From: Peter Kantchev -

Subject: electrostastic

Dear Mr  Ciuffoli. This is the information you've requested:

1.Original QUAD ESL-63 AUDIO Transformer  $240 ( SH/H: $12/USA; Italy $40
single, $65 double)  
 Custom made Transformers for Electrostatic Loudspeakers(made in USA):

2.Full range transformer     $440 (SH/H:  Italy $40 single, $65-2x)  

3.Low frequency transformer  $440 (SH/H  Italy $40 single, $65-2x)

4.High Frequency transformer $180 (SH/H   Italy $20 single, $30-2x)

5.Mylar DUPON 6mk-
(for two full range spks)       $19  ($8 sh/h)

As you know QUAD uses 2x transformers per speaker.
The custom made tansformers are push-pull - one per speaker.
Sorry, the Shipping/handling is expensive for Italy.

All transformers are 100 watt for the specific range.Kant