A Survey of Foster 443742 Variants: Measurements
This story originally appeared at InnerFidelity.comI'm going to spend the week parsing the differences between a number of the variants of the Foster 443742 (seen on page H-4 of this .pdf). This survey will include: Fostex TH900, TH900mk2, and TH610; Massdrop THX00; Denon ADH-D5000; and the E-Mu Teak stock, and with optionally available Rosewood and Mahogany cups.
The top-of-the-line model from America's leading headphone manufacturer, these are bulky, heavy, very business-like in appearance, and very, very good.
The ESP-9 is dual-powered: from the AC line, or from the input signal itself, The power supply is rather large and heavy, and appropriate in appearance to the phones. Amplifier connections are via wires with spade lugs attached, and speaker connections are made to the rear of the power supply. A front-panel switch selects speaker or headphone operation, and terminates the amplifier outputs with 10 ohms in the Phones position.
Construction is typically top-of-the-line Koss: Rugged, nicely finished, and apparently very durable, and the phones are easy to handle. (Many headphones are so loosely pivoted on their headbands that they swing into impossible positions whenever you pick them up.)