tubehunter
16-09-2014, 06:42
Hi All,
Well after living and swearing by a Passive pre I've finally built an Active pre that proves me wrong.
I recently moved to using the Quad 405 amplifiers as my Kef 105 require a power rated between 40 to 200 watts, my valve amp was just not powerful enough.
Also there's the issue of the Quads inverting the phase.
I designed a simple SRPP circuit using the 6n6p this inverts the phase and brings some awesome bass and dynamics.
I regretted selling the first prototype to someone here so had to build myself another.
This time I went for the two box approach which is popular with higher end designs, makes sense to separate the noisy AC environment from low level signal one.
I've must say those new Mundorf MCap EVO Oil sound very good.
Anyway some pictures
http://i514.photobucket.com/albums/t350/halx00/Mobile%20Uploads/2014-09/120E4D5F-6AD9-435D-9927-F5850DC43C93_zpsbudhmoq8.jpg (http://s514.photobucket.com/user/halx00/media/Mobile%20Uploads/2014-09/120E4D5F-6AD9-435D-9927-F5850DC43C93_zpsbudhmoq8.jpg.html)
http://i514.photobucket.com/albums/t350/halx00/Mobile%20Uploads/2014-09/90A971C5-BCAF-4EE7-9F50-F08C108BE12A_zpswe52rk5s.jpg (http://s514.photobucket.com/user/halx00/media/Mobile%20Uploads/2014-09/90A971C5-BCAF-4EE7-9F50-F08C108BE12A_zpswe52rk5s.jpg.html)
http://i514.photobucket.com/albums/t350/halx00/Mobile%20Uploads/2014-09/35204965-3362-444D-8AB4-2A9F8CC4618F_zpsh2vdn4cl.jpg (http://s514.photobucket.com/user/halx00/media/Mobile%20Uploads/2014-09/35204965-3362-444D-8AB4-2A9F8CC4618F_zpsh2vdn4cl.jpg.html)
http://i514.photobucket.com/albums/t350/halx00/Mobile%20Uploads/2014-09/C7FF0085-85D9-4F46-AB04-2A56230BA235_zpsarhmled4.jpg (http://s514.photobucket.com/user/halx00/media/Mobile%20Uploads/2014-09/C7FF0085-85D9-4F46-AB04-2A56230BA235_zpsarhmled4.jpg.html)
http://i514.photobucket.com/albums/t350/halx00/Mobile%20Uploads/2014-09/E294B6BA-28B8-4E20-B6EE-5ECF0AEEC1C3_zpslsslqs19.jpg (http://s514.photobucket.com/user/halx00/media/Mobile%20Uploads/2014-09/E294B6BA-28B8-4E20-B6EE-5ECF0AEEC1C3_zpslsslqs19.jpg.html)
http://i514.photobucket.com/albums/t350/halx00/Mobile%20Uploads/2014-09/8B5CC90A-1292-4303-89BE-46ADA2898B17_zpsjss3rz1f.jpg (http://s514.photobucket.com/user/halx00/media/Mobile%20Uploads/2014-09/8B5CC90A-1292-4303-89BE-46ADA2898B17_zpsjss3rz1f.jpg.html)
http://i514.photobucket.com/albums/t350/halx00/Mobile%20Uploads/2014-09/7897F0CC-EAE6-4DCF-95E7-94DB1FD2F564_zpsltapiwpa.jpg (http://s514.photobucket.com/user/halx00/media/Mobile%20Uploads/2014-09/7897F0CC-EAE6-4DCF-95E7-94DB1FD2F564_zpsltapiwpa.jpg.html)
http://i514.photobucket.com/albums/t350/halx00/Mobile%20Uploads/2014-09/A08F7D20-9EFD-466B-83B2-9E2F776469DE_zpsgwip1jdc.jpg (http://s514.photobucket.com/user/halx00/media/Mobile%20Uploads/2014-09/A08F7D20-9EFD-466B-83B2-9E2F776469DE_zpsgwip1jdc.jpg.html)
http://i514.photobucket.com/albums/t350/halx00/Mobile%20Uploads/2014-09/51069764-78FE-449E-8D46-3DC858EC8767_zpsj0si20pz.jpg (http://s514.photobucket.com/user/halx00/media/Mobile%20Uploads/2014-09/51069764-78FE-449E-8D46-3DC858EC8767_zpsj0si20pz.jpg.html)
http://i514.photobucket.com/albums/t350/halx00/Mobile%20Uploads/2014-09/B2FCB192-B3A5-437F-9BBA-CEC57951EF22_zps7puzanui.jpg (http://s514.photobucket.com/user/halx00/media/Mobile%20Uploads/2014-09/B2FCB192-B3A5-437F-9BBA-CEC57951EF22_zps7puzanui.jpg.html)
http://i514.photobucket.com/albums/t350/halx00/Mobile%20Uploads/2014-09/DB7C1174-7113-445A-998E-C417267D1616_zpsx9qxjlxa.jpg (http://s514.photobucket.com/user/halx00/media/Mobile%20Uploads/2014-09/DB7C1174-7113-445A-998E-C417267D1616_zpsx9qxjlxa.jpg.html)
http://i514.photobucket.com/albums/t350/halx00/Mobile%20Uploads/2014-09/5F25DED1-0464-445F-9F37-A55CA9C811A2_zpsbwfbgqee.jpg (http://s514.photobucket.com/user/halx00/media/Mobile%20Uploads/2014-09/5F25DED1-0464-445F-9F37-A55CA9C811A2_zpsbwfbgqee.jpg.html)
http://i514.photobucket.com/albums/t350/halx00/Mobile%20Uploads/2014-09/5189C357-610E-4622-AF91-F769425BAD5B_zpsd8dv42eg.jpg (http://s514.photobucket.com/user/halx00/media/Mobile%20Uploads/2014-09/5189C357-610E-4622-AF91-F769425BAD5B_zpsd8dv42eg.jpg.html)
Well after living and swearing by a Passive pre I've finally built an Active pre that proves me wrong.
I recently moved to using the Quad 405 amplifiers as my Kef 105 require a power rated between 40 to 200 watts, my valve amp was just not powerful enough.
Also there's the issue of the Quads inverting the phase.
I designed a simple SRPP circuit using the 6n6p this inverts the phase and brings some awesome bass and dynamics.
I regretted selling the first prototype to someone here so had to build myself another.
This time I went for the two box approach which is popular with higher end designs, makes sense to separate the noisy AC environment from low level signal one.
I've must say those new Mundorf MCap EVO Oil sound very good.
Anyway some pictures
http://i514.photobucket.com/albums/t350/halx00/Mobile%20Uploads/2014-09/120E4D5F-6AD9-435D-9927-F5850DC43C93_zpsbudhmoq8.jpg (http://s514.photobucket.com/user/halx00/media/Mobile%20Uploads/2014-09/120E4D5F-6AD9-435D-9927-F5850DC43C93_zpsbudhmoq8.jpg.html)
http://i514.photobucket.com/albums/t350/halx00/Mobile%20Uploads/2014-09/90A971C5-BCAF-4EE7-9F50-F08C108BE12A_zpswe52rk5s.jpg (http://s514.photobucket.com/user/halx00/media/Mobile%20Uploads/2014-09/90A971C5-BCAF-4EE7-9F50-F08C108BE12A_zpswe52rk5s.jpg.html)
http://i514.photobucket.com/albums/t350/halx00/Mobile%20Uploads/2014-09/35204965-3362-444D-8AB4-2A9F8CC4618F_zpsh2vdn4cl.jpg (http://s514.photobucket.com/user/halx00/media/Mobile%20Uploads/2014-09/35204965-3362-444D-8AB4-2A9F8CC4618F_zpsh2vdn4cl.jpg.html)
http://i514.photobucket.com/albums/t350/halx00/Mobile%20Uploads/2014-09/C7FF0085-85D9-4F46-AB04-2A56230BA235_zpsarhmled4.jpg (http://s514.photobucket.com/user/halx00/media/Mobile%20Uploads/2014-09/C7FF0085-85D9-4F46-AB04-2A56230BA235_zpsarhmled4.jpg.html)
http://i514.photobucket.com/albums/t350/halx00/Mobile%20Uploads/2014-09/E294B6BA-28B8-4E20-B6EE-5ECF0AEEC1C3_zpslsslqs19.jpg (http://s514.photobucket.com/user/halx00/media/Mobile%20Uploads/2014-09/E294B6BA-28B8-4E20-B6EE-5ECF0AEEC1C3_zpslsslqs19.jpg.html)
http://i514.photobucket.com/albums/t350/halx00/Mobile%20Uploads/2014-09/8B5CC90A-1292-4303-89BE-46ADA2898B17_zpsjss3rz1f.jpg (http://s514.photobucket.com/user/halx00/media/Mobile%20Uploads/2014-09/8B5CC90A-1292-4303-89BE-46ADA2898B17_zpsjss3rz1f.jpg.html)
http://i514.photobucket.com/albums/t350/halx00/Mobile%20Uploads/2014-09/7897F0CC-EAE6-4DCF-95E7-94DB1FD2F564_zpsltapiwpa.jpg (http://s514.photobucket.com/user/halx00/media/Mobile%20Uploads/2014-09/7897F0CC-EAE6-4DCF-95E7-94DB1FD2F564_zpsltapiwpa.jpg.html)
http://i514.photobucket.com/albums/t350/halx00/Mobile%20Uploads/2014-09/A08F7D20-9EFD-466B-83B2-9E2F776469DE_zpsgwip1jdc.jpg (http://s514.photobucket.com/user/halx00/media/Mobile%20Uploads/2014-09/A08F7D20-9EFD-466B-83B2-9E2F776469DE_zpsgwip1jdc.jpg.html)
http://i514.photobucket.com/albums/t350/halx00/Mobile%20Uploads/2014-09/51069764-78FE-449E-8D46-3DC858EC8767_zpsj0si20pz.jpg (http://s514.photobucket.com/user/halx00/media/Mobile%20Uploads/2014-09/51069764-78FE-449E-8D46-3DC858EC8767_zpsj0si20pz.jpg.html)
http://i514.photobucket.com/albums/t350/halx00/Mobile%20Uploads/2014-09/B2FCB192-B3A5-437F-9BBA-CEC57951EF22_zps7puzanui.jpg (http://s514.photobucket.com/user/halx00/media/Mobile%20Uploads/2014-09/B2FCB192-B3A5-437F-9BBA-CEC57951EF22_zps7puzanui.jpg.html)
http://i514.photobucket.com/albums/t350/halx00/Mobile%20Uploads/2014-09/DB7C1174-7113-445A-998E-C417267D1616_zpsx9qxjlxa.jpg (http://s514.photobucket.com/user/halx00/media/Mobile%20Uploads/2014-09/DB7C1174-7113-445A-998E-C417267D1616_zpsx9qxjlxa.jpg.html)
http://i514.photobucket.com/albums/t350/halx00/Mobile%20Uploads/2014-09/5F25DED1-0464-445F-9F37-A55CA9C811A2_zpsbwfbgqee.jpg (http://s514.photobucket.com/user/halx00/media/Mobile%20Uploads/2014-09/5F25DED1-0464-445F-9F37-A55CA9C811A2_zpsbwfbgqee.jpg.html)
http://i514.photobucket.com/albums/t350/halx00/Mobile%20Uploads/2014-09/5189C357-610E-4622-AF91-F769425BAD5B_zpsd8dv42eg.jpg (http://s514.photobucket.com/user/halx00/media/Mobile%20Uploads/2014-09/5189C357-610E-4622-AF91-F769425BAD5B_zpsd8dv42eg.jpg.html)