Amp-fx EP Booster & Preamp // Handmade in Berlin.

Amp-fx EP Booster V. 3,5

THE discreet FET preamp for round and harmonious basic sound.

This has been the fastest selling Amp-fx pedal. A small 'always-on' preamp of top-notch quality. There is no better solution to fatten up your tone and add some sparkle (otherwise I would build that). It changes everything that enters towards: better, thicker, brighter, more present and more brilliant. The circuit is based on the legendary preamp of the Echoplex EP-3 tape-echo. In addition to the fantastic sound, the space saving design and the simple operation have also given the small pedal a lot of fame.

The tiny pedal will give you up to +20dB of shimmering clean boost. Its secret is a 2N5457 JFET. A hard to find barrier-layer field-effect transistor. It is know for its tube like amplification. The booster masters everything his exotic colleague from America can do and more. To adjust the height, depth and gain, there are 4 DIP switches behind the floor plate. Once set, they are left as they are.

It is tiny. Can be overseen, can't be overheard.
Technical data

The pedal has a TRUE BYPASS (no sound change when OFF) and comes with an elegant blue status LED.

9V - 18V DC Power supply via Boss-style power supply: Higher voltage = more Dynamic range = more Headroom = the signal has more space to unfold before it is cut off (clipping). Battery operation is not possible due to the pedal size.

Right = Input and DC Power
Left = Output. The popular Hicon 'Pancake' jacks fit easily.

Box dimensions:
93 x 39 x 31mm (L x B x H)

Current draw:
Less than 3mA.

Input Impedance:
1M ohm.

Output impedance:
1k ohm (minimum).

Super silent operation. Good supply-voltage filtering, no hum, zero background noise.

Best components used. Quality before quantity! Hand crafting takes time. I can't build as many pedals as others, but I can build better ones ;)

Solid and built with love:
Treat it well and it will survive us both.

A good place in your signal chain.

This actually is a booster that you turn on only once. You will fall in love with the new crisp sound and never switch it off again. (So the last thing to break will be the foot switch). But it shines in many positions:

Right after the guitar as a 'sound improver' and line driver to generate the necessary thrust for the effect chain. Works with all pickups very well.

Before the overdrive / distortion for more drive, bite and crunch in the sound.

After the overdrive / distortion for more brilliance and volume.

Modulation and delay perform better behind the EPB.

In the effect path of the amplifier as a volume boost.

Last in the chain right in front of a clean amp for significantly warmer and fuller sound.

But really just try out every possibility you can think of. One mans noise is another mans symphony. After all, I am just the engineer. You are the artist. Good luck my friend.

129 Euro.

The preamp gives you tons of options. Here's how to set it up:

The big black knob selects the gain factor.

Switch #1: +3dB Boost
OFF = Select gain between 0dB (unity) and +17dB .
ON = Select gain from +3dB till +20dB.

Switch #2: Bright switch
OFF = vintage mode
ON = modern mode = Amplify more high end, perfect for Humbucker.

Switch #3: strong bass boost.
For bass players. Everything down to 20Hz will be there.

Switch #4: weak bass boost.
Compare to the purple and blue line in the frequency response.

PCB with 4-pole DIP switch & mini manual.
I'm quite happy with it.
The story of the internal switches.

The Xotic EP booster version 1 (up to serial number 11012) had two internal switches. One for 'Bass Boost', one for 'Bright'. The guitar community immediately fell in love with the sound of the device, but were disturbed by the fact that the signal was amplified even with the knob all the way down. It was a bad buffer. The output was always louder than the input.

So in version 2 the bass boost was replaced by a + 3dB switch. If this is 'off', the output volume will be the same as the input volume when the knob is down. This is called 'unity gain' or 0dB gain.

Amp-fx has brought back the Bass Boost switch in two different flavors: Switch # 3 and # 4. Both boost the bass frequencies. Switch # 3 is much more drastic than # 4. If # 2, # 3, and # 4 are set to 'off', the signal has the largest center lift (mint green line). Each of the three switches bends the frequency response to be a 'more flat EQ', red line).

The Xotic V2 EPB have the bass always boosted at a maximum (#3 ON). A two-stage emphasis on the mids is only possible with the Amp-fx EPB.

Amp-fx EP-Booster. Handmade in Berlin.

3 year warranty

1 month return policy
Frequency range from 20Hz - 10kHz at maximum gain.

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