Catalinbread - Dirty Little Secret Deluxe - Plexi-In-A-Box & Boost Pedal

The ultimate Marshall Plexi emulation and fully-customizable amp-in-a-box experience.

The Dirty Little Secret Deluxe represents the next logical step in Marshall Plexi emulation, reaching beyond the preamp circuit and adding the rest of the amp for an extremely authentic take on everything inside that chassis. Our original DLS circuit has been tweaked and upgraded throughout, now featuring a phase inverter, power amp sim and output transformer as well as some new features and the most requested modifications for the original. One such addition is a toggle switch on the outside to select between Super Lead and Super Bass modes, and we’ve also externalized the Presence knob to easily dial in your preferred Marshall flavor. Also added is a piece of the Dirty Little Secret—a single preamp tube simulator—as a built-in boost circuit that can be used independently of the main circuit. You can run the boost and DLS in any order you like; put the boost before the DLS for a high-powered saturated tone or after to pummel the front end of your amp. A new tightness knob lets you shave off the sub-bass for a little extra clarity or completely attenuate the low end for some cool thrash metal tones. A Line Out jack gives you a dedicated +10dB output that you can use with a mixer or DAW, and you can use both outputs simultaneously. Between the Boost, order selector and the external Super Lead/Super Bass modes, the Dirty Little Secret Deluxe is engineered to be a total performance tool that does the line justice.

EFFECT OVERVIEW

The Dirty Little Secret Deluxe represents the next logical step in Marshall Plexi emulation, reaching beyond the preamp circuit and adding the rest of the amp for an extremely authentic take on everything inside that chassis. Our original DLS circuit has been tweaked and upgraded throughout, now featuring a phase inverter, power amp sim and output transformer as well as some new features and the most requested modifications for the original. One such addition is a toggle switch on the outside to select between Super Lead and Super Bass modes, and we’ve also externalized the Presence knob to easily dial in your preferred Marshall flavor. Also added is a piece of the Dirty Little Secret—a single preamp tube simulator—as a built-in boost circuit that can be used independently of the main circuit. You can run the boost and DLS in any order you like; put the boost before the DLS for a high-powered saturated tone or after to pummel the front end of your amp. A new tightness knob lets you shave off the sub-bass for a little extra clarity or completely attenuate the low end for some cool thrash metal tones. A Line Out jack gives you a dedicated +10dB output that you can use with a mixer or DAW, and you can use both outputs simultaneously. Between the Boost, order selector and the external Super Lead/Super Bass modes, the Dirty Little Secret Deluxe is engineered to be a total performance tool that does the line justice.

MANUAL OVERVIEW

If you’re reading this, the secret is out! What started as a fourth version of our flagship Dirty Little Secret ended up as this, the Deluxe version, which I’m sure you’ve already played before reading this. Quite frankly, we don’t blame you, and right up front we want to extend a hearty “hope you enjoyed it,” which you undoubtedly have. If you haven’t, good news! This manual will explain everything in great detail, be you a “play it first, who needs a manual” type or a “whoa there, let’s check the paper first” type.

The Dirty Little Secret Deluxe is dedicated to all things Marshall, featuring an all-discrete circuit with a preamp, phase inverter, power amp sim and output transformer. A built-in footswitchable boost modeled after a clean Marshall preamp and effect order switch gives you a fully-customizable amp-in-a-box experience.

Before we get to it, thank you for your purchase. There would be no Catalinbread without you, and we made this especially for you. You, the person reading this, right now. Pat yourself on the back.

CONTROLS

MASTER:  A descriptor that’s normally a formality, this knob occurs before the phase inverter and output transformer rather than at the end of the circuit, just like a real amp. We designed the output stage to be more impervious to input saturation than most power sections, so really cranking it doesn’t alter the tone in an extremely noticeable way. However, those that plan to use the DLS DLX as an always-on can find some subtle sag and gentle compression living within the whole of the volume knob.

PREAMP: We’ve taken the original preamp control and tweaked it to deliver a wider gain range with more cleans on the lower end and more cranked Marshall tones on the higher end.

PRESENCE: Formerly an internal trimmer on the original, the Presence control is a powerful low-pass filter that attenuates frequencies by 3dB above 1.59KHz when turned all the way down, and the cutoff point climbs to an indistinguishable frequency by the end of the turn.

BOOST: The boost circuit is actually one of the tube emulation building blocks that make up the DLS itself. When you run the boost before the Dirty Little Secret, it acts as another “preamp tube” added to the front end of the device for some saturated JCM900 tones. When run after, it makes everything louder without sacrificing clarity. WARNING: please see note in “Effect Order” section below.

BOOST VOL: The boost circuit is actually one of the tube emulation building blocks that make up the DLS itself. When you run the boost before the Dirty Little Secret, it acts as another “preamp tube” added to the front end of the device for some saturated JCM900 tones. When run after, it makes everything louder without sacrificing clarity. This knob is a volume control for the Boost side, so at lower points in the knob’s turn, the boost signal can get below unity gain. This helps you dial in maximum tone shaping for combining the two effects.

TREBLE/MIDDLE/BASS: These are the classic Marshall amp tone stack values that we all know and love, highly interactive as always. These values are taken directly from the amps themselves, and the entire tonestack circuit is passive, meaning that noon is not flat on either knob. The Bass control in particular isn’t flat at noon, and most players of actual Plexi amps keep this control pretty low. When switching between modes, the TMB tonestack values are swapped as well, lending complimentary toneshaping to each.

SL/SB TOGGLE: The most requested mod in the history of Catalinbread has arrived; a toggle to switch between both modes. Impossible in the original due to space and function constraints, this allows you to switch between Super Lead mode, a cutting, upper-midrange-heavy tone, and Super Bass mode, a smoother, smokier tone with a lower midrange emphasis.

HOW IT'S SHIPPED

Who doesn't love the sound of a boost circuit slamming the front end of an amp? For many of us, this was our first introduction to "stacking," where two gain-generating devices are coupled such that the level of the first controls the amount of available distortion of the second. We ship the Dirty Little Secret Deluxe with this principle in mind: with the boost side occurring before the Dirty Little Secret side, you can push the whole arrangement into gooey saturation at will with a single stomp. And since the boost side is modeled after a clean Marshall preamp, this lets you conjure up some cranked JCM800 and 900 tones right out of the box. You can switch the order via internal switch. More on that below. 

UNDER THE HOOD

TIGHTNESS: Depending on the kind of music you’re playing, you may expect a certain “tightness” from your amp. In real terms, what we call “tightness” is in reality bass attenuation via a subtle high pass filter. This particular high-pass filter is designed to cut nothing audible when turned down, and cuts up to ~230Hz at maximum for a full bass cut extending into low mids.

EFFECT ORDER: Are you a “boost into drive” or a “drive into boost” kind of player? Now, you can be both. This switch reroutes the order of the boost and the DLS circuit. Running the boost into the DLS allows you to use the boost as an extra gain stage to really saturate the front end, and running it afterward lets the boost act as an inline gain coupler for your own amp. WARNING: The “Boost Level” knob can cut all volume when turned fully down. If you’re planning on using the pedal in “DLS—>Boost” mode, make sure you start with Boost Level at 0, then edge the knob up until you find the desired level while adjusting your amp volume accordingly. It can get very loud.

LINE OUT: This is located on the rear panel of the DLS DLX, and is a dedicated +10dB output for direct recording or mixing. You can plug into both the standard out and the Line Out simultaneously, to run to an amp and mixer at once. Please note that this means the dry signal is boosted to +10dB, and that if you’re unaccustomed to thinking about loudness in those terms, that means it will be much louder. In fact…WARNING: Make absolutely sure you’re plugged into the correct jack before playing. When connected to Line Out, even your dry, unaffected signal gets boosted 10dB. If you’re not expecting it, your amp will be ok but your ears/pets/neighbors may not be. Make sure you are aware how you are plugging into this device!

BUT WAIT THERE'S MORE: Because of the Line Out/standard out split, this pedal is equipped with a pristine output buffer to preserve signal integrity. With that said, the Dirty Little Secret Deluxe is equipped with buffered bypass. The tone won’t change, but the pedal will not send a bypass signal unless power is plugged in. You may never have noticed, but some of you will, and now you know!

DESIGNER'S NOTES

Who among us hasn’t been completely enrapt by either the Marshall Plexi amps themselves or records on which they were utilized? I am but a statistic in this regard.

I’d be hard pressed to name every album that I love that was recorded with Marshalls, but I can definitely name a few examples. In Utero and Drive Like Jehu’s Yank Crime (RIP Rick Froberg) are two of my favorite guitar albums ever recorded, with the former using a Plexi and the latter using a JCM800. I have very intense and specific memories of jumping up and down on my parents’ bed begging them to play the Police’s Synchronicity LP; Blur’s Parklife was the first cassette album I ever bought with my own money. Both Summers and Coxon are notorious Plexi players, and among the innumerable Plexi-kissed albums out there, both of those albums specifically shaped my musical taste for the better.

Taking on a classic platform was a daunting task, because the current MKIII edition is, well, the third revision of this circuit and thus the most highly refined. I was working at Pro Guitar Shop when that pedal came out and I still remember the hoopla around it. Andy filmed a special demo video for it and everything. It definitely delivered, and after looking at the circuit it was clear that everything possible had been done to extract every last drop of tonal potential from the parts. How does one step in and take the pedal world’s go-to Marshall-in-a-box device and change it in such a way that it sounds even more like a Marshall?

I wanted the sound of other pedals running into a Marshall amp in totality. As it turns out, the DLS preamp is tough to improve upon, and so I had to look at what wasn’t there as opposed to what was. What we have is an incredible Plexi preamp. But that’s not exactly an amp, is it?

The solution was to add all the other components that make an amp an amp. There’s a MOSFET-driven phase inverter and power amp sim, along with an output transformer to inject a little iron into the signal path. Having the Boost circuit mimic the preamp section of the DLS gives you a six amp experience: Turning just the boost on gives you chime-y Marshall cleans, using just the DLS side gives you a cranked Plexi, and running both together gives you the sound of a roaring JCM. Plus, you get Super Bass and Super Lead versions of each. I designed this for performance capabilities beyond what many drives can provide.

The result is all the grunt and kerrang of a Plexi preamp with all the light compression and sag of the rest of the amp. To me, that is the real Plexi experience. I spent more time tweaking and adjusting this circuit than perhaps any other I’ve ever worked on, and I firmly believe you’ll like it as much as I do and see it as a worthy successor.

POWER SUPPLY

The Dirty Little Secret DLX accepts a center-negative DC power supply capable of supplying 9 volts and at least 7mA of current (over is fine). Plugging in anything other than this (center-positive, AC, higher voltage) will damage the pedal, maybe even beyond repair. Check your supply and make sure it says all the right stuff. Plugging in the wrong supply will void the warranty and possibly summon a puff of ozone-tinged smoke. Trust me, you’d hate it.

WATCH THE DEMO HERE