New KT150 tubes?

I second that thought. If they are checking tube life, that may take some time I suppose

As far as I know the KT-120 tube as well as the 6550we have a useful life of 2000 hrs.

10-28-13: Booboobaer
Actually Xtil6 I have about 200 hours and they are still opening up.I have been told by Paul Weitzel that I should give them at least 500 hours to start seing what they can do. This is not unreasonable since I saw the same results with the KT 120.

1/4 of expected life just for break-in? OK, got a 10000 shares long market order on TS. LOL!

My KT120s must have more than 3000 hours on them by now, and no signs of drifting bias or sonic issues yet...they still sound strong.

Yeah...after 3000 plus hours I think these are starting to break in...by next June they should be gettin' real good.

Regarding the KT-150. It is not known yet if this tube is a drop in replacement for the KT-120. I'm awaiting info from the ARC engineering dept. on this issue. The KT-150 puts out more power than the KT-120 which could mean it draws more heater current than the KT-120 does. When I get more info on this, I will share it here. Until that time, I would be very careful using this tube.

According to the New Sensor data sheet on the KT150, the heater current is not less than 1.75A and not more than 2.0A and for the KT 120 it's not less than 1.7A and not more than 1.95A. So, they're pretty close in that regard.

There may be other characteristics, physical, mechanical or electrical that may preclude using the KT150 in applications that are designed for the KT120. Physical size is an obvious one.

Unfortunately, due to the shape of the KT150 I can only assume that emergency rooms will eventually be dealing with those who've decided to cram them up their...uh...nevermind...innapropriate...sorry...

Joe ... that's an interesting bit of data. I understand that ARC is looking at the KT-150 now.

Here's my little dilemma. My KT-120s have about 1900 hours on them. According to Gary (Hifigeek1) and ARC, I'm just about at the end of their useful life and should get ready to replace them. I wonder how much longer it will be before ARC announces yeah or nay??

11-13-13: Wolf_garcia
Unfortunately, due to the shape of the KT150 I can only assume that emergency rooms will eventually be dealing with those who've decided to cram them up their...uh...nevermind...innapropriate...sorry...
Wolf_garcia (Threads | Answers | This Thread)

Fortunately not something you have to worry about ... well broken in with plenty of room. I bet break-in was shorter than your KT120s?

It seems ridiculous that somebody would claim 1900 hours is "near the end of their useful life" for KT120s unless that person was trying to sell you something...that would make perfect sense. I'm shooting for 5000 hours or more for my 120s, which should bring me to the point where 150s are much less expensive than during the current feeding frenzy.

Wolf ... point taken. All I can say is that ARC and Gary (Hifegeek1) are touting the company line here. I contacted Kal at ARC by e-mail. He continues to hold that 2000 hours is when both the KT-120s and the 6550 WE regulator tubes should be replaced.

If the 120s or any tube for that matter start to SOUND bad, become hard to keep biased, or explode and destroy your hamster sleeping in his ball next to the hifi (this is sad as you should never leave the hamster in the ball)...then certainly they should be replaced.

what gives you the idea the 150's will be cheaper in a few years?? the 120's haven't really gone down that much since they came out a few years ago. wolf, i have two 502's running in mono {yes, they have a lot more headroom now driving my 1b mid/tweet panels} that would be $750 to buy 150's ( 8 of them) instead of about $300 for 120's. big difference here. is the 150's adding another 10 watts to the amp going to really make a difference for the cost. at $60 a tube i would jump right on them,not at $90. mike at jolida (i spoke to him about this already--the 150's) says they will work with the 502 amp but would hold off getting them right now because they are testing them now to see what the best bias would be to run them at. my mono 502's now with the 120's in are pushing 140 watts at 550 v's. mike said the 120's could be run at 600 with no problem

what gives you the idea the 150's will be cheaper in a few years?? the 120's haven't really gone down that much since they came out a few years ago. wolf, i have two 502's running in mono {yes, they have a lot more headroom now driving my 1b mid/tweet panels} that would be $750 to buy 150's ( 8 of them) instead of about $300 for 120's. big difference here. is the 150's adding another 10 watts to the amp going to really make a difference for the cost. at $60 a tube i would jump right on them,not at $90. mike at jolida (i spoke to him about this already--the 150's) says they will work with the 502 amp but would hold off getting them right now because they are testing them now to see what the best bias would be to run them at. my mono 502's now with the 120's in are pushing 140 watts at 550 v's. mike said the 120's could be run at 600 with no problem

True. True. 150s are priced to the current market, and my hoping they'd be cheaper eventually is simply wishful thinking...today if needed I'd just get another set of matched 120s as they seem to be a relative bargain and sound great.

11-13-13: Hifigeek1
Regarding the KT-150. It is not known yet if this tube is a drop in replacement for the KT-120. I'm awaiting info from the ARC engineering dept. on this issue. The KT-150 puts out more power than the KT-120 which could mean it draws more heater current than the KT-120 does. When I get more info on this, I will share it here. Until that time, I would be very careful using this tube.
Hifigeek1 (Threads | Answers | This Thread)

Good morning Hifigeek1.

I was musing upon whether any further 'evaluation in progress' reports may have filtered out from ARC Central ?

Rgds.

Nothing yet. Still life testing

Thank you for the update Ffg1 , hopefully we may receive some direction early-ish in the New Year .

Talked to ARC yesterday. Tubes are still in life test but apparently will be quite a bit more costly than the KT-120. Whether people will want them at the price they end up being, is difficult to say but KT-150's may not be cost effective.

I understand that Upscale Audio has a batch of KT-150s in stock that are being tested. Not for sale yet, but possibly early next year. Retail pricing not set yet either, but early thought is more than the KT-120s, which as an aside, may take a price increase (TBD).

Put it to you this way. If the KT-150 is twice as expensive as the KT-120, I doubt it would be cost effective for me unless the useful life of the tube increased proportionally with price. Otherwise, I'd be sweating bullets every minute the rig was running.

I heard a buzz that ARC may complete life testing the KT-150 in February/March next year. My current set of KT-120s is ready to be replaced now. I'm inclined to retube my amp with the KT-120s and catch others' comments and reactions.

Happy Holidays,

Bruce

Are there any integrated amps out that come with KT150's?

Icon Audio is already featuring 'em. They sort of beat everybody to the punch with those.

Ayon Audio offers the Orthos XS with KT150 power tubes.
http://www.ayonaudiousa.com/us/products/amplifier/kt88-series/orthos-xs/pictures.html
Looks like they would be great in the winter up north LOL!!

I can't imagine my amp sounding better than it does with 120s, and unless an amp is designed around the 150s to be more powerful I don't see spending the bucks on 150s...thus 120s become a serious bargain.

Thank you once again Hfg1 for keeping we ARC'rs in the loop

Were the utilization of the KT-150 to prove technically compatible , I do hope , regardless of pricing , that ARC R&D leave such a decision up to the end user rather than deciding not to sanction the option on cost alone.

Presumably ARC are considering the price that they would wish to charge for ARC Factory approved valve sets.

Jasper.

The feedback I'm getting is that the tube has a beautiful midrange so we shall see.

The review of the Icon Audio, KT150 tubed amp was very favourable, but Icon Audio makes very good, well designed and priced amps, designed in the UK and built in China. I am not sure that not being designed for a specific tube, precludes the benefits of retubing. For example the ARC REf 110 retubed with KT120's sounds much closer to the ref 150.

I agree though that cost may be a clincher for some, particularly if you need a larger number of tubes, than the 4 I would need for the Ref 75. I never actually advocated making the change, just pondered on what the ARC reference amps would sound like with the 150 tube.

Bifwynne..KT-120's....2,000 hours.

Oooops my bad on the last post...disregard. Tsushimal they are technically compatible as far as I know at this point. ARC would not be life testing the tube if it wasn't. It remains to be seen what ARC says about the specs however.

Sounds promising Hfg1 , the last time I ran this past the main UK distributor being a number of weeks past the situation ,as far as was aware at that time , was that the Ref 75 would be Circuit/Traffo compatible , the Ref 150 he thought more doubtful !

The situation might have been misinterpreted however ,and the situation may well have developed since that time.

We wait upon the Judgment of Zeus !

Cheapest 150s I've seen are $300 for a quad.

Wolf ... when speaking with Upscale Audio, one of the guys slipped that the KT-150s may rtail for about $100 per tube, or thereabouts. However, that price is not fixed yet as I mentioned above.

Even still ... if that is indeed the final price, it's almost twice that of the KT-120s. And ... unless the KT-150s have longer life, I'll probably take a pass, unless I inherit some money and get an itch to road test um' on a whim. I use my rig pretty much every day. The cost of tubes will get prohobitively expensive.

Let's see what somes back in user comments.

Happy Holidays,

Bruce

Hifigeek1, any more info from ARC on the KT150's? For those of us running 4 KT120's in a REF75 or VSi75, what would the new power rating be? If there really is a sonic benefit, the cost of a quad, at $300-$400 would be cheap as an upgrade to an $8000 unit.

Still life testing and it is unclear if ARC will even sell these tubes due to the cost of each tube. I was told the tube exhibits a superb midrange. When I hear something after CES, I will post it to the thread.

Gary (Hifigeek) - looking forward to reading your reactions after CES.

Hopefully, even if ARC should decide NOT to sell/or use the KT-150s, it will at least advise whether the KT-150s may still be used in ARC amps at the customer's option. IOW, that the KT-150 will not damage those amps that are already cleared to use the KT-120s.

It's bitter cold here in Philly. Hope the weather is better on the West Coast.

BIF

Good morning Gary (Hifigeek).

Merely wondering whether there has been any further progress reports coming out of ARC Central ?

One would presume a bare minimum test time in line with ARC's retail tube guarantee regardless of any decision whether to retail directly or not.

I am at the 1,990 mark on my Ref 150 KT120s and was curious about replacing with KT150s. I called Kal at ARC who has been an invaluable resource in the past. I asked when ARC would be done testing the KT 150s. He told me that ARCs position is that it views the life testing of Kt 150s as a "rumor". He could neither confirm nor deny whether that tube was being tested or if was even being considered for testing in the current line. Of course, he was very polite but very firm. I ordered 8 KT120s

if the come anywhere nere the Tesla Vršovice kt88 in sound I will gladly pay $7-800 for an octet. The Eat KT88 which I believe to be the same as the tesla are fetching $1400 for the quad which is crazy money for (most of us . that being said those KT88 had air and space Carnagie Hall compared to local bar) like nothing Ive heard before or since.Too bad they were a bad match for my hard driving rogue 120s.

Has anyone here heard the Eats and the 150s?

Nothing yet from ARC.

People please do not ask ARC what the status of the KT-150 is. Thanks.

Andreas Hoffman (owner and designer) from Octave has cleared the KT150 for use in the V110. He did also mention if you have a V110 you will only be able to hear the sonic differences but get no more power out of the KT150 without a circuit re-design. He said he likes the KT150 sound a lot (didn't mention why) and is considering re-designing the V80 to accommodate the KT150 for the higher power.

Hmmm, standard ARC Central Obfuscation ! I had enough of this when inquiring as to the current situation over ARC's lack of customer disclosure in regard to their phasing out of the 2Uf Teflon coupling capacitors on the Ref 150 .

I sincerely hope that you have not been in any way compromised over this Gary !

Tsushima1, please explain what you meant when you posted that ARC was "phasing out of the 2Uf Teflon coupling capacitors on the Ref 150." I own the Ref 150 so I have a real interest.

Although I barely care what ARC says about most things, I'm tempted to ask them about the 150s simply because I was asked not to.

FAO ~ Bifwynne ,

http://www.audioaficionado.org/audio-research/23028-arc-coupling-capacitors.html

You should have no concerns as long as you experience no necessity for ARC to replace any of your 2uF coupling capacitors ,note post #17.

(I trust that posting the above does not contravene any forum rules ? , my apologies to the Mod's in advance and please delete should this be the case )

Thanks Tsushima1. I read the various posts in the attached link. I suspect that ARC had either supplier issues and/or there were performance improvement gains by going with the new caps. My Ref 5 SE and Ref 150 both have the "old" white Teflon monsters.

I'm a big ARC fan and I believe that if ARC is using different coupling caps, it made the switch-out for good reason. I recall that I had to wait about a year before ARC called me to upgrade my Ref 5 to the SE version. One of the reasons for the delay: supplier problems. But as I said, it may be there are reliability or performance issues with the Teflon caps. Dunno.

Maybe if Hifigeek catches this thread, he will chime in.

If they have reliability and/or supply issues with their tef caps why don't they go with Vcaps. At their asking price, their entire Ref line should have Vcaps in them. Not those no brand name white caps that appear to have some reliability issues.
Just sayin' you know.....

its not a reliability problem, they just found a new cap they like the sound of better.

Can we please get this thread back on KT150 tubes?