xlr8or Posted April 10 Share Posted April 10 4 hours ago, sly_bastard said: Reference was correct they are both a4 8k. November 1968 production. 2 Link to comment Share on other sites More sharing options...
vivianbl Posted Monday at 05:35 AM Share Posted Monday at 05:35 AM Participated in a Quad ESL 57 thread and interacted with a guy who was strongly recommending GM70 amps for my Quad ESL 57s (modernised). I currently use Class A Audion Silver Night Anniversary PSE 300B mono blocks.. Very happy with these, but my interest has been piqued! “Vivian Blacker Yes, somehow the Quad matched well with all my Single ended amplifier using big transmitting tube like GM70,211,845,813..... two Single ended amp with 300B (PSE 12W) and 6C33C (18W) does not match with Quad sound.” “…..It is even better if you can find GM70 amplifier, sonically better than 845 , higher power, rugged and graphite GM70 is pretty cheap at $60-$80 for a pair. Russian tubes are much more reliable than Chinese 845 tubes.” “…….GM70 is my top sounding tube. Its sound to me is superior to 845/211 tube, and you can save lots of money on GM70 tube and buy better output transformer.” Wondering people’s view on these and what options are available/ worth considering for SE/PSE Class A GM70 amps with my ESL 57s? 7 1 Link to comment Share on other sites More sharing options...
Nickelle Posted Monday at 06:13 AM Share Posted Monday at 06:13 AM Hi, I had my ESL57's for years and have used many amps to run them over that time, from SS to valve amps, by far the best sound I achieved was from my Conrad Johnson MV60 SE with KT 120 tubes. I have since (recently) sold my ESL57's and bought Harbeths Super HL5plus which sound as good to my worn out ears as the 57's also using the CJ MV60. As its about the synergy of equipment interacting with each other I would be trying to loan the said amps to try them. On paper the GM70's are a decent tube, there is plenty to read online about them. The trick is finding an amp that complements the Quad’s impedance curve; clearly not so easy, and why amps that double their power into lower impedance loads (i.e. the Pass Labs XA30.5) would likely make the Quads HF sound louder or brighter. Solid-state push-pull amps often do this. That’s why I had thought of a 300B push-pull amp. It wouldn’t do this and if its output transformers were truly excellent Earle Hand winds his transformers. Maybe contact Earle for sound advice. I bought a 300B from Earle Weston and it paired extremely well with the Quad ESL 57's. Earle comes highly recommended, he is a great guy. No affiliation. just bought some good gear from him over the years. Happy Hunting. 2 1 Link to comment Share on other sites More sharing options...
vivianbl Posted Tuesday at 02:48 AM Share Posted Tuesday at 02:48 AM 20 hours ago, Nickelle said: Hi, I had my ESL57's for years and have used many amps to run them over that time, from SS to valve amps, by far the best sound I achieved was from my Conrad Johnson MV60 SE with KT 120 tubes. I have since (recently) sold my ESL57's and bought Harbeths Super HL5plus which sound as good to my worn out ears as the 57's also using the CJ MV60. As its about the synergy of equipment interacting with each other I would be trying to loan the said amps to try them. On paper the GM70's are a decent tube, there is plenty to read online about them. The trick is finding an amp that complements the Quad’s impedance curve; clearly not so easy, and why amps that double their power into lower impedance loads (i.e. the Pass Labs XA30.5) would likely make the Quads HF sound louder or brighter. Solid-state push-pull amps often do this. That’s why I had thought of a 300B push-pull amp. It wouldn’t do this and if its output transformers were truly excellent Earle Hand winds his transformers. Maybe contact Earle for sound advice. I bought a 300B from Earle Weston and it paired extremely well with the Quad ESL 57's. Earle comes highly recommended, he is a great guy. No affiliation. just bought some good gear from him over the years. Happy Hunting. Thanks for your contribution/ information. Yes I too have used a range of SS and Valve amps with my 57s - Different power ratings and designs that all sounded really good. The previous valves have all been push pull design. My current class A PSE 300B has provided greater resolution and extra “magic” to the presentation. Must add that with advice/ guidance from Xlr8or on changes to the driver valves the SQ has gone to another level and my records and CDs have never sounded better. I did a lot of reading and consultation before taking the plunge on these preowned amps. - Many people had advised against the use of SE with 57s! Anyway, my curiosity about GM70 based SE/PSE amps has been piqued as I have never heard any and don’t have any idea of their character. Hence the post. Any feedback would he appreciated. Does anyone here have or know someone who has a SE/PSE GM70 amp,? By the way, I’ve got 2 pairs of 57s. One pair is a late ( 1983/4 ) production original that I use in my study. The use of a GM based amp would be with My main listening room pair. It is a John Hall construction that has many “ tweaks” - results in more extension at both ends of frequency spectrum, allows use of higher powered amps, goes louder, more neutral higher frequencies m. . Haven’t needed to use subwoofer or super tweeters! My urge to stack has subsided! 1 Link to comment Share on other sites More sharing options...
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