Is there a doctor in the house?
Walk with me for a second. Vacuum tubes and effect pedals. They're something of in-laws of each other, right? Or your friend's friend. Or your grandparent's sibling. They're definitely in the same orbit and have stake in what's going on, but they really don't overlap all that often. It's like going to a wedding and seeing your cousin's other cousins. You know what we mean?
In any case, there is a lot of shared stake when it comes to tubes and pedals. Both are pretty sizable parts of your whole sound, though again, not a lot of crossover. Mostly, these worlds are very separate. Though sometimes, you're sat across from your cousin's other aunt at the reception and you have an interesting conversation. Let's talk about it.
This is the EarthQuaker Devices ZEQD-Pre Tube Preamp.
Doctor's Orders
Introducing the EarthQuaker Devices ZEQD-Pre Tube Preamp
With our cast of characters, we're starting with a few key Ohioans. The first is EarthQuaker Devices. Akron's finest, you know 'em, you love 'em. They're kicking off their 2026 with a really cool collab. Off the heels of their Easy Listening Analog Amp Simulator*, EQD has decided to launch 2026 with a pedal sure to fire up even the most reclusive, cross-armed amp nerds checking their texts in the back of the room.
Which does play a part, here
The second Buckeye State native we're talking about today is the illustrious Dr. Z. Of Dr. Z Amplification, the good doctor has more than his fair share of independent, boutique, amplified classics under his belt. Dr. Z's approach to amplification has long involved the bare necessities and foundations of great tube amps: Great tubes.
Today's EQD and Dr. Z collab, perhaps unsurprisingly, has quite a bit to do with tubes – their role in a sound, their response to different kinds of playing, the way they can strut their stuff in more ways than you might initially think. The EarthQuaker Devices ZEQD-Pre is an all-analog, true-blue tube-driven preamp pedal designed in close collaboration with Dr. Z Amplification to reproduce the authentic tube response of a Dr. Z amplifier.
This pedal in question features an actual EF86 pentode preamp tube, the same type Dr. Z commonly calls upon in his work to produce such hi-fi sounds with particular touch response and playability. The pedal is then built out by EarthQuaker with all the sound, reliability, and connectivity they've become famous for to stick the landing for Dr. Z fans, EQD fans, tube fans, pedal fans, and just about anyone in between. Let's not spoil it all at the jump, though. Let's talk about what we've got.
From EQD to EQZ
EarthQuaker Devices ZEQD-Pre Tube Preamp Design and Tones
With the ZEQD-Pre, we're treated to a pretty robust but quite streamlined amp-like experience. The ZEQD-Pre can perform in a variety of ways – as an amp simulator or as an "extra" channel to your existing amp, for instance. Let's get into what we're working with.
EarthQuaker Devices ZEQD-Pre Tube Preamp Design
The ZEQD-Pre centers around a very intuitive setup that mirrors the simplicity of other Dr. Z amplifiers. Made to really finagle by being played rather than a control basis, this is a pedal to be found out rather than intellectualized*. Truly, it's a welcome experience when you get to work with an authentic preamp tube.
The sound's in the fingers rather than the head, as it were
With this pedal, EarthQuaker Devices set out and created an authentic, amp-like control experience. At the helm, we get the ZEQD-Pre's two "channels."
"You hit this pedal on and your amp just becomes huge. And it's not just distorted and clipped, it's just this big, big sound that is produced with this tube." - Mike Zaite, founder of Dr. Z Amplification
- Level – Give the ZEQD-Pre's right footswitch a stomp and you're off to the races. The basic "channel" of the ZEQD-Pre is instantly very recognizable to fans of tube preamps with character. Rolling through the Level control, you get the ZEQD-Pre louder or softer, no surprises there. However, this response does lead into the ZEQD-Pre's authentic tube response feel as you dig in deeper on notes at lower settings or let things ring out more on higher ones. The EF86 produces plenty of amplified oomph to play with and some good tonal flexibility as you run through your usual repertoire.
- Three-Band EQ – On this first "channel" of the ZEQD-Pre, we're met with amp-style tone controls for Treble, Bass, and Mids. Classic, right? These three controls shape the preamp character of the pedal closely as you work through the various tones you get with the real-deal of a preamp tube. This experience expands, however, when we hit the other footswitch.
- Boost – Hit the leftmost footswitch to engage the ZEQD-Pre's onboard Boost effect. Acting more as a second channel to this Dr. Z pedal experience, the Boost footswitch bypasses the EQ section to get down to simpler, meatier, more muscley and distorted tacks. This second channel certainly plays more into the ZEQD-Pre as an individual element of a signal chain, and we'll talk about that in a second, but just for now, know that Boost retains a lot of the amplified authenticity the entire experience is going for.
EarthQuaker Devices ZEQD-Pre Tube Preamp Tones
The central experience of the ZEQD-Pre is very fitted for players seeking out extra spins on their existing tones. With the ZEQD-Pre, you can imagine another channel on your favorite amp that has the tube muscle to drive whatever's following downstream. Put the ZEQD-Pre in front of your favorite tube amp and get an in-depth opportunity to shape its own distorted character on a smaller, more focused scale. The ZEQD-Pre has buckets of tube-born force behind it to really give your distorted Orange or Mesa a run for its money along with the nuance to bring something new to the table.
Though with no other amp in the picture, the ZEQD-Pre doesn't bow out just yet.
Dial "Z" For...
EarthQuaker Devices ZEQD-Pre Tube Preamp Further Functions
Part of what EarthQuaker Devices brings to the ZEQD-Pre that really elevates the experience is a robust setup of connections for translating its tube tones outside of your traditional guitar-and-amp setup. Sharp-eyed readers might notice the ZEQD-Pre's side XLR out connection. Here's where some of the EQD magic really starts to shine.
The ZEQD-Pre features a balanced male XLR out connection, the kind you might see on other similar modern, amp-like devices. This XLR out is – you guessed it – a DI out ready to bring the tones of the ZEQD-Pre straight to the stage or studio without an amp altogether. In situations you might want the preamp tube sound of the ZEQD-Pre straight into the recording board or the peace of mind that your back won't hurt in the morning the night after your gig, the DI out is a perfect solution. The DI out retains the tube tones of the EQD through a high-fidelity output connection with a number of bells and whistles along the way to turn it up to an eleven.
- Ground Lift – Okay, maybe not the most thrilling, maybe not the most glamorous, but always good to have. EQD's ground lift switch keeps things airtight and operating as they should, no matter how you're using the pedal.
- Cabinet Simulation – Okay, maybe a little more exciting, eh? Directly inspired by EarthQuaker's Easy Listening Analog Amp Simulator, the ZEQD-Pre is outfitted with an all-analog cabinet simulation for its XLR DI out. This cabinet simulator is completely analog – no menus, no impulse responses, no weird digital artifacts, nothing. Meant to help in translating the authenticity of the preamp to the room and give it that extra je ne sais quoi of an amp through a cab, this cabinet simulation fits right in with what the ZEQD-Pre is after. It can also be completely bypassed on its dedicated switch's push/push basis.
- Headphone Amp – One more little nugget carried over from the Easy Listening is the ZEQD-Pre's 1/4" headphone output. Yes, with the ZEQD-Pre, you get both authentic tube tones and a way to get washed in them completely silently. This function also opens up the ZEQD-Pre's functionality as just a helpful utility tool in your studio as you try out different effect setups or practice silently, which is always a welcomed addition when inspiration strikes.
The ZEQD-Pre operates with EarthQuaker's classic true bypass switching and standard nine-volt center negative power supplies at 500mA minimum, making it overall ready to set up and play at the drop of a hat.
Dr. Z Amplification founder Mike Zaite and EarthQuaker Devices founder Jamie Stillman
EarthQuaker Devices ZEQD-Pre Tube Preamp Final Thoughts
With the ZEQD-Pre, EarthQuaker Devices presents a loving tribute to their Ohio brethren. Dr. Z amps are an institution in themselves in boutique tube amp circles, and that's never something to count out. The expertise and artistic ear on display with the ZEQD-Pre is sure to translate when the pedal is fired up in your signal chain, out to a PA system, into your studio's board, or otherwise. It's not often you get an authentic tube experience in a package such as this, so for that, there's sure to be a tube amp fan out there raring to go and eternally grateful. Vacuum tubes and effect pedals – can they coexist? With EarthQuaker and Dr. Z, the proof's in the pudding.
