Vintage HiFi Audio Forum
Audio Discussion => DIY => Topic started by: OldiesButGoodies on February 10, 2014, 10:03:56 PM
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I recapped most of the caps in this preamp on Sunday and tested it, finding it still sounded like something was off. Tonight I ripped the chassis apart again and replaced every last electroytic I could find with new ones (except two .38uf caps that I did not have available). Just finished putting it back together and am listening to a 96k 24b recording on it right now. Sounds pretty darn good for a seventies piece of equipment. Not sure this can be my official backup pre yet, but it sure was fun fixing it up...
>:D
(http://i1122.photobucket.com/albums/l538/namikis/IMG_7349_zpsec472312.jpg) (http://s1122.photobucket.com/user/namikis/media/IMG_7349_zpsec472312.jpg.html)
The prev ignored area before:
(http://i1122.photobucket.com/albums/l538/namikis/IMG_7351_zpsf4d1ecec.jpg) (http://s1122.photobucket.com/user/namikis/media/IMG_7351_zpsf4d1ecec.jpg.html)
After:
(http://i1122.photobucket.com/albums/l538/namikis/IMG_7357_zps3cf4f607.jpg) (http://s1122.photobucket.com/user/namikis/media/IMG_7357_zps3cf4f607.jpg.html)
Very nice board layout - the schematic is printed on the board:
(http://i1122.photobucket.com/albums/l538/namikis/IMG_7350_zps18c82f4e.jpg) (http://s1122.photobucket.com/user/namikis/media/IMG_7350_zps18c82f4e.jpg.html)
Testing:
(http://i1122.photobucket.com/albums/l538/namikis/IMG_7361_zpsdcbb93ce.jpg) (http://s1122.photobucket.com/user/namikis/media/IMG_7361_zpsdcbb93ce.jpg.html)
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You are no longer CaptainTapeDeek. I suggest CaptainCapman, or CC or something like that.
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Some of the best sounding recordings ever were done in the seventies.
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Agree, though there are some from the 60s that are amazing as well.
The other thing about seventies hardware in general (and this Pro Control Four pre is no exception): the headphone sections kick butt. They are leaps better than anything I hear today (short of dedicated high-end headphone amps).
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Too many chips in that Soundcraftsman for me! I like chips in my cookies, not in my electronics. I prefer discret components in my electronics.
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Best solid state preamp I ever heard used op-amps.
But my backup preamp is another tube Audio Research SP-6.
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This was fun project but a s Carl says, all those chips show up in the excessively solid state sound. I will continue the search.
The soundcraftsmen may be enuf as a backup while I slowly replace the RCA jacks in the C-19. I would love to find a tube pre that match the rest of the system well. That is in the watch list.
I also need to replace the Infinitys - that may take time unless I just part them out, which feels like a crime.
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Nice work CTD. Are all those ICs part of the signal path or part of some very sophisticated input switching and other non audio
Circuitry? Cant imagine any designer running the audio through 2 dozen ICs. One single, high quality op amp per channel is more than
enough. Either way just enjoy it.
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The Pro Control Four is not from the 70s it is actually from the mid 80s... somewhere around 1985 or 1986 if memory serves...
http://www.audiokarma.org/forums/showthread.php?t=334917&page=3 (http://www.audiokarma.org/forums/showthread.php?t=334917&page=3)
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i std corrected