How to prototype with valves / vacuum tubes? 12AX7 or 6N2P adapter !


A bit more reach… with a Koy Boost!

A clean boost is a very useful guitar pedal since it can raise the output of quiet guitar pickups to deafening levels rock levels.  For this essential pedal project and often made in a basic way, I decided to embellish it with koy fishes  using an acid etching technique.


Dynamic Prototyping Pedal – Sound UNIQUE not CORPORATE nor BOUTIQUE!


This quote was the inspiration behind this build, because guitar amplifiers, effects, and music gear in general, in recent years has forked into 3 lanes ( from the same road ) :

  • The mass corporate production, which has millions of dollars for marketing, R&D, production and distribution. The benefits are consistency, warranty  and availability ( often they are not cheaper so I’m not going to add it as benefit). The downside is that they might not have high end quality parts, the musician gets a generic sound, low resale value, and some might be just copies of other well know products.
  • The boutique industry is smaller because it has small production runs, has little money for marketing and usually relies  on word of mouth and social media for promotion. The positive  things are non generic sounding ( usually), small production runs which means that less people have it, passionate people with specialized expert skills run the company, possible higher re-sale value if the brand gets more famous, and often durability and features are better. The negative side are high prices, limited availability and limited warranty.
  • DIY ( Do-It-Yourself) and craft industry, well, there are huge communities about it, these are people who build their own gear, from kits or  they find all information online and use the standard methods for electronic prototyping. On the upside there is the satisfaction and pride of making things, people learn new  facts and skills, yetrhave no limit of customization. The dark side is lack of consistency, the kits are usually copies of corporate and boutique gear, quality control is low, and they might be built just by someone who can pick up a soldering iron and not very unique because of that.

I personally wish to have unique tone, and created that opportunity by developing a portable Dynamic Prototyping Pedal. The original idea was:


Then I built it and looked like this. I realized that with it I can change the parts and play the result immediately in a true bypass fashion.


After using it for a while I realized it needed something more and I decided to add a second proto board.


Camera: Nokia Lumia
Year : 2016

The BOSS RC-3 is a compact loop station in a stomp box format that allows up to 3 hours of recording in stereo, and is compatible with a multitude of instruments and devices. Overall I think its a great jamming tool, either alone at home or with a band.  It can be operated with the in-built footswitch, or, with an additional external footswitch that makes it even easier to use in a live scenario because it opens up the possibility to scroll around the memory banks and set the rhythm with a foot. This video is a great tutorial.


The BOSS external foot switching in this pedal works in continuity mode, and the changes happen when the circuit continuity is broken. In other words the circuit is operated with a N.C. switch ( Normally Closed Switch ) which opens when the button is pressed.


Picture of required materials.
Picture of required materials.

List of materials:

  • Enclosure ( Plastic or metal,according to your budget )
  • 2 x Heavy duty SPST momentary footswitch
  • 2 x SPST latching toggle switch
  • Stereo 6.3mm jack
  • 22AWG cable
  • Soldering iron and solder.

To wire it up you can use this schematic.



Finished box.
Finished box.


After drilling and soldering it all together grab a stereo jack cable plug them together, and the result will be a switch that will help your methodical inspiration to come out and stay for eternity, somehow.


Switch and pedal together
Switch and pedal together




The Chime in a box, call it TAVTIB!


The Tweed American Vintage Tone in Box, I call it TAVTIB! The carry around brush to color your tone and sound like your self without breaking your back carrying a huge and heavy amplifier around.

The idea came to existence after finding a few articles about how some FET transistors have a tube-like transfer characteristic and produce harmonic distortion similar to tube triode, this meaning that they can sound a bit like a tube amplifier at low voltage.


After looking around the web for a while I found RunOffGroove and a project called the Fetzer Valve. This project was the first of many projects concerning adaptation of tube amps in to preamp/distortion pedals , the circuit it self is a popular DIY booster and  building block in larger circuits such as amplifier emulations in pedal format. Visit the page you will find lots of options.

I wanted american vintage sound with heavy mids and sweet highs of a Tweed era amp that could be styled easily due sensitive touch response with my P90 pickup. There are a few pedals in the market that could be purchased but the price was so high that motivation to close the wallet is instinctive.


TAVTIB specifications:

Technology: Vacuum Tube Emulation at low voltages with N-channel JFETs

Controls: Gain, Bass, Middle, Treble,Volume and Input selector

Input: 1

Output: 1

Special Features: True-bypass

Power supply: 9V DC with 100 mA (minimum)

Size (Height x Width x Depth ): 55mm x 83mm x 110mm

Weight: 150g