14-05-2023, 04:02 PM
Wotcha Tracy, hope your in good fettle. I've bought several OPT's from John @ Primary Windings and used them in several valve amp builds. They are very well wound with decent specs for a really good price. Primary & secondary windings are interleaved, primary's have high inductance and sufficient laminations for decent LF response, L leakage is low as is pri/sec C. Windings are well impregnated with varnish. I've tested them from 10hz up to 100khz, with NFB and a decent design I got 20hz to 45khz -1dB, not bad for about £100 each.
After leaving the EU cheap OPT's & other iron is harder to find, Toroidy in Poland - https://sklep.toroidy.pl/en_US/index is still good value but less so than previously due to customs fees & a weaker exchange rate etc.
Andy.
After leaving the EU cheap OPT's & other iron is harder to find, Toroidy in Poland - https://sklep.toroidy.pl/en_US/index is still good value but less so than previously due to customs fees & a weaker exchange rate etc.
Andy.
