I had great success using 60-70 watt ARC tube amps when I ran Quad 63s (mine were Crosby modified). I went from the 57, which was augmented with a sub and ribbon tweeters and found the 63 (without the need to supplement) to be the better all around speaker, but it lacked the "magic" of the original 57. Guess which speaker I kept, had restored and still use (in my second system)?
Quad ESL-63 and low-powered amps; Sun Audio, Atma
Looking for opinions about suitability of low-powered amps with my 63's. I currently have an Audio Note M3 pre, CJ MV-60 amp. Importantly, I cross the Quads at line level at 100 hz, first order with nice Vandersteen MH-5 crossovers to Vandy 2wq subs. So the main amp is relieved of much work below 50 hz or so.
Specifically, I am looking at Atma-sphere s-30 MkII OTL 30 watt amp, and possibly even a Sun Audio 2a3 SET 3 watt amp.
Given my crossover, does this lighten the load (power or impedance) in such a way that these amps would work fine? I imagine the Atma will have no issues, but what about the Sun?
Finally, I would love to hear any opinions about the relative sonic characteristics I might hear between the CJ, Atma and Sun. I listen to 50% acoustic jazz, 25% classical, 25% rock. 60% on vinyl... SOTA w/Grace 714 and Grado Ref Sonata1. CD is CEC transport to Audio Note 3.1 Signature. I value musicality and rich midrange over endless detail and "neutrality".
Thanks all.
Specifically, I am looking at Atma-sphere s-30 MkII OTL 30 watt amp, and possibly even a Sun Audio 2a3 SET 3 watt amp.
Given my crossover, does this lighten the load (power or impedance) in such a way that these amps would work fine? I imagine the Atma will have no issues, but what about the Sun?
Finally, I would love to hear any opinions about the relative sonic characteristics I might hear between the CJ, Atma and Sun. I listen to 50% acoustic jazz, 25% classical, 25% rock. 60% on vinyl... SOTA w/Grace 714 and Grado Ref Sonata1. CD is CEC transport to Audio Note 3.1 Signature. I value musicality and rich midrange over endless detail and "neutrality".
Thanks all.
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- 46 posts total
The 63’s have 4ohm load from 6khz-12khz and then an even lower (epdr) of 5ohms combind with -40 degree phase at 14khz. This indicates an amp that needs to be able to drive 4ohms as it’s best feature, not as a secondary feature. Which means (for tube if you can get it) an output transformer that’s specifically wound for 4ohms use, not 8ohms with a 4 ohm tap. https://www.stereophile.com/images/66Quadfig01.jpg " Dropping below 6 ohms below 50Hz and between 5kHz and 18kHz, with minima of 3.5 ohms at 10Hz and 13.85kHz, this represents a reasonably demanding load for an amplifier to handle. Tube amplifiers would be best used from their 4-ohm tap (if they have one), though any solid-state amplifier that more or less doubles its power output into 4 ohms compared with 8 ohms would have no problems driving the Quad." Cheers George |
Willemj, I also find it hard to swallow that all perceived differences in amplifier sound are due to issues like clipping. My biggest problem with statements like that is the same problem I have with the objectivist camp in general: it assumes we understand why amplifiers sound the way they do to our ear/brain interface. I don't think we know even a small fraction of that. So how can anyone assert that this or that is the sole cause of sonic differences in amplifiers? It presumes perfect knowledge no one has. |
- 46 posts total