@chungjh ... do a search in the Forum for old posts about the ARC VT 100. I recall that some years back, a couple of techie members explained why biasing the VT100 is so hard, ... and a tad dangerous for non-experienced, non-techies.
I don't recall if you mentioned your budget, but someone mentioned the ARC Ref 150SE as a possibility. I own that amp and it is a stunner.
I have question for you that should be answered by a techie. If your ESLs have an impedance of 30 ohms in the low end of the spectrum and 3 ohms in the treble, is a tube amp a good choice for you? Your ESLs operate almost like a giant capacitor.
I ask because many tube amps have high'ish output impedances. Even the Ref 150SE has a "low'ish" (for a tube amp) .55 output impedance off the 4 ohm taps in the bass region; the amp's output impedance creeps up with frequency.
I mention this because a tube amp's output impedance may color the sound based on Ohm's Law principles. See, e.g., John Atkinson's bench test report on Ref 150 at:
Audio Research Reference 150 power amplifier Measurements | Stereophile.com
Based on the impedance figures you mentioned, I calculate that if you used the REF 150SE as your amp, the treble could be shelved down by approximately 2 db as compared to the bass. Check with a techie. You could even call ARC customer service.
Or, if Ralph Karsten (Atmasphere) catches this thread, perhaps he could weigh in. Ralph manufactures high quality OTL tube amps. I recall that Ralph posted a while back that he uses his amp to drive ESLs. Maybe Ralph could explain the whole impedance matching business.
Good luck with your search.
Bruce
I don't recall if you mentioned your budget, but someone mentioned the ARC Ref 150SE as a possibility. I own that amp and it is a stunner.
I have question for you that should be answered by a techie. If your ESLs have an impedance of 30 ohms in the low end of the spectrum and 3 ohms in the treble, is a tube amp a good choice for you? Your ESLs operate almost like a giant capacitor.
I ask because many tube amps have high'ish output impedances. Even the Ref 150SE has a "low'ish" (for a tube amp) .55 output impedance off the 4 ohm taps in the bass region; the amp's output impedance creeps up with frequency.
I mention this because a tube amp's output impedance may color the sound based on Ohm's Law principles. See, e.g., John Atkinson's bench test report on Ref 150 at:
Audio Research Reference 150 power amplifier Measurements | Stereophile.com
Based on the impedance figures you mentioned, I calculate that if you used the REF 150SE as your amp, the treble could be shelved down by approximately 2 db as compared to the bass. Check with a techie. You could even call ARC customer service.
Or, if Ralph Karsten (Atmasphere) catches this thread, perhaps he could weigh in. Ralph manufactures high quality OTL tube amps. I recall that Ralph posted a while back that he uses his amp to drive ESLs. Maybe Ralph could explain the whole impedance matching business.
Good luck with your search.
Bruce