@monreq,
the Sakura is a low cost amp that delivers the goods.. 
...i bought the amp because of its novelty and the fact that it gave me more value supplying me with spare tubes.....
spending more money than what is cost you to acquire the amp is not a wise imho......
if the selling price at the time was 4,500 instead of 3,500 i would probably have not purchased that amp... 
you can even buy the same amp for 3000, here, http://www.pinoydvd.com/index.php/topic,123275.0.html
For me it's the sound that counts. The stock Sakura is basically good. Doing the right modification that will rival the P20K up amps is a steal. As for now, I could say that the sound is near to a real tube amp (not pentode but push pull type tube amp) for me, and others that already heard it. It's insane if I am the only one who can appreciate the sound. If many did appreciate it means, I am on the right track. My point is to rival amps that are in the category of P20K up. So, it's fair enough to spend some to make this amp be a rival of those amps in that category. In D.I.Y, with proper modification,I can have the sound that I really want...and for me my objective is to have the natural analog sound. Sabi nga ni Mang ROd (Trodt Tube Amp creator) "nasa tenga yan panu matimpla ng tama ang tunog ng Amp. Di mo makukuha ang tamang tunog sa computation lang. Kailangan may actual adjustment din na kung saan doon mo talaga maririnig ang tamang timpla. Pero kailangan at pinaka importante marunong ka talagang makinig. Kasi kung hindi, magiging sintunado ang tunog ng amp mo o di tama." Sa audio industry maraming kayang gumawa ng amp, pero konti lang ang marunong magtimpla ng tamang tunog. Kaya kung gusto natin pagandahin and tunog ng set up natin, kailangan muna alam natin ang tunog na tama. Musical Instruments etc. Di natin basta puwedeng palitan na lang ang bawat components sa tweaking. Kailangan din alam talga natin epekto nito sa tunog kung malaki or maliit ba ang effect niya. Trial and error din to get the proper sound. IYan ang natutunan ko kay Mang Rod.
Alam mo yan sir Tony, you are experienced in your field. Ang pinagkaiba lang natin mahilig ako mag explore kahit wala sa libro. Sa totoo lang wala kasi ako pambili ng tube amp ni Mang Rod kaya ako nagkakaganito. Masyado ako nagandahan sa gawa niya kahit nung dati na di pa niya na introduce iyong "interstage coupling transformer." Ewan ko kung iyon nga tawag dun. Basta iyong transformer ni Mang Rod ang nagdadala ng ganda sa amp niya. Kaya nga may ibang tube amp na branded kahit anung ganda, parang walang buhay or manipis tumunog. Kasi nga iyong transformer ang problema.
Cheers.
