Hybrid dual monoblock amplifier
HT-120
Tube soul. Absolute control.
Our reference. Two independent monoblocks in one chassis, each with its own 300 W toroidal transformer, fed by a class A tube input stage. Handcrafted in Poland.
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Hybrid topology Class A tube input, solid state power -
2 x 120 W into 8 Ω, 180 W into 4 Ω -
Dual monoblock Two 300 W transformers -
Jantzen Z-Cap Coupling capacitors -
Hand wired Built one at a time -
Listening By appointment
Crafted to inspire
The HT-120
The sound
Natural. Dynamic. Effortless.
The HT-120 sets out to disappear. A tube stage running in class A gives the music its body and its colour; the solid state output sections hold everything in place, so quiet passages stay quiet and loud ones never harden.
With 120 W a side into 8 ohms and 180 W into 4, it has the current to drive real loudspeakers in real rooms without ever sounding like it is working.
- Rich, natural midrange from the class A tube stage
- Deep, controlled bass
- Airy highs without harshness
- Effortless dynamics at any level
- Fatigue free over long sessions
Inside the HT-120
Hybrid engineering. Timeless performance.
A dual monoblock design in a single chassis. Each channel gets its own 300 W toroidal transformer and its own power supply, so one channel can never rob the other.
The tube stage runs on stabilised heater and anode supplies of its own, and the mains arrives through EMI filtering and a dedicated DC blocker.
- Tube input stage Two 6SL7 tubes in a custom designed SRPP stage, class A.
- Solid state power stage Bipolar output devices in class AB, for grip and headroom.
- Selected components Jantzen Audio Superior Z-Cap coupling capacitors throughout.
- Clean mains EMI filtering, a dedicated DC blocker and digital management.
Every figure, in one place
Technical specification
Topology
- Type
- Hybrid stereo amplifier, dual monoblock
- Preamplifier stage
- Tubes, class A, 2 x 6SL7
- Preamp circuit
- Custom designed SRPP stage
- Final stage
- Bipolar configuration, class AB
- Coupling capacitors
- Jantzen Audio Superior Z-Cap
- Mains conditioning
- EMI mains filters, DC blocker, digital management
- Transformers
- Two separate 300 W toroidal audio transformers
- Supplies
- Stabilised heating and anodic voltage for each preamp, separate supply for the power stage
Performance
- Output power
- 2 x 120 W RMS @ 8 Ω, 2 x 180 W RMS @ 4 Ω
- Max input voltage
- 5 V RMS
- Input sensitivity
- 0.7 V RMS
- Input impedance
- 50 kΩ
- Power factor
- 600 VA
Connections
- Analogue inputs
- 1 to 3 unbalanced RCA line
- Optional inputs
- Bluetooth
Physical
- Dimensions
- 430 mm (D) x 435 mm (W) x 185 mm (H)
- Weight
- 25 kg
Specifications as published by OSV Audio. Bluetooth is an option, not fitted as standard.
Trusted by audiophiles
Reviews & Awards
The press has reviewed the HT-50 to date. These are reviews of that amplifier, not of the HT-120.
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ConvinceMeAudio
It's extremely weighty, very resolving, very punchy, excellent black background, enormous stage. It excels at driving inefficient bookshelves and moderate tower speakers, offering excellent control over mid-bass and sub-bass frequencies. Its ability to create a holographic image and provide tonal density makes it competitive with significantly more expensive integrated amplifiers.
Koji YouTube · 28:42
Video review
Watch ConvinceMeAudio on YouTube, opens in a new tab -
The Greek Audio Geek
It's so much better than it has a right to be. I'm not sure I've ever heard an integrated at or near this price… that comes anywhere close to this. This was able to produce that rhythm, that timing, that pace, that openness, that airiness.
YouTube · 16:55
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HiFi Pig
Everything was there that you needed: bass power, treble detail, and a beautiful midrange.
Janine Elliot November 2023
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HiFi Knights
One hell of an amp that outperforms most of those I know, and some more expensive ones too.
Marek Dyba November 2024
Highly recommended
Read HiFi Knights, opens in a new tab -
Audio Muzo Fans
A sound full of colour and natural dynamics, yet without the haze and heaviness so often associated with tubes.
December 2025 translated from Polish
Rekomendacja
Read Audio Muzo Fans, opens in a new tab
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HiFi Pig 5 star review -
Audio Muzo Fans Rekomendacja -
Bass Player Magazine Gear of the Year 2019 awarded to JK Amplifiers, the workshop OSV Audio grew out of
Video reviews
The press has reviewed the HT-50 to date. These are reviews of that amplifier, not of the HT-120.
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11:45 OSV Audio HT-50: Polski wzmacniacz, który zawstydza gigantów?
audiomuzofans.pl
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28:42 The Tungsten-V2, Immanis & Susvara MONSTER! OSV HT-50 integrated amplifier
ConvinceMeAudio
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16:55 Best Kept HiFi Audio SECRET? OSV Audio HT-50
The Greek Audio Geek
Built by hand, heard for years
Craftsmanship without compromise.
Every HT-120 is assembled by hand in Poland by people who care as much about your music as you do. From hand wiring to the final listening test, we take the time the amplifier needs.
We build in small batches. Nothing leaves the workshop until it has been listened to.
Experience OSV Audio
Book a private listening
Hear the HT-120 in your own system. Book a private session at our workshop, or in your own room.
Tell us what you listen to and where you are, and we will arrange it.
