Reading across the forums it would appear increasing numbers of Ref owners are loosing patience with Obfuscation Central and are electing to run with KT150's .......
"I ordered 8 KT150s for my Ref150 from Upscale Audio on Friday - I had them overnighted. Before installing the KT150s I re-biased the original KT120s to the specified 65mVDC. I have a device that plugs in between the power cord and outlet letting you see how much energy you are consuming. It also displays real time wattage and amps. My thinking was to take a reading with KT120s installed and then with the KT150s (set to the same bias) level to see how much additional power the KT150s required. The results are: KT120 (331 watts / 3.04 amps) and KT150 (336 watts / 3.10). The difference does not look significant. I don't know how really meaningful these numbers are and would appreciate anyone's thoughts.
The installation went perfectly - I have had no issues so far. I took temperature readings of the internals and the case with an IR thermometer and did not see notable changes.
I have about 6 hours on the KT150s and I am glad I made the switch. Improved bass, more space around instruments, more meat on vocals and a huge improvement on the sound of guitar strings. I will post additional comments when I have more hours logged. Thanks to all for the great information influencing my switch to the KT150s! " |
I just ordered a quad of KT150s for my Jolida 502p because I live on the edge...also they hit my magic cheapness number on Ebay, so I guess I live on the edge of cheapness. |
I completely forgot how old this thread was, and I just re-read the whole thing (something I never do)...I've been using some Sovtek kt88s and Tung Sol 6550s from my "barely used" tube stash once I sensed recently that the 120s might have been finally losing it...I'd like to publicly thank those tubes for stepping in before they're sadly put back in the drawer. I might make some sort of LED lit display for my collection of spent tubes since I love the way they look. I just stuck some new Gold Lion Premium "matched everything" 12Ax7s in my amp and although they sound amazing (really), they DON'T GLOW worth a damn, a fact thetubestore warned about in their hype...they're worth every penny though. Also, in case anybody is keeping track, the 150s cost $269 a quad including shipping. |
Wow great price Wolf. But sue to write how they sound especially compared to the KT120's. |
Wolf_ whilst In no way insinuating you to be a Numb Nutz....around valve gear, however, i'd be inclined to back the bias right off of the incumbent valves, insert the 150's, then steadily increase bias back to to circuit spec or close to on the conservative side for a while. |
I've been using tube amps since about 1962 (albeit that was my cousin's white Bandmaster guitar amp), and anytime my Nutz get into a thread, well, it's a good thing...note that with all of those tube guitar amps nobody cared one bit about warm up or bias...we silly kids had no idea what bias was (I assume the repair dudes did). In any case, I've swapped the tubes out of my Jolida plenty and always turn the bias WAY down...after dialing the bias back and sticking new tubes in (and looking out for explosions or large flames) I wait a while and reset it, then check it again hours later...most tubes seem to stay in bias fairly well after the first warmup tweak, but I'm a serial tube finger burning bias freak anyway so I'll be poking it with my meter probes willy nilly. |
Happy to report that the 150s are great...not unlike the 120s initial impression of effortless expansion of the whole frequency spectrum, and it seems the amp is a little louder, although that could be my imagination...little more heat but no biggie, bias is even and holding fine (after initially biasing them to the 500mv amp specs, all of the tubes were up 50mv when I re-set them later, no clue why but at least they were even!). My only criticism is that there's less filament glow like my newly installed "hidden filament" GL 12AX7s...I want more glow damnit, but will learn to live with it somehow...at least my Mullard 12AT7s look alive... |
@ David12, I'm curious as to whether you attended the GS series soirée at KJW1 this weekend past? |
No, I did'nt know it was on and I don't get to the wicked city very often, it's to expensive and time consuming. Did you go? I wonder if they had ARC's new GS amp series there, not that I would be tempted to buy them, I am very happy with my amp.
I do go to Guilford Audios get togethers just south of Reading , when Trevor puts them on and excellent they are. |
Hey guys, with your KT150's installed in your REF75 and 150 respectively, was clearance with the cage an issue? Do you have to leave it off. You would not want to "encaged" those beautiful glowing 150's would you??
Me, i have been operating my Classic 120 monos with cage off for years. Not that i have a clearance issue as i use 16 6550 SED Winged C.
I am considering replacing the Classic's with a REF75 or 150. Will likely audition both in my system to see which one can drive my Verity Parsifal Encore most efficiently. My room is fairly large (15.5' x 25' x 7.5'). Would love to audition a REF75 with KT150's but my dealer's demo has the 120's in it. He tells me that the REF75 is sonically superior to the 150 but in my room and with my speakers, the 75 may run out gas at high listening level, hence a 150 being a better fit. Will have to see for myself. He's got 2 used REF150 for sale (customer trade in) that i could get a great price on. |
Smoffatt, the ARC Ref 75, you have to leave the cage off, but I agree it is good to see those tubes. I understand this is NOT true of the 150 and other models, the top can stay on.
When I auditioned the Ref 75 with Wilson Duettes, I compared it with the then new VSi75 integrated and a Ref 110, retubed with KT120's. No competition, the 110 was near the 75, but still a clearly audible difference. An experienced reviewer and owner of many ARC amps, commented that the company periodically puts out a barnstorming power amp in the 50 to 100 watt range, one that people remember for decades. He thought the Ref 75 was one of these. Mine certainly is'nt going anywhere. Besides I am retiring next week, I can't afford constant upgrading. I don't know how to improve on the Ref 75, much south of $30000. |
Smoffat, I replaced my GNS modified Classic 120s driving Verity Parsifal Ovations with an ARC Ref. 150 about 6 months ago. The amp is tubed with KT 120s. I must say that the improvement was remarkable, with tighter bass, a less colored midrange, and more extended highs. I was unsure before making this change if the Ref. 150 would really make all that much difference but it did. In fact, the improvement in my system by replacing the amps was greater than replacing my GNS modified Ref. 1 preamp with a Ref. 3.
Randy |
Ordered KT150s for My Reference 250s Today . |
Veerapaneni ...my Ref 150 is almost ready for a retube. The KT-120s have almost 2000 hours of use on them.
I am frustrated that ARC will not bless the KT-150 for use in their current Ref series. At this point I have only ONE question: will the KT-150s damage my Ref 150? Period.
I'll take my chances on life testing and sound quality. I just want to know the answer to that simple question. Will I damage my Ref 150
Though a non-techie, the KT-150 additional current draw looks immaterial as compared to the KT-120. The GS-150 and Ref 150 specs look identical. I infer that the GS-150 is a goosed up Ref 150, with just a prettier fascia. It is not even clear to me that the GS-150 has better innards.
Take a look at the ARC web site and check the GS-150 and Ref 150 tech specs ... IDENTICAL in every reported aspect!!!
As many of you who follow my posts know, I am an ARC fan. But I am getting a tad irritated by ARC's refusal to answer my question: will the KT-150 damage my amp???
Bruce |
The latest data from my uber-scientific research regarding "damage from 120s/150s due to filament draw" says they will not damage a god damned thing. You can read more about this study in my earlier post, and if they damage your ARC it will be the first ever reported incident of this sort of damage and I'll send you a little certificate to commemorate the event. Totally worth the risk...and to update the status of MY new KT150s: They are GREAT sounding 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. |
Whoa!!! Pause it there, please. @Smoffatt, would you care to re-read my post of the 12th Inst, perhaps paying a little more attention to the punctuation.
@Bifwynne, please note the above.
For my part, I am no stranger to frustration with Obfuscation Central myself, remember 'Capacitor Gate'?.
Whilst recently discussing the GS150 with an ARC sales rep and the main ARC distributor for Europe, I asked whether they had utilized the stock output transformer from the Ref150 line, merely deigning to output the 16 Ohm winding? I was assured that the OPT's as sported on the GS line, had been the subject of an re-design to the winding spec.
They could not elaborate any further, however, one might hypothesise this to indicate larger 8 and 4 Ohm winding sections over the Ref OPT?!?!? |
Will the Ref 150 work with KT 150 tubes, probably yes, but is it optimized to be used with KT 150's, probably not. That is why they developed the GS 150. |
Brf ... you touch on my very question. How does the GS-150 differ from the Ref 150, save the fascia and the tubes?
Not getting any definitive answer to my question. In the absence of any information to the contrary, all I can see is that the GS-150 and Ref 150 share identical specs ... on paper. I concede that published specs do not speak to whether other important components have changed ... but so far, no information in the public domain ... yet. |
Tsushima ... more importantly, the main question is whether ARC changed the innards of the GS-150, principally the components that would handle the increased current demands of the KT-150 tube. Specifically, the power tranny and other passives that drive the tube.
At this point, all I have to go on are the published specs of the Ref 150 and the GS-150, which are IDENTICAL!! I can surmise and infer all day long. I have only one question. Will the KT-150 damage or prematurely age the innards of the Ref 150. That is ALL I care about and I can't seem to get a straight answer. |
It would seem that the Death Star may be working on an 'Authorised' tech modification (cost of a handful of resistors and the odd cap unknown at this time) to some of the current production Ref/KT120 models, in order to optimise the utilization of the KT150, Ref 150se anyone!
This would of course enable relatively recent customers to retain any remaining factory/dealer warranty, whilst also affording the proud owner the facility of purchasing ARC factory tested sets of the new OPT's.
Curiously I raised the same point several weeks back, opine-ing, that as frustrated Ref owners were undoubtably going to go Off-piste anyway, that ARC may as well offer an upgrade service and make a few $$$ out of the situation, rather than expecting hordes of Ref owners to upgrade, lemming like, to GS, merely because they are the only officially sanctioned
models within the portfolio sporting the KT150.
Anyway, perhaps an avenue for you consider BiffWhine! |
GS line hit the stores yet? |
Tsushima1 ... I asked my ARC authorized tech to contact ARC's repair folks to find out if ARC is offering any kind of an upgrade kit for the current Ref amp line. He is unaware that such is the case, but said he would check.
I also asked him to try an get a definitive answer to my Q about using the KT-150s in my Ref 150. Namely, whether the KT-150s will damage or prematurely age my amp. I am looking for a "YES," a "NO" or "DON'T KNOW" answer.
I think he will get the "same old-same old" answer as the rest of us.
|
Here's an update. FWIW.
My ultimate goal is replace my ARC REF separates including Classic 120 monos with a very good integrated while maintaining (to some extent) the sonic attributes of my current set up. Discussing my options with an ARC dealer yesterday, he was saying that the GSI75 with KT150's is due out in early 2015. It will probably be introduced at CES in January for a release to market thereafter. He is checking with ARC to get a release date and wether it will sport a Phono stage and a DAC in the same box as originally announced by ARC a few months ago. Me, i don't think that they can put both in the same box for obvious reasons hence the delay.
OTOH, what about a REF75 with KT150. He told me that ARC will not ship a REF75 or REF150 with KT150 even if a customer ask for it and willing to pay the added cost. Although the specs are nearly identical for the REF150-GS150, he says that those are only the tip of the iceberg. The electrical design of the GS150 is different from the REF150 and is optimized for the KT150.
He is not sure if the amp is going to age prematurely with KT150. This is an ARC question to answer. |
Thanks Smoffatt. Looking forward to learning about the circuitry changes in the GS-150. So far, the ARC web site gives no clue. |
Spoke with DG at ARC today and he said electrically engineering has signed off A OKAY for use with the KT 150 with the
ARC amps below. But from a Mechanical standpoint one must take note with clearance and observe the larger 150s can vary on glass height with Cages and such could be a close call in some situations etc.
Enjoy, Merry Christmas
Johnny R Audio Connection
VSI 60
VSI 75
Ref 75
Ref 150
Ref 250
Ref 750
|
I don't own an ARC amp, but having followed this issue I feel I can finally sleep at night knowing the suspense and drama presented to the ever cautious ARC owner by the 150 dilemma is finally resolved. Whew...now I gotta buy some stock in Tung Sol. |
There are a quite a few ARC amps where the tubes will not clear the top cover. Be advised. |
Thanks Johnny R ... finally a straight no BS answer.
Johnny, one other question. The GS-150 and Ref 150 spec identically on the ARC site. Everything .... distortion, power supply, bandwidth, whatever. So what changed??
Also, will ARC sell KT-150 tubes for regular stock Ref amps and at what price?
Johnny ... you are the best. |
@Bifwynne, what little I have managed to extract thus far,
Rewound Output Transformers ?!?!? Although I cannot see ARC not utilising the extant Cores and bobbins as sported on the Ref150.
A reworked, and 'perhaps' influential , shortened circuit topology, with a handfull of resistors and the odd capacitor enabling optimisation of the KT150.
And , errr, yes, KT150's.
For my part I am somewhat disappointed that the facility of the 16 Ohm tap has been omitted, however were this to enable the utilization of an improved winding spec then C'est la Vie.
Jasper. |
Note to self: Start selling larger tube cages and top covers to ARC amp owners with KT150s...maybe a lid bulge? |
Jasper .... I am perplexed by the hype surrounding the GS-150. On paper, the GS-150 specs identically to the Ref 150, except for the KT-150s and possibly a different output tranny.
I am sufficiently familiar with ARC's product line to have the status to ask ... what changed? Maybe better passives??? .... maybe the output trannies sound better??? I would like to understand why and how the GS-150 is better and different than the Ref 150, other than its new "package" and use of KT-150 tubes.
BIF
P.S. I am getting an uncomfortable feeling that ARC's old guard is being replaced by marketing/business geeks. An old saw from business school is that if you can't improve the product, ... change the package. I am concerned that that is what the GS-150 may be ... a Ref 150 in a new package.
I look forward to being proved wrong because I am an ARC fan. |
Call me a rebel CJ told me flat out NO, but I just replaced the kt120's in my CJ premiere 12's with kt150's,60 hours in no issues ,been monitoring the transformers to see if they get hot ,no issues.the sonic difference is astounding in my system.I have had these amps for18 years,and have run 3 brands of 6550's 3 brands of kt88's,for almost 3 years kt120's.I switched to kt120's beccause of better bass and better dynamics,but I always felt they brought a little touch of electronic edge,I didn't know if that was coming from somewhere else in the chain.Back to the 150's,the sound is so dramatically better,I will never go back unless my amps blow up or I do.Dynamics like nothing I have ever heard,no grain or edge,best bass ,best and deepest soundstage ever and most musical |
Such a rebel! Especially when you consider that no amp has ever been reported to have blown up from 120s or 150s. |
Dakingat55,
Please keep us updated on how your amps are doing with the KT-150's. I'm too chicken to try them right now.
Thanks! |
The current heap of hot glass in my simple Jolida has been amazing me lately...the 150s seem to have settled in and sound so damn good I'm STOKED with them. |
Joeinid just want you to know that I'm having no issues at all.yesterday I had a lot of my audio friends and audio business contacts over to here the magic thats going on in my system.The amps were running for 5 hours,and pushed them to their limits a lot off that time,again no problems at all.everyone who was there had the same comments ,ie,best dynamics I ever heard ,totally grain free,the instruments,sound so full and rich,imaging and stage depth huge.I can honestly say going from kt120's to kt150's is the single biggest improvement i ever made in my system.ill try keep you up to speed thanks David |
David,
Thank you again. I appreciate your input very much and I am so happy you are enjoying the new sound. I have the ART monos and an ARTsa. I was also told no on the KT-150. I can't imagine them blowing up the amps but may affect ultimate longevity going forward. I have a small integrated that will accept KT-150's and plan on hearing them in that one first. Thanks again! |
Wow! your art amps are impressive,that's a good way to go ,to try it on the smaller amp first.I usually see Bill and Lew at ces ,2 years ago they were raving about how much they were liking the kt120's,last year they were not officially at the show as vendors ,but I ran into Bill ,Lew ,and Jeff their engineer in the hallways at the show .I asked about the kt150 and Bill said he had just acquired some but hadn't had a chance to test them yet .Jeff was concerned because of the higher filament voltage and that my amps transformers were not optimized for that tube,Bill didn't seem to be worried that the amp couldn't handle it ,more that,some of their customers still like to use 6550's and thats what the amps were designed around.Anyways I have always been a huge fan of there products and enjoy my amps and my ct5 pre amp,maybe someday art's.thanksagain |
FYI: ARC owners. I spoke with Chris Ossana from ARC on Monday about an issue involving the white Teflon caps in my Ref 5 SE and Ref 150.
During the course of the call, I asked Chris about the KT-150s ... again. Chris continues to tow the company line. Chris said that ARC engineering has NOT approved the KT-150s for use in the current Ref amps; only the "new" GS-150 amp.
No one could say they are a bigger ARC fan than me, but I am getting big time irritated by the approval lag. ARC has been life testing the KT-150s for well over a year. I admit that I am not a techie, but from what I can glean from the web, aside from a little more current draw, the "120s" and the "150s" spec almost identically.
Further, ARC's published GS-150 specs look almost identical to the published Ref 150 specs. I smell a marketing rat here.
Even still, I will not chance risking my amp until ARC sprinkles holy water on the KT-150s. But I am getting annoyed big time.
My KT-120s are ready for replacement. I already blew 2 bias resisters because an old tube arced. I would like to buy 2 quads of KT-150s from Upscale Audio but am waiting on ARC. As I said above, I smell a marketing trick to sell the "new and improved" GS-150 that specs identically to the Ref 150, but for the KT-150s.
Sorry for the cynicism.
Happy New Year.
Bruce |
Thank you David,
Let's hope we all get some official good news this year regarding KT-150's. I plan on ordering my first quad as soon as the stores are open. I'm looking at another week or so before they are installed and singing.
Happy new year everyone.
Bruce,
Keep the faith. I know of some reviewers and speaker makers who have been using KT-150's in their Ref 75's for quite some time with zero issues. Also, if you notice, the new ARC Galileo series of gear is not marketed as "reference" yet it is more expensive. Early reports are great but I'm not spending that much for them. |
Joeinid .... the Ref 75 uses only 2 pairs of KT-150s. The Ref 150 2 quads. The Ref 250, I think 3 pairs per channel. My gut tells me that there is NO issue, but I am not a techie and I will not give advice or do something that is crosswise to ARC.
As far as the GS-150 is concerned ... yes it costs a small fortune. But other than a designer skin and a 2 tap (4 and 8 ohms) output tranny, I'm still waiting to learn how the innards differ from the Ref 150. On paper, the two amps spec identically.
Joe ... I'm annoyed because my tubes have 2000 hours logged on them and are ready (crying) to be replaced. One old tube already arced and took out bias resisters. I really want to use the KT-150s ... but won't because ARC has NOT sprinkled holy water on the new tubes.
I'm annoyed because ARC has had their hands on the KT-150s for some time now and should be able to report the results of life testing. I repeat what I said ... I smell a marketing trick here. Or, ARC doesn't have enough KT-150 tubes for current GS-150 production needs AND for current Ref amps.
Either way, it's annoying. If it's a cheap marketing trick, I'm pissed. If it's a supply issue, ARC is not the only tube vendor in town. |
I totally understand. I was told flat out "no" for my ART monos and ARTsa. I don't mind because I love them the way they sound and I'll take the chance if I choose to install KT-150's in my amps. At least we know of some ARC users actually using the KT-150 without problems. I suspect they (ARC) will never sanction the KT-150 and also suspect the Reference series and Galileo series are similar but we'll never know unless someone does a full breakdown.
ARC may not be the only vendor but there is only one manufacturer of these tubes. If I were you, buy the KT-150 and enjoy them. Life is way too short. You've already had problems because of a bad KT-120, I doubt you'll have any more or different issues with KT-150's. In fact, I believe the KT-150 will last longer and sound better. |
Your gut tells you there is no issue with 150s as does my previously noted survey. This must be digestion related. |
I too waited anxiously for ARC to bless the KT150 s with the Ref 150 when I reached 2,000 hours on my KT120s in the summer. But they didn't, so I purchased another set of ARC KT120s.
I have owned 2 ARC amps and 3 preamps and have always purchased my tubes directly form ARC due to the comfort factor, but the reports were so good on the KT150, that I managed to meet with an insider at ARC who assured me that, unofficially, the KT150s were recommended for the Ref 150. Purchased a matched set from Upscale and can say they are better than the KT120s. Just sorry I didn't take that shot earlier cause I now have a full matched set of KT120s with only 500 hours on them.
Go with the KT150s. You won't regret it. |
Bifwynne, I agree that there seems to be "ulterior motives" , in ARC not blessing the use of KT150's in the reference series. It is a mistake too, no one is going to sell reference series amps to buy the new Galileo series, because they want to use KT150's. If it is policy not to pronounce on the new tubes, it is losing customer loyalty.
I have about 200 hours on my KT150 equipped Ref 75 and no problems at all, apart from not being able to put the lid back on. No biasing problems, excess heat from transformers, nothing. The only advice I have received from a dealer is, the more power tubes you need, the more risks to the amps there may be, so the Ref 75 would be the safest to re tube. I can not say if this is true or not. In any event, the KT150's are a big step up in the Ref 75, IMHO. |
