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500 Series Tube Mic Preamp
MSRP: $1149

The LaChapell Audio Model 583s was the world’s first vacuum tube mic preamp designed for the 500 series format. It is still the only 500 series module to properly power the tube with 250V of TrueTube™ technology. Unlike some other vacuum tube mic preamps for the 500 series, we do not starve the tube of voltages in any way. And, since this all occurs within the 583 module, there is no worry of harming your 500 series power supply. With dual drive knobs to separately drive the input and output, the 583S provides total flexibility to explore a broad sonic pallet enhancing its versatility for all of your recordings.

583Smk2 Angle Image


Lachapell audio 500 series modules icon
500 Series Tube Mic Preamp

The 583s was the first ever tube mic preamp for the 500 series. It is extremely versatile, allowing a wide range of sonic options from clean to harmonically rich. It’s great for use on almost any source with almost any mic.

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TrueTube™ Powered Tubes

TrueTube™ technology supplies both the plate and filament of the tube with the proper voltages they need to access the full characteristics of the tube. Other designs cannot supply the needed 250V and don’t have the headroom or harmonics that characterize that classic tube sound.

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Autoswitching front panel Hi-Z input

The front panel Hi-Z input allows the 583S to be used as an instrument preamplifier. When a 1/4″ jack is inserted into the Hi-Z input, the 583S switches into instrument mode, bypassing the input transformer so the instrument accesses the tube directly.

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Dual drive knobs

The Dual Drive knobs on the 583S 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.

VPR Alliance certified 500 series module
API/VPR Certified

The 583S is certified by the VPR alliance giving you the assurance that it operates within specifications. Even though we properly power the tube with 250V, the 583S draws no more power than other modules (and less than many). You can fill a properly powered frame with 583S mic preamp modules with no problems whatsoever.

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Boutique Quality Transformers

With a Cinemag input transformer and Jensen output transformer, the 583S mic preamp maintains a boutique quality signal chain from I to O. Every aspect of the 583S has been designed for sonic quality that will last for generations.

THD+N0.10% (minimum)
Lachapell Audio 983s two channel rack mount tube microphone preamp (mic preamplifier) Example 1


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.

Lachapell Audio 983s two channel rack mount tube microphone preamp (mic preamplifier) Example 2


With the Dual Drive knobs set to INPUT 75% and OUTPUT 25% with the PAD off, you will get tube harmonics and natural tube compression.  This is a  great place to start when using ribbon or dynamic mics that need a little harmonic color.

Lachapell Audio 983s two channel rack mount tube microphone preamp (mic preamplifier) Example 3


The 583S 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.



Yes! The 583S mk2 and the 583e have been tested and approved by the VPR Alliance. 

Since the LaChapell Audio TrueTube technology current draw is within VPR limits, you can load up your entire frame with Mk2’s without issues. There’s a wide variety of power supply options in the market today. On top of that, there are several non-tube modules on the market that pull much more current than LaChapell Audio gear. As such, regardless of the module, it’s a good idea to check the user manual of the power supply you are using to make sure it has enough current capacity.

Our modules were designed to meet API’s VPR certification standards. As such, the API series of 500 series power supplies are our first recommendation. But there are others that we’ve found to be very reliable options such as the Purple Audio Sweet Ten.

This is a question that we are asked often and the answer is no. Yes there is a glowing vacuum tube in your 500 series module but it is a 9A type preamp tube. This is the same type used in the AKG C-12, Telefunken 251, etc. While these mics only have one section of the tube active, they also have less internal volume for the tube to cool and yet the surface temp of these mics never exceed room temperature. As long as you don’t block the venting that is already part of the 500 series power supply you will be just fine.

The 583S mk2, 583E, 500TDI and 500DT will get warm but nothing more than any other 500 series module drawing 110-120ma. It’s never a good idea to block or cover ventilation holes that are on top covers of the 500 series power supply.

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 583 and 983 are the same preamplifier and use one 12AX7 per channel.

TIP: When selecting different tubes for different sounds, use the -20 pad technique mentioned earlier. Engaging the pad and using Input gain to compensate will feature the 12AX7’s character and allow you to hear the differences between tubes much more than if the input transformer was part of the signal.

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, M83 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.

Not at all. From the beginning we set out to not only make the first tube preamp for the 500 series, but the world’s first HIGH-VOLTAGE tube preamp for the 500 series. Think of the 583, 500DT and 500TDI as having a secondary high-voltage supply within the unit. All LaChapell Audio 500-series modules with tubes feature both a full 250 volts to the plates and a full 12 volts to the filament. This is the proper way of powering a vacuum tube and, more importantly, allows the tube to behave the way it was design sonically without stress from a lack of power.

The 983 & 583 preamps currently use the Cinemag CMMI-10PCA microphone input transformer and a Jensen JT-11-DM line output transformer. The Hi-Z input on the 983/583 amps is transformer-less.

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.


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