Has anyone tried KT150s in their ARC Ref 110?

Hi all,

Was wondering if any ARC Ref 110 owners have tried the KT150 output tubes in their Ref 110. Seems like ARC is testing out the KT150 in the current production amps and while officially not yet sanctioned, they seemed to have tacitly ok'ed the trial of the KT150 in Ref 75 and Ref 150 amps from various user comments on different forums.

I would be interested in hearing if anyone has tried this output tube in their Ref 110. If yes, at what bias? Any sonic impressions compared to either the 6550s or KT120s would be very much appreciated. Thanks
Cmalak ... to the best of my knowledge, ARC has not approved, tacitly or otherwise, the use of the KT-150 tube in any of its amps -- current models or previous versions. Folks who drop the KT-150 into their ARC amps do so at their own risk.

Another member who owns a Ref 210 asked the same question as you. I already cautioned him about using the KT-150 in his amp for two reasons:

First, the Ref 110 and 210 amps don't have as beefy a power transformer or power supply as the current Ref amps. The current Ref amps were specifically designed to run with KT-120s. By contrast, the Ref 110 and 210 amps were designed to run on 6550 tubes.

Second, even if KT-150 tubes "appear" to run ok in the Ref 110 or 210, no one has any idea if the long term use of the KT-150 will prematurely age the amp.

Personally I serious suspect that using the KT-150 on current or immediately prior version Ref amps will do NO harm. BUT ... we have serious bucks tied up with our gear. Why take even a small chance. I suggest that we give ARC time to sort this out.

Btw, I own a Ref 150 and am itching to drop the KT-150s into my amp. However, until ARC authorizes the new tube's use, I am holding pat.

Bifwynne...if I remember correctly, you had the Ref 110 before the Ref 150. Did you ever try the Winged 6550C SED tube in the 110 vs. ARC's standard issue Svetlana 6550? If yes any thoughts on that tube?
Cmalak, actually, I used to own the VS-115, which was the Ref 110's baby brother. Some said it sounded 85 to 90 percent as good as the Ref 110. Anyway, that's history.

The VS-115, when first released, used SED 6550 "Winged C" tubes. They were very nice tubes!! Later, ARC switched over to the KT-120s. In my opinion, the KT-120s had it all over the 6550Cs.

I'm pretty sure ARC said it was ok to use the KT-120s for the Ref 110. Frankly, I think it's a no-brainer. Btw, I think one can pick up KT-120s from reputable tube vendors for less than $50 bucks a tube.

I suggest you wait until ARC officially approves the KT-150 for your Ref 110. I am waiting for ARC to approve the use of the KT-150 for my Ref 150, and I think there is less risk with my amp than your Ref 110.