dpFX Pedals

Welcome to dpFX

2026-01-03T21:42:00.000+02:00

- Solutions for musicians. Select from our listed products or ask for a custom build or a mod.
- Visit our e-shop to see what's currently in stock

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✭ All products are handmade and serial numbered ✭

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Too Much Hiss? 6 Quick Ways to Silence Your Headphone Amp / Reduce White Noise

2026-01-03T21:27:00.063+02:00

Is your headphone amplifier making a noticeable background hiss or white noise? Don’t worry—your unit is likely working perfectly.

Headphone amps for pedalboards are often designed to be loud and powerful, which can sometimes reveal background noise you might not hear through a regular guitar cabinet. In many cases, the “hiss” isn’t a fault in the pedal—it’s just a setup issue.

Here’s a 2-minute checklist to get your practice rig actually silent.

Also make sure to check our headphone amps

1. Check Your Volume Balance (Gain Staging)

This is the #1 cause of hiss. If you send a very quiet signal into the headphone amp and then crank the amp’s volume to hear it, you’re amplifying the background noise along with your guitar.

--> The Fix: Turn the volume UP on the pedal or preamp before the headphone amp. If you headphones amp has an INPUT knob, make sure to also turn it all the way up, or until the point that distortion might occur. Then, turn the headphone amp’s volume DOWN. You’ll get the same loudness but a much cleaner sound.

2. Watch Out for Sensitive In-Ears

Not all headphones are the same. Modern in-ear monitors (IEMs) can be very sensitive. They can pick up the “noise floor” of analog gear more than larger studio headphones.
--> The Fix: If the hiss is annoying with earbuds, try plugging in a pair of over-ear headphones. The background noise usually disappears immediately.

3. Check the impedance of your headphones

Most headphone amp manufacturers list the recommended headphone impedance in their specs, and they should provide this information if you need it. Using headphones outside this range—either too low or too high—can affect sound quality and increase background noise.

--> The Fix: If your headphones don’t match the amp’s recommended impedance, try using a pair that falls within the suggested range (or slightly higher) for optimal performance.

4. Isolate Your Power

Headphone amps are usually at the very end of your signal chain. If they share a power source with other digital pedals (like reverbs or delays), digital clock noise or other noises can leak in and cause whining or hiss.
--> The Fix: Give your headphone amp its own isolated output on your power supply. Avoid daisy-chain cables if possible.

5. “Garbage In, Garbage Out”

A headphone amp acts like a magnifying glass—it amplifies everything fed into it. Noisy pedals or guitar pickups will sound louder through the amp.
--> The Test: Turn your guitar volume to zero. If the hiss disappears, the noise is coming from your guitar or earlier pedals, not the headphone amp.

6. The “Phone Charger” Buzz

If you use the AUX input on the headphones amp to play along with backing tracks from your phone or laptop, you might hear a hum or digital whine. This is usually a small ground loop caused by your device’s charger.
--> The Fix: Unplug your phone or laptop from its charger and run it on battery power while you play. The hum should vanish instantly.

Summary

Analog headphone amps naturally, even the smaller and simpler ones have a tiny bit of “character” or warmth that digital interfaces don’t, but they shouldn’t be overly noisy. The amount of hiss usually depends on the type of IC used at the amp’s core and other aspects of the circuit design. Follow these steps, and your headphone amp will deliver clean, powerful sound with minimal hiss.

Important Note:

The tips in this guide are starting points, typical suggestions, not absolutes. Every headphone amp, pedalboard setup, and pair of headphones is a little different, and every musician’s ears and preferences are unique. Use these steps as a framework to troubleshoot and improve your sound, but trust what you actually hear over any rule or recommendation.

Tips for soldering switches without melting them

2025-12-27T22:33:00.001+02:00

While there are various types of switch terminals, one of the most common forms used in pedal-building is the solder-lug terminal found on panel-mount electromechanical switches.

But how do you solder them?

When a switch has solder lugs, they are typically located on its underside, where wire is soldered to the lugs to create a solid, conductive connection. This method forms a permanent bond between the switch and the wire, making solder-lug terminals one of the most reliable solutions, even for high-current loads.

In these switches, the solder lugs are surrounded by plastic, which is prone to melting if overheated—especially in cheaper switches. If the plastic melts, it can shorten the switch’s lifespan or even render the switch unusable.

Tips for soldering without damaging them:

Use a soldering iron that can be set to the desired temperature.
Tin the wires before attaching them to the switch’s lugs.
Use a no-clean flux if necessary.
ALWAYS check the switch’s datasheet provided by the manufacturer for information on the soldering heat resistance of the plastic. A typical specification for small toggle switches is often listed as follows:

- Maximum soldering temperature: 250 °C
- Immersion time: 3  seconds
- Maximum soldering frequency: 2 times

While the above specs is just an example, it applies to a lot of switches out there. If you can't find the datasheet of the switch you have on your hands, use the above specs as a starting point.
Soldering times and temperatures should not exceed the recommended ranges specified for each switch. Do not operate the switch during or immediately after soldering—wait at least 2 minutes.
If you messed up a soldering, don’t try to fix it right away—wait at least 5 minutes for the switch to cool.

> While the next tip is usually unnecessary for pedals, I’m including it for anyone who might find it useful elsewhere, especially when high voltages are involved:

You can’t always add shrink tubing, but covering the solder joint with it helps protect against debris that could cause corrosion and also reduces strain. Adding an epoxy seal to the bottom of the switch is another way to provide extra protection.

- DIY Tips -

Vocal EQ & recordings

2025-12-27T22:33:00.000+02:00

Photo by Ken Barton on Unsplash

A Practical Approach to Vocal EQ in 10 steps

Because every voice is different, there are no universal EQ presets that guarantee great results.

The most reliable method is to start neutral, listen critically, and make adjustments based on what you hear.

The steps below outline a solid workflow for shaping vocal tone effectively.

Steps:

1. Start with a flat EQ curve. Do not rely on any EQ preset or curve you found online. Always remember that sometimes a non-flat response may already exist due to mic characteristics and its inherent tonal coloration.

2. [Low Cut <60Hz] Roll off the low end as it typically doesn't hold any useful vocal content. Instead, it can contain unwanted rumble, mic stand noise etc. In some cases, you might find it useful to rise the cut-off frequency up to 90Hz.

3. [120Hz] Boosting around 120Hz reinforces low-mid energy, may ad warmth but may cause boominess if boosted too much. Cutting it reduces low-mid body and can make the voice sound thin, even too thin if overdone.

4. [300-600Hz] Boosting this area may cause boxiness(*), especially in booth recordings. A subtle cut in this region usually mitigates the issue.

(*) Audio engineers often use the term “boxy” to describe a vocal or instrument tone that has an exaggerated midrange resonance, typically in the 300–600 Hz region. It sounds as if the audio is coming from inside a small wooden box—(sometimes dull, hollow, congested, and lacking clarity.)

5. [1-2kHz] Usually a slight cut here is helpful, since boosting can make vocals sound nasal. Depending on the nature of the singer's voice and the mic choice you'll have to fine tune this area accordingly. Boosting too much can make vocals harsh rather than just nasal.

6. [4kHz] This area is more commonly associated with presence and aggressiveness. While nasal overtones in this region are less universal, subtly cutting 4kHz may reduce harshness or glare, not just nasality. If, after cutting slightly the 1-2kHz range, you still notice nasal overtones, try a subtle cut on the 4kHz area as well.

7. [5kHz] Boosting around 5kHz enhances vocal presence and brings the voice forward in the mix, especially if the recording is already dull; however, be cautious as it can amplify sibilance ("S" and "T" sounds) and make everything more "hissy". A subtle cut in this region can reduce harshness while maintaining clarity, particularly useful if the vocal sounds too bright or fatiguing to the ear.

8. [6–8 kHz] This range adds clarity, definition, and intelligibility to the vocal, helping consonants and articulation "cut through" the mix. Boosting can make the vocal more present and detailed, but excessive boosts may accentuate sibilance and create a harsh, edgy, or fatiguing tone. A subtle cut can tame harshness without dulling overall brightness. If sibilance persists after adjusting 5 kHz, use gentle EQ adjustments in this band instead.

9. [8–12kHz] Boosting this range enhances brightness, clarity, and the perception of detail. Over-boosting can lead to exaggerated brittleness, or a hyper-detailed sound. Cutting this range reduces high-end sharpness but may dull the vocal if overdone.

10. [12–16kHz] Often called “air” range. Boosting this range adds airiness, openness, and a sense of space. Too much boost can create an unnatural, hyped top end or introduce hiss from the recording environment. Cutting this area is rarely necessary unless correcting harsh, overly bright recordings.

General advice: Always EQ while listening in context with the mix, not soloed, for best results. This avoids the common trap of over-EQing isolated vocals.

Important Note: The frequency ranges and suggestions outlined in this guide are starting points, not absolutes. Every microphone has its own tonal character, and every voice is unique—shaped by gender, age, tone, and technique. Use these steps as a framework to train your ear, then adapt based on what you actually hear. Trust your listening judgment over any preset frequency.

- DIY Tips -

Sunn Beta footswitch connector assembly

2025-12-27T22:32:00.018+02:00

Assembly of the circular connector the Beta Lead and Beta Bass use for footswitch connection to the back of the amp.

Check here the fully assembled Beta footswitch.

1. 2. 3.

>>> Contact Us for custom requests <<<

- DIY Tips -

Active vs Passive Matrix Mixers: How to Choose the Right One

2025-12-27T22:32:00.017+02:00

Why "Active" is the only way to route signals without compromising integrity.

>> Check our active matrix mixers here <<

Introduction: More Than Just a Splitter

If you are diving into the world of parallel processing, feedback loops, or complex signal routing, you have likely encountered the concept of a Matrix Mixer. Either we are talking about mono or stereo matrix mixer, it is the ultimate tool for sound design—allowing you to send any input to any output, create feedback loops, and blend multiple effects in parallel.

But not all matrices are created equal.

One of the most common questions I get at dpFX Pedals is about the difference between passive and active matrix mixers. While passive units are significantly cheaper and require no power, they suffer from inherent physical limitations that can mess with your tone and the fidelity of the resulting sound. Here is why we strictly design and build Active Matrix Mixers, and why your pedalboard depends on them in case you choose to include them in your setup.

The Problem with Passive Mixers

Passive mixers are essentially a network of resistors and potentiometers . They work by attenuating signal through resistive division rather than managing it. When you use a passive matrix, you run into three unavoidable issues:

1. The Cross-talk "Nightmare"
In a matrix mixer, you have multiple inputs and outputs connected together. In a passive design, these connections are never truly isolated. Adjusting a knob on "Channel A" changes the electrical resistance seen by "Channel B."
The Result: You turn down one volume knob, and suddenly another volume changes too. It creates a "leaky" system where signals bleed into paths they shouldn't be in.

2. Impedance Loading (Tone Suck)
Guitar signals are, in most cases, relatively high-impedance. Passive mixers place a heavy load on your signal chain, acting like a blanket over your sound unless preceded by a buffer.
The Result: You lose high-end sparkle, volume, dynamic range, and overall clarity—the notorious "tone suck."

3. Insertion Loss
A passive mixer cannot maintain unity gain. Just by plugging in, you lose volume that you can never get back without adding a booster pedal later in the chain. Insertion loss is topology-dependent and increases as more signals are summed or split.

The Active Advantage: Why We Use Buffers

An Active Matrix Mixer uses operational amplifiers (Op-Amps) to manage the signal. It requires power, but the benefits are non-negotiable for professional audio:

- Effectively isolated through buffering: We design our mixers with buffered inputs and outputs. This means every channel is effectively isolated through buffering. You can turn Knob A to 100% and Knob B to 0% without them ever interacting or bleeding into each other.

- Impedance Preservation: High-impedance inputs ensure your guitar pickups see the load they were designed for, preserving every detail of your treble and attack.

- Unity Gain & Boost: Active circuits allow us to set the "Unity" volume exactly where it needs to be, or even provide gain to boost a weak signal, if required

- Phase Correction: Active circuitry allows for phase inversion. This is critical in parallel mixing, where blending an effect with your dry signal can sometimes cause phase cancellation (a thin, hollow sound). Active mixers can flip the phase to fix this instantly. Phase inversion is practically unavailable in passive resistor-based matrix mixers, while trivial in active designs.

Conclusion: Don't Compromise Your Routing

A matrix mixer can be the brain of your pedalboard's routing. Using a passive version is like putting bicycle tires your new car—it might roll, but you'll never get the performance you paid for.

Whether you are looking for a standard router or a custom solution for a specific rig, an active buffering architecture ensures that the complex sounds you create are exactly the sounds your audience hears.

Quick Note
This article is written for musicians, not as a full technical deep dive for engineers. Some concepts are simplified to explain how passive and active matrix mixers behave in real-world pedalboard setups, rather than covering every possible theoretical design or edge case. The focus is on practical use and musical results.

Expression Pedals polarity schematics

2025-12-27T22:31:00.001+02:00

There are countless expression pedals in the market and if you take the time to check the specifications that each manufacturer gives for their own model you will see that there a differencies.

One of the most important specifications you must check before buying (or building) an expression pedal is what many manufacturers call the "polarity". The term in our case is obviously not referring to a voltage but to the way the output of the expression pedal is wired to the internal potentiometer.

On the left we've marked the 3 ways an expression pedal is usually wired. You will often see those three "polarities" marked as TRS, RTS and TS.

- DIY Tips -

Two simple audio uses for 2N5458 JFETs

2025-12-27T22:22:00.002+02:00

2N5458 is a quite common JFET transistor for audio applications, pedals, pre-amps etc.

(datasheet by on-semi)

On the image you can find two simple applications:

i) a buffer (e.g. before a tone-stack)

ii) a pre-amp/boost

The component values are real and both circuits can be used as is.

The boost circuit can be stacked with another similar stage to increase the gain, just make sure you use the correct type of output capacitors for both stages.

Adding a 100μF capacitor in parallel with the source resistor of the 1st stage will also give you increased gain and might overdrive the 2nd stage producing some smooth clipping, but it definitely depends on the level of the input signal.

The circuit of our STENTOR boost is actually a modified version of the above examples.

- DIY Tips -

Full Product List

2025-12-26T22:32:00.000+02:00

A list of all our available products (not the custom ones)
dpFX Full Product List

Getting the Best Sound from Your Piezo Pickup: What a Buffer Really Does

2025-11-30T00:10:00.026+02:00

Piezo pickups are extremely sensitive, and often that’s both their biggest strength and their biggest problem. They can capture the natural attack and character of an acoustic instrument — but only if they’re connected to the right kind of input.

Most amps, pedals, and mixers simply don’t have the high-impedance input a piezo really needs, which often results in a thin, nasal, “quacky” sound, or even boomy if the amp is set in loud volume, which often causes annoying feedback.

That’s where a piezo buffer comes in.

A proper buffer presents the pickup with a very high input impedance (in this case around 10MΩ), allowing the pickup to respond the way it was designed to. The result is a fuller, more natural tone with better dynamics and less noise. Subtle details — like the wood resonance of a double-bass or the body warmth of an acoustic instrument — come through clearly instead of being lost.

For players using Realist or similar upright-bass pickups, this makes a big difference, especially on stage.

Here you can see a simple mini-buffer I often make for such cases. Additionally, the custom unit shown here combines a 10MΩ piezo buffer with a variable high-pass filter (20–200 Hz). The buffer keeps the tone natural and open, while the HPF lets you control low-end boom and stage rumble — a common challenge with double-bass. This allows you to keep the fundamental notes strong while tightening the low end and avoiding feedback.

Whether you’re going straight into an amp, DI, or pedalboard, a good piezo buffer is one of the easiest ways to improve clarity, consistency, and playability with any acoustic or upright-bass pickup.

Piezo Buffers Explained: Better Tone, Less Noise for Acoustic Instruments

2025-11-30T00:09:00.018+02:00

If you play double bass, cello, acoustic guitar or any other instrument with a piezo pickup, you know the struggle:

sometimes you plug in, and the sound is thin, "quacky," or brittle. Other times, the low end is so boomy it causes feedback instantly.

Often, musicians that use such instruments, especially bass players come to me with this exact issue using various pickups (such as Realist, K&K, Underwood, JourneyTek, Vic's pickups, etc). While they loved the natural character of the pickup they also felt they were losing the deep, warm body of the instrument when plugging into standard amps.

[The Solution: The 10M Buffer]
The culprit is usually Impedance Mismatch. Most guitar/bass amps and mixers have an input impedance that is too low for a piezo sensor (usually around 1MΩ). This "chokes" the signal, killing various frequencies.

For such cases, I usually design a custom High-Impedance Buffer (10MΩ) that may include additional features, depending on the instrument, the pickup type and the musicians needs. Think of this as opening a wide gate for your signal. By raising the impedance to 10 Mega-Ohms, the pickup can "breathe," restoring the full, rich tone that the instrument actually produces acoustically.

[A 'secret' Weapon: The Variable HPF]
Restoring the bass is great, but on a big instrument like a double bass, it can sometimes be too much, especially on a hollow stage or in a boomy room. That’s why, when needed I pair the buffer with a Variable High-Pass Filter (HPF), adjustable from 20Hz to 200Hz. It lets you choose a cutoff frequency anywhere between 200Hz and 20Hz through a single control knob, making it ideal for removing unwanted low-end frequencies that can cause feedback, boominess, or excessive sub-bass.

[Conclusion]
The result? A signal chain that keeps the "wood" in the tone without the "mud" in the mix. If you are struggling with your acoustic tone, you might not need a new pickup—you might just need the right buffer.

Feel free to reach out via the contact form if you need a custom solution for your acoustic rig!

Matrix Mixers, active

2025-11-29T23:05:00.000+02:00

4x4 Matrix Mixer with AC coupled inputs & outputs

Below, there is a list with some of the active Matrix Mixers we've built in the past. If you need a custom made mixer just email us your specs.

4x4 STEREO Matrix Mixer, AC coupled
4x4 Matrix Mixer, AC-coupled INs & OUTs (mono)
4x4 Matrix Mixer, DC-coupled INs & OUTs (mono) (for mixing audio with CV)
12x12 Custom Matrix Mixer with DC Coupled inputs & outputs, (mono) (for mixing audio with CV)

Here are a few photos with a couple of our past paint-jobs:

12x12 Custom Matrix Mixer with DC Coupled inputs & outputs

4x4 Matrix Mixer with inserts instead of separate input-output jacks

4x4 Matrix Mixer, DC coupled, for mixing audio with CV

KRAMA Parallel Blender, all versions

2025-11-29T23:02:00.001+02:00

Parallel Blenders for instruments, synths, keyboards, line level signals, piezo pickups and a variety of other uses.

KRAMA, our parallel blender, has been in the market for many years and comes in various versions, each with different functions.
In this page I've listed all versions, both the discontinued and the currently active ones.

If you need a customized version please let me know.

- KRAMA-3+, 3-Loop blender with phase inversion, Parallel/Series setting & stacking order selection - active product

- KRAMA-3, 3-Loop Blender with Dry Mute & phase inversion - under redesign

- KRAMA, 2-Loop Blender, V3.0 (Type-1) - active product

- KRAMA II, 2-Loop Blender, Loop Selector - under redesign

- KRAMA Parallel Blender with Pan, phase inversion & XLR out. (dual rail supply inside) - discontinued

- KRAMA, 2-Loop Parallel Blender (1st version) - discontinued

Nomenclature:
KRAMA (Ancient Greek: Κρᾶμα) is the result of mixing two or more metals or other materials producing a somehow homogeneous mixture.

Compact PEAVEY footswitches

2025-11-29T22:59:00.007+02:00

Small footprint foot-switches for PEAVEY Amps. (e.g. XXL / Transtube Special 212 / Revolution 212 / Special 212 II / Revolution 112 II / 5150 Blockletter / 6505+, etc)

> PEAVEY 5150 Blockletter

> PEAVEY XXL

> PEAVEY 6505+

Check here all the available models or contact and let us know if you have a specific request.

Buffered Splitters

2025-11-29T22:59:00.006+02:00

Buffered Splitters that don't suck your tone.

dpFX Pedals builds custom buffered splitters by your request.

Below are some of our standard models. Check inside for prices and availability:

>> Contact Us for a custom request <<

.All the splitters here.

Pedals Store

2025-11-29T22:59:00.000+02:00

2-Loop KRAMA Blender, V3.0 (Type-1)

2025-11-29T22:50:00.037+02:00

2-Loop pedal blender, with Parallel/Series loop placement & kill dry function.

This blender is suitable for bass, guitar or any other instrument with conventional magnetic pickups, but it's also suitable for use with instruments equipped with piezo pickups that demand higher input impedance. You can of course use it with line level devices, synths, keyboards, etc.

KRAMA V3 (Type-1). Specifications in brief:

▹ Two independent, parallel loops A, B

▹ Parallel/Series loop placement selection through toggle switch (scroll lower for more info)

▹ Dry blend & Volume knobs for both loops. A, B knobs set the Return volume.

▹ Kill Dry toggle switch for instantly muting the dry signal.

▹ Boost up to +6dB for A, B & Dry (can be set to the value you specify)

▹ Phase inversion for both loops A & B ensure that you will overcome any case of phase cancellation during the blending process when using pedals that reverse the phase. [The phase inversion takes place after the Returns.]

▹ Standard TS jacks (6.35mm, 1/4")

▹ Input impedance: 10MΩ

▹ Return input impedance: 1MΩ
▹ Output impedance: 100Ω (OUT, SND)

If you want different impedance values please specify it prior to ordering.

▹ Power supply: 9-24V (center-negative). The higher the voltage, the greater the available headroom (~6Vpp@9V | ~10Vpp@12V | ~16Vpp@18V | ~22Vpp@24V).

[Do not exceed the recommended 9V supply voltage. Doing so may damage the circuit.]

▹ Current draw: 14mA

▹ Enclosure dimensions: 120 x 95 x 35mm (4.72 x 3.74 x 1.37in)

▹ Weight: 340gr

Details:

KRAMA gives you the ability to split your signal, route it through two separate loops, and blend them together with your dry signal. The signal volume of each loop (A and B), as well as the dry signal, can be controlled independently through the A, B, and DRY pots, which also offer a boost of up to +6dB.

EXTRA FEATURE: Parallel/Series switch.
- When set at 'Parallel', the two Return signals are mixed in parallel with the dry signal.

- When set at 'Series', loops A & B are placed in series with A being before B (A->B). The dry signal is still blended in parallel with the signal coming in Return-B. The A-knob is inactive since RETURN-A is directly routed to SEND-B, and the signal flow in the loops goes like this: SEND-A -> Loop A -> RETURN-A -> SEND-B -> Loop B -> RETURN-B

you can also use it as:

Mixer: Mix the signals of three separate sources by connecting them to 1.IN, 2.RTN-A, 3.RTN-B. These can be either different instruments, pedal chains or a combination.
Splitter: Split your INPUT into two outputs (SND-A, SND-B) without 'coloring' or degrading the original signal.

The above functions can be combined in many different ways, offering increased functionality and versatility.

IMPORTANT NOTES:

- To avoid hum, ground-loop buzz, and other possible noise, you should use an isolated power supply and avoid powering KRAMA from the same power cord used for other pedals.
- If you use this pedal to send the output to more than one amp, be sure not to create any ground loops, as they will most likely generate noise. If you need isolation check our isolated-output products.

▻ KRAMA-3, Triple Loop Parallel Blender

▻ KRAMA-ii Blender, Loop Selector

▻ Splitter-3x, Isolated w/ DI & phase reverse

BUY IT on our e-shop

Nomenclature:
KRAMA (Ancient Greek: Κρᾶμα) is the result of mixing two or more metals or other materials producing a somehow homogeneous mixture.

Piezo Buffer with Variable HPF

2025-11-29T22:49:00.006+02:00

Piezo Buffer for high impedance transducers, with Low cut filter.

This compact, always-on buffer features a 10MΩ input impedance and a variable high-pass filter (HPF) adjustable from 200Hz to 20Hz, which can be bypassed via footswitch. The buffer’s very high input impedance makes it ideal for piezo pickups that require proper loading to maintain full frequency response and natural tone when connected to amplifiers or pedals.

The active variable HPF, positioned after the buffer, lets you choose a cutoff frequency anywhere between 200Hz and 20Hz using the control knob. With a 12 dB/octave slope, it’s ideal for removing unwanted low-end frequencies that can cause feedback, boominess, or excessive sub-bass. It will work equally well with other active or passive instruments, as well as pedals, preamps, or in FX loops.

The foot-switch gives you the option to toggle the HPF in and out of the signal path in real time, allowing direct comparison between the filtered and unfiltered sound. The buffer always remains active, so your tone stays consistent.

> When & why you need It?
Piezo transducers can sound thin, harsh, or boomy when plugged directly into an amp or pedal due to impedance mismatch. This custom buffer provides the correct 10MΩ load, ensuring your pickup delivers its full tonal range—clear highs, balanced mids, and tight, natural lows.
Then, the HPF lets you tame unwanted sub-bass and boominess, tightening the sound and reducing stage feedback.

> Quick-start

- Typical Setup: Instrument → [Buffer + HPF]→ Amp / Preamp / Effects Chain

With the knob you can dial in just the right amount of low-end control.
- Start with the HPF around 12 o’clock, then adjust by ear to control feedback and tighten the low end.
- For upright bass, try 9–12 o’clock (≈150–100 Hz) to reduce boom, or 1–3 o’clock (≈60–40 Hz) to clean up stage rumble.
The above suggestions are only starting points and not rules that apply everywhere and always. The ideal setting each time depends on your pickup, instrument, amp, venue, volume, etc.
- Always make sure to check your amplifier’s EQ first.

Specifications:
▹ Input impedance: 10Mohm
▹ Output Impedance: 100ohm
▹ Voltage Required: DC 9-24 Volt (Use 12-24V if you need more headroom)
▹ Polarity: Negative tip
▹ Current draw: 7mA @ 9V
▹ Aluminum Enclosure, dimensions: 122 x 66 x 39.5mm [4.8 x 2.6 x 1.57in]
▹ Weight: ~250gr.

This device can be built according to your own custom specifications. Contact us.

▻ mini buffer (10M) with variable output impedance

▻ Ground Loop Isolator

▻ Impedance Changer

▻ 4-way splitter/switcher

2-input mixer, with volume controls & phase reverse

2025-11-18T18:39:00.013+02:00

2-mono inputs, mixed down to a single output. (Piezo compatible)

This compact mixer combines two mono (TS) input signals into a single mono (TS) output. Each input channel (A and B) has its own dedicated volume control, and input B includes a phase-reverse switch for solving phase-related issues when blending signals.

The mixer accepts both instrument-level and line-level (unbalanced) signals. Its 10MΩ input impedance makes it ideal for piezo pickups, which require very high impedance to preserve clarity and frequency response. Of course it is perfectly suitable for use with regular pickups as well.
(Note: If for some reason you require lower input impedance just let us know when you place your order)

If you need additional headroom—for example, when handling particularly hot line-level signals—the mixer can be powered with up to 24V, providing approximately 22Vpp of headroom.

The extremely high input impedance and low-impedance output ensure optimal interaction with your gear, helping your signal maintain maximum clarity, tone, and dynamics.

A few possible uses:

- Mix the signals of two instruments and route it to a single amp.

- Mix the signal of an instrument and a microphone preamp.

- Convert the output signal of a stereo guitar to mono and experiment with how the phase-inversion affects the resulting sound (e.g. useful for the 1978-Gibson ES-355).

- Convert a stereo signal to mono by mixing the L & R channels together.

Specifications:

▹ TS input (A,B) Impedance: 10Mohm

▹ TS output Impedance: 100ohm

▹ 2 knobs (A, B) for input volume control

▹ Phase inversion toggle-switch for input channel-B

▹ Power supply range: 9-24V (polarity: center negative)
▹ Approximate headroom vs supply voltage: 7Vpp@9V || 10Vpp@12V || 22Vpp@24V

▹ Current consumption: 8mA (@ 9V)

▹ Aluminum Enclosure, dimensions: 115 x 60 x 32 mm (4.43 x 2.38 x 1.22 in)

▹ Weight: 185gr.

(this is actually another version of our TRS to TS mixer)

▻ Matrix Mixer 4x4

▻ Stereo Effects Mixer

▻ Splitter 3x Isolated with DI & phase reverse

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Matrix Mixer 12x12, DC Coupled, Active

2025-11-13T20:46:00.003+02:00

Active, DC Coupled Matrix Mixer 12x12, for mixing Control Voltages & Audio

The device’s inputs & outputs are DC-coupled and can be used for Audio and Control Voltage mixing. The circuit is designed in a such a way so that it actively rejects the crosstalk among all inputs & outputs. It is suitable for instruments (guitar, bass, etc), synths, eurorack signals and any kind of line level signals.
All volume pots behave in a regular fashion, that is when the knob is fully counter-clockwise, no signal from the associated input passes into the mix. As the knob is advanced clockwise, a greater portion of the signal passes into the mix. (At max position there is unity gain.)
The mixer works with standard 9V pedal power supply which internally is converted to dual rail supply (-15V,0,+15V) in order to achieve greater stability and maximum headroom for the ICs inside.

IMPORTANT NOTE: When mixing multiple audio or CV signals you have to take into consideration the level of each signal you route to the inputs and set each knob to the appropriate level in order to keep everything inside the headroom span and avoid distortion. The device can easily handle signals that are at line level or much higher but since all inputs are DC coupled extra attention is required when summing multiple signals from different sources.

Specifications:

▹ TS 6,35mm inputs & outputs
▹ Input impedance: 1MΩ
▹ Output impedance: 330Ω
▹ Required power supply: 9Volt DC, Polarity: center negative
▹ Current draw: 500mA
▹ Weight: 2.28 kg
▹ Enclosure Dimensions: 275x173x65mm (10.82'' x 6.81'' x 2,56'')

▻ AC Coupled Matrix Mixer 4x4

▻ KRAMA-3 Triple Loop parallel blender

▻ Stereo Pedal Mixer

*/* I don't keep stock of this mixer. Please contact me for orders. */*

Low + High Pass Filter (in series)

2025-10-15T21:20:00.004+03:00

Clean-up your signal with LPF→HPF variable filters in series

This active filter is consisted of a variable Low Pass and a variable High Pass filter placed in series (LPF→ HPF).

For the LPF you can select a cut-off frequency anywhere inside the range 220Hz-16.5kHz by using the respective knob and for the HPF you can select a cut-off frequency anywhere inside the range 200Hz-20Hz by using the respective knob. The curve of both filters is quite steep offering a 12dB/octave attenuation.

The LPF will help you “clean up” the low end of you signal and the HPF will help you “clean-up” the harsh high end of your audio signal such as fret buzz, string noise, and higher harmonics or noise produced from other effects in your chain such as distortion pedals.

The device It will work fine with active or passive instruments, as well as with other devices such as synths, pedals, preamps, or even in FX loops. It can also be used with line level signals.

▹ HPF Cut-off frequency range: 200Hz-20Hz (12dB/octave)
▹ LPF Cut-off frequency range: 220Hz-16.5kHz (12dB/octave)
▹ Input impedance: 5Mohm
▹ Output impedance: 100ohm
▹ Voltage required: 9V (max 24V)
▹ Polarity: Negative tip
▹ Current consumption: 10mA
▹ Weight: ~123gr.
▹ Enclosure dimensions: 93x40x32mm (3.66 x 1.52 x 1.26in)

▻ HPF 200-20Hz with footswitch

▻ Impedance changer

▻ LPF 220Hz-16.5kHz

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Harmonic Triangle

2025-10-15T19:39:00.010+03:00

Explore the geometry of sound — shape your tone with the Harmonic Triangle.

The Harmonic Triangle is a powerful analog effect designed for creative tone shaping, advanced sound sculpting, and dynamic performance control. Making use of classic state-variable filter technology, the Harmonic Triangle offers expressive frequency filtering, variable resonance, gain, and practical output level adjustments. Unique to this pedal, the FREQ parameter can be externally controlled in real time via a standard TRS or TS expression pedal input.

The Harmonic Triangle is designed for guitarists and other musicians seeking unique harmonic enhancement and frequency sculpting. The pedal features 4 control knobs—FREQ, BW, Gain, and Volume.

Controls

- FREQ (Frequency)

Sets the center frequency of the bandpass filter.
Precisely controls the filtered frequency, from deep bass to upper mid-range (130Hz-2.1kHz).
Expression Input: Lets you sweep the FREQ parameter in real time for wah-like or filter effects.
Typical applications: Lower settings emphasize bass and warmth. Higher settings accentuate presence and upper mid-range for lead tones.

- BW (Bandwidth/Q)

Controls the Q, the sharpness and width of the frequency notch.
Lower BW settings yield a broad, smooth peak for subtle EQ or tonal coloration.
Higher BW settings produce a more focused, resonant peak for pronounced “cocked-wah” or notch filter effects.
Use higher settings for expressive, cutting solos or for accentuating specific frequencies.

- Gain

Adjusts the boost applied by the filter.
At high gain settings, combined with extreme frequency settings the filter can produce rich harmonic distortion and fuzz, especially with aggressive picking or humbucking pickups.
Subtle gain settings allow clean boosting for texture and drive.

- Volume

Controls overall output level for balancing with other pedals and amp input.
Essential for unity gain operation or volumes matched to performance needs.

- Expression Pedal Input

Use a standard TRS or TS expression pedal (ideally with a 50k log potentiometer).
Plug into the “Expression” jack to control the FREQ knob with your foot.
This creates dynamic sweep effects, similar to traditional wah pedals but with a more versatile frequency range and resonance.

▹ Voltage required: 9-24V (using 12-24V will provide you a little more headroom)

▹ Polarity: Negative tip
▹ Current draw: 9mA
▹ Enclosure Dimensions: 122 x 66 x 39.5 mm [4.8 x 2.6 x 1.57 in]

▹ Weight: ~260gr

▻ 4-band Equalizer, active
▻ Variable HPF 200-20Hz

▻ Variable LPF 220Hz-16.5kHz

▻ Impedance changer

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2-way, isolated, buffered Splitter (mini)

2025-06-23T20:12:00.011+03:00

Mini, 2-way isolated, buffered splitter. (V2.0)
- check the old/discontinued version here -

This is the 2nd Version (V2.0) of our classic mini splitter, with 2 buffered outputs. It's perfect for guitar, bass or any other instrument with similar pickup outputs, synths, etc and it can also handle line-level signals from any device.
The first output is transformer-isolated to prevent ground loops when connecting to multiple amplifiers. It also includes a convenient Phase-Reverse switch. This isolated output can even be connected to a balanced input. (TS jack).
The splitter allows you to split your instrument's signal without any degradation in clarity or tone. Both outputs precisely match the input signal level (unity gain).

Send your instrument's signal to two amps simultaneously, avoiding ground loops.
Send your signal into two pedal-boards, and a recording device (usually through a DI). While you play and hear your actual sound, you can record your clean signal at the same time. (in case you need it e.g. for re-amping)
Servers as a buffer.

▹ Voltage Required: DC 9-24 Volts (higher voltage gives you more headroom)
[Do not exceed recommended voltage! It may damage the circuit.]
▹ Max Current draw: 4.5mA @ 9V
▹ Input impedance: 4.7MΩ (can be set higher or lower if you request it)
▹ Output impedance: Output 1: 170Ω / Output-2: 100Ω (the impedance of output-2 can be set to a value of your choice)

▹ In the isolated output you can connect either balanced or unbalanced equipment.
▹ Equipped with indicative LED to show you when the pedal is powered.
▹ Enclosure dimensions: [ inches: 3.65 x 1.52 x 1.22 ], [ mm: 93 x 40 x 32 ]
▹ Weight: ~130gr.

▻ Splitter-3x, Isolated w/ DI & phase reverse
▻ 3-way isolated splitter
▻ Ground Loop Isolator

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2-way, isolated, buffered Splitter (old version)

2025-06-23T20:11:00.001+03:00

-- This version was discontinued (06/2025) --

>> CHECK HERE for the new version (V2.0) <<

This signal splitter has 2 buffered outputs and is suitable both for bass and guitar. The first output is isolated using a transformer in case you want to avoid ground loops when sending the output into different amps and it is also equipped with a Phase-Reverse switch. The isolated output can also be connected either to a balanced or unbalanced input.
The splitter gives you the ability to split the signal of your instrument without degrading your signal's clarity or tone. Each one of the outputs is equal to the input. Suitable for both bass and guitar or any other instruments with similar signal-levels (it can also handle lower line level signals)

▹ Send your instrument's signal to two amps simultaneously, avoiding ground loops. ▹ Send your signal into two pedal-boards, and a recording device (usually through a DI). While you play and hear your actual sound, you can record your clean signal at the same time. (in case you need it e.g. for re-amping)

▹ Voltage Required: DC 9-18 Volts (higher voltage gives you more headroom)
[Do not exceed recommended voltage! It may damage the circuit.]
▹ Max Current draw: 6mA @ 9V | 9mA @ 18V
▹ Input impedance: 3MΩ
▹ Output impedance: ~700Ω
▹ In the isolated output you can connect either balanced or unbalanced equipment.
▹ Equipped with indicative LEDs to show you when the pedal is powered.
▹ Enclosure dimensions: [ inches: 3.65 x 1.52 x 1.22 ], [ mm: 93 x 40 x 32 ]
▹ Weight: ~130gr.

▻ Splitter-3x, Isolated w/ DI & phase reverse
▻ 3-way isolated splitter
▻ Ground Loop Isolator

HYBRIS guitar preamp, FET-based

2025-06-05T13:28:00.023+03:00

FET based preamp offering a wide range of gain characters & tones.

The HYBRIS features four cascading FET gain stages and operates on 9V to 18V DC, allowing for a wide spectrum of tonal responses depending on the supply voltage. This means the Gain knob's behavior changes significantly - especially at lower settings.

With 9V supply, even with the Gain knob turned down, you’ll still get some grit - it's not a fully clean sound. As you turn the gain up, distortion comes in quickly. At higher settings, HYBRIS delivers high-gain tones that verge on fuzz-distortion.
With 18V supply, the pedal's character changes noticeably. With the Gain at minimum, the tone is very clean, though a slight grit may still appear depending on your guitar’s pickups. It can function effectively as a clean boost with EQ shaping. You'll also get: Increased volume, Enhanced Headroom and slightly different high-gain tonal response.

→ Tip: While supply voltage is a matter of personal taste, we recommend running HYBRIS at 18V to experience its full potential and dynamic range.

Knobs/switches:

▹ Gain: Sets the amount of overdrive/distortion. Includes a treble-bleed capacitor for tone consistency as gain changes.

▹ Volume: Controls the overall output level.

▹ Bass/Mids/Treble: Classic 3-band EQ inspired by Soldano Hot Rod tone stack.

▹ Hi/Lo toggle switch: Selects between two different gain structures.

▹ MaxGain-Footswitch: Instantly engages maximum gain, overriding the current Gain knob setting.

▹ Boost Vol.: Adjusts output volume only when the MaxGain footswitch is engaged. Its effect depends on the current Volume knob setting.

▹ True bypass

▹ Voltage Required: DC 9-18 Volt

[Do not exceed recommended voltage! Doing so may damage the circuit.]

▹ Polarity: Negative tip
▹ Current consumption: 3mA@9V / 4.5mA@18V

▻ dOTRsmoker-120 FET preamp

▻ 80s RIFFS distortion with boost

▻ NEMESIS+ Fuzz w/ expression

▻ ALASTOR mosFET Overdrive

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Nomenclature:
Ὕβρις (Hybris or Hubris) was an ancient Greek concept that referred to excessive pride, arrogance, or overconfidence, especially when it lead a person to defy moral laws, the gods, or societal norms. It had several different meanings depending on the context. In legal usage, it was used for cases of assault or sexual crimes, theft of public property, and in religious usage it meant emulation of divinity or transgression against a god.