Here's FXDB's interview with Pravudh Sirinapaphaisarn of CircuitFX:
How did CircuitFX start?
In 1983, I had education about how to build and fix tube radios and tube amplifiers. I also worked in R&D for a surge protection system for almost 10 years.
One day, I visited the GuitarThai.com forum and showed them my pedals. Someone asked me to build pedals for him and they talked a lot about my pedal modifications and etched enclosures, possibly I was the first to etch pedal enclosures in Thailand. That is start of CircuitFX.
The main goal of CircuitGX is to sell PCB's for DIY'ers, not pedals, but most people know the handmade effects and my login (on GuitarThai) is Effectmaker.
I didn't get any help from others, my knowledge came from my job and education, but I did help lot of Thai DIY'ers myself and some of them became pedal manufacturers after that.
Obviously from Circuit + FX (effects).
I asked my brother who is an art director to create my logo. I told him how my pedals enclosures look like.
What sets CircuitFX apart from other builders?
I have no idea.
How do you start on a new pedal?
When I have some inspiration or a new idea I will start to test and spend a lot of time to complete them.Can you tell us something about the production process?
I build my pedals in my house and do it all by myself.
I design and make my own PCB's and for the enclosures I use etching and polishing to finish them.Is parts selection important?
Most of the time I use standard parts but sometimes I will use poly caps in the audio path of some pedals.
Which of your pedals makes you most proud?
I'm most proud of my Echo-6 pedal because it's not like any other pedal in the world.
If a pedal does not make me happy while building I will not do it.
Which of your pedals is the most popular?
Chorus and delay pedals are my best sellers.
Who uses your pedals and for which genres?
I build pedals after my own taste and if people like it, then can order them.
Some famous guitarists in Thailand use my pedals.
What does the future of CircuitFX look like?
No plans for the future. I'm not a business man, if you need a pedal I will take your order.
Are you working on any new products?