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
Hans, the bypass caps installation is apparently a simple matter that can be done by any technician. ARC supplies instructions/schematics with the caps. Best to contact ARC directly and speak to Leonard. Guido
Mithc Guidocorona compared the Ref 3 to the Ls25mark 2, not the Ref 2 Mark 2. The Ref 2 mark 2 is a much better sounding preamp than the LS 22.
Hello arc160 , the Dutch importer told me only that the 4 bypass caps will not make my REF 3 better .So I 'am very interested what will be the result in your amp.Please keep me updated when you have let them installed.
Regards Hans
The Netherlands
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?
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