Mentmore M100 Michaelson and Austin

Some of the best were the Stax class A amps, the DA 80 and 100s. I also used Krell KSA 50s, Musical Fidelity 270s and possibly Meridian 605s. As you can see these were from the late 80s and early 90s. I used other amps earlier but these were better. A friend uses a rebuilt Heathkit tube amp from the early days of stereo on the 57s I sold him in the 70s and it sounds great. It sounds as if you have addressed all the major weaknesses of the 63s. The 63s are a hard speaker to proscribe for, they don't need a lot of power but you can use a powerful amp if you stay within their capabilities. I am not a tube user but they work well with the Quad, perhaps you could post a query here or on the HIFICRITIC site as to which tube amps work best. There are many dedicated Quad users on the latter and they would welcome a description of your modifications. Hope this helps. Stan

Thanks for that Stan. I ended up not bidding on them. They went on ebay for £880, which was more than I would have paid for them anyway.

Do you have any experience of using single-ended amps with 63s? I'm being offered a pair of 211 monoblocs, rated at 35 Watts. I'm currently using an Art Audio Quintet, PP EL34 25W. It sounds totally gorgeous. Had bad experiences with SE before, always preferred PP. But the 211 amp on offer should be top quality and an exceptionally good price. It's tempting.. Might be the bee's knees.. Waddaya reckon?

My 63s are radically modified - I discarded the entire resonant superstructure provided by Quad, and mounted the panels in a frame made of MDF and concrete, decoupled the electronics, full set of rebuilt panels. They sound sublime.

What other amps have you used with 63s? Very interested to hear of discontinued ones. I seem to remember that the late great Julian Verreker recommended the 57s as a fine match for the NAP250. Bizarre idea! Must try it with the 63s one day!

Thanks for picking up my thread, Stan, look forward to reading your thoughts.
Simon

Thanks for that Stan. I ended up not bidding on them. They went on ebay for £880, which was more than I would have paid for them anyway.

Do you have any experience of using single-ended amps with 63s? I'm being offered a pair of 211 monoblocs, rated at 35 Watts. I'm currently using an Art Audio Quintet, EL34 25W. It sounds totally gorgeous. Had bad experiences with SE before, always preferred PP. But the amp on offer should be top quality and an exceptionally good price. It's tempting.. Might be the bee's knees.. Waddaya reckon?

My 63s are radically modified - I discarded the entire resonant superstructure provided by Quad, and mounted the panels in a frame made of MDF and concrete, decoupled the electronics, full set of rebuilt panels. They sound sublime.

What other amps have you used with 63s? I seem to remember that the late great Julian Verreker recommended the 57s as a fine match for the NAP250. Bizarre idea! Must try it with the 63s one day!

Thanks for picking up my thread, Stan, look forward to reading your thoughts.
All the best
Simon

They were tested in HiFi Choice no.44 in 1986. They did not recommend them. they said " This amp offered a mixed performance.the treble rolled off early, removing some air and sparkle from the sound, while the high frequency power delivery was poor. The stereo reproduction was to a high quality but the bass performance was not in the same league". Unless they are very cheap there are better choices. These amps were rated at 100 watts, but into a 4 ohm load one channel driven they produced only 3.7dBW rather than their 20 dBW rating at 20 kHz. I was a Quad dealer for years and used and sold 63s and this does not look like a good match to me. I hesitate to give any recommendation as all the amps I used are long discontinued.