MARQUETTE AUDIO LABS

* Since 1994 *

Manley Slam Stereo Limiter / Mic Pre


SLAM! stands for "Stereo Limiter And Micpre" and it pretty much describes what it will do to most VU meters. Manley had to put a switch on this limiter to drop its internal VU meters down 3 & 6dB to keep the poor little needles from bending- it'll get LOUD fast (hence the exclamation mark). And on top of being an amazing pair of (actually four) Limiters, and Class A tube mic preamps, it also has masters degrees in DI, AtoD and DtoA, VU and PPM but that was too much for an acronym.

When it comes to classic gear, especially classic limiters, we can all agree numbers like LA2s, 1176s, 2264s, and others come to mind. What if all those sounds were to be found in one stereo tube unit. Interested? Manley combined their favorite Electro-Optical circuit (ELOP®) with a damn fast FET based brick-wall limiter reminiscent of some cool classics. And they added a sidechain filter that can remove low frequencies that makes it more useful for a variety of tasks, while retaining that easy, "it just works" quality that has made it a favorite for vocals everywhere. The FET-based limiter has different desirable characteristics that both optimise the signal for digital recording, due to the brick-wall capability, and let you dial in how clean or crunchy, or punchy, and how loud and proud you want it.

The SLAM! starts with tube Mic Preamps on both channels with switchable phantom power and phase reverse. There's plenty of gain for you in this new tube circuit, up to 60dB with 20dB more in the limiter- plenty for soft singers using low output ribbon mics. The input attenuator is right up front, like a variable pad so your loud rock 'n' rollers won't cause a problem either. Track direct with the Direct Instrument input or bring your line level inputs into the SLAM! for processing.

Got some Digital to deal with? No problem. There is a slot in the back for our optional 24 Bit/96KHz Analog to Digital converter and 24 Bit/192KHz Digital to Analog converter card. This allows you to record directly to your computer or workstation and provides a convenient way to use a digital insert to jump into the analog realm and back. An AES digital input receives your stereo digital signal to convert to analog for processing by the SLAM! when the DAC input is selected. Or just take advantage of this killer DAC and use the DAC Output for monitoring, listening, or to go out to some other analog processors or tape machines.

Get it LOUD... two different and distinct limiters per channel:

The ELOP® LIMITER: The Electro-Optical Levelling Amplifier circuit, the ELOP®, still the favorite for vocal tracking, shows up here with its new switchable side-chain high pass filter making it much more useful for mixes and other tracks as well. One of the most appreciated aspects of our original ELOP® is the simplicity of a two knob limiter, which is optimum for demanding pro recording pressures. You can still grab two knobs and have complete control of level and dynamics and be ready to hit that record button. Intuitive controls and a straight ahead signal path through quality components simply works.

The FET LIMITER: Here's a new fast FET based "brick wall" limiter that spans the range of clean predictable limiting to the grunge and gravel that other FET based limiters are desired for. The FET RELEASE control allows you to dial up a variety of colors. There is even a "CLIP" setting that provides as round a shape as has ever been available. We aimed at "sound" first, then experimented with circuits until we heard what we wanted discovering fresh approaches that provide a very wide range of useful dynamic control. For example, you can set up for a fast brick wall limiter with slower releases for minimum artifacts, or go with the faster releases to get some crunch and then get extreme loudness. The Attack control is unusual too providing the sonic control common with its historic brothers but very unusually retaining the zero overshoot "none-shall-pass" brick wall that defines a real limiter. And it's punchy! As the saying goes, "Louder is better." The SLAM! optimizes levels to analog to digital converters with ballz, warmth and loudness verging on silly or just clean and safe.

What is especially nifty is the ability to use the ELOP® and FET limiters together at the same time dialing in whatever amounts of each effect you like. Every limiter has its own character or sound and here Manley has combined two powerful world-class tools that can be uniquely blended and mixed to taste and purpose. Even the metering is appropriate for each limiter so you can easily see how each is contributing.

Metering on the SLAM! is exceptional. The two full size real VU meters show you the raw input levels, the final output levels, and the ELOP® Limiter gain reduction in the traditionally preferred format for visually displaying apparent loudness. VU's are cool. Noticing how mastering engineers often need a switchable pad on their VU's because the "optimised" levels tend to pin the needles in the red, the SLAM! VU's also have a 0, -3dB, -6dB switch to help with this situation. There are also very fast and super accurate multi-color LED ladder peak meters that display the input and output levels and the FET gain reduction, and some combinations. They will do Peak, Peak Hold timed, and Peak Hold until reset, and also allow you to manually set where the individual bars change colors to match your other gear. And with maximum clean I/O levels of +30 dBu, it is a lot more likely you will use these meters to see what's clipping downstream. It probably won't be the Manley tube line drivers inside!

The back panel should keep everybody happy. All the usual XLR's for transformer balanced I/O and 1/4" phone jacks for direct unbalanced I/O. There are four TRS jacks for inserting external EQ into the sidechains and another connector for linking multiple units for surround. It's all here. The optional 24 bit converters are a brand new design that insures the lowest possible conversion jitter even with questionable sources. It will lock to an external clock via the digital input and is 44.1, 48, 88.2, 96, and 192KHz capable. The DAC output is always available. There is even a twisted way to patch the SLAM! so that you can have the MIC PRE/ELOP feeding an EQ, (or some other thing), returning back to the SLAM!, feeding the FET LIMITER side chain and the A to D converter.

The SLAM! also seems a natural as a mastering tool. The FET limiter works great on mixes, and the ELOP® now has a high pass filter switch that is spot-on for mastering. There's also a new mastering version which eliminates the mic preamps, adds detented controls replacing the pots, and provides extra metering options.

Designer's notes:

There have been a few changes to the SLAM! since the brochure was printed. The SLAM! was in the 'planning stage' when we wrote the brochure. Nothing removed; "more & better" added.

The SOURCE selections have been changed. We moved the PHANTOM POWER switch to the back panel, so that we could add a High Pass Filter for the mic input on one setting and separate the DI (Instrument) input from the DAC. The Phantom switch on the back also removes the likelihood of big pops, which were possible with it being on the SOURCE switch.

The ELOP® limiter now works like our VOXBOX® which pioneered the idea of limiting the mic signal before it hits any active stage. The ELOP moves to the line stage when LINE or DAC is selected. The ELOP sidechain allows 3 different HP filters on a toggle. The 200 Hz setting has been tailored for vocals and adds a touch of de-essing.

The Power Switch is now a lit EAO button. The big change is the decision to make the Power Supply an external unit. This removes some heat and magnetic fields from the main box. The new Power Supply is in a 7" x 4" x 5" box that is easy to mount or place in the bottom of a rack. A seriously humongous 16 pin connector, and 6' cable connects the two boxes.

The back panel has seen the most changes and now has 22 jacks including the big power supply connector. There are now 8 Bantam jacks in a mini-patchbay that handle the side-chain inserts and linking functions. You can insert EQs into the ELOP® Limiters, FET limiters, and there are more jacks to mix in an external signal to the side chains. There is a pair of jacks that allow easy linking for 5.1, if you have 3 or 4 SLAM!'s. Speaking of Linking, all previous Manley compressor limiters, require both channels to be set-up for near identical settings rather than the more common "just set the Left side". The SLAM! allows both methods. The "L Side" method is the "STEREO LINK" mode and is quick and convenient but, like others, uses a mono mix for the side-chain. The "BOTH & EXT" adds the rear panel link jacks which allows 5.1. Both or all 6 channels should be set similarly. This mode is usually better for mastering as it responds to the true peak level of the channels rather than an artificial mono mix.

The digital inputs and outputs are now XLR for AES/EBU standards and we added a BNC for Word Clock and Super Clock input. The BNC was added for your convenience and not because it will help this unit's jitter performance. The jitter spec is "Almost Zero" and probably unmeasurable regardless of whether it is locked to its own crystal, the AES input, or the Word/Super Clock. A 7-way rotary switch selects 44.1, 48, 88.2 or 96K, AES IN, Word Clock and Super Clock, for the AES output data rate. Notice we didn't say "sample rate". This ADC and DAC always use the internal 192K sample rate! Truly amazing sample rate converters based on SHARC DSPs are used to almost eliminate (not just reduce) jitter and provide the sonic benefits of 192K sampling, even at 48K or 44.1 data rates. These are very fast exceptional sounding world-class converters.

The ADC also has a pair of switches for DITHER and NOISE SHAPING and WORD LENGTH, plus something unusual: a filter select switch. We believe that the manufacturer's choice of filter is one of the biggest differences that affect the sound of a converter, so we give you 3 choices, 80K minimal effect, 20K Analog, (a passive filter similar to the 18K on the Massivo), and a 20K Digital FIR for something comparable to other converters. We also have 3 filters on the DAC side set for 20K, 40K gentle, and 80K. All of these are passive and quite subtle and useful. There is a dedicated balanced +4 phone jack output for the DAC, so these can be tube-converters or high end solid state. The ADC is similar, but tube or passive(!) front end, that allows a mastering EQ to be cleverly used in this chain.

The DI or Instrument input is a 1/4' jack also has a new twist. With a 1/4" plug in all the way, the input impedance is 100K, pulled out 1/2 way becomes 20 meg which reduces pickup loading and allows all the highs to get through. Lots of gain too. By the way, the tube circuits in the SLAM! are brand new designs similar to the ones first used in the Manley Steelhead phono stage, which is getting incredible reviews. This circuit allows high gain, very low noise and distortion and without resorting to negative feedback. The all-new "Manley Sound" and feature list.

The SLAM! represents the most elaborate and ambitious product ever from MANLEY, with 4 super-limiters, state of the art digital converters & metering, & tube circuit design, and a loaded back panel. Whether used as a pro front end, analog insert in a digital world, or just for outboard limiting, this box sets the new standard.

W.C. Hutchison
Chief Designer
Manley Laboratories


Features & Specifications

  • Input Tubes: 2 x 12AT7A NOS GE specially selected by Manley Labs for lo-noise and stable bias
  • Output Tubes: 2 x 6414W NOS USA dual triodes
  • MANLEY transformer coupled Balanced Inputs and Outputs
  • Micpre: Selectable 48V phantom power and PHASE REVERSE
  • Gain: 60dB max Micpre, 43dB max DI, 20dB max Limiter Gain
  • Input Impedance: 2000Ω Micpre, 1MegΩ DI
  • FET Attack approx. 100uS; Release 10mS to 2Sec; Ratio: better than 20:1
  • ELOP Attack approx. 10mS for 6dB GR; Release 2.5 Sec; Ratio: 10:1
  • AES 24Bit 192KHz upsampling from 44.1, 48, 88.2, & 96KHz
  • A to D 24Bit 96KHz (for now)
  • Frequency Response: 5Hz to 60KHz
  • Maximum Output : +32dBm, +30dBm (into 1KΩ load)
  • THD+N <.05% @ 1KHz Dynamic Range: 115dB typical
  • Output Impedance: 200Ω
  • Power Consumption (120/240 VAC): less than 100 watts
  • Size 19" X 12" X 3.5" (occupies 2u)
  • Shipping Weight: 25 lbs.


  • See also: SLAM! Mastering Version

    BASE UNIT ANALOG SLAM!: $6,600.00
    Digital I/O Interface option factory-installed: $2,500.00
    MASTERING VERSION SLAM! $7,600 USD more info
    Please call Dave at (510) 581-3817 for product information and your price.