Xumbug and Joe ... I don't think I'm contradicting the comments and caveats posted above by saying that even if the Ref 210 "seems" to work ok, how can one know for sure whether using the KT-150s will, or will not, prematurely age the amp over the long term. To me 100+ hours is not "the long term."
Maybe it won't hurt the amp, but I surmise that Xumbug dropped some major bucks to buy his Ref 210. Unless he has DEEP pockets and doesn't care, my advice is wait until ARC approves the KT-150s for his Ref 210.
I sure as sh*t, I am not dropping those pups into my Ref 150 until ARC gives the green light. So, I'm taking my own advice. |
07-07-14: Xumbug
Hi joecasey,
You say that with conviction. Are you confident that there will not be any issue's? Would love to know what the difference in sound quality will be! I know someone is rolling KT150 in a Ref 210. I think he has ~100+ hrs without issues. Sound is generally more meat on the bone. My caution to you is this guy has many amps and DEEP pockets so doesn't care if it blows up. |
Hi joecasey,
You say that with conviction. Are you confident that there will not be any issue's? Would love to know what the difference in sound quality will be! |
Hi Bifwynne, Thanks for the response! I will be a little more patient then and will wait another month or two and hopefully someone will have more definite answers for me. It will be great if the 150's can be used! |
Regarding which of the ARC Reference amps would be most likely to accomodate the KT150, I did get some advice from a dealer in ARC about 9 months ago. The advice was the fewer the number of output tubes, the less likely there was to be a compatabilty problem. This means of course, that the Ref 75 I have, was the best candidate. This was NOT a go ahead to try it though. |
Chances are that the 120 to 150 swap is not as big an issue with the ARC amps designed for the 120s as going to 120s in an amp originally designed for the 6550. The issue in my mind is the QA done by ARC on the tubes they sell and warranty. Putting 150s in w/o ARCs blessing imparts two risk factors, one that the circuitry will not handle the tube and two, that tube variation may contribute to failures due to potential incompatibility. It's all about how the individual accepts the risk/benefit ratio. On buying a used amp I would send it back to ARC for a tune up unless it was essentially new. Did that w/ my VT200 even though it was a pain. |
Xumbug .... as a general matter, I would be remiss to advise fellow ARC owners to drop KT-150s into their amps unless ARC said it was ok. Much of the discussion in this thread pertains to dropping KT-150s into current vintage ARC Ref amps, namely the Ref 75, 150 and 250. These amps were specifically designed to handle the KT-120s. The design changes included a beefed up power transformer and power supply.
Admittedly the predecessor Ref amps (namely the Ref 110 and 210) are able to handle the KT-120s. However, as reluctant as I would be to drop the KT-150s into the current Ref amps (such as my Ref 150) until ARC sprinkles pixie dust on the tube, I would be even more circumspect about the earlier version Ref amps.
My thought process is that these earlier amps may not have sufficient power supply head room to handle the additional demands of the KT-150s. And that doesn't even speak to whether the KT-150s are compatible with the older circuit designs.
Just my humble opinion.
I get that you are ready for new tubes since you have 2300 hours on your KT-120s. And those pups are ripe to the point of rotten. I sure wish ARC would fish or cut bait already.
And since poor Kal and Chris at ARC have been pummeled with a million calls about the KT-150s, I'm afraid they will confiscate my amp if they suspect I directed anyone else call them. LOL :) |
07-04-14: Xumbug
I have a pair of Ref 210 that have been upgraded to the KT120 with full resistor replacement by AR. My problem is: The tubes now have 2300hrs on them and I might need to swop them out. Do you think I can put the KT150 in them?
Xumbug (Answers | This Thread) Yes, Go for it! |
I have a pair of Ref 210 that have been upgraded to the KT120 with full resistor replacement by AR. My problem is: The tubes now have 2300hrs on them and I might need to swop them out. Do you think I can put the KT150 in them? |
Djcxxx .... one other issue comes to mind. I'm thinking about resale issues. If I was interested in buying a preowned ARC amp, I would ask the owner if he rolled the KT-150s. All things being equal, if I could buy the same model, sans KT-150, I likely would. Having said that, this concern would be moot the moment ARC officially approves the use of the KT-150. |
If one is willing to accept the responsibility (i.e. cost) for any problems that ARC deems due to use of an unauthorized tube then it is a no brainer. The problem arises when customers believe the manufacturer should assume that responsibility. |
Tsushima1, have you rolled KT150 in your ARC amp? |
This is all very encouraging, it sounds like use is spreading, with or without ARCs approval. Personally I am in no rush and will carry on waiting for ARCs final word, I do'nt wish to void my warranty. As I suspected, it seems the 150's can give a big lift to the sound, but time will tell. My dealer and the UK distributor, still seem to have no view on it yet. |
Tsushima1, awesome review from your friend. Does this mean you are going to stop typing about the no-brainer upgrade and do it for yourself? What does "actually" mean in your first sentence? Is that to imply that if someone isn't sitting around wringing their hands about a set of new tubes, they just aren't living their life to the fullest? LOL. |
And for the interest of members that 'actually' have a material interest in this matter, further comment from a guy in Florida running with an Ref75/KT150 combo~
" That is a good assumption. I have also heard that "when or if" they "sanction" the KT150s they will offer their products at different price points depending upon the tubes the gear is being sold with.
I am closing in on the 150 hour mark on my REF75/KT150 combination and can tell you this upgrade is a no brainer. First 10 hours expect a much fuller an rich sounding experience with amazingly fantastic midrange, but slight attenuation of the higher octaves of what you are used to with KT120s: BUT right out of the box, you know you have something special. By 25-50 hours of listening there is no attenuation of upper octaves and all sounds incredibly balanced with a richness and fullness I have NEVER experienced with a tube amplifier. When you get past the 100 hour mark, you will hear things you have never heard; literally. I was listening to BlueCoast ESE #1 Dayan Kai first cut with a buddy of mine. We have heard this cut many times as my buddy likes to use it as reference. My system is upstairs, my wife was away and my 3 dogs were downstairs. My buddy says, someone is breaking into your house. I laughed as he ran downstairs, my three dogs sleeping, all doors closed and I said, that is background noise of the album you are hearing for the first time.
Listening to Eva Cassidy, Live at Blues Alley, listen for the clinking of glasses in the background as well as the deterioration and raspiness of her voice as the album progresses. Pretty unique in the difference pre and post KT150s. As it turns out she was sick with the flu at this recording and she wasn't happy with the way she sounded, although I think it is sublime but you can clearly hear the progression. It was like listening to the recording for the first time.
One warning. These tubes are so good at resolving that all little nuances of digital recordings (especially if your speakers are capable below 40Hz) made from master tapes, not direct digital become noticeable. This presents a problem for some people while others love it.
For those of you with a REF75 and relatively efficient speakers, be prepared for your audiophile friends to shake their heads telling you that there is NO WAY that is a 75watt amp.
For those questioning whether or not to make the change, go for it and enjoy. The best 350 I have ever spent on audio, bar none."
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A little further information via 'Our man' In Costa Rica.
"Today, I went to see (and hear) the ref150 with the kt150... The owner told me it was the dealer who suggested the use of kt150, has only 62.2 hrs on the clock, but absolutely no problems... The dealer told him that an ARC representative told him it was safe to use them, he already tested a unit with kt150 with 3500 hrs so far and recomended based on his experience..."
Has ARC issued any guidelines, as yet, to their distributors and dealers with respect to this matter?
Or, have a couple of them simply 'Gone Off The Reservation' |
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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. |
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. |
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. |
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. |
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! |
Apologies for the double post Folks!
Until such time as ARC issues an official statement, sanctioning the use of KT150's in specific model's, I quite understand your cautiousness in this regard Bifwynne. |
Tsushima1 .... very interesting bit of news ... but I'm still not dropping those pickles into my amp until ARC says it's ok. Why the wait? Dunno. But until ARC sprinkles pixie dust on the KT-150s ... not in my amp. |
From the same unsubstantiated source.
Marc, If not too much of an imposition would you mind inquiring, via your dealer, as to ARC's position with respect to the REF150 please.
"I was told that they recommend them in all kt120 based products. But you can also call arc yourself..."
We are still but Agaricus bisporus to the omnipotent Audio Research Company. |
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From the same, as yet, unsubstantiated source.
Marc, If not too much of an imposition would you mind inquiring, via your dealer, as to ARC's position with respect to the REF150 please.
"I was told that they recommend them in all kt120 based products. But you can also call arc yourself..."
We are still but Agaricus bisporus to the omnipotent Audio Research Company. |
Comment from an ARC REF75 owner residing in Seattle.
"Call ARC. My dealer did, and they told him to tell me to go ahead and put them in my Ref75." |
Wow...Jolida DID update their site...I stand corrected. |
Confessions: I don't own an ARC amp, but I approve of them generally, and I'm really in no hurry to try 150s so no amps shall be harmed around here. Also, I check my bias on the factory upgraded (I mention that fact to show I care) Jolida 502p I DO own fairly often for no reason other than I have a meter and enjoy risking knuckle burns. I've noticed the LEDs used for bias setting on this amp are very accurate so really the meter is unnecessary, but I do it anyway...500mv per the manual, and the bias on the 120s stays on track really well, even after over 2 years of abuse. According to the Absolute Sound mag I got yesterday, Jolida just put out a new line of power amps with KT150s called "Luxor", and since Jolida hasn't updated their website since 2004 you have to dig through United Home Audio's site to find anything about them. Somebody get those guys a publicist! |
The "life testing" of 150s has taken so long that it's starting to freak me out.. Wolf -- Look at the bright side. The longer it takes the life testing the longer tube life it has (Duh). I'd consider it a good thing. But I already have the blessing of Octave for my amp. Another thought - Since they now have a new amp that uses the KT150 they must like them. I'm just waiting for my local tube guy (Jim McShane) to sell them. |
Wolfy ... you'd be quite fortunate if it was JUST the tubes. Unauthorized tube use could cost you the amp.
Who in their right mind would willfully and knowingly abuse their ARC amp by using tubes that weren't sourced from ARC. Shocking!!!
Sorry if I'm pushing into your personal business, but please confess ... how often do you check the bias of the tubes? Do you religiously set the bias at 65 mV??
Just tryin' to be a friend. :)
P.S. Upscale Audio sells the KT-150 for $92 a pop. :) |
Last thing I need is somebody coming to my door at 2AM to confiscate my tubes. Or maybe that's the second to last thing...in any case it's a thing. |
Wolf .... I am VERY, VERY upset. Nola Speakers used KT -150 tubes in a Ref 75 .... So far, because KT - 150 life testing is ongoing, Nola may (??) have used the tubes without an ARC pixie dust sprinkle. I may turn this over to ARC for disciplnary follow up -- abuse of equipment. Could result in equipment confiscation. :) LOL
www DOT theaudiobeat.com/newport2014/newport2014_favorites.htm
P.S. -- I wonder if Nola got dispensation. |
The "life testing" of 150s has taken so long that it's starting to freak me out...I can't take it...keeps me up at night...what will ARC say? What if they say NO? Then all my excitement about pickle shaped overpriced retro-tech microphonics resisting room heater dildos will have been for NOTHING. Damn... |
As an fyi -- ARC recently told me KT-150 life testing continues. Hopefully, I will survive ARC's life testing process. Seems like it will take a life time. :)
Bifwynne (System | Reviews | Threads | Answers | This Thread) Wow, you ask ARC? Didn't know you're a CERTIFIED FREAK-IN AUDIO RESEARCH TECHNICIAN? |
Just to be fair, I only recommend and use tubes from ARC. They are 'properly' matched and tested for at least 24 hrs at RATED VOLTAGES prior to being shipped. ARC products are too expensive to play Russian roulette with. |
Ariess ... a related issue to the one you just mentioned pertains to resale. My ARC Ref 150 amp is used. I'm not sure how I'd react if I learned that the prior owner used KT-150 tubes if ARC had not blessed their use as of the date I extended an offer. Of course, if ARC sprinkled pixie dust on the KT-150s by the time I was ready to make an offer -- then no harm, no foul.
As an fyi -- ARC recently told me KT-150 life testing continues. Hopefully, I will survive ARC's life testing process. Seems like it will take a life time. :) |
Let me clarify, Alon in now Nola Speaker. KT-150's are still in life test with over 4,000 hrs on one set of tubes. This is good news. I'm sure they will be a drop in replacement for ARC amps that came from the factory with KT-120's. That being said, I'm still waiting for the ARC engineering dept. blessing. Hopefully it will be soon. |
Tli...what you suggest requires bravery and utter selflessness well beyond what most would be willing to risk...and a little over 300 bucks. |
I could imagine there are a number of people who are running KT 150's in their REF75 (or other amps) but would not want to volunteer that information in a public forum for fear of voiding their warranty. Knowing that Carl Marchisotti has made the switch and is happy is enough to try it and upscale audio and others sell matched quads of KT150's. The real issue for some may be whether
they are willing to break the principle of their warranty with ARC and use something (even if its safer and better) that is not approved. I myself have cut the tags off my mattress though the warning says I would void my warranty to do so. |
Wow! What we need now is a volunator to try KT150 on his ARC amp. Is anyone willing to do that? |
No mods other than the typical bias adjustment with new tubes. |
HiFigeek That is very interesting to hear about the ARC Ref 75, running KT150's, you saw at the show. Did Carl say there had to be any modifactions to the Ref 75 to take the new tubes?
I will also hold out for ARCs opinion when endurance testing of the KT150 is over. |
No...we need to wait...when 120s were thought to possibly be a threat to mankind itself and reported amp issues relative to higher heater demands were exactly zero...zero...we were cautious and...well...uh...nevermind. |
I was at The Show in Newport Beach this weekend and walked into the Alon Speakers room hosted by their designer Carl Marchisotto. Low and behold he was running a ARC Ref 75 with KT150's in it. He said, and these were his words, the differences between the KT120's and the KT150's "were transformative." No other room at the show including ARC dealers, were running KT150's. I did not ask Carl where he got the KT150's from or if ARC was a co- sponsor of his room. The plot thickens. |
Appreciate feedback from someone who tried them in CJ gear (their techs stay on the official stance, not even supporting the KT120s). I am pretty happy with the KT120 in my LP140m, seeking more depth in imaging and a bit clearer highs. |
I don't have an answer for you. I will have to differ to ARC and wait, but I am getting impatient. I will ask again next week. |
Gary ... I don't like to guess or talk about stuff above my pay grade. So, I checked the New Sensor web site and copied the following specs:
KT-120
Plate resistance - 3000 ohms
Heater characteristics - 1.70 to 1.95 A
Plate current 135 to 165 mA
Plate dissipation 60 watts
KT-150
Plate resistance - 3000 ohms
Heater characteristics - 1.70 to 2.00 A
Plate current 150 to 180 mA
Plate dissipation 70 watts
I really don't know if the increase in plate dissipation current or plate current draw is electrically significant. Perhaps you can weigh in. However, to the extent that plate resistance is an important spec, the two tubes share the same stat.
Regards,
BIF |
