Thöress 300B monoblock power amplifier Specifications

Sidebar 1: Specifications

Description: Monophonic single-ended-triode tubed power amplifier. Tube complement: one 300B, two EL803S. Input: 1 line-level. Maximum output power: 8Wpc into 16 ohms (12dBW ref. 1W into 8 ohms). Input impedance: 100k ohms. Input sensitivity: 3.25V RMS. Output impedance: transformer matched to 4, 8, 16 ohms (see text).
Dimensions: 13.4" (343mm) H (including tubes) by 5.9" (152.5mm) W by 23.3" (597mm) D (including output terminals). Weight: 28 lbs (12.7kg).
Serial numbers of units reviewed: None found.
Price: $12,995/pair. Approximate number of dealers: 6.
Manufacturer: Reinhard Thöress, Martinstrasse 17, 52062 Aachen, Germany. Tel./Fax: +49 (0)241-4091368. Web: US distributor: Audioarts, Inc., 210 Fifth Avenue, Suite 301, New York, NY 10010. Tel: (212) 260-2939. Web:

Reinhard Thöress
US distributor: Audioarts, Inc.
210 Fifth Avenue, Suite 301
New York, NY 10010
(212) 260-2939

manisandher's picture

I've just received my Thöress 300B monos, set up by Reinhard to work with Elrog 300B output tubes. Feeding my Tune Audio Anima horn speakers (109dB/W@1m), I have to say I have the most satisfying sound I've ever managed to achieve in this hobby. I concur with Art's description of the sound, though the Elrog tubes are substantially better than the regular Full Music tubes.

Reinhard took a frequency response measurement of the amps before shipping them out to me. The measurement was taken on the PRIMARY side of the OPT, with a 5 Ohm wire wound resistor as dummy load across the secondary. (He believes this is the best way to take the measurement as the OPT secondaries do not carry a ground potential.)

The amps measure -3dB at 7.5Hz and 150kHz. Also, there is virtually no OPT resonance above 150kHz. Pretty good for a SE amp with zero feedback! And as I said, they sound utterly fantastic.