HEADPHONE TRANSFORMERS

We offer a range of headphone transformers for single ended drive and drive from an ac coupled cathode follower.  A range of taps are provided on some models to give flexibility in the driving circuit and the headphone impedance.  It is always best to use all all the secondary windings to get he best high frequency response.  To select the ratio you want connect 1,2,3 or 4 windings in series and then connect any unused windings in parallel with the selected ones.

CHOICE OF TRANSFORMER  The transformer should ensure there is enough voltage and current (power) to drive the headphones.  The ratio of the transformer and the impedance of the headphones will determine the reflected load seen by the valve. It does not matter if the headphones see a reflected impedance of the valve which is lower than the headphone impedance.  The lower the impedance seen by the headphones the better.   The anode will see the headphone impedance multiplied by the ratio squared.

All types are supplied in a fully shrouded package.

TWO TRANSFORMERS are required for a stereo system.

		HEADPHONE TRANSFORMERS
TYPE	Application		Max Ratio	Pry Z (ohms)	Sec Z (ohms)	Primary inductance (H)	POWER (Watts at 50 Hz)	DC mA	Size	Core
8988	SE		16 or 11: 1+1+1+1	10k	600/300/150/40	41	2	40	D	Gapped M6
8976	SE		10:1+1+1+1	2k0	300/150/75/18	17	10	80	M	Gapped M6
8968	SE 10% NFB		15:1+1+1+1	8k4	600/300/150/40	40	10	30	J	Gapped M6
9351	SE EL84 Triode		12:1+1+1+1	5K0	600/300/150/40	20	5	45	F	Gapped M6
8665	AC coupled		12:1+1+1	10k	600/150/70	137	2.5	0	k	50% Mumetal