Suggested DIY output transformers

for some of the schematics on this site


Baxandall 2x5 W class A 2xEL84

E-I 25x25 mm stack

Primary 2x1650 turns d=0,15 mm

Secondary 2.5 ohm - 42 turns d=0,7 ; 7,5 ohm 29 turns 15 ohms 29 turns d=0,9 mm


Mullard 2xEL84 /schematic to be available soon/

E-I 28x28 mm stack

Primary 2x1650 turns d=0,11 mm

Secondary 96 turns d=0,6 mm


Crystal 104 2xEL84 + 1xEL 84 /6P14P

Transformer 1

E-I 22x30 mm stack

Primary 1140+860+860+1140 turns d=0,16 mm

Secondary 140 turns d=0,64 mm

Transformer 2

E-I 16x30 mm stack

Primary 1000 turns d=0,18 mm

Secondary 30+20 turns d=0,59 mm


DIY Paralleled Push-pull /Circlotron/ 12 W /2xEL84/ 6P14P


E-I 25x25 mm stack

I. 2x50 turns d=0,9 mm

II. 2x80 turns d=0,9 mm

III. 2x740 turns d=0,31 mm


DIY Paralleled Push-pull /Circlotron/ 30 W /2xEL34/


E-I 28x45 mm stack

I. 2x45 turns d=2,0 mm

II. 2x58 turns d=1,4 mm

III. 2x250 turns d=0,4 mm

IV. 2x380 turns d=0,4 mm

V. 2x450 turns d=0,4 mm


More practical transformers to come

check regularly