The two-channel Chandler Limited | Zener Limiter is a recreation of the EMI TG12413 limiters found on vintage EMI mixing and mastering consoles, with enhanced attack and release features, plus a distortion generator function.
While remaining true to the sound of the vintage TG limiters built by EMI for Abbey Road Studios, the Chandler Zener Limiter adds new controls and features, including switchable input impedance for driving the unit soft or hard, sidechain filtering and more. The Chandler Zener Limiter not only emulates the slower response curves of the EMI-modified Altec 436 compressor (which became the RS124) and the faster ones of the Fairchild 660, but also a response curve unique to the Chandler limiter that's a combination of the two. The Chandler Zener Limiter also has a unique THD switch that disengages the limiter threshold allowing the signal to pass through the entire audio path and sidechain. The result is a smooth tape-like distortion with a high-frequency bump that gives a special presence to instruments and vocals, effectively bringing them forward in a mix without the phase anomalies caused by aggressive EQing. In dual-mono operation, you can run the Zener Limiter's channels in series, with one providing compression, while the other acts as a distortion generator. However you use it, the Chandler Zener Limiter sounds phenomenal on any source, adding generous helpings of vintage character and presence.
Chandler Limited EMI TG12413 Zener Limiter - Just the Facts :
- Two-channel limiter based on vintage EMI circuits
- THD switch generates smooth distortion with high-end presence bump
- Switchable input impedance for soft- or hard-driving the unit
- 11-position attack, 21-position release, side chain filtering, and Comp 1, Comp 2, and Limit settings
Chandler Zener Limiter - Under the Hood
Based on vintage circuits from the EMI RS tube and TG console limiters, the Chandler Limited Zener Limiter adds powerful features and flexibility to enhance the old designs for modern studio use. By way of a little electronic background, the Zener diode, for which the Chandler Limiter gets its name, was a new take on standard diodes, which only passed current in one direction with a drop in voltage. The Zener diode, depending on how it was biased, could pass current in reverse, once the “breakdown” voltage was reached. (Breakdown is the minimum reverse voltage that makes the diode conduct in reverse.) Zener diodes offer the advantage of being easier to match for symmetric clipping over a wide range of voltages than other types of diodes. This behavior is what makes the Zener Limiter such an effective tool for master bus compression.
Chandler Zener Limiter controls
The Zener has selectable input gain and input impedance which enables it to replicate different versions of the EMI RS168 and TG12413 limiters. The high gain setting is 12dB higher and is similar to the “Vanderlism” setting of the RS168 Zener prototype. The low gain is closer to the TG12345 console input but is still hotter than the unity gain input of the TG12413 mastering console version. Input impedance is 300 ohm in High and 1200 ohm in Low.
This is a 21-position gold contact audio taper switch that controls the level
going into the compressor/limiter. Simply turn it up to drive the unit into harder limiting.
THD (Total Harmonic Distortion)
The THD toggle on each channel disengages the limiter threshold so that
the channel will stop limiting but signal still runs through the entire audio path and sidechain. The effect is a smooth pleasing distortion with a high-frequency bump caused by the discrete amplifiers and Zener diode limiting circuit. The input switch drives the signal to more or less distortion. Interestingly the THD function takes a clean sine wave signal and gradually triangulates it as you increase the input control, but more importantly, does not clip the signal in any way. It's possible to drive the THD past the 2% marking on the front panel by increasing the signal into the Zener from an outside source.
At unity gain input with the Input switch on full, you'll get about 2% THD. If this is increased to +4-5dB, distortion will increase to around 5% without clipping, which is many times that of tape. One excellent use of this is to patch the two Zener channels in series, using the first to limit and the second for THD. You can then use the output control of the first channel to drive the second into higher THD percentages while lower the output of the second to control overall level. Very retro.
Another 21-position gold contact switch set for +/-10db of gain control in 1dB increments. Use this for makeup gain during hard limiting or to drive the Zener's second channel into a higher THD range.
Comp 1, Comp 2, Limit
Comp/Limit - is a very important control for tailoring the overall tone of the unit. Comp 1 is a 2:1 ratio with slower time constants that was originally designed by EMI engineers to emulate the Altec 436/RS 124 EMI modified Altec compressors. Limit is much faster and designed to emulate the response curves of the much-loved Fairchild 660. Comp 2 is a new setting designed to put you halfway between the two original settings and essentially gives you the compression curve of Comp 1 with faster release times similar to Limit.
Sidechain filtering was added to the Zener for ultimate flexibility. In situations where a TG1 compressor may be too aggressive, the sidechain, combined with other Zener modifications, makes this new TG useable in nearly every situation. With this control, you can prevent low-frequency information between 30Hz to 300HZ from feeding the limiting circuit. It's very effective when you need more gentle compression or limiting action while maintaining that special TG sound. Excellent for mixes, subgroups, bass, and even hard slamming kick drums. (You need to try this!)
The attack control combined with the sidechain filter is the heart of the Zener's flexibility. The RS168 and all TG versions of the limiter had preset attack times until now. On the front panel, you'll notice that setting 2 in white is the original attack time, while the remaining settings are new additions. Since the attack times were generally quite quick, especially in Limit mode, most settings are slower. These are extremely effective on drums and bass when combined with sidechain filter.
A special feature of all EMI Limiters from the RS114 tube limiter, RS124/Altec compressor, RS168 Zener prototype, TG12345 console limiter, and TG12413 mastering limiter was that they all shared a special set of six release times. This is a very important part of the EMI and TG sound. The Zener preserves these settings in all their glory but also greatly expands on them adding further to the flexibility and tonal character. The new release control is 21 positions with the original 1-6 release times marked in white with parentheses.
As with the previous versions of the TG Limiter, the Link system is relatively primitive. To link channels, you must not only set the Link control to stereo but also set the controls on each channel to match settings. Since all controls on the Zener are stepped with high-quality resistors, matching channels for stereo use is very easy.
Zener Limiter origin story
The EMI TG12413 Zener Limiter is the ultimate TG limiter issued in celebration of the 75th birthday of Abbey Road Studios. The TG12413 Zener Limiter was conceived by Chandler Limited designer Wade Goeke and is based on the vintage EMI circuits used to record The Beatles and Pink Floyd. It continues the tradition of EMI Limiters started in 1954 with the RS114 tube limiter and the 1968 RS168 Zener Limiter. The Zener Limiters were also part of the 1969 TG12345 console channel and the 1974 TG12413. This newest version borrows from the RS168 Zener Limiter and TG12345 console strip to make a new full-featured and flexible unit for modern use.
What the pros are saying about the Zener Limiter
Just plugged in my new Zener compressor AND HOLY F@*K........HOOOOOLY FFFFFFFFFF@*K. 'Nuff said. - Greg Wells (Deftones, Mika, Pink, Rufus Wainwright)
I have used Chandler Zener and TG compressors on every album I've done since they've been made. I think I can honestly say about half the guitars I've ever done have been TG preamps. These would include drums and guitars on albums for The Shins, The White Stripes, The Strokes, The Raconteurs, Manchester Orchestra, Stars, Alanis Morrisette, Jason Mraz, U2, Elton John, Beck, etc. Pretty much every album I've been a part of for the last ten years or more has had Chandler gear on it. That would include TG Preamps and EQ. Zener, Germanium and TG compressors. - Joe Chiccarelli
Chandler Limited Zener Limiter heard on:
Beyoncé - Lemonade
Curve Bender EQ (Mix Bus), RS124 Compressor, Zener Limiter, TG1 Limiter, Mini Rack Mixer (Tony Maserati)
Beyoncé - 4
Selected tracks mixed through Mini Rack Mixer, and Curve Bender. Vocal through Zener Limiter. (Tony Maserati)
Courtney Love - “You Know My Name / Wedding Day”�
TG2-500 Pre Amp (Bass Guitar), Germ 500 MKII Pre Amp (Bass Guitar), Curve Bender (Drums - Kick), Zener Limiter (Drums - RM), TG Channel MKII (Drums - OH, Guitars), GAV19T Guitar Amplifier (Guitars), Little Devil Pre Amp & Little Devil EQ (Guitars & GTR Synth DI) - Michael Beinhorn
Jason Mraz - “93 Million Miles”�
From the Grammy-nominated album, Love Is a Four Letter Word
Zener Limiter: Lead Vocal, Acoustic Guitar
TG1 Limiter: Drum Room (Tony Maserati)
Lady Gaga - Born This Way
Selected tracks mixed through Mini Rack Mixer and Curve Bender. Vocal through Zener Limiter (Tony Maserati)
Robin Thicke - Blurred Lines
Mini Rack Mixer (Drums), TG1 Limiter (Vocal Verses), Zener Limiter (Vocal Hooks), Curve Bender (Mix Bus) - Tony Maserati
Sam Smith - “In The Lonely Hour”�
Curve Bender, Zener Limiter (Mix Bus), TG1 Limiter (Drums)
The Beatles - Love
Curve Bender, Zener Limiter, TG1 Limiter
The Strokes - Pink Martini
TG2, TG1, Curve Bender, Zener Limiter, Germanium compressor
White Stripes - Icky Thump
TG2, TG1, Zener Limiter, Germanium Compressor, Curve Bender (Joe Chiccarelli)
If you've been trying to decide which compressor/limiter to put on your 2-bus for maximum flexibility, character, and classic sound, Chandler Limiter has your answer: The EMI 12413 Zener Limiter. For more information, call or chat online with your PAD Studio Specialist - or order yours today.
- Channels: Stereo/dual mono
- Circuit: Discrete, transistor
- I/O: XLR
- All connections transformer balanced pin 2 hot
- POWER: ±28V
- Requires Chandler Limited PSU-1 MKII Power Supply. The PSU-1 Has An Internal Switch For Setting Voltage To 120V Or 220V (115V/230V)