ARC Ref 110 with KT 150 tubes

I'm sorta with Joecasey, only because I want Bifwynne and Jasper to turn their attentions to the 6550 tube in the ARC preamp. Now that the SED 6550 winged C's are out of production, and apparently nothing else is as good, some have questioned if a KT88 can substitute. Imagine Gold Lions, Shuguang Treasures, Penta Labs or Psvanes...hmmmmmm

I used to own the ARC VS-115 amp which came stock with Svetlana SED 6550 winged Cs. ARC later approved the KT-120 for use in the VS-115. IMO, the KT-150 ... hands down ... was a big improvement over the SED 6550 winged C. Better dynamics. Better bass control. More headroom. Just plain sounded better.

Having said that, I couldn't stop "wining" when the Svetlana factory burned down and reliable SED 6550 winged Cs became scarce. As my fellow ARC preamp and source component owners may know, the SED 6550 winged C was used in the power supply of many ARC source components and preamps. ARC now uses the 6550WE, which I believe is made by Sovtek.

IMO, I think the difference between tube types is of much greater import in ARC's amp gain circuits as compared to the preamp or source component power supplies. IOW, I think the 6550WE, or the 6550 Tung Sol re-issue (also made in Russia) works just fine in the power supply applications.

Perhaps Al or Ralph could better explain why (if at all) that might matter.

Signing off for a glass of whine.

Thank you David, I am aware of that particular thread you have referenced.
However, the point that I am attempting to highlight is specific, and pertinant, to owners of these particular models who are still within the term of the manufacturers warranty.

I do not doubt that ARC Central has circulated some form of internal communication within their own distribution network, However, unless I am mistaken, at this point in time, there remains to be seen Any such affirmation, of this sanctioning, as made public by ARC! Indeed, we still labour under the farcical situation of ARC customer support continuing to
Refute any such official sanctioning of the use of the KT150 within the Reference line.

Therefore, as I commented earlier, IF, your Reference equipment is still under factory warranty then the Only and pertinent source of confirmation must surely come, Verbatum, from ones own dealer responsible for facilitating that factory warranty.
David, I am curious as to whether you may have contacted KJW1/ Absolute Sounds recently in this regard?

Jasper.

Jasper
I have contacted my dealer, but not recently and they made no comment on the KT150s. I got tired of waiting and just changed to the 150s anyway, with a big improvement.

If you were really sneaky and the amp broke down, you could just put the old 120s in, that the amp came with and take it to the dealer. I never said that and of course, would not stoop so low. A large number of people have been using the 150s in the Ref series, for a long time, with no problems. I decided to switch when I was told that a significant number of rooms in the last RMAF were using 150 equipped ARC Reference amps. If it is good enough for dealers and manufacturers, it's good enough for me. I understand you want to be 110% certain of ARCs view on amps within their warranty.

The thing about dealers and manufacturers to consider; for audio shows they may have also installed different value resitors, redesigned a circuit, changed a power supply, etc, etc. I'm not saying don't try KT150's, just understand the risks without blaming ARC in the event of a failure. You do understand the risks and the sound you are enjoying is the result but the 150's are so new to the market....does anyone know in what manner they will fail? All tubes fail at some point, just sayin. Have fun.