The LaChapell Audio Model 992 is a two channel fully balanced all-tube preamplifier and instrument input amplifier. Meticulously hand assembled, every aspect of the 992 speaks of our dedication to quality of sound and solid, robust construction. With a total of eight vacuum tubes the 992 will awaken your ears with its warm melodic character and rich low-end response.
But, what makes the 992 such a powerful preamp is the level of control the user has over both the input and output stages. Allowing the user to actually throttle gain in or out of either the input stage (for loads of character) or the output stage (for a more clear, transparent response) by way of fully variable potentiometers secures the 992 as one of the most flexible vacuum tube preamps available in today’s market.
The Dual Drive knobs on the 992EG provide an incredible array of tonal options. The input knob drives the input to the first vacuum tube and the second knob drives the input to the output tube. Together, you can dial in sounds from pristine to warm and harmonically rich.
The pad switch not only provides a -20dB gain reduction for high input sources, it also works with the Dual Drive knobs to create color and headroom options. Engage the pad and dial in warm tones with lots of headroom.
The 992EG chassis and front panel are incredibly robust ensuring your 992EG is not just a piece of gear for now, but one that will be handed down for generations.
Everything in the 992EG is designed to be best in class. Every component, transformer, wire and tube has been meticulously selected for performance and longevity.
The front panel Hi-Z input allows you to plug a bass or other instrument directly into the 992EG. As an instrument front end, the 992EG allows for natural tube compression and harmonics to any input source.
The Illuminated VU knobs make it easy to see what the 992EG is doing. It runs from a separate signal chain so there is no interference with the amplified signal.
|INTERNAL GAIN||0 to >74dB|
|FREQUENCY RESPONSE||10Hz to 100KHz|
|MAX OUTPUT (1% THD+N)||+24dBu|
|TUBE COMPLEMENT||4 x 12AX7 / ECC83|
4 x 12AU7 / 5814
CLEAN GAIN, HIGH HEADROOM
With the Dual Drive knobs set at INPUT around 25% and the OUTPUT around 75% with the PAD off, you will get a very clean and pristine sound. The distortion is very low with no added harmonics and there is a ton of headroom. This is a great starting position for those wanting a clean tube sound regardless of the microphone type.
TUBE HARMONICS AND COMPRESSION
With the Dual Drive knobs set to INPUT 75% and OUTPUT 25% with the PAD off, you will get incredible tube harmonics and that natural tube compression. This would be a great starting position for those wanting to hear what the 992’s harmonics are all about. It’s also a great place to start when using ribbon or dynamic mics that need a little 992 harmonic color.
HEADROOM AND WARMTH
The 992 provides great sonic versatility. With the -20 dB pad engaged and the INPUT set to around 50% you will hear a rich roundness and warmth. With these settings the mid-range will move forward and the input headroom is increased as well.
FREQUENTLY ASKED QUESTIONS
Extra venting isn’t required but it is recommended, especially in warmer environments such as outside venues in the sun.
The 992EG will get warm. Eight vacuum tubes WILL generate heat. For this reason we recommend leaving a single rack space empty above the 992. It’s never a good idea to block or cover ventilation holes that are on top covers of the 992EG.
Yes. But we recommend using the -20 db pad or be comfortable with only rotating the input knob to about 9 o’clock max. With high output mics it is a good idea to start with the input knob at 9 o’clock and the use the output control to achieve line level. From there you can play with coloration and harmonics. Be aware that with high output mics, the preamp is already starting with a very large signal. It is not going to require much INPUT gain to generate harmonics and even distortion. But, then again, that might be what you’re after!
All LaChapell Audio products feature a 2 year warranty on parts and labor for issues relating to manufacturing. The tubes have a 6 month warranty. Please see the Digital Audio Labs Warranty page for more information.
The 992EG features (4) 12AX7’s and (4) 5814’s. The 5814 tube is a ruggedized version of the 12AU7. The 12AX7’s are the tubes that provide the most gain and are driven with the INPUT control.
Yes. The manual will provide guidelines in this regard. The 2-bay 583’s (583E and the original 583S) have square openings that are intentionally designed to allow users access to the 12AX7 and replace with other like tubes for additional flexibility. Generally speaking, it’s the input tubes (the 12AX7s or 12DW7s) that would be replaced if you are looking to alter the sound of the amplifier. The 992’s output tubes require a critical balancing step so, for that reason we don’t recommend messing with these. In any case, if there’s ever a question related to swapping out tubes PLEASE give us a call.
LaChapell Audio has been incredibly fortunate in having a great user base. We’ve had folks like Brad Paisley, Hans Zimmer, Phil Keggy, Depeche Mode and other personally choose our preamps over others for critical productions. Many studios in Nashville, LA and the rest of the world rely on LaChapell Audio to track the sound they want.
The 992 currently uses the Jensen 115k microphone input transformer and a Jensen JT-11-BMCF line output transformer. We also use the Cinemag CM-DBX for the Hi-Z input stage.
First, it provides for the basic need to attenuate the input signal for “hot” or loud sources. For example, there are some microphones out there that generate such a large signal that a pad is required in order to prevent unwanted distortion.
The second reason is for sonic shaping. All LaChapell Audio preamps place the -20dB pad function in such a way that, when engaged, the gain contribution from the input transformer is effectively eliminated. When that loss of gain is made up by dialing in INPUT gain, the user has essentially traded transformer gain with vacuum tube gain. As a result, the distortion is different, the frequency response is different, etc. User who use this this technique express hearing more “air” and “depth” to the sound. It’s not always preferred but it demonstrates the preamps sonic flexibility. A couple areas where this technique is routinely used are drum overheads and stereo piano overheads.
LaChapell Audio preamps are unique in how they provide gain control to the user. Our Dual Drive knobs provide separate INPUT and OUTPUT gain controls for increased sonic flexibility. This is key to LaChapell Audio’s reputation of being so versatile. In short, the INPUT gain control is where you can dial in harmonic color. The OUTPUT control drives the very clean, natural sounding output stage. The contrast isn’t extreme, but discovering the perfect balance between these controls for whatever might be connected to the preamp is what makes LaChapell Audio preamps so much fun to use.