KT-120 Tubes
 

anyone know what mods have to be done to the reference 210 in order to make full potential of the kt-120 tube that audio research now uses in it's amps in place of the 6550 ?

I am using them in my VSi55 with no issues. I spoke to tech support at ARC and they indicated that no changes would be necessary and to just check & adjust bias to the factory setting. I would give ARC a call to verify, but my hunch is that they give you the same advice. Please let us know.

intouch1...it's a drop-in replacement for Ref 110 and Ref 210. Talked to ARC and there are no mods required. If you go down the KT-120 route from ARC, you will have to wait because they currently have limited supplies that are enough to meet all current production models that are coming out with the new tubes. So if you decide to get KT-120s from a tube supplier, make sure they are 4 sets of matched quads for your 210s and make sure they are properly biased. I would call ARC for bias settings but when I talked to them, they said they are set at the same bias setting as with the 6550s.

markmck79... Welcome to AA! :wave:

this was Kalvin's from Audio Research reply:


Yes, I would recommend retubing with the new KT 120s instead of the 6650s. The KT 120 is more dynamic and plays better bass. However, this is not a direct replacement. The Ref 210s must be updated for correct operation. The update can be performed in the field by a qualified electronic technician or at the factory. The cost of the factory update is $250.00 plus shipping.

I am surprised. When I talked to ARC they told me drop in replacement for all current production models. I was asking specifically about my Ref 110s. Interesting. I will call again to ask one more time to make sure. Thanks

i think the kt-120's require more heat to deliver more power.

love to know
 

I received kt 120s from arc and dropped them in my Ref 110 with same bias.
Only have 30 hours on them. Clearly more power all around, slightly better in just about every way except perhaps presence region which is still a touch harsh on certain cds (or is it revealing a slight harshnes in my cd player-BelCanto pl-1?)----will wait for at least 100 hours tube break-in before I come to any definitive conclusions.
Cal at ARC did not mention the need to make any mods to Ref 110. I would love to know if mods would be advisable in any event.
Could it be that prototype Ref 150 with transformer changes and larger power supply was designed solely to accommodate the kt 120s or was this in the design stage prior to kt 120s and simply the first of the new generation of ARC amps which will trickle up?
Ref 150 preproduction prototype was shown at Definitive Audio in Seattle 2 weeks ago. There is a Wilson Audio video floating around showing it.

Hi A-R guys,

I'm willing to obtain more info on the REF 110. Actually, this Stereo amp could be of interest for my WILSON SASHA.
What do you think? Is it a better amp with the 6550s ou with the new KT120s?
Will the future REF 150 replace the long time existing REF 110?

What are the shortcomings of a REF 110, if any. I need a very fast amp (with perfect timing; attack and decay of the notes), with natural timbre, and a deeply layered soundstage. I value true transparency i.e. not high frequency emphasis, but real acoustic changes from CDs to CDs or even from tracks to tracks on the same CD (depending on variable the recording conditions).

Would I be able to obtain all that criterias with a REF 110?

Finally, are these two big fans really annoying or just a little wisper that your brain can easily forget.

Thanks a lot in advance for your inputs.

I would not consider the REF 110 or 210 for that matter a fast amp.

With that said, I heard the REF210 (with the new tubes) with the Sasha's and it was awesome. I was very surprised how good the sound was. For me, I thought this combo sounded the best and I have heard the Sasha's with VTL, Lamm and Boulder.

I did not hear the Sasha's directly with the REF 110 (Sophia III)i, so I can't comment on the sound. But I would be careful and make sure the 110s have the juice to drive the Sasha's given their impedeance dip.