MooneeBeach Posted August 16, 2018 Share Posted August 16, 2018 Hi tube people I bought a used MC275 power amp a few months ago and have only just started thinking about the tubes installed. At the moment there are: 12AX7A tubes substituted with JAN12AT7WC tubes, and 12AT7 tubes substituted with JAN5751 tubes + (Gold Lion KT88) Can anyone tell me if this is a good combination? What are the sonic differences likely to be? Any guidance would be greatly appreciated. Sean Link to comment Share on other sites More sharing options...
kelossus Posted August 16, 2018 Share Posted August 16, 2018 33 minutes ago, seaninbrisbane said: Hi tube people I bought a used MC275 power amp a few months ago and have only just started thinking about the tubes installed. At the moment there are: 12AX7A tubes substituted with JAN12AT7WC tubes, and 12AT7 tubes substituted with JAN5751 tubes + (Gold Lion KT88) Can anyone tell me if this is a good combination? What are the sonic differences likely to be? Any guidance would be greatly appreciated. Sean Aren't the 12AT7's lower gain than the 12AX7's? I always thought the NOS Telefunkens were the way to go for the 12AX7's and the Siemens for the 12AT7's. Link to comment Share on other sites More sharing options...
MooneeBeach Posted August 16, 2018 Author Share Posted August 16, 2018 52 minutes ago, kelossus said: Aren't the 12AT7's lower gain than the 12AX7's? From the quick research I did online yesterday, this seems to be true, although it's not an issue in my system. Link to comment Share on other sites More sharing options...
mloutfie Posted August 17, 2018 Share Posted August 17, 2018 My favourite 12ax7 is psvane http://psvanetube.com/wordpress/store/products/12ax7-tii-pair-or-single/ 1 Link to comment Share on other sites More sharing options...
kelossus Posted August 17, 2018 Share Posted August 17, 2018 5 minutes ago, mloutfie said: My favourite 12ax7 is psvane http://psvanetube.com/wordpress/store/products/12ax7-tii-pair-or-single/ Fantastic tubes. I had them in my C220 Preamp with great results. 1 Link to comment Share on other sites More sharing options...
Happy Posted August 17, 2018 Share Posted August 17, 2018 Psvane bulbs generally excellent highly underrated Link to comment Share on other sites More sharing options...
kelossus Posted August 17, 2018 Share Posted August 17, 2018 Also a nagging question. Why did you change the 12AX7s to 12AT7s? I am sure Mcintosh utilize 12AX7's for a reason? Link to comment Share on other sites More sharing options...
MooneeBeach Posted August 17, 2018 Author Share Posted August 17, 2018 I didn't - I bought the amp (used) like that. Link to comment Share on other sites More sharing options...
unclekanus Posted August 19, 2018 Share Posted August 19, 2018 On 16/08/2018 at 4:23 PM, seaninbrisbane said: 12AX7A tubes substituted with JAN12AT7WC tubes, and 12AT7 tubes substituted with JAN5751 tubes + (Gold Lion KT88) Hi Sean. I would definitely be putting the 12at7's in the 12at7 sockets and the 5751's in the 12ax7 sockets if it's not like that already. That would be the correct way to do it and would give you a more accurate baseline as to how it's supposed to sound. 1 Link to comment Share on other sites More sharing options...
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