Hi, since in Europe I need to find an alternative to the Edcore output transformer.
Have put in an order for a bespoke version:
10W, single ended tube output transformer for 8K Ohms to 4/6 Ohms.
Primary impedance in range around 8000 Ohms
preferab [/quote]ly (though 6000-8500 is OK).

They have made some prototypes and initially did mention some problems eg. prototype #2:
"My second prototype unit improved in performance from the first but not enough to meet our specified limits in frequency response of ±1db from 70Hz to 15kHz.
I meet the high end of the frequency limit 15kHz for ±1db for all secondary taps BUT I don’t meet the low end of the frequency limit of 70Hz (-2.30db) for any of secondary taps."

Now they came back with two graphs (need to scroll below) for prototype #3, saying they are improving but not entirely there.
Can you help me interpret them, I have trouble doing so. Thanks in advance



(main thread for my build.)