The HVO is the result of a question I asked myself -- is it possible to make a solid state pedal that sounds like a good
I have been dissappointed in all of the overdrive pedals that I have tried over the years. They all lacked
dynamics and sounded like mush. The ones that used discrete transistors instead of opamps sounded better, and I think this is
because opamps use a large amount of negative feedback, which kills dynamics. Even the pedals using discrete transistors still
didn't sound as dynamic and rich as good tube amps, though. I think part of the reason for this is that they are running at
a low voltage, 9V or 18V compared to at least 250V in a tube amp.
I decided to try to design a solid state pedal that mimiced
a tube amp as much as possible. The unique properties of a tube amp are that the preamp gain stages use triode tubes and run
at very high voltages. When over-driven the grids of the triode tubes conduct and clamp the input voltage.
The I-V characteristics
of transistors are very non-linear and very different than a triode tube characteristics. After much research and thought, I
eventually came up with a way to make a transistor behave much like a triode tube. Normally transistors have characteristics
that are very similar to a pentode vacuum tube. By using some ideas that others came up with and a few of my own, I succeeded
in making the transistors behave like triode tubes.
By using high voltage transistors and a proprietary internal power supply,
I was able to run the transistor gain stages at 250V. This is about the same voltage that's used in tube amps.
When I powered
up the first prototype and played a few notes, I was shocked as how much it sounded like a tube amp. All the harmonics and dynamics
were there. It sounded better than any other overdrive pedal I had tried. There were still a few bugs to work out, but
I had the answer to my question -- yes, it is possible to make a solid state pedal that sounds like a good tube amp.
took about 6 months of tweaking to get the prototypes working perfectly. Most of that time was spent minimizing noise
and getting the most amp-like tone.
The final results have far exceeded my expectations, and I am very excited about this pedal.
I'm confident that those of you who give it a try will find that it is the best overdrive pedal you have ever heard.