Reference 75 with KT150's?

[ariess]

Pretty weird. I wonder if someone up high decided that they should keep the KT150's as unique pairings with the GS line
to provide GS with more differentiation from the Ref series (see long sordid debate about whether GS150 is different than Ref 150 with KT150s,
awhile back ARC said they were the same, than about the time they may have backed off recommending KT150s in Ref gear they may have
begun saying the GS150 was unique).

[dizzie]

Originally Posted by ariess

Pretty sure it was in their Newsletter about their love and recommendations of KT150s.

Sent from my iPhone using A.Aficionado

ariess,

Do you know when the latest newsletter was delivered? I subscribed months ago and I have not received any newsletters. In fact, because I have not received any newsletters, I subscribed via three different email accounts. Nothing is coming through. And yes, I check spam and trash before deleting.

[JWJW]

Originally Posted by JWJW

Can you do?
Has anyone verified with the factory?
Improvement in sound?
Any issues with hitting wires or top cover?

I don't remember the gentleman's name (I think started with a C???). He was VERY knowledge and helpful. We talked for a good 20 minutes about the design differences between the MC275 and the Ref 75 and tube amps in general.
He stated the amp was "not designed or tested with the 150's."

[cmalak]

JWJW...you most likely talked to Calvin. He is the customer service guy that responds to all incoming enquiries over the phone. He has been consistent in saying this to incoming enquiries over the transom/phone lines because officially ARC has not yet sanctioned the KT-150 in the current Ref series amps. Unoficially, at shows and various dealer demos, many ARC customers have talked to the likes of Dave Gordon and other ARC representatives who have sanctioned the use of KT150s especially in the Ref 75 but also seemingly with the Ref 250s and 150s, from various accounts here and on other fora (Agon and such).

Again, this is the maddening bit about the inconsistent messaging from ARC on this issue and the related issue of where the GS150 Galielo series amp falls within the ARC lineup. Piss poor launch and communication on their part and it's unfortunate.

[JWJW]

Originally Posted by cmalak

JWJW...you most likely talked to Calvin. He is the customer service guy that responds to all incoming enquiries over the phone. He has been consistent in saying this to incoming enquiries over the transom/phone lines because officially ARC has not yet sanctioned the KT-150 in the current Ref series amps. Unoficially, at shows and various dealer demos, many ARC customers have talked to the likes of Dave Gordon and other ARC representatives who have sanctioned the use of KT150s especially in the Ref 75 but also seemingly with the Ref 250s and 150s, from various accounts here and on other fora (Agon and such).

Again, this is the maddening bit about the inconsistent messaging from ARC on this issue and the related issue of where the GS150 Galielo series amp falls within the ARC lineup. Piss poor launch and communication on their part and it's unfortunate.

If the amp sounds incredible with the 120's, why risk a $9,000 piece with changing to the 150's….which the manufacturer doesn't recommend? If (and I hope soon) get a chance to own a RF75, I'll probably just stick with the 120's unless AR starts shipping the units with 150's. Just my two cents….

[2fastdriving]

Originally Posted by JWJW

If the amp sounds incredible with the 120's, why risk a $9,000 piece with changing to the 150's….which the manufacturer doesn't recommend? If (and I hope soon) get a chance to own a RF75, I'll probably just stick with the 120's unless AR starts shipping the units with 150's. Just my two cents….

There's no risk. They've been telling us to do it for months. If they changed their policy (which I still dont believe) it's only because of politics and sales of the galileo stuff.

[Puma Cat]

Can any of you guys enlighten me as to what the rationale for using the KT150s, over the stock KT120s is? Is it because it is supposed to sound better, make more power, or both?

I know that for the Conrad – Johnson folks, that almost everyone that used 6550s in C-J tube amps, and replaced them with KT 120s, preferred the KT120s over the 6550s. But, because of the way the transformer were wired for amps originally designed to use 6550s, you wouldn't get actually any more power out of them. They sure sounded better with KT120s, though. I put them in and never looked back. The nice thing is is that Conrad – Johnson was really clear about the benefits. They said that you can use them in any of the later-gen 6550 Amps, and they would sound better.

All that being said, I think the Ref75 is one very sweet-sounding amplifier, KT120s or no. I like that amplifier a LOT.

[Bobvin]

Well, my REF75 had only about 40 hours on it and I put the 150s in. Immediate improvement. Now some of that is likely the amp breaking in, going through its phases, but there was quite an improvement in the dynamic punch. My old room, which closed, had dynamic slam in spades (Sasha1, Ref3, Ref110) but I was worried that, in my new room which doesn't close (open to the rest of the house) my new Alexias, Ref10, and Ref75 were not delivering the dynamics I cherish in Wilson speakers. Drop in KT150s, problem solved. Like the old room, I need to be listening at slightly elevated volume (85-95db) for the music to be viscerally meaningful. I may swap the 120s back in for comparison, but my rig is sounding pretty great right now, and I haven't even begun to tweak out the room.

[tima]

Originally Posted by Bobvin

Well, my REF75 had only about 40 hours on it and I put the 150s in. Immediate improvement. Now some of that is likely the amp breaking in, going through its phases, but there was quite an improvement in the dynamic punch. My old room, which closed, had dynamic slam in spades (Sasha1, Ref3, Ref110) but I was worried that, in my new room which doesn't close (open to the rest of the house) my new Alexias, Ref10, and Ref75 were not delivering the dynamics I cherish in Wilson speakers. Drop in KT150s, problem solved. Like the old room, I need to be listening at slightly elevated volume (85-95db) for the music to be viscerally meaningful. I may swap the 120s back in for comparison, but my rig is sounding pretty great right now, and I haven't even begun to tweak out the room.

Thanks for the report. Could you give a couple examples of music passages you use to gauge "dynamic slam"?

[Harlequin]

Bob, as a matter of interest, on average, what attenuation numbers are you running on the Ref 10 whilst hitting 90-95db in your room ?

Jasper.