Introducing the world’s first ultracapacitor-powered, “convertible,” directly-heated triode (DHT) linestage – the Vinnie Rossi LIO DHT PRE.

Have you ever wanted to hear what Class-A, directly heated triodes really sound like?  LIO DHT PRE is the only linestage to reveal the full sonic glory of DHTs by taking out of the equation the noise and distortion-producing elements commonly found in DHT amplifiers such as driver tubes, output transformers, feedback loops, cathode resistors, bypass caps and other sources of coloration. The triodes are powered by LIO’s internal ultracapacitor power supply and patented “SPVR” super-regulated filament supplies to achieve what some consider the ‘holy grail’ of DHT linestage design – the lowest possible noise, hum, and microphonics using a purist circuit topology.

When the Vinnie Rossi DHT PRE is used with any LIO configuration, you will be rewarded with the most direct and emotional engaging connection to the finest sounding 4-pin DHT triode families ever made!

“I put a spell on you…”

More than any other tubes used in a linestage, the 4-pin DHT family of tubes compatible with LIO DHT PRE offers you:

  • The richest tone
  • The most fully fleshed-out harmonic structures and soundstage layering
  • Awesome dynamics and attack
  • Midrange/vocals with a “reach out and touch the performer” effect
  • Music that becomes more lifelike across the entire frequency spectrum.

  • The resolution, openness, and flow to your music with LIO DHT PRE is exquisite – but most of all, you will enjoy a heightened sense of realism and emotion album after album that will leave you under a spell!

    Volume Control Features (included with all DHT PRE modules)
  • LIO NUDE RVC volume control module: uses the finest Vishay Nude Z-Foil resistors, delivering 64 discrete 1dB volume control steps that are precisely matched between channels. You will always achieve exactly the right volume level with perfect channel balance and imaging.

  • DHT Tubestage Features
  • Proprietary slide-switch “convertible” design compatible with: 2A3 / 45, 300B, PX4 / PX25, 101D / 205D, and SV811 / SV572 DHT triode families.
  • Class-A, single triode per channel (no driver tubes)
  • OTL (no output transformers used)
  • Zero Feedback
  • Purist, grounded-cathode design (fixed bias)
  • Dual “SPVR” patented, super-regulated filament supplies – fed from external linear DC supply (measuring approx. 6.5″ wide x 9.0″ deep x 3.75″ tall / 10 lbs.)
  • Yamamoto solid Teflon tube sockets / Vishay Nude Z-Foil resistors
  • Included tubes: EH 2A3 Gold-Grid (matched pair)

    Gain: Approx. 6 – 9 dB (depending on tube used)
    Frequency Response: From 10Hz to >250kHz (+/- 0.5dB), ultra-high bandwidth design
    External linear DC power supply dimensions: 6.5″ wide x 9.0″ deep x 3.75″ tall
    Weight: 10 lbs