New KT150 tubes?

Certainly in my Ref 75, the 120's and 150's are a straight swap, using the same bias range on the VU meters. No problems with my amp after about 50 hours use.

As for ARC, I suppose you might say, why should they approve the tube swap when they want you to buy their new range. It's still annoying to their loyal customers however.

Thanks for this re-assuring comment Norfish. I feel the same way as you did before making the swap to the REF150. I will audition a REF75 in my system first and make a sonic assessment. If i feel that i need more "bottom end grip" i will audition a REF150. Will likely audition with KT120's.

Upstream i have a GNSC modded REF3 LE (Limited Edition) and REF2 Phono (not SE version). Steve was a great audio guy. Too bad GNSC is now defunct but with the new amp/preamp models that ARC has released in the last 3-4 years, i'm not sure a company like GNSC would be very relevant today as much they were 5 years ago. My Classic 120's were modded in 2005 including the balanced inputs from SE. The REF3 and REF2 Phono were done in the spring of 2010 a few months before GNSC was shut down.

Agreed David. Take a look at the ARC web site and stare at the GS-150 and Ref 150 specs. The GS-150 specs identically to the Ref 150, but for a few extra watts of rated power ..., no doubt because the GS-150 uses KT-150 tubes.

If the GS-150 has different innards, ARC should say so. Bad marketing in my opinion. At this point, as a consumer, all I see is a retro'ish looking fascia and KT-150 tubes. If that's all there is, one would be crazy to part with the extra cash for this new entry to the ARC line-up.

In the 60s, we used to describe good looking so called muscle cars as "no-go showboats." Until I hear otherwise, that's what I think of the GS-150.

Really annoyed with ARC. My amp is close to a retube and I would like to drop in the KT-150s. All I want to hear from ARC is that the KT-150s will NOT damage my amp. I'll take my chances on sonics and tube life.

Hey Bif, don't sweat it. The post above from Tsushima1 states that he ordered KT150's from Upscale and put them in his REF150 with no apparent issues. All is good.

You can not order KT150's from ARC because Kalvin will ask what amp you want to put those in and if you say a REF150 he'll tell you that the amp will blow up and take the house with it. You know why? Imagine each owner of a REF75-150-250-750 calling into ARC for matched pairs/quads/octets of KT150's. If they commission the use of the KT150's in those amps they will likely be "stuck" with a BIG stash of KT120's that no one would want and to make matters worst, most of their older amp models won't "sport" the use of the KT120. I don't think that ARC want people to trade their REF150 for the new GS 150. They just want to keep their little precious KT150's for that new GS series.

Having said all that, you can now call Kevin and get a matched set of Octet for your REF150, put them in and enjoy the music!!!! If you wait for ARC's blessing on the 150's the KT200 will be out.

Smoffat, let me be clear. I am not interested in ARC's precious cache of KT-150s. I understand that ARC will charge $200 a tube. I have no intention of paying $1600 for 8 tubes ... period. Instead, I will probably buy 2 quads from Upscale Audio. Upscale is charging about half that.

I only want to know one thing and one thing only. Will the KT-150 damage or prematurely age the Ref 150? That is it.

Oh ... and as far as Tsushima is concerned, he is in no position to know the answer to my question. Just because the KT-150s presently "work" in his Ref 150 is not responsive to my question.

OTOH, if I learned that the innards of the GS-150 were identical to the Ref 150, then I could fairly infer that the KT-150 would do no harm.