F. Lawrence II, founder of the Teletronix Engineering Company in Pasadena, California in the early 1960s.
The LA-2A is a hand-wired, tube-based, compressor.
It uses an electro-luminescent panel together with a cadmium-sulfide light dependent resistor to provide gain reduction, which, in the LA-2A, is called the T4 cell. The properties of the T4 give the LA-2A its unique character by making it an entirely program dependent design. The attack time is 10 milliseconds and the release time is about 60 ms for 50% release and 0.5 to 5 seconds for full release, depending on the previous program material.
Three versions of the LA-2A were made until 1969.
The LA-2A was inducted into the TECnology Hall of Fame in 2004.

Urei 1176

The Urei 1176 was a major breakthrough in limiter technology. It brought to the professional audio industry for the first time a true peak limiter with all transistor circuitry and superior performance on all types of program material. The 1176LN retains all of the features of the 1176 but generates 6db less noise. In addition a redistribution of noise spectrum leaves even less noise in the sensitive 500hz to 3Khz range.
Since its introduction in 1968 the 1176 has become the industry leader.
The 1176LN will carry on that tradition with the following plus features:

FET Gain Reduction ahead of first stage. No tricky balancing required ever. No distortion adding element in gain reduction circuit.

Push button selection of four different compression ratios , to satisfy every program requirement.

ULTRA FAST attack time...... independent of the degree of limiting. Extremely stable operation.... no costly maintenance... no tubes to select or replace.

Stereo operation of two units easily accommodated, so speak in one channel causes equal limiting in both.

Contemporary styling ... eye pleasing industrial design.

Limiting is accomplished in the 1176LN by utilizing  a FET as a voltage variable resistor, ahed of the first stage of amplification. Unique circuitry permits severe limiting without added distortion, and no balancing is ever required. Attack time is adjustable from less than 20 microseconds to 800 microseconds. Using the tone burst method , a 50 kHz peak is fully stabilized at the limited level within one cycle. Release time is also adjustable on the front panel from 50ms to 1.1 seconds.

A feature of the 1176LN is the use of pushbutton switches to select compression ratios. 20:1,12:1, 8:1 or 4:1.
Another pushbutton switch assembly selects meter functions and applies power to the unit.
Provision is made for remote metering.

Chandler Limited TG1

The Chandler Limited TG1 is a recreation of the classic EMI TG12413 Limiter used in custom EMI and Abbey Road recording and mastering consoles from the late 60's. The TG Limiter was originally designed to be like the Fairchild 660/670 which was loved by many EMI engineers, including Geoff Emerick, but ended up with a very special sound all its own. These rare pieces were never commercially available and only EMI owned studios had access to them. Our version has been remade from the original design information and circuit board drawings as provided by Abbey Road and EMI to ensure extreme authenticity!  TG equipment was used on many classic records and this Limiter was featured on every channel of TG consoles used to record The Beatles "Abbey Road", several Pink Floyd records including "Dark Side of the Moon", Paul McCartney, and the Rolling Stones.  The Limiter/Compressor features an all discrete circuit with transformer balanced input and output. The limiting element is a rarely seen diode network that produces smooth, pleasing distortion. The warm open sound, often compared to a Fairchild 670 set to stun, is very audible and squishy sounding while maintaining its clarity and high frequency response.

The Fairchild Compressor/Limiter

The Fairchild is available in two versions. The 660 (mono) and the 670 (stereo).
Its design uses a single push pull stage of amplification, the result of this is a signal that has no distortion or noise under all conditions.

The attack time of the unit is extremely fast  - .50 microseconds (1/5000 of a second) and a release time of 3 to 25 seconds that provides real flexibility.

The unit can be used as a limiter or as a compressor.
A 2 to 1 ratio as a compressor or as a limiter with 30 to 1 ratio.
Of course you can operate it anywhere between these two.