Nattawut Uamkruea, blogger and audio gear maker who passionate in vacuum tube, audio & music.
Producing electronics projects since high school. Seriously upgrade and modify vintage audio equipment for “Real Sound” concept.
He is a co-founder of Soundaries and Sentimental Studio, all audio solution provider.
Experienced and lively explore the listening rooms & audio shops in Japan as his most favorite to do.

Monday, August 5, 2019

Fantastic Feastrex Speaker Experience

Yamanashi is one of beautiful prefecture in Japan.

Not far from Mount Fuji and has many great fruit farms that so interesting.

Feastrex company located near the mountain in Nirasaki city.

The owner, Akiyama-san also do business with forest and rare mushrooms too.

He is smart guy and has so many special knowledge especially electronics & music too.

Feastrex word came from "Feast" that mean Celebration and "Rex" that mean King.

So "Feastrex" mean Celebration of the King!

Main specialty of Feastrex is field coil electromagnet speaker and only single driver

fullrange speaker in bass reflex cabinet.

You can see his website here http://www.feastrex.jp/indexeng.html

In my opinion, sound of this system is nice transient, dynamic with minor detail

and tone of every music instruments are real & joyful cause from missing crossover network.

Compare with his AlNiCo version, field coil easily won in micro details & sound stage

but AlNiCo still better than others in fullrange league.

Nice experience for me and my Japanese friend : Kubota-san.

Got more ideas and techniques back home. ;)


Main room with many speakers.


Prototype speakers & parts. 


Beautiful cone from "Washi" paper.


Interesting audio system!


EMT-930st, very nice quality and sound.


Sony SACD player and custom preamplifier.


CV4055 Push pull tube amplifier with all FineMet core transformers.


Field coil power supply with FineMet core transformers & chokes, film capacitors and SiC diodes.


Special parts wait for using.


Fantastic craft work for wood cabinets. 


Nice cross section of Feastrex!


Akiyama-san explain techniques to my friend Kubota-san.


Memorial picture of us!


Cheers!!!

Tuesday, March 12, 2019

Thailand Triode Meeting 2019 - January 16-19 : Audio

Next chapter after

http://mellowgroovy.blogspot.com/2019/02/thailand-triode-meeting-2019-people.html

Here are audio gears and what we do in TTM 2019.

Thanks again for our friends who brought their professional equipment, knowledge and kindness to share with us.

Everything cannot happen without all of you, this is true magic moment for Thailand team and all participants.

If I've forgot somebody or some stories please blame my brain not my heart.

Thanks guys!


Almost Thailand team with master Jean Hiraga.

From left back : Nattawut (me, organizer team, Soundaries co-founder), Tanawat (organizer team, Soundaries co-founder), Thana (speaker owner), Tosapol (organizer team), Monsan (organizer team, homemade field coil speaker system owner), Wasu (organizer team, turntable owner).

From left front : Kritapas (head of organizer team), master Jean Hiraga, Amnuay (speaker owner).


First was Thai team had produced prototype of field coil drivers assembled in open baffle, Mr Monsan took responsibility for this project.

2 of 15 inch woofers & compression driver with horn from 3D printer!

Homemade power supply and crossover network. Everything are prototype for experimental but sound fantastic and we've got suggestion to improve from many people here.


We brought all of these stuffs from Bangkok to Chiang Mai!


Tune up along the event. So fun!


My new push pull amplifier based on WE131A use with P&C pre-amplifier for this system.



Finish assemble field coil speaker sets and do GPA 604-8E next.


Mr Wasu with beautiful GPA 604-8E from Great Plain Audio.


Using with Altec 612 plan cabinet.


Suzuki-san from G.I.P. also interest in our homemade field coil speaker system.


Master Jean Hiraga suggest Mr Monsan how to improve field coil power supply.


Night party in this room.


Martina Schoener who was a DJ with her selected music.



Next was the main speaker for an event.


We've using Altec A5 : 515B woofer & 288C compression driver with 1005B horn.

Crossover network has custom designed by Jean Hiraga and then components selected and assembly by me. 

Other improvements are from Jean Hiraga with decades of his experience.


Then we need to damp inside Altec cabinet with felt.


He's attach felt with glue by himself!



Inside cabinet after felt attached.


Mr Thana who has Altec A5 in his home too also interest so much.


Modify diaphragm with silicone damping.



Adjust some components at actual listening location.



Amazing component! This Mica capacitor was fulfill the mid range. 


Replace original Aluminium diaphragm with Pascalite diaphragm from GPA.


Also damp metal horn with Blu Tack!


This is WE13A replica from Mr Sasamoto who ship this large system from Japan to join this event!

Jean Hiraga also introduce before demo this amazing mono system.


Japan team work so hard for set up the system.



Custom amplifier with large WE241B tube.


Fantastic sound from Grommes amplifier.


Digital setting gears.


People also help and suggest along demo.


Jean Hiraga introduce before phono shoot out period.


Mr Kritapas prepare equipment using in shoot out.


Use awesome GM70 tube amplifier from Benny Glass (Aqua Blue) with JBL Paragon.



Thorens TD-124 with Denon DL-102 mono cartridge is the subject.


First was adjustable EQ phono preamplifier from Martina Schoener.


Next was Mr Praditchya with his LCR phono preamplifier.


Me with Air-Capacitor in RIAA EQ was the last.


Light from Jean Hiraga, thanks so much!


Audience for vote!



Mr Praditchya was the winner! Martina & me were the co-second from vote.


Mr Praditchya's LCR phono preamplifier in wooden box.


My phono preamplifier with separate power supply.


Interesting lecture from Master Jean Hiraga about historical of loudspeaker and how crossover network important.


My dream came true, I've got autograph from Jean Hiraga on cover of his own book.

Thanks Benny who brought this book to me from Belgium!


Next was cool lecture from Chris Chang (Etracer) about tube matching and harmonic distortion.


Final setup : Altec A5 + JBL 075 tweeter and JBL Paragon

P&C 262B tube preamplifier and P&C WE91 300B monoblock amplifiers

GM70 SE from Aqua Blue

NOS 16 x PCM56-K DAC from Monsan Labs

Moon 230D with TCXO clock as transport


Listen live recording from Nagra IV-S reel tape together.


Aqua Blue "LED" glow in the dark! 


Until we meet again in some of next Triode meetings.

Cheers!!!