The other day, I had the opportunity of comparing the GE 6550's against the new KT150's. An interesting AB, although the amps were not the same, so this has to be taken into consideration. The amps were a friends ARC Ref 150SE and his ARC VT100Mk3. As most can expect, the SQ was quite different, the newer amp had it all over the older design, but the older GE 6550's were nice in the mids..perhaps on a par with the newer amp. Everywhere else, there was no contest. Only thing I took from this listening session was that the old GE 6550's are still an excellent sounding tube, although I think probably easily outclassed these days by the new KT150.
Anyone Compared the New 6550/KT88s out there in their Amps?
- Thread starter MylesBAstor
- Start date
Even though most people seem to prefer the KT88 to the 6550 in the Cary, I've heard that the vintage Tung Sol 6550 is quite good in the amp. Trouble is, they seem to be 900 or more per quad, which is why I'm curious about new production tubes.
My SLI-80 won't take the KT150. They've got a brand new integrated built around that tube.
My SLI-80 won't take the KT150. They've got a brand new integrated built around that tube.
Hate to say this, but there is a very good reason why the many companies, including Cary, are now modifying their amps to take the newer tubes ( KT120 and the KT150). IME, there is a wide difference in SQ between the best KT88 and even the KT120's...nevermind the KT150's!
Congratulations! Zesto makes wonderful-sounding components, and the principals are delightful!
Thanks Ron. I have a Leto 1.5 and the BIA 120. Wonderful gear and George is a great guy with whom to chat.
If anyone would like to try the Winged C 6550, let me know. I have several of these in very good condition - tested on a Maxi Matcher.
The SLI80 will take the 120 but not the 150. Cary has a new SLI100 which was designed around the KT150. I don't know about their other amps.
Is it your experience that the KT120 is superior to the KT88 even in the magic midrange?
Yes, it's my experience that the KT120 is superior to the KT88 across the board, even in the midrange...although the GE6550's were excellent in that region. The KT150 is another BIG step up over even the KT120! Personally, I think these new tubes are a game changer, as such I wouldn't consider any new tube amp unless it could incorporate these tubes. Many of my a'phile friends feel the same way, which is why they too have moved away from the KT88/6550 designs. Remember there are folks who think they can just roll these tubes into their existing gear that was never designed for these tubes, and then they come away scratching their heads as to why the SQ is what it is, plus they typically blow their transformers...ultimately
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Not at the moment. Apparently there are a few others who are attempting to come to market. BTW, you could ask your same question about any/ all of the other tube manufacturer's... most of whom are located in Russia and the East.
No company is safe but aren't KT88s made by a number of different companies? That was my point.
Sure KT88's are made by different companies..with varying degrees of quality control. However, I would suspect that IF Tungsol went belly up, that there would be no time before another company stepped in. ( There must be quite a few companies that probably wish that would happen). The new tubes are gaining popularity world wide....and I think unlike the KT88/6550's, the market is actually expanding for these tubes. ( Notice how many tube amp manufacturers are changing their models to accommodate them, and with very good reason, IMO)
BTW, there is also nothing to stop you from ordering spare sets if you are concerned about this! That's what i did.( although NOT for the reason that you gave)
BTW, there is also nothing to stop you from ordering spare sets if you are concerned about this! That's what i did.( although NOT for the reason that you gave)
I was thinking more from the manufacturers' perspective. If you design a component based on a tube that is not available it could be an issue. I think this is why some designs are so popular since the tubes are readily available.
I don't know if my amp (Zesto BIA 120) can take KT150s. I will have to ask them.
I don't know if my amp (Zesto BIA 120) can take KT150s. I will have to ask them.
Hi Davey.
Too each his own I guess, but I disagree with your above comment and so do many other users. To me the Tung Sol KT 120 is the most solid state sounding output tube I have ever heard. Dry Dry Dry, no bloom! I guess some people like that. The KT150s are supposed to be a big step up but have not heard them. Many manufacturers like ARC and CJ are moving from kt120 to kt150. Rogue still uses the TS KT 120 as standard equipment in their amps so they obviously disagree with me.
I think companies switched to the KT 120 to make their amps produce more watts (watts sell) and because they are tough tubes that rarely fail, not because of sound quality.
By the way, both Psvane and Treasure produce KT120. I tried the Treasure KT120z and they sounded spectacular for 2 weeks, much better than the Tung Sols, until they started to have trouble holding bias. Went through two quads with Rachel at Grant Fidelity then finally gave up.
Mendel, let’s be clear, in the few amps that I have heard the KT120’s, they were superior sounding to the amps that I heard that were using KT88’s or 6550’s. (Certainly in their bottom end capability and overall dynamic punch, not so much in their midrange capacity) But, and this is a big factor, IMO, the KT150 is a big step up over the KT120. Having heard the KT 150 in quite a few amps now, and owning an amp that utilizes the KT150, I can absolutely tell you that it is like I stated before, a game changer!
If you have a chance to listen to an amp that utilizes the KT150, and was designed for them...not where someone has rolled them in...probably disastrously so, I highly recommend that you do so.
If you have a chance to listen to an amp that utilizes the KT150, and was designed for them...not where someone has rolled them in...probably disastrously so, I highly recommend that you do so.
That sounds about right by Davey.
Although tubes and their inherent sound is an extremely personal thing, you can also custom design the sound you want out of your amplifiers with the choice of tube you prefer, simple as that!
In the past when we had the CJ ART preamp driving the Premier 8A monoblocks, they were fitted with a full set of 6550C tubes directly from CJ. After a few years we tried the KT88 series and that was nice but I wouldn't say better, just different. We then converted the Prem 8's to the "XS" model triode version, incorporating EL34's, which halves the power output from 275w to around 140w, the presentation was superb!
During this time our reference speakers were the big Maggie's MG20 series and it was a wonderful sounding system; Until... The Apogee Divas took over.
Now for the Divas to sound best, the EL34 version wasn't the best config. The Prem 8's were sold and we ordered a pair of Prem 12's fitted with the original 6550C's that were used in the Prem 8's. Once again this drove the Divas to glorious levels without any strain whatsoever and with less power compared to the Prem 8's, the power of the Prem 12's was more than adequate to drive the Divas. This is partly due to the extra headroom of the 6550 compared to any KT88 or EL34.
Having lived with this type of sound, power and quality for nearly all my adult life, I'm very familiar with the KT88, KT90, EL34, 6550A, B & C grade tubes.
Forward 13 years from 2005 to date, now having used the KT120 more significantly in all power amps I've had in Australia, I can definitely agree with Davey, the KT120 is a far superior tube, and the KT150 is definitely a game changer!
I strongly recommend anyone to audition the new CJ ART150 or the ART 300's, it will shatter all preconceived notions of tube performance.
I can certainly understand why someone may experience the KT120 as being dry or solid state in nature with no bloom... but that's the interesting turn! That dryness and bloom can be sorted out in full affect when you partner a KT120 amplifier with the right tube preamp, either with the Mullard M8080's or a refined version of the 6922 or 6N30P, the combination with the KT120 is marvelous!
With a KT150, not only is it a game changer but a mind changer!
Sometime down the line I will modify my LP125m's to accommodate the KT150's. This will be a project in development directly with CJ as these LP125's are my final amplifiers. As for now, I'm absolutely enjoying the KT120's and to the extent of how they truly control and drive the CLX's, effortlessly! Of course with the right preamp to match, which is a huge factor in getting your system to sound musical rather than be used as a switching device...
Cheers to KT120 & 150! A game and mind changer indeed!
RJ
Although tubes and their inherent sound is an extremely personal thing, you can also custom design the sound you want out of your amplifiers with the choice of tube you prefer, simple as that!
In the past when we had the CJ ART preamp driving the Premier 8A monoblocks, they were fitted with a full set of 6550C tubes directly from CJ. After a few years we tried the KT88 series and that was nice but I wouldn't say better, just different. We then converted the Prem 8's to the "XS" model triode version, incorporating EL34's, which halves the power output from 275w to around 140w, the presentation was superb!
During this time our reference speakers were the big Maggie's MG20 series and it was a wonderful sounding system; Until... The Apogee Divas took over.
Now for the Divas to sound best, the EL34 version wasn't the best config. The Prem 8's were sold and we ordered a pair of Prem 12's fitted with the original 6550C's that were used in the Prem 8's. Once again this drove the Divas to glorious levels without any strain whatsoever and with less power compared to the Prem 8's, the power of the Prem 12's was more than adequate to drive the Divas. This is partly due to the extra headroom of the 6550 compared to any KT88 or EL34.
Having lived with this type of sound, power and quality for nearly all my adult life, I'm very familiar with the KT88, KT90, EL34, 6550A, B & C grade tubes.
Forward 13 years from 2005 to date, now having used the KT120 more significantly in all power amps I've had in Australia, I can definitely agree with Davey, the KT120 is a far superior tube, and the KT150 is definitely a game changer!
I strongly recommend anyone to audition the new CJ ART150 or the ART 300's, it will shatter all preconceived notions of tube performance.
I can certainly understand why someone may experience the KT120 as being dry or solid state in nature with no bloom... but that's the interesting turn! That dryness and bloom can be sorted out in full affect when you partner a KT120 amplifier with the right tube preamp, either with the Mullard M8080's or a refined version of the 6922 or 6N30P, the combination with the KT120 is marvelous!
With a KT150, not only is it a game changer but a mind changer!
Sometime down the line I will modify my LP125m's to accommodate the KT150's. This will be a project in development directly with CJ as these LP125's are my final amplifiers. As for now, I'm absolutely enjoying the KT120's and to the extent of how they truly control and drive the CLX's, effortlessly! Of course with the right preamp to match, which is a huge factor in getting your system to sound musical rather than be used as a switching device...
Cheers to KT120 & 150! A game and mind changer indeed!
RJ
Big Dog RJ nailed it. Everything he stated i agree with 100%.
Having owned a number of amps that utilized the KT88's, the 6550A's and EL34's, I can say that those amps were great in many ways. As some of you may remember, I had a very high opinion of the ARC D70Mk2 with 6550's/or KT88's. Superb amp, BUT now easily outclassed by amps that utilize the newer tubes. I suspect that those who have not heard the new KT series of tubes, particularly the KT150's, probably have a hard time relating to this; but my only comment would be to go and listen for yourself to one of these amps, and then come back here and report. I'm very very sure that you will completely understand why Big DogRJ and I are in complete agreement. As I stated before, IF i were in the market for a new tube amp, there is now no way I would consider one that limited the listener to the older tube series...6550 or KT88!
Having owned a number of amps that utilized the KT88's, the 6550A's and EL34's, I can say that those amps were great in many ways. As some of you may remember, I had a very high opinion of the ARC D70Mk2 with 6550's/or KT88's. Superb amp, BUT now easily outclassed by amps that utilize the newer tubes. I suspect that those who have not heard the new KT series of tubes, particularly the KT150's, probably have a hard time relating to this; but my only comment would be to go and listen for yourself to one of these amps, and then come back here and report. I'm very very sure that you will completely understand why Big DogRJ and I are in complete agreement. As I stated before, IF i were in the market for a new tube amp, there is now no way I would consider one that limited the listener to the older tube series...6550 or KT88!
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