navin advani
Well-Known Member
Does Steve still winds the odd pair? He used to be highly regarded in the Singapore DIY community. I was told he is unable to do custom jobs nowadays.
Ishikawa san did every winding manually in a manual jig and then took the finished bobbins to another old man who used to work for Tango. The second gent would do the vacuum impregnation, lamination and pot the transformer. Ishikawa san would then do final testing including for HV and then it will be good to go. Both were finicky, eccentric yet adorable folks. I hope and pray they live long.
In my limited understanding I find following differences between a normal transformer and OPT
1. Normal transformer only deals with 50Hz/60Hz, whereas OPT has to deal faithfully with the entire audio spectrum.
2. the primary and secondary in an OPT has predefined Impedence, which the winder has to maintain.
3. High Impedance always acts as a low pass filter, in spite of that an OPT gas to faithfully produce up to 20K Hz sound.
4. OPT tend to saturate and this will limit the output (watts)
The biggest problem and cost point I see is that OPTs are normally all wound by hand with the winding lay alternating between primary and secondary sectikons. This is a terribly painful process and the winding must be kept very tight. Steven Tay, Mr. Ishikawa etc.. are all eccentric gents.
I do not know if either of them wind today.