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€11,830 pledged of €19,900 goal
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By Mathias Poets & Alex Poets
€11,830 pledged of €19,900 goal
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What is a prototype?

A prototype is a preliminary model of something. Projects that offer physical products need to show backers documentation of a working prototype. This gallery features photos, videos, and other visual documentation that will give backers a sense of what’s been accomplished so far and what’s left to do. Though the development process can vary for each project, these are the stages we typically see:

Proof of Concept

Explorations that test ideas and functionality.

Functional Prototype

Demonstrates the functionality of the final product, but looks different.

Appearance Prototype

Looks like the final product, but is not functional.

Design Prototype

Appearance and function match the final product, but is made with different manufacturing methods.

Production Prototype

Appearance, function, and manufacturing methods match the final product.

447bb8dc26021a2e6d12d782f4fa831c original

Prototype Gallery

These photos and videos provide a detailed look at this project’s development.

About this project

The poets One is a multi-channel guitar preamp performing all the great rock distortion tones from brightly flared crunch to brutally dark high gain.

It emulates classic and modern tube amps with true analog sound circuitry in order to avoid the monotony of digital amp modeling. Use it anywhere with all the convenience possible – standalone or controlled with your smartphone.

The poets One has four channels, each representing a different gain stage with its own unique voice. It offers you a very bold soundscape with a variety of distinctive amp tones, seamlessly transitioning from blues to classic rock or hard rock to metal. Bubbly sparkling crunch sounds are possible as well as a dark and punchy high-gain pandemonium. Plug into the poets One, and playing the first notes you'll notice the amazingly tight bottom-end and the crisp treble. Harmonically rich and detailed chords go along with resonating single notes, even when cranking up the gain further. Let's give you an idea of what the channels sounds like:

Texas Twang: A shimmering bright and very dynamic sound with sparkling distortion on top, inspired by the tweed amps of the early sixties. Great for Jazz, Country and Blues.

British Classic: This channel nails the sound of amps like Marshall’s Plexi and Super Lead. It offers a crunchy, growling distortion which is adjustable in a wide range with your guitar’s volume. A perfect match for any kind of rock, blues and punk.

British Modern: A “High Gainer” with creamy compression that invites you to explore all the varieties of metal sounds – from eighties Heavy Metal to brutally dark.

U.S. High Gain: In the tradition of Californian high gain amps, this channel offers you an ultra fast attack, a vivid reaction and virtually unlimited gain reserves. Suitable for any kind of clear and powerful lead sounds, it is adjustable for a wide range of musical styles.

Controlling the preamp can be easily done with just two buttons: A true bypass switch for enabling or disabling the unit and up to six presets that can be selected by pushing a momentary switch. The pedal’s state and the active preset are visualized by six LEDs.

You can use your smartphone to modify existing sound presets or create new ones. The poets One app provides the following functions: channel selection, preset selection, storing and retrieving the presets. Additionally, the sound of a preset can be adjusted by controls for Boost (Texas Twang only), Gain, Volume, Treble, Bass and Mid (amp voicing).

The poets One remote app
The poets One remote app

For power supply, use a 9V battery or a supply unit with 9V – 12V and (-) polarity on the inside (“BOSS standard”). The power consumption will be about 55mA max. Two LEDs allow monitoring of the supply voltage – green: voltage is okay, red: change battery by time.

Bluetooth is supplied by a certified Microchip Bluetooth Low Energy (BLE) module. For switching the wireless connection on or off, you need to press and hold the select button for more than 3 seconds. The BLE status is visualized by a blue LED.

Creating the poets One

In October 2015 we started looking for a small, affordable guitar preamp with several channels and a dynamic sound that comes as close as possible to high quality tube amps. And it should have smartphone based real-time operability and all the convenience that comes with it.

But we found nothing to fit the bill. It seemed that there was merely the choice between an analogue stomp box with only one good sound configurable via potentiometers or a digital modelling device with intuitive setup but poor sound.

So what constitutes a “convenient device with a perfect guitar sound”? How can all the advantages of analogue and digital worlds can be combined? That was the point at which we decided to create the “poets One”. Here are the main features we put on our wish list:

  • Stompbox sized preamp for maximum mobility and acceptable cost
  • Four channels with different basic amp sounds from Tweed to Rectifier
  • True analogue signal path with tube-sounding distortion and high dynamic response
  • Every sound must be adjustable in its voicing, tone color, gain and volume
  • Battery or power supply unit operation with voltage monitoring
  • “Two button” design – true bypass and preset retrieval (momentary switch)
  • Convenient smartphone based real-time adjustment via Bluetooth
  • Possibility to save and retrieve sounds to several presets
  • Visualisation of presets with high luminance LED
  • Stage friendly standalone operation (Bluetooth disable function)
  • Input stage suitable for all kind of guitar pickups
  • Output impedance suitable for a connection to any (clean) amp

We started with the development of the analogue audio section of the circuit. Because our device should be battery powered we decided to use semiconductors instead of valves to emulate tube sound as close as possible. Another point is that the settings-adjustment circuitry should be digital to allow smartphone based control. In addition, digital control components can’t withstand the high voltage common to tube circuits.

It was a stony road. We tested hundreds of diodes, op amps, capacitors and other components which would be responsible for a perfect sound and added several weeks of LTspice simulation. The goal was to emulate tube distortion without compromising dynamic response and to avoid the noisy and jarring sound typical when using semiconductors for signal clipping.

Another major challenge was the tone stack design. In particular the mid filter should be able to manipulate the preamp’s voicing range from “classic tweed” to “modern metal”. We achieved this by designing a filter where the amplitude, centre frequency and Q-ratio can be adjusted with just one control.

Upon completion of the sound stages the first prototype had been created – albeit a breadboard design with mechanical switches and potentiometers.

The breadboard prototype
The breadboard prototype

The next challenge would be to develop a digital control that doesn’t affect the audio quality. Checking out a lot of digital switches and potentiometers, it turned out that only a few components on the market would be suitable for our purposes. We envisaged that the link between control circuit and smartphone would be an Arduino equipped with a Bluetooth low energy (BLE) module. But we soon realised that the open source Arduino software is not efficient enough for our needs. Additionally the Bluetooth module had a big issue with latency.

So we developed a completely new control unit, coded our own operational system for the underlying Atmel microcontroller and chose a professional Bluetooth module with the possibility to implement a private BLE stack.

While we where at it, we also decided to create a complete new housing. Almost every FX pedal uses Hammond aluminium cases. But using Bluetooth inside a metal case isn’t ideal and it also seemed a good idea to have a modern design with a direct view into the inner PCB and several LEDs. Eventually we designed a 3D-printed housing with a massive transparent cover out of hardened plexiglass XT.

Designing and printing the housings
Designing and printing the housings

Having a functional breadboard design is one thing – creating a professional mixed signal SMD unit on a multilayer PCB another. Parallel to the programming of an attractive iOS app with intuitive handling we had to suffer disappointment on our first PCB. Due to the high gain of the audio circuit and the pulses on the digital part of the power supply caused by the BLE module we had several EMC issues. Furthermore, numerous SMD film capacitors downgraded the audio quality and therefore we had to take a step back and replace them with through hole parts. At that time we began to work with professional German manufacturing companies in order to ensure the best manufacturing quality possible for PCB and SMD soldering.

SMD assembly of a prototype
SMD assembly of a prototype

During the entire development process our guiding principle was to make no compromises in respect of sound. After nearly one year of work, two PCB redesigns, a new ground concept, a special power supply circuit and different revisions of the case we finally had a fully functional “golden master”. And after half a year of testing the poets One on stage, in the studio and practice rooms with professional guitarists we are proud to present it to you on Kickstarter:

The poets One.

About us

Hey there, this is Mathias and Alex Poets from Hanover, Germany. Mathias is an electronic engineer and experienced in building, servicing and repairing tube amps. Alex studies computer science at the university, he is proficient in app development and embedded programming. We just wanted to know if it’s possible to create a true analog guitar preamp with tube-sounding distortion and a smartphone based control, which we started developing nearly 2 years ago: the poets One. For further information on us check out our bio. :-)

Why support us?

The development process involved many of our (musician) friends who always were on hand with help and advice. Without them we wouldn't have come as far as proudly presenting the poets One here on Kickstarter. Please join our little community and help us by backing this project. Due to the expensive high-end audio components and the SMD assembly it's not possible to manufacture small quantities of the poets One at acceptable costs. Depending on the funding level, we will have to acquire either 3D-printers or injection molds needed for the manufacturing of the housings.

If you are ready to accompany us, please support our campaign and spread the word! Become a backer and help us bringing the poets One into the world.

Risks and challenges

With over 25 years of experience in electronics manufacturing (Mathias was a leading manufacturer of PC diagnostic hardware in Europe) we have many contacts in the business. The obstacles of manufacturing high quality electronic devices within the intended timeframe are well known to us. As we're relying on several local manufacturing sites, we don’t have the timing or quality issues you will face when manufacturing in Asia. Our preamp will be thoroughly ”made in Germany”. Unexpected component shortages may result in a delay in the production schedule. In order to prevent this, our component selection strategy has always considered acquiring the components from multiple sources.

The development of the iOS app is nearly finished and at the end of the beta testing phase. The programming of the Android app is currently in progress.

The first stage of manufacturing the poets One is the acquisition of components, which will run simultaneously with the making of PCBs and the 3D-printing respectively injection molding of housings. The second phase includes electronic manufacturing, followed by assembly and testing. Shipment will start four months after the campaign’s end.

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    Premium Supporter Package

    1x poets One
    1x extra housing in the color of your choice (there'll be a few options to choose from)

    Be super supportive and select this package! You'll be able to switch the color of your poets One. How cool is that!

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Funding period

- (60 days)