Gary, my non-tech instinct (surmise) is that the KT-150 should be a drop in option for ARC's current Ref series amps (75, 150, 250 and 750). I base this conjecture on the following facts: (1) the KT-150 plate draw is just a few milli-amps more than the KT-120; and (2) the KT-150 plate impedance is very close to the KT-120.
In the former case, I would be surprised to learn that the current Ref amps already beefed up power tranny couldn't handle the slight power draw increase. In the second case, if the KT-120 and 150 tube impedances are in the same neighborhood, I would think that the output tranny should do a good job with impedance matching.
If my recollection of the facts is correct, I am puzzled why the KT-150 isn't a non-brainer tube rolling option. I'll double check the KT-120 and 150 specs and report back if my recollection is faulty.
I wonder if ARC's reluctance to "sprinkle holy water" on the KT-150 has anything to do with the pending 2014 introduction of the new G series gear, which apparently will use the KT-150. Well .... as I have written before, I trust ARC and will not drop in the KT-150s until ARC blesses the new tube. I have too much invested in my gear to impulsively drop a component into my Ref 150 until ARC says its ok. |
I have no idea.. I will have more info after next weekend after the hi-fi show in Newport. |
Here's some pics:
www DOT theaudiobeat.com/highend2014/highend2014_arc.htm
Gary, TAB says the new models "are 'reimagined' versions of current models." Do you know yet if the G series incorporates new or improved technology, other than the KT-150 tubes.
Just speculating of course, but if the G series is essentially repackaged existing products, the use of KT-150 tubes may permit one or both inferences (or surmises) that (1) the existing product line can handle the tubes and (2) that ARC completed "life testing." |
I believe the pic on the web site is the G integrated amplifier. |
I just started a new thread where I report on ARC's new G series. I have a URL x-ref to where you can see pics and prices.
It's a new "higher-end" series which is priced higher than the "normal" Reference product equivalent analogues; namely: the Ref 5 SE and Ref 150. There's also an integrated version of the Ref 75. The G series is really gorgeous and uses the new KT-150 power tube.
Looking forward to reading and learning more about the G series. |
Gary (Hifigeek), does the G series employ some new technology? Or is it some type of super reference amp designed to mate with the Ref 10 and Ref Phono 10?? |
Haven't the foggiest idea. They normally don't post pics of products that are not available yet. The G series will be very expensive, that's for sure! |
Gary (Hifigeek), I caught that pic too. Just a peek though. What's with all the suspense?? |
The new G series will use KT150 power tube. According to the usual ARC way of doing things, there sure be a way to upgrade existing amps to KT150. Fingers crossed. |
If you go to ARC's new web site you will see what looks to be their new amp. It's not out yet however, and the curious thing is...it's using KT-150's. Surprise! They don't tell me anything. Are the KT-150's downward compatible you ask? No answer yet.. |
Tubes and VU meters...I put my Squeezebox on the VU setting a lot. It makes digital seem warm and comforting. |
I see that Quicksilver is now offering their V4 and Silver 88 monos with the Kt150's. Anyone heard either of these yet? (Added bonus - the tubes are completely exposed, therefore lowering the amp's "lame-osity" quotient, WolfÂ…). |
I agree. Tubes are the ultimate audio eye candy. If sound quality and value is equal between two amps, I'll take the one that shows the glass every time. |
I think it's lame to design a tube amp that doesn't allow you to easily see the tubes...The Rogers EHF 200 gets my vote for current KT150 design champ. |
Well Folks, at long last, we may observe at least one product line where ARC is intent upon an implementation of the KT150.
http://www.monoandstereo.com/2014/05/audio-research-galileo-line-new.html
Reference 150 and 250 SE upgrade models perchance?
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What if Putin decides to get back at the "West" by cutting off the supply of KT150s? What will audiophiles do then? 8^) |
David12, better that than a puff of white or black smoke from your amp. ;^) |
It's all a bit like waiting for the college of Cardinals to elect a new Pope. Perhaps there should be a chimney in Minesota, so we can all wait outside for the puff of white or black smoke. |
Milimetr ... that's a great explanation. I'm sure the factors you describe are (or were) also under consideration by ARC.
Quite honestly, I'm not sure what "life testing" entails. Perhaps it involves running the tube in actual operation in the amp to check if it has a deleterious effect on other components. It might involve long term subjective sonic testing. Not really sure.
That's why although I am personally interested in following the outcome of ARC's testing process, I'm not so curious to plop those tubes into my ARC until ARC gives the green light. |
Ok. I have similar concern.
Have an aplifier designed to work with 6550/KT88 family of tubes.
Now I have KT120 installed - ok by manufacturer.
I was considering using KT150 im my amplifier, but manufacturer adviced not to do so. The point is not that both KT120 and KT150 have almost the same current draw. The point is different characteristics (curves) in KT150.
When used in amplifier with plate voltage lets say - 485 V and fixed bias point using KT150 will lead to use the tube in non optimal characteristic point (not the most linear part of characteristic). This is at least explanation I got from amplifier manufacturer.
Using KT150 in their optimum requires output transformer to be specially wound for them as well as setting proper working plate voltages. |
Wait...it's been another 2 days of waiting for Kal's testing results...I can't handle the suspense...I'm in audio LIMBO... |
Traded some e mails with Kal at ARC. He reported that ARC is still doing life testing on the KT-150. Kal declined to provide any further information or advice. That's all there is to report. |
@David12, you asked "if you are using an auto bias amp, you need a matched pair or quad of tubes. If you are using an amp, like the ARC power amps, where you have to set the bias yourself, does it matter if they are matched or not?"
Yes, ... I think it does matter for the reason I explained above. In both the ARC Ref 75 and Ref 150, each tube pair has a "set" tube and a "slave" tube. As you know, only one tube, the "set" tube takes the bias adjustment. The "slave" tube bias has to read between 58 mV and 73 mV in order to be in spec. So matching is important.
In addition, and this comment (or better, "guess") is best expanded on by techs like Gary (Hifigeek1). Gary is an authorized ARC service tech. That is there may be other electrical parameters that should be matched, like power output. Obviously, if that is a key spec, I intuit that in a push-pull configuration, if tube output power doesn't match within spec, the waveform could be distorted. I'll stop there because I am now way north of my pay-grade.
Bruce |
Can I ask a stupid question, plainly, if you are using an auto bias amp, you need a matched pair or quad of tubes. If you are using an amp, like the ARC power amps, where you have to set the bias yourself, does it matter if they are matched or not?
I agree with Bifwynne, I am not going to put KT150's in my ARC ref 75, until ARC says it is ok. It is the most expensive bit of kit I have ever bought and I can't afford for it to go up in smoke, or to void my warranty, by making the change.
In fact I have just bought a really nice 2nd hand Skoda car with low mileage. With a trade in, it cost about the same as the ARC. It makes you think how your sense of what is good value, can get a bit warped, in this hobby. Not that I am complaining about the ARC, it is a wonderful amp, I hope to be still using in 15 years. I suppose it's a question of which one of us blows a capacitor first, sobering thought |
There seems to be some confusion regarding 120s or 150s, and I like it. |
@Wolf .... of course not Wolf. Many reputable vendors match tubes. It just happens to be IME that ARC matched power tubes bias much easier in my amp. Btw, for the sake of clarity, I am referring to KT-120s.
As an fyi, my amp has a bias "set" tube and a "slave" companion for each pair of tubes, which are configured in push-pull topology. The way the tubes are biased is that I can adjust bias (65 mV)for the set tube, but not the slave.
If the tubes are well matched, the slave will show a bias voltage ranging between 57 mV and 73 mV. If the slave tube bias is out that range, the amp will not operate within spec.
As I said, even though I have bought "matched" tubes from private venders, sometimes the slave doesn't fall within the spec range. IME, this hasn't occurred with ARC spec'd tubes.
Now, as to the KT-150s, that's right, ARC has not blessed using that tube ... yet. Will it work?? Dunno. Some have tried it in their ARC amps and report great results. Will it hurt the amp? Dunno. Will just have to wait for ARC to approve the tube.
Wolf ... like most A'goners, my gear represents a significant monetary investment. In particular, my amp is a pricey piece of kit. Maybe I'm just being over-cautious, ... but until ARC says the KT-120 will not damage my amp, I'm not experimenting. I will defer gratification.
Cheers. |
I purchased a quad of kt150s from uncle kev at upscale.
I've had them in my primaluna prologue premium integrated for about three weeks now, replacing the stock el-34s. Wow! what an upgrade. Finally giving me that deep bass punch; it struck me like I bought a new amp when i dropped the needle on Talking Heads Stop Making Sense. At the same time all the sweet midrange is still there.
Absolutely no issues. The tube cage does need to be removed |
I'm confused...Only ARC has matched sets? Have other matched sets proved unreliable? I don't understand what that means since you say they haven't approved them for use, but then I'm easily confused. Many Ebay sellers know what they're doing and are rated by the customers so there's that, and my experience with non frozen or overpriced KT120s worked out fine. |
Wolf ... I checked eBay. Right you are. Number of vendors offering to sell KT-150s for prices you mentioned above. Even still, I have three concerns.
First is that ARC hasn't approved the tube for use in its amps yet. I suspect that the additional current draw is not signficant, but I don't want to experiment with my amp.
Second, my amp requires matched tube sets. I've had some difficulty in sourcing pairs that match well. So far, only ARC has been able to provide reliable matched sets.
Third, I do not know anything about the reliability of the eBay vendors. At least with vendors ARC and Upscale Audio, I am comfortable that the tubes are properly run in and tested before being sold.
In short, it might cost me $700+ to buy 2 quads just to satisfy my curiosity .. although I am curious about the tubes. |
I'm a bass player who doesn't fish. |
04-20-14: Wolf_garcia
BASE NOTES...man..."Base fishing anyone?"
LMAO, Base fishing? No, not quite. I do however find 'Angling' for the Lesser Pedantic Grammar Pilchard considerably more edifying, Altho, a somewhat 'predictable' feeding habit does tend to leave them incapable of resisting the bait/bate as proffered.
;0} |
Ebay had that price from somebody a few times...seems actually fair. |
Hey Wolf, where are sourcing the KT-150. A quad for $300 is not bad. |
BASE NOTES...man..."Base fishing anyone?" I may get a quad of 150s (300 bucks is the magic number here) and plop them in my Jolida and just stand back with a fire extinguisher and wait...either it blows up and destroys my entire neighborhood or the tubes actually work. Is a tiny increase in heater current really causing people to wait on these? I say MAN UP people...and report back. |
I shall update If/When there is any response to the following,
Quote:
Originally Posted by cesare59
After 70 hours of use i can say that kt150 it's a must for vsi75 owners!
Soundstage IS wider and deeper! Midrage it's more realistic then with kt120!
Only bass in my system are lean than before..."
My question,
"Most interesting cesare59, Do you feel that the base notes on passages of music, familiar to you, have in fact altered sonically? Or, That due to a shift in emphasis perceived elsewhere in the spectrum you are mostly experiencing a different balance to those familiar passages." |
Was just trolling on the Upscale Audio website and noticed they are listing the KT-150 for $92 per tube. I also checked NewSensor's posted stats for the KT-120 and KT-150. The KT-120 filament draw ranges from 1.75 to 1.95 amps. In contrast, the KT-150 is reported to pull 2 amps. To my non-techie head, the extra draw is not significant. Nevertheless, I will not drop the KT-150s into my Ref 150 amp until ARC officially clears the tube. Hopefully Gary will have something to report shortly. |
Good evening Gary.
I was wondering whether you had been in receipt of any further 'Official' news?
If so ,I sincerely hope that you have not been 'Clipped' for such temerity, And are not currently propping up a flyover, somewhere in Minnesota! |
I shall try and ask this week. |
Thanks for the update Tsushima. Hopefully Gary (Hifigeek) will catch this thread and post another ARC update on status. |
I only ask that the poster understands the posted words, and at least attempts to use them correctly...example: "potency" makes little sense in the context of this exchange, and "intentional parapraxis" is an oxymoron. My criticism in this case avoids "mixed metaphor" as it is nothing if not direct, and sort of fun...man...I need to get out more... |
We have another ARC VSi75 owner, commenting elsewhere, in respect of his unsanctioned adoption of the KT150. He reports that no obvious anomalous behavior has manifest itself,as yet,from either amplifier or himself.
Commenting further, it would appear that he considers the substitution to have been quite efficacious.
"I'm so glad to tell you that this is the greatest improvement I 've ever heard for the money!
Maybe a 15 hours - break in is just a little bit to say that Vsi75 is born for KT150, but soundstage is wider and deeper than ever!
Bass is more bass and midrange is so natural and 3D through my Sophia 3!"
It would be useful if these guys were in a position to monitor bias readings and transformer/circuit temperature.
Perhaps I may make a few inquiries, and post any further information on this point.
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Wolfy ... I think what Tsushima1 is saying is that you are a lowbrow. LOL
Not to worry ... my wife says the same about me. ;-) |
Oh, I seldom underestimate the 'potency' that is the playful use of the intentional parapraxis, or indeed the deployment of the mixed metaphor in bringing forth the 'small' man with their need to indulge in pompous grammatical correction , particularly when they have little of value to add in respect to the subject under discussion.
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Anyone try these out in Rogue Audio equipment? |
Wolfy ... you kill me. :) |
Florid language notwithstanding, never underestimate the potential of good natured criticism of pretentiously misused words, sloppy grammar, and self indulgent obfuscation, as it can reveal the insecurity of the offender and the air pressure sustained by the gasbag. |
Wolfy Wolfy , really now , am I to be so misconstrued !
Surely a somewhat weak and Sophomoric humour cannot be the sum total of your input on this matter ! |
Wolf.... please, let's keep it clean. Naked tubes ... really! |
Does "valve denudation" involve removing the glass tube? That certainly would have impact on longevity, and thankfully there is little "prescience" in audio, especially since these tubes have been clearly vetted by others. My bet is that ARC has piles of 120s to get rid of before sticking 150s in their amps. |
