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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
elberoth2's avatar
elberoth2
1,223 posts
 
Arcl60 - you should go an extra mile and get NOS TungSol Black Plate 6550 tube. The improvement is not trivial, and much, much greater than what can be acheived by putting DR tubes (I have both DRs and NOS 6550 in my Ref 3).

We discussed it over here:

ARC Ref 3: Tung-Sol 6550 in power supply?
arcl60 OP
24 posts
 
Hi Reference 3 Owners,
I replaced the tubes from my reference 3 with Sovtek 6H30 (matched tubes) and 6L6GC from SED.
The overall performance improved, but i was not fully satisfied, then i re checked my full system in term of cabling and speaker connection, then i discovered that my pair of JBL 2405 tweeters were not connected properly (they were not on phase : the + plug was on - cable and the - plug on + cable). I guess i did some tests in the past when my LS25MKII get sold and i think i tried several things to improve the performance of my spare preamp an Audia flight Pre to improve it at LS25MKII level without success !!!, it was just a bad thing !
So now the image is much much better, i'm satisfied with the overall result and i found the Reference 3 totally different in term of 3D image than the LS25MKII. The LS25MKII is providing a flat image in comparison with the Reference 3 with really gives a 3D image with a lot of space all around the instruments and voice. In comparison with LS25MKII the voices seem a little bit behind, so i need to be familiar with that new sound image. It maybe required more time on the tubes to get the voice as they were with the LS25MKII.
I checked inside my Reference 3 and the bypass capacitor are in place if i well understood where they are located (just behind the 4 golden capacitors), so i don't need to get some from Audio Research.
For the 6550 tube in place of 6L6GC can i just remove the 6L6GC and put a 6550 tube on the power supply stage ?
If yes, i will do the try with a new Sveltana 6550c i have in spare, and i will order a Tung-Sol 6550 Black plate as suggested by Elberoth2
So if you can confirm me for the 6550 tube it will be nice
Laurent
hikejohn
69 posts
 
While I am looking for a new pre amp...and have considered the ARC Ref 3...I have heard that there have been a number of revisions to the unit...changes...given ARC's history that should be expected...has anyone document any changes.??? if they actually exist

J
markwatkiss
508 posts
 
As I understand there are at least 2 iterations of the original REF 3.If you are considering purchasing used that would be a fair question to ask.
guidocorona
4,298 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
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