I have to say, I love the sound of my amp, but it would be good to have the option of a different sounding tube. |
I agree that the 150's are not cheap, though compared with some other NOS tubes, $100 is petty cash. If I did look at them, it would'nt be for the extra power, a recent review in a UK magazine, HIFI World, of a KT150 integrated, suugests that they produce a different, more refined sound to the 120's. If they were interchangeable with the 120's without modification, it would give you a way of periodically changing the sound of your rig, which was relatively painless |
They should be good for at least 2000 hours is'nt it? That in practice, is a long term and if not stressed to near maximum output, as they are'nt in the ARC, I suspect it's a lot longer than that. Standing in front of your amp, saying "die dam you", probably is'nt going to work. |
I had a word with the UK importer at a small show over the weekend. He has tried the 150's in his amp and was'nt impressed. Good for a guitar amp, was his response, too rich, too much midrange bloom.
He said the 150's would be ok in the Ref 75, which I have. He thought the Ref 150 would'nt be ok. There would'nt be a high enough plate voltage to drive more tubes than the 4 in the ref 75. Just what he said, I have'nt heard the KT150's myself. I too would welcome feedback from ARC, I could'nt find an E-mail address to contact them, on the website. |
Bifwynne If you or anyone else could report back with a definitive answer from ARC, that would be great. To just remind you, the UK importer said the Ref 75 should be OK, not the 150 and above, but I would rather hear what the company has to say. |
I second that thought. If they are checking tube life, that may take some time I suppose |
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. |
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 |
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. |
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. |
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. |
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. |
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. |
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. |
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. |
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. |
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. |
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. |
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. |
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. |
