Can a tube system play metal? Listening notes on 300B and 45 amplifiers

Tube amplifiers have a reputation for being soft: warm, sweet and slow, fine for jazz and voices but out of their depth with thrash, death metal and fast double-kick drumming. In 2019 one listener set out to test that reputation on Demograf Audio equipment. He is a drummer who plays rock and metal, and he took his own music to two systems: a headphone system built around a Demograf Audio CS4397 tube DAC and a 300B amplifier, voiced by its owner for jazz, and a system with a new amplifier on 45 triodes driving full-range loudspeakers and planar headphones. These are his listening notes.

These notes come from the Demograf Audio side: they were written in 2019 by a listener who today has a commercial relationship with Demograf Audio. They are one enthusiast’s subjective impressions, not an independent review and not measurements. The units described are earlier builds; the current models are Hyperion (CS4397 DAC), Atlas (300B) and Solaria (45).

Why test a tube system on metal?

For this listener, metal is the hardest test of an amplifier. Distorted guitars, blast beats and dense mixes expose smeared bass at once, and in his view a deformed low end is the surest sign of a weak amplifier. Jazz told him little in a quick comparison; his own thrash and death metal tracks made the differences obvious at once. On the forum, the CS4397 DAC had a reputation for not being able to play metal at all, so he came to check.

The 300B amplifier with the Beyerdynamic T1

He listened through the first-generation Beyerdynamic T1, a 600 Ω headphone, with the volume control at around one to three o’clock. His summary of the 300B amplifier:

• Tonal balance: slightly light with the T1, with a midrange that is soft and pleasant rather than bright.
• Bass: not fat but precise and fast, enough for any music, with clearly audible decays.
• Treble: crystal-clear, which also makes flaws in recordings audible.
• Metal: thunderous, as it should be, and fast enough for thrash. He enjoyed death metal too; for black metal he thought it might be a little bright.
• Rock, jazz and blues: pure pleasure, in his words.

At first he told the host that the amplifier sounded bright. Then he realised the cause was the first-generation T1 and its treble peak: his own amplifier at home smooths that peak, while the 300B amplifier showed the headphones as they are, strengths and weaknesses alike.

Against another small maker’s headphone amplifier

At home he used a headphone amplifier by another small independent maker with his own DAC. He liked that combination on metal for its heavy, dark bass. The Demograf Audio amplifier, he wrote, was a different story: it showed at once that his DAC was the weak link in his chain. He described its speed as just right and its bass as textured, present in the right amount without exaggeration. Both amplifiers made him want to dance, but he heard the Demograf Audio amplifier as more realistic and more truthful in timbre.

The DAC with darker planar headphones

The turning point came with a different pair of headphones: a TDS-7 planar rebuilt by the maker Snorry in Audeze LCD-3 housings, played from the Demograf Audio DAC through an Audio Note amplifier.

• A very cohesive, juicy and full sound, with more detail than he had heard from planar headphones.
• Dark headphones with mighty bass: from every kick drum and bass-guitar note came a wave, as he knows it from concerts.
• On death metal he could tell which of five toms the drummer was striking, not just when a stroke landed.
• Guitar distortion sounded exactly as much as a carefully set-up guitar should have, and he could hear the gaps between riffs.
• Against the TDS-7, the T1 felt hurried, as if the drummer were rushing; with the TDS-7 he stayed for an hour and a half, even on tracks he does not usually like.

Because the TDS-7 is dark and the DAC and amplifier are light, the combination came out balanced, without obvious peaks. His conclusion: the system demands good recordings and shows them as they are, and it can play metal. You simply have to choose the right headphones.

A 45 amplifier on thrash metal

Later in 2019 he visited another owner, who had just received a new Demograf Audio amplifier on 45 triodes and also listens to metal. They played mostly Sepultura, Slayer and Metallica, through full-range loudspeakers and through TDS-15 planar headphones rebuilt by Snorry.

With loudspeakers

• The 45 is not a powerful tube, but the amplifier drove both the full-range loudspeakers and the hard-to-drive TDS-15.
• A warm, full-bodied sound with thunderous bass that conveyed the mood of thrash metal.
• Very fast, with a charismatic presentation that he found well suited to heavy music.
• Treble without glare, and a very deep stage, which he considers important in metal.

With the TDS-15

• A very deep but narrower stage.
• Monumental bass, less heavy than the TDS-7’s but with more snap, at a similar speed.
• Midrange and bass with strong bite and good decays, and an aggressive presentation overall.

He summed it up as tube warmth combined with a high speed suited to heavy metal, an excellent midrange and the grip to drive demanding headphones. Building a system of loudspeakers and headphones for a genre recorded as poorly as metal is hard, he added, and the point is to enjoy the music.

What these notes suggest

• Speed and bass control matter more than “tube” or “solid-state”. What made metal work in both systems was fast, textured bass without bloat.
• Headphone matching decides. A revealing tube chain with bright headphones can turn harsh; with darker planars the same chain sounded balanced.
• Voicing matters. The 300B system was tuned for jazz. Not every listener agrees with these notes: one independent listener found the same 300B amplifier too soft for heavy music, as we report in Demograf Audio 300B amplifier and CS4397 DAC: a headphone system reviewed by listeners.

The honest answer to the question in the title is: yes, a tube system can play metal, if the amplifier is fast and controlled, the headphones suit it, and the recording is good enough to survive a revealing chain. The best test is your own music.

Which Demograf Audio piece fits

• Fast bass for rock and metal: Solaria, a single-ended Class A integrated on two 45 triodes, 2 W per channel, for headphones and high-sensitivity loudspeakers, also available as a push-pull version with double the power.
• A warmer midrange with weight: Atlas on 300B triodes, 5 W per channel, with 6.3 mm and 4-pin XLR headphone outputs.
• The source: Hyperion, the CS4397 DAC, with a solid-state output or a tube output stage on EF14, EL8, AL4 or ML6. Our guide to power triodes in single-ended amplifiers compares the 300B and the 45.

Every unit is made by Dmitriy Gubchenko. Each is made to order with a one-year warranty (extra warranty available: +1 or +2 years), so tell us which headphones and music you use before the build starts.