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Vintage Audio (record players, hi-fi etc) Amplifiers, speakers, gramophones and other audio equipment. |
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20th Jul 2017, 2:17 pm | #21 |
Dekatron
Join Date: Sep 2005
Location: Seaford, East Sussex, UK.
Posts: 5,997
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Re: Quad II amplifiers
I had a pair of Concerto's but they are big and need to be in a very large room to be appreciated. I replaced the crossover caps and they did sound good with plenty of dynamics and bass but got rid of them as they needed cosmetic work and the wife was never going to tolerate them.
Speakers are a very personal choice. I am currently using Castle Harlech's which have the advantage of looking good. Being transmission line they are very dependent on room position. I found them very dry when driven by a good quality solid state amp but sound brilliant with my valve amplifier. Reviews of vintage speakers are very mixed. One of the factors will be the condition of the crossovers and drivers but there is also plenty of hype. I recently picked up a pair of 70's B&W DM4's which get generally good reviews (they were £15). They are OK compared with some of the cheap modern junk but I am not ecstatic. |
20th Jul 2017, 8:58 pm | #22 |
Pentode
Join Date: Feb 2015
Location: Conwy, Clwyd, UK.
Posts: 246
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Re: Quad II amplifiers
I use JR149s with my quad II amplifiers and they sound lovely. Very natural, lounge/wife friendly size and appearence, and can be had for £300 or thereabouts without difficulty.
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21st Jul 2017, 12:17 am | #23 |
Moderator
Join Date: Mar 2012
Location: Fife, Scotland, UK.
Posts: 22,870
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Re: Quad II amplifiers
The quad electrostatic speakers are open-backed, so they have to be placed well out from any wall to the rear, and you definitely need a larger than average room to get reasonable results.
My big transmission lines are best not tucked right into corners, or else the bass gets over-done. They go against the wall OK, but are moved in a couple of feet from the corner. The combination of a bass frequency and a sound pressure level dictates that a certain amount of air needs to be pumped. No speaker design, no fancy badge, no big price tag, can get around this. It is a physical property of the air between you and the speaker. Smaller speakers are faced with a compromise involving cabinet pressure versus lowest note reproducible versus sound pressure capability at low frequencies. All to often their designer conceals the lack of deeper bass by putting a bump in the frequency response at the bottom end of a limited response. The so-called one-note-bass. The illusion works quite well on drums, but it comes apart when there is a played bass theme. Pick your speakers to suit your room - it's the best you can do in the area of the biggest compromise in reproducing music. David
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25th Jul 2017, 10:43 pm | #24 |
Octode
Join Date: Feb 2009
Location: Wallasey, UK.
Posts: 1,311
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Re: Quad II amplifiers
Is there an impedance from the Quad output transformers to consider too? 15ohm? I have a pair of KEF 104/2 speakers that I like very much with valves, but their impedance is 4ohm.
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25th Jul 2017, 11:03 pm | #25 |
Dekatron
Join Date: Nov 2010
Location: Oxford, UK.
Posts: 4,982
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Re: Quad II amplifiers
The Quad II output transformer can be wired for 15 ohms or 7 ohms
But then again the ESL57 impedance drops progressively from 5kHz (about 10 ohms) to 15kHz (2 ohms). But I seem to recall that the 104/2 had a target design to present as close to a resistive (4 ohm) load to the amplifier, and simultaneously correct each driver for a flat acoustic response. As a result the crossover is very complex indeed. |