New Acoustat 120VAC to 15VAC Adapters / Transformers, Part Number TTA35TT, or A7300-01.  Each bid quantity is for One (1) Transformer.  You may bid / buy any number, up to the total quantity available above.

These were purchased at an industrial liquidation earlier this year, and they are brand new in the original factory boxes.  Best I can determine, they were made by Acoustat to supply power to some kind of electrostatic speaker system.  However, they should work great for any application where you need a small amount (150mA) of 15VAC power.

Update: According to one of our customers who has bought several of these, they are for most Acoustat Spectra 22 and 33 models, and the Spectra 2200 and 2300 models. The electrostatic speakers which used these had the 2123 interface.

According to the calipers

Overall length:  2.160 (excluding cord)

Overall width:  1.685"

Depth:  1.539" (excluding plug prongs)

Cord length:  6' (six feet)

According to the transformer label:

ACOUSTAT
PLUG IN CLASS 2 TRANSFORMER
UL LISTED E97199
MODEL NO: TTA35TT (A7300-01)
INPUT 120V 60 Hz 9W
OUTPUT: 15VAC 150mA
MADE IN TAIWAN