New KT150 tubes?


Has anyone any experience with these pretty new tubes. There are already one or 2 amps I know of, that use them. The review of one of these amps in a UK magazine suggested they were a little warmer and more natural sounding than the nearly new KT120's

The article also suggested they were a straight swap for KT120 based amps, with no adjustment necessary. They are more than twice the cost of KT120's, but still not too costly compared with NOS tubes. I know changing from KT88's or 90's to 120's. did require some amp modification. I have an ARC reference 75 and might want to try the new tubes at some point, ARC don't seem to have a customer E-mail service, to ask the question
david12
However,

When one considers that It would appear ARC have been 'life' testing this valve for over a year now, Albee that in conjunction with the development of a new product line, I find it inconceivable that ARC-R&D have not concluded whether the KT150 is safe to run, or otherwise, In specific models within the current Reference line.

Therefore, why there is still no official directive in this regard from ARC is, at best, a mystery, at worst, close to the choreographed confusion of real farce!
Tsushima1 ... I believe to a near certainty that the KT-150 will do NO harm to my amp. Nevertheless, I will not drop that tube or any other tube type into my amp until and unless ARC formally announces its approval. Period.

I don't know why ARC is taking this long to announce its approval. Maybe "life testing" takes this long. Or, maybe the delay is wrapped up in some way with ARC's pending release of the new G Series. Dunno.

As an aside, I still have about 1000 hours of life on my KT-120s. So, in a way, other than mere curiosity, I'm in no rush. Also, the KT-150s will cost twice as much as the KT-120s. Why the extra cost??? Haven't a clue. Supply and demand??? Dunno.
My 120s refuse to die, and there is no reason 150s should cost much more than 120s, except for greed and market demand, which makes the world go around. That and momentum in space and gravity...or something.
Well folks, further somewhat encouraging news ~

"@bsandovalb, Do you know whether the owner of said Ref150 had sought/obtained official sanction for this, either from ARC Central or an ARC authorised dealer ?"

"Hi, in fact, the owner is the local ARC dealer, he also put kt150 on two ref75 owners.... Both also very happy!"

Only to be countered shortly after by this ~

"I sent aquestion to Audio Researchon using KT150 and this is his response:

One user has filled in a contact request from the website Audio Research
It follows below the summary of the data filled by the user:
Name: FRANCISCO
Surname: CANO SANCHEZ
Message:
Hi. I own AR Ref 110 and AR Ref 150 (Bi Amp, B & W 802D). I wonder if I can use the new Tungsol KT150 in my two amp, and if so, how to adjust the Bias"

"Hello Francisco,

The KT150 has not been approved for use in the Ref 150.

Best Regards,"

Kalvin Dahl
Customer Support Manager
www.audioresearch.com
service@audioresearch.com.

Now, does this mean~

ARC-R&D Has conducted full testing of the KT150 in the Ref150, concluding that the extra draw of eight OPT's left too little of a safety margin with a Single mains transformer?

Or,

Testing of the KT150 within our current Reference Line is still on-going, therefore at this time "The KT150 has not been approved for use in the Ref 150"?

Or,

Just be grateful for this single line of Obfuscation.

Is it really too much to ask for a reasonable disclosure on this matter, set in context?.

We're testing now to be complete, and conclusions have been drawn, again, Is it really too much to expect an official statement to be made, together a list of which models are, or are not, cleared for use with this Fekin Tube!!!

If only Mushrooms had teeth, we could be pulling them out with pliers.
Tsushima1, why get so wound up over a tube change from 120's to 150's? Ive heard the ref150 and it is a stunning amplifier out of the box. There is also some serious time involved in life testing. You see, you cant just test 1 set of tubes in 1 amplifier, you must test a multitude of tubes under various real world conditions, voltage variations and speaker loads. ARC must also see how the tube acts in a given circuit when mis-biased. It would probably surprise you how many people don't bias properly or frequently. If you want to try the kt150's, cowboy up and buy 2 quads and drop them in your amp. If they sound great then you have your answer, if they blow a resistor or two and you have to take your amp in for repair, then you would also have your answer. At the end of the day though, we would all be outraged if ARC said "sure, try them" and they cause a problem. There would be a thread started here on Audiogon slamming ARC for shoddy testing procedures.

In due time, Im 100% positive ARC will green light the 150 for use in their current product line, just be patient.