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' |
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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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. |
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, have you rolled KT150 in your ARC amp? |
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. |
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. |
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? |
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! |
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 :) |
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. |
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. |
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! |
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! |
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. |
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. |
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. It's your amp and you can do whatever you want. There are players and spectators ... what makes the world turn. |
I am going to call Kalvin at ARC and ask him about the use of the KT150 in my Ref 110. I suspect that they haven't nor will they test it in the older generation Ref amps (unless there is sufficient demand/enquiry on the part of owners to do so)but will push them to see if I can get a definitive answer. I will also ask about current Ref amps and if I get an answer will report back.
Separately, if the answer definitively comes back as no for my specific question of dropping the KT150 into my Ref 110, does anyone here have a view as to whether the Winged 6550C SED tube is preferable to the KT120 tubes in the Ref 110? It seems like of all the 6550 variants, the Winged SED version is the top dog and often goes for big bucks but wasn't sure if anyone here has compared it, either to ARC standard issue 6550s or to the KT120?
Would appreciate any input on this front. Thanks. |
As an ageing cynic, really ARC have no interest in showing the 150's will work in the current Reference power amps. They have the reputation of bringing out new models faster than a Milan fashion house. I would put money on them having a range of Reference power products, using the 150's, within a year or so.
" Step this way Sir for the new super reference Power amp, the 120's are so last year"
An unworthy thought I know. |
Cmalak -- I haven't tried the KT150 in my Octave V110 but I have tried the SED 6550 and the KT120. Both have very similar sonic signatures. When I was looking for SED EL34's a few years ago (had the Octave V70se then)I met with Jim McShane and he told me about the quality of SED tube taking a nose dive. He said that Arc was the largest customer for SED tubes. In fact when I got my V70 the SED 6550 was the stock tube with the SED KT88 as an option. The KT88 is a much warmer sounding tube. |
As an ageing cynic, really ARC have no interest in showing the 150's will work in the current Reference power amps. They have the reputation of bringing out new models faster than a Milan fashion house. I would put money on them having a range of Reference power products, using the 150's, within a year or so.
" Step this way Sir for the new super reference Power amp, the 120's are so last year" Anything is possible. New SE model, KT120 inventory too high, haven't decided if new resistors are needed ... I have a friend interested in ARC Ref250. The only reason hasn't pulled trigger is uncertainty of KT150. He spoke to a big ARC dealer past Mon and dealer said ARC is very happy with sound of KT150 in Ref amps and should work fine without problems. But since ARC hasn't officially endorse using them, he can't officially endorse them either. Friend is exploring other options so I think the uncertainty has some negative effects on sales. |
At this point I do not recommend using the SED6550 (winged C).
Before production stopped, (the factory burned down supposedly), these tubes became very problematic. I only use the 6550we at this point. |
And from another Costa Rican based corespondent, seeking advise, in respect of an amplifier to drive his Martin Logan CLX speaker,
"Problem solved.
You are absolutely right, following those who recommended to test the amp at home, I did just that and I found the ARC 150 to be just right in the sense that it gives me the full bodied presence I wanted, plus the prerequisite of better imaging and full range of frequencies. Like I said, I tested it and it's staying here. One more additional reason is the dealer brought it with the KT150 tubes already installed, so it made a huge difference. Thank you all for helping solve this little riddle and let me say I am happy. It worked great." |
A very recent comment posted on another forum, Dealer/User location as yet unknown.
"My dealer got confirmation i can use the kt150 in my ref750s. They also suggested i wait a bit because they mention with the amount of tube in the 750s, ARC find it difficult apparently to match a large number of kt150 so far. This would not be an issue with smaller amplifier using less tubes. Not sure what to make of it but i will likely upgrade to the kt150 in the near future anyway..."
__________________ |
Thanks for the update. I think the evidence now is significant enough to call the verdict. I shall upgrade my Ref 250 to KT 150 when the current KT 120 is up for replacement. There should be good improvement in the performance. |
I doubt very much whether we will hear of any 'Official' sanction, If at all, in respect to the utilization of KT150's within the current Reference range (in particular to the 75W and 150W models) for quite some time until after the initial retail launch of the Galileo series.
When one considers that their implementation of the KT150 is a notable component element, not merely audibly, but also in the marketing of the New product range (perhaps even more so) then ARC are unlikely to shoot themselves in the pocket on this one. |
Merely wondering whether anyone has news of any recent development on this?
Perhaps slightly tangential yet of interest. It would appear that Allnic Audio are now shipping their KT120 amplifiers, T2000 integrated, A2000 stereo power amp and M3000 monos, sporting KT150's.
" "After listening late into the evening I can say that installing the KT150 valves into the T2000 yesterday has transformed the sound to an extent I would not have thought possible.
It has dramatically improved in all respects. Everything is much more clearly defined, better articulated and more accurately represented.
The first most notable aspect is how much more quiet the background now is.An 'electronic' background has been replaced by the real ambience of the concert hall.
When listening to a favourite 1984 LP recording of Mahler's 4th and with eyes closed there was no hint of there being speakers in the room at all. What was there was a vividly clear sonic picture of the orchestra in the concert hall and I was sitting midway back in the stalls.The physical space was practically visible.
Each instrument was more accurately represented in terms of its characteristic tone, colour and dynamic range and also where it was in the three dimensional space of the concert hall. It was both proportional and in perspective.
The other improvement was in timing and flow. The music flowed more naturally, with more energy and life making the listening pleasure more intense. The KT 150s have made a significant improvement, which for a couple of hundred pounds
is remarkable."
Way to Go AR Central( Where is that I'm with stupid emoticon when you need it) |
I was going to get a set of 150s, but now the fun has been ruined by all this yammering... |
Tsushima 1 is your T2000 a mk1 version . |
@Andrewrona, I was conveying the information from the position of a somewhat frustrated ARC owner, A form of self flagellation if you will! |
Frustrating is right.
I will start with I have not heard KT150's yet, and don't own an Audio Research amp...
I do have an amp that will work with them however.
But I will say this thread with Audio Research probably went way over the top with ARC owners being way too concerned, and way less about the KT-150.
I believe Audio Research is probably the biggest Tube manufacturer still in the united states, maybe the world.
My answer to why Audio Research has not "Approved" this tube is by far simpler than what is being talked about here...
They are afraid far less about the KT150 killing YOUR amp than they are about it Killing their Current inventory when nobody wants to buy the 10,000 or who knows how many KT-120 matched tubes they already have in inventory ready to go!
As soon as they say 'GO' on the KT-150 officially on the website or wherever who is going to buy all those already KT-120 AR certified sets sitting on the shelf?
Just something to think about. |
I realize you meant AR is one of the biggest tube "users" in the world, but I'd be willing to bet Fender makes their tube inventory look minuscule. Guitar amp companies don't seem to use large tubes like 120s and 150s much if at all (bass amps, with a few exceptions like the mighty Ampeg SVT, are mostly SS) beyond EL34s, EL84s, 6L6s and 6V6s...those are the power tubes of choice generally, and they use a LOT of 'em. I would buy another set of 120s in a heartbeat and likely should since mine are getting a little worn and 150s cost about twice as much...although I did see a quad for under 300 clams recently...hmm.... |
Wolf, .... Undertow makes an interesting point, but ... the KT-150 will list for twice the price of the KT-120. I am dubious that ARC will get stuck with thousands of KT-120 tubes even if the KT-150s are approved for use in the current product offerings.
I've used approximately 75% of the tube life of my KT-120s. I may spring for 2 quads of KT-150s, but not from ARC. Too damn expensive. The good news is I understand that the KT-150s have a life span of 4000 hours. |
hmm, anyone know what the life expectancy of the KT-120's are? I should have about 3000 hours of actual play( more if you include standby) on mine after 2 years of use in January. A quad of the KT-150's is running anywhere from $329~$400, so they are not pricey and could use any incremental power improvement I can get with the Prima Luna Premium integrated amp and Maggies. |
David256, ARC has unofficially said that their tested and calibrated KT-150s will sell for almost $200 per tube. By contrast, ARC sells KT-120s for about $100 a tube. Way over my what I will spend for a tube. By contrast, Upscale Audio is charging about half those amounts.
When ARC blesses the KT-150, I'll probably go to Upscale. No f***ing way I'll spring for $200 a tube from ARC. My current set of KT-120s is getting long in the tooth. I might spring for the KT-150s with or without ARCs blessing ... maybe
Btw, I read somewhere that the KT-150 has a life span of 4000 hours, which is twice the suggested limit for KT-120s. Let's see what is officially reported, all of which I suspect will be shortly after the ARC G Series is released.
BIF |
Another titbit from elsewhere.
" My dealer has checked with Audio Research and apparently I would be able to put the KT150 in my 750s tube amp without any modification to the units. The only reason I cant do that now is because they claim they dont have enought KT150s on hand to properly match the quantity I need for the 750s. I guess this means they might adjust the bias of the KT150 in such a way that it works with my units. I have no ETA from them since they claim being very busy with the G series at the moment.
I am tempted to try sourcing the KT150s myself but given I am not them impact of the bias current have and the matching issues as well if I was to get them from the web, I guess I will be patient. I only have 700 hours on my 750s anyway so I can live with the set of KT120s I have for now! " |
It's been a while - any updates on arc kt150 acceptance and release dates of G series? |
Sent another message to Kal. Waiting for a response. I asked him how the GS 150 differs from the Ref 150. The specs are identical, except the GS 150 uses KT150 tubes. I think there's a marketing wrinkle here. |
I had an E-mail from someone who went to RMAF and noted an ARC ref 75, tubed with KT150's. I contacted the manufacturer, whom I won't name, but is a well respected US company. He kindly replied saying the KT150's are a straight swap with the same bias setting and no modification required. He also said he thought the sound was a real upgrade. I had already been told by a retailer for ARC, he thought this would be the case, but may not apply to larger amps using more tubes, such as the Reference 150.
When I have some time, I am going to be brave and find some KT150's and give it a go. |
David, mere speculation, however I suspect that the ratio of output tubes to mains Transformer(s) might be the issue, rather than power output per se. |
I have Ref 250 and my dealer told me I can just swap KT120s with KT150s without any modification . I am going to do this pretty soon. |
Veerapaneni, has your (ARC?) dealer been given *Official* sanction from ARC Central for the utilisation of KT150's ? |
Does anyone know if you can put the 150's in AR REF 210 monos. |
@Tsushima1
yes. That what he told me . He went for training to ARC couple of weeks back, and you have to just swap 120s with 150s. Nothing more to be done. I am going to do that soon , My tubes only have 700 hrs and thinking twice to waste them :) |
Veerapaaneni ... I e mailed ARC about using the KT-150s in the current Ref line and whether the GS-150 (soon to be released) and the Ref 150 have different innards. So far, no answer.
Here's my cynical speculation. I think the GS-150 WILL sound better than the Ref 150 only because it uses the KT-150 tubes. Otherwise, until someone tells me that the GS-150 has different innards than the Ref 150, I think it's just a dressed up Ref 150 with KT-150 tubes.
I hope an ARC dealer or ARC service tech catches this thread and disabuses me of my cynical comments. I WANT to be wrong, so please someone disabuse me. But so far I see no rational reason for ARC continuing to be officially mum about dropping the KT-150s into their current Ref line. In the meantime, I wait.
BIF |
I have heard from a number of people using KT150's in their ARC reference 75. The only problem is that the tube is taller, so the top of the amp can not be refitted. This does not apply to the 150 or other amps in the ARC line. I have ordered a quad from Upscale and will report the results, assuming the house does'nt burn down wnen the amp catches fire.
I am with BIF, I am sure ARC's silence is connected to the new amps fitted with KT150's. They want us to go out and buy their new shiny amps. |
Whilst I, And for the most part, concur, with David and Bif regarding this Conspiracy Of Silence from ARC Central, especially in respect of the models sporting a Single Mains/Quad Output ratio, I am a tad less optimistic for the ratio as sported on the Ref150. Although this ratio may still prove safe and workable, within the performance envelope of the KT150 /REF150, under a marginally altered bias setting for the Master tubes ?!?!? |
Well the KT150's have landed and are in my Reference 75. No sparks, explosions or other calamity, oh and they sound pretty good too. Right off the bat, I would describe a tight deep base and a deeper soundstage as initial, favourable impressions.
As Tsushima1 indicates, this is only feedback for the 75, not the 150 or other ARC amps using more than 4 tubes. I am using the same bias as the KT120's. |
David12 and Tsushima ... I took a close look at the specs for the KT-120 and KT-150. Take what I say with a grain of salt because I am not a techie, but the current draw, plate dissipation and impedance specs of the two tube types are very similar. I surmise that any additional power demands that the KT-150 would place on the power transformer and other relevant passives would not be significant.
And I continue to wait.
P.S. to David -- how close was the "slave" tube's bias spec to the "set" tube's 65 mV bias number? I ask because for some reason that I cannot explain, IME, the delta between Upscale sourced KT-120 "set" tubes and "slave" tubes specs can be as much as 5+ to 8 mVs??? Not so with ARC matched tubes. |
Gary (Hifigeek1) ... still no official word from ARC yet about dropping the KT-150s into its "standard" current Ref amps???? Has the new G series gear hit the stores yet???
In a private message from Kal a while back, he mentioned that the GS-150 is the best sounding amp ARC that has made to date. He did not answer my question about how the innards of the GS-150 changed from the Ref-150. On paper, they spec identically. |
