ST-85 Stereo Amplifier


This compact Stereo amplifier, using 4 EL34 tubes, delivers a solid 60 watts per channel and offers a full measure of the “VTL sound,” but at a real world price. Using the classic workhorse tube that was the foundation of the VTL sound, the EL34 models are studies in compact chassis with short signal paths. These rugged amplifiers are capable of delivering an exceptionally large sweet sound space from any satellite, mini-monitor or small floor-standing system. Listen to what one critic called “the weight of the brass, especially the trombones, is sensational”, and “… made me aware of just how good these units are at portraying those subtleties in music reproduction that matter to audiophile music lovers.” We accomplished this seemingly contradictory goal through careful engineering… An audiophile “best buy.”
ST-85 Black Finish
ST-85 top view
ST-85 back view

Functionality features

  • Compact Stereo Amplifier ideal for entry level systems
  • Musical sounding EL34 tubes in the output stage
  • Tetrode/Triode Switchable
    • 60 Watts per channel in tetrode
    • 30 Watts per channel in triode
  • Extruded aluminum front panel with luxurious, modern look – black and silver options available
  • Front panel comes with a window of thick tinted glass where you can see the glow of tubes


pdficon_smallST-85 Data Sheet

Technical Specifications

Vacuum Tube Complement 4 x EL34, 4 x 12AT7
Output power
20Hz – 20kHz <3% THD
Tetrode: 60 Watts, Triode: 30 Watts
into 5Ω
Class of output operation AB1
Input sensitivity 0.68V @ 60W
Input impedance 100kΩ
Optimum load range 2Ω – 8Ω
S/N ratio -95dB, 120Hz @ 60W
Power consumption Idle = 140W, Full power = 500W
Primary mains fuse rating 100/120V = 6A Ceramic Slo Blo, 220/240V = 3A Ceramic Slo Blo
B+ fuse rating 0.5A fast acting ceramic
Dimensions W x D x H 16 x 12 x 7 inches (40 x 30 x 18 cm)
Weight 45lbs (20.5kg) unpacked, 55lbs (25kg) packed


…The final ST-85 has in my opinion the characteristic sound of the great VTL which is quick and detailed enough without strain, open, natural, able to engage with any kind of music as long as the speakers are not inefficient or that the listening room is significant in size (in this case, you should consider products that are more powerful). But I remember that in an environment of about forty-five square meters what would be a decent local home dedicated to music, the ST-85 connected to the pre TL 6.5 and the electrostatic speakers Quad 2905 was more than appropriate and worthwhile, the ST-85 even with genres as demanding as opera played in full faculties, I never had the feeling the sound was limited to only 60 watts per channel…

…with a power of 60 watts per channel, which in the golden years of the valves was the maximum, and with a sound as that of the VTL, which is a reference, I recommend the ST-85 as a ‘bestbuy’ for those who want to make the jump to valves and ensure that the investment in time as well as in quality would pay off.

Read the full review here…

- Massimo Cives, Audio Review Italy, No. 308, February 2010


Read the full review here…

- Lonnie Brownell, Stereophile, February 1999