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Audio Research REF 3

Dear all ARC REF 3 owners,
I just bought an REF 3 preamp which has replaced my LS25MKII preamp. To be honest i'm little disappointed by the result so far, but i guess tubes have to be replaced. My concern is especially on the sound image which is not precise as my LS25MKII image was.
The number of hours of used displayed by the my REF 3 is 1670 but i realized that hours counter increased only for full hours of used, so i can estimate the number of hours of the tubes inside my REF 3 to be the double i guess.
My question is the following
What do you recommend for tubes replacement and source for the replacement of REF 3 tubes.
I used sovtek, EH gold, and 6H30-DR on my LS25MKII and i was pleased with all those tubes even if i didn't find the DR much better than the 2 other brands.
Thanks in advance
ARCL60
arcl60
guidocorona
4,114 posts
 
According to ARCDB.WS, only 1 revision was ever made to Ref 3, and this was about 6 months after release. . . the 6G6 in the power supply was replaced by the SED 6550C, and 4 bypass caps were added. . . the bypass caps were apparently planned since day 1, but were not available from the supplier at first customer ship date. See:
http://www.arcdb.ws/REF3/REF3.html
arcl60 OP
24 posts
 
Hi,
Could someone please confirm that the 6L6GC can be changed by a 6550c with no risk. I guess i should the 4 by pass capacitor on directly on the back of the board where the 4 golden caps are located (0.024 µF cap i guess)
Thanks in advance
PS : i'm starting to be extremely happy since news tubes are into my Ref3 !
arcl60 OP
24 posts
 
Hi Audiogon's Members,
I changed the tubes on Ref3 and it really starting to be much better in term of definition. My tubes should have around 20 Hours, so i guess it will improve again.
I'm very impressed by the 3D image of the preamp which for example place the voice at the right depth vs my old LS25MKII which provided a less deeper image.
What will be the benefit to put a 6550C in place of 6L6GC ?
Is the difference very import in term of image and definition ?
Best Regards
Laurent
guidocorona
4,114 posts
 
Laurent, I do not have direct experience with 6L6GC. . . however, according to ARC, the SED 6550C is supposed to yield greater extension, linearity, and authority than 6L6GC. G.
hansk46's avatar
hansk46
109 posts
 
Hello Arc160 , yes you can change the 6L6 by the 6550C.The 4 bypasscaps are on the back of the board where the 4 golden caps are located.The bypasscaps ( 0,0024 mF ) are C111-114 , don 't mount them on the board , but leave some distance ( about 5 mm ) to the board.
Greatings from the Netherlands Hans
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