Custom 300B Class A Monoblock Tube Power Amplifiers
- Location
- US
- Source
- Reverb
- Posted
- 24 Jun 2026
- Last seen
- 2h ago
RADAR is a price search engine. We link to the original listing — we never sell direct. Transactions happen on the source site.
RADAR is a price search engine. We link to the original listing — we never sell direct. Transactions happen on the source site.
For sale: a pair of hand-built 300B monoblock power amplifiers, designed and assembled by an experienced electronic engineer. These amplifiers use a single-ended Class A topology and deliver around 9W RMS per channel, making them an excellent match for high-sensitivity loudspeakers.The amplifiers come with Electro-Harmonix 300B output tubes and are built using carefully selected high-quality components, including Audyn-Cap MKP-QS capacitors, Russian K40Y-9 paper-in-oil capacitors, F&T capacitors, TECH-CAP capacitors, and MPC722 precision resistors.Specifications: Topology: Single-ended, pure Class A Output power: approx. 9W RMS per channel Output tubes: 1x Electro-Harmonix 300B per amplifier Rectifier tube: 1x 5U4G / 5AR4 per amplifier Driver tube: 1x 6SN7 or equivalent per amplifier Transformers: Western Electric output and power transformersIdeal for audiophiles looking for a refined, organic and highly musical 300B tube sound.
Generating expert take…
Western Electric traces its origins to 1869 in Cleveland, Ohio, where Enos Barton and Elisha Gray founded a modest workshop for telegraph and electrical equipment. Relocating to Chicago as the Western Electric Manufacturing Company, it quickly gained prominence through ties to Western Union and, by 1882, became the exclusive manufacturer for the Bell Telephone Company under AT&T's umbrella. This heritage positioned it as a cornerstone of American telecommunications, pioneering audio innovations like the world's first audio limiter and laying groundwork for broadcast technology that influenced modern sound reproduction.
While historically dominant in telephone hardware and infrastructure, Western Electric's enduring legacy in hi-fi centers on vacuum tubes and electron tubes, revered for their tonal purity and dynamic range. Revived in recent decades, the brand now focuses on high-end audio components, including 300B power triodes, single-ended triode amplifiers, and select drivers prized by tube enthusiasts for authentic, uncompressed sound.
Today, Western Electric occupies a niche boutique position in the high-end market, appealing to audiophiles and vintage collectors who value its authentic recreations of legendary parts. Its products command premium prices, embodying unparalleled heritage and engineering precision that outshine mass-market alternatives, cementing its status among discerning hi-fi buyers seeking timeless excellence.
See all Western Electric listings on RADAR.
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