CAD 300 SEI
The purest expression of single-ended triode.
🔗 Manufacturer websiteDescription ⌄
Cary Audio CAD 300 SEi — single-ended triode integrated amplifier. The CAD-300SEi is Cary Audio's landmark single-ended triode integrated amplifier, producing 15 watts per channel in pure Class A with zero global feedback around the legendary 300B output tube. Oil-filled coupling capacitors, 1% metal film resistors, dual EI laminate output transformers rated at 200% duty cycle, and hand-soldered copper terminals throughout create a vanishingly low noise floor of –90 dB below rated output. Speaker taps at 4Ω, 8Ω, and 16Ω accommodate a wide range of loudspeaker sensitivities, and a ¼" headphone output is included for private listening.
Technical background
Single-ended Class A topology using 300B output tubes — one tube per channel, no negative feedback. 6SN7 input and driver stage. The purest, most linear amplifier topology, widely regarded as the most musically natural design ever made.
Design story
The CAD-300 Sei is Cary Audio's purist statement — a hand-wired, point-to-point 300B SET integrated. Single-ended topology with no negative feedback. Built in Raleigh, NC since the 1990s and continuously refined. Requires high-efficiency speakers (90dB+).
Best for
Single-ended triode devotees wanting the purity of 300B amplification in an integrated format; high-sensitivity speaker owners 300B tube enthusiasts; SET purists; audiophiles with high-efficiency horn or full-range speakers Single-ended triode listening system; high-efficiency speaker pairing; intimate listening room
Awards & press
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Features ⌄
- 300B single-ended triode — 15W pure Class A with legendary naturalness and warmth
- Zero-feedback design with point-to-point silver solder — maximum signal purity
- Exceptionally low noise floor — finest tonal textures emerge effortlessly
- Remote-controlled volume, headphone output — elegant everyday usability
- Single-ended Class A 300B output — the most musically natural amplifier topology for high-efficiency speakers
- 15W pure Class A — deceptively powerful with 90dB+ sensitivity speakers