ChatGPT answer
https://chatgpt.com/c/68a5ebde-4a9c-832c-83e4-160cc2d34140
what amp for quad esl 57 speakers
ChatGPT said:
The Quad ESL-57 is a legendary electrostatic speaker, but it’s also notoriously picky about amplifiers. Because of its impedance curve (dips below 2 ohms at high frequencies, ~16 ohms in the midrange) and its limited power handling (about 15–20 watts before arcing risk), you can’t just throw any amp at it. The wrong amp can literally fry the panels.
Here’s what works well:
✅ Best Matches
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Quad II tube monoblocks
– Classic pairing. About 15 W from KT66 tubes, very safe for ESL-57s. -
Other low-to-medium power tube amps
– EL34 or KT66 push-pull designs (15–30 W) are ideal.
– Popular choices: Leak Stereo 20, Radford STA-25, EAR 509, or modern tube amps with good current handling. -
Modern tube options
– VAC, Audio Research (lower-powered models), Conrad-Johnson.
⚠️ Solid State (use carefully)
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Some early British SS amps (Quad 303, Quad 405 with protection mods) can be OK.
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Avoid high-powered, wide-bandwidth solid-state amps (like big Krells, Brystons, etc.) — they can arc the panels.
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If you go SS, pick something stable into low impedance, but not crazy powerful.
– Quad 303 (45 W) is a famous safe match.
– Spectral, Naim, or newer current-limited designs can also work with caution.
❌ Avoid
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Big, high-current amps (Krell, Mark Levinson, modern Class D) — risk of frying the speaker.
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Amps over ~50 W continuous power.
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Anything unstable into capacitive loads.
👉 In summary:
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Best safe choice: A 15–25 W tube amp (Quad II, Leak Stereo 20, Radford STA-25).
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Safe solid-state: Quad 303, possibly a carefully chosen Quad 405.
Do you want me to suggest current production amps (modern gear you can still buy new) or are you mainly interested in vintage classics that match the ESL-57’s heritage?