KT150 v KT120 Tubes

[Priaptor]

Thanks Myles, that makes sense to me. The meters read the same because the bias point did not change, so no (or minimal) power gain, but yeah they should last longer running a little more in their SOA region. Also possible the KT150 is designed to provide more power gain than the KT120, natch.

Different transformers imply different output impedance, beefed up wire and core for the extra power, or both.

So are KT150's widely available now? Seems like this arose last year but they were very hard to find.

They are easy to find. Tube Depot shipped same day as I ordered them.

 

[DonH50]

Thanks.

 

[mauidan]

They're $2./tube less at:

http://www.upscaleaudio.com/tung-sol-kt-150/

 

[joeinid]

Myles,

Do you have any knowledge either way about KT-150 in Conrad Johnson amps? Just curious. And, have you heard the ARTsa stereo version of the ART amps? Is it worth considering?

 

[Priaptor]

They're $2./tube less at:

http://www.upscaleaudio.com/tung-sol-kt-150/

I wonder what the "cryogenically treated" schtick is.

 

[mep]

I wonder what the "cryogenically treated" schtick is.

I have no desire for frozen tubes. The greatest audio tubes ever designed and built by the best tube companies in the world were never frozen.

 

[Priaptor]

I have no desire for frozen tubes. The greatest audio tubes ever designed and built by the best tube companies in the world were never frozen.

I guess I should take mine out of the freezer then

 

[joeinid]

https://tubedepot.com/pages/black-sable-faq

http://www.tubeman.com/cat8_1.htm

I do think they can, and do, sound better


CRYOGENICALLY TREATED VACUUM TUBES for the audiophile.
Cryogenic treatment is a process where a product (VACUUM TUBES)is tempered in a deep freeze process(-300F) for 48 hrs. This process produces a permanent change in the metals inside this product making it stronger and longer lasting. Tools, instruments, knives, razor blades, machinery parts have been Cryo Treated for many years.Why do this to tubes?Tubes are mostly metal inside so Cryo treating tubes has the following benefits: permanent change in the metals at the molecular level(more uniform grain structure of metals), longer lasting, tightens internal parts of the tube allowing for more efficient operation. and superior conductivity!SONIC IMPROVEMENTS FROM "CRYO TREATED" TUBES:
LOWER NOISE FLOOR,lower distortion, extended frequency response at the extremes, greately increased resolution and transparency. You will hear information from the recording you barely, or never heard before, especially at the back of the stage! Bass response is greatly improved, treble is sweeter but more extended. Cryo treated tubes just sound much better and more effortless than a non-treated tube!!! THIS CATALOG SECTION
CONTAINS ALL THE ULTRA PREMIUM CRYO TREATED TUBES WE CURRENTLY HAVE, BOTH SMALL SIGNAL AND POWER.THIS IS THE MOST COST EFFECTIVE WAY TO TWEAK YOUR SYSTEM!!

 

[LL21]

https://tubedepot.com/pages/black-sable-faq

http://www.tubeman.com/cat8_1.htm

I do think they can, and do, sound better


CRYOGENICALLY TREATED VACUUM TUBES for the audiophile.
Cryogenic treatment is a process where a product (VACUUM TUBES)is tempered in a deep freeze process(-300F) for 48 hrs. This process produces a permanent change in the metals inside this product making it stronger and longer lasting. Tools, instruments, knives, razor blades, machinery parts have been Cryo Treated for many years.Why do this to tubes?Tubes are mostly metal inside so Cryo treating tubes has the following benefits: permanent change in the metals at the molecular level(more uniform grain structure of metals), longer lasting, tightens internal parts of the tube allowing for more efficient operation. and superior conductivity!SONIC IMPROVEMENTS FROM "CRYO TREATED" TUBES:
LOWER NOISE FLOOR,lower distortion, extended frequency response at the extremes, greately increased resolution and transparency. You will hear information from the recording you barely, or never heard before, especially at the back of the stage! Bass response is greatly improved, treble is sweeter but more extended. Cryo treated tubes just sound much better and more effortless than a non-treated tube!!! THIS CATALOG SECTION
CONTAINS ALL THE ULTRA PREMIUM CRYO TREATED TUBES WE CURRENTLY HAVE, BOTH SMALL SIGNAL AND POWER.THIS IS THE MOST COST EFFECTIVE WAY TO TWEAK YOUR SYSTEM!!

Hey Joe...been a little while. Can you use KT150s in your CJ ARTs? Would be most curious to know what happens if you try it.

 

[joeinid]

Hi Lloyd,

I don't know. I am waiting for official confirmation from CJ. Even if it's not recommended, I'm not worried. The ART monos sound amazing with the KT-120's

Hey Joe...been a little while. Can you use KT150s in your CJ ARTs? Would be most curious to know what happens if you try it.

 

[LL21]

Hi Lloyd,

I don't know. I am waiting for official confirmation from CJ. Even if it's not recommended, I'm not worried. The ART monos sound amazing with the KT-120's

 

[Priaptor]

https://tubedepot.com/pages/black-sable-faq

http://www.tubeman.com/cat8_1.htm

I do think they can, and do, sound better


CRYOGENICALLY TREATED VACUUM TUBES for the audiophile.
Cryogenic treatment is a process where a product (VACUUM TUBES)is tempered in a deep freeze process(-300F) for 48 hrs. This process produces a permanent change in the metals inside this product making it stronger and longer lasting. Tools, instruments, knives, razor blades, machinery parts have been Cryo Treated for many years.Why do this to tubes?Tubes are mostly metal inside so Cryo treating tubes has the following benefits: permanent change in the metals at the molecular level(more uniform grain structure of metals), longer lasting, tightens internal parts of the tube allowing for more efficient operation. and superior conductivity!SONIC IMPROVEMENTS FROM "CRYO TREATED" TUBES:
LOWER NOISE FLOOR,lower distortion, extended frequency response at the extremes, greately increased resolution and transparency. You will hear information from the recording you barely, or never heard before, especially at the back of the stage! Bass response is greatly improved, treble is sweeter but more extended. Cryo treated tubes just sound much better and more effortless than a non-treated tube!!! THIS CATALOG SECTION
CONTAINS ALL THE ULTRA PREMIUM CRYO TREATED TUBES WE CURRENTLY HAVE, BOTH SMALL SIGNAL AND POWER.THIS IS THE MOST COST EFFECTIVE WAY TO TWEAK YOUR SYSTEM!!

I never heard of this. Thanks.

Given that the supposed life on these KT150s are greater than 4000 hours I may be cryogenically treated (assuming my kids will pay the price) before my next set of tubes.

 

[mep]

https://tubedepot.com/pages/black-sable-faq

http://www.tubeman.com/cat8_1.htm

I do think they can, and do, sound better


CRYOGENICALLY TREATED VACUUM TUBES for the audiophile.
Cryogenic treatment is a process where a product (VACUUM TUBES)is tempered in a deep freeze process(-300F) for 48 hrs. This process produces a permanent change in the metals inside this product making it stronger and longer lasting. Tools, instruments, knives, razor blades, machinery parts have been Cryo Treated for many years.Why do this to tubes?Tubes are mostly metal inside so Cryo treating tubes has the following benefits: permanent change in the metals at the molecular level(more uniform grain structure of metals), longer lasting, tightens internal parts of the tube allowing for more efficient operation. and superior conductivity!SONIC IMPROVEMENTS FROM "CRYO TREATED" TUBES:
LOWER NOISE FLOOR,lower distortion, extended frequency response at the extremes, greately increased resolution and transparency. You will hear information from the recording you barely, or never heard before, especially at the back of the stage! Bass response is greatly improved, treble is sweeter but more extended. Cryo treated tubes just sound much better and more effortless than a non-treated tube!!! THIS CATALOG SECTION
CONTAINS ALL THE ULTRA PREMIUM CRYO TREATED TUBES WE CURRENTLY HAVE, BOTH SMALL SIGNAL AND POWER.THIS IS THE MOST COST EFFECTIVE WAY TO TWEAK YOUR SYSTEM!!

That all sounds great, but I have yet to see any scientific verification of these claims with regards to vacuum tubes. It would be easy enough to prove if it were true.

 

[joeinid]

Just like all cables sound the same

That all sounds great, but I have yet to see any scientific verification of these claims with regards to vacuum tubes. It would be easy enough to prove if it were true.

 

[mep]

Just like all cables sound the same

Not hardly. Any 'improvements' in audio tubes such as noise and gain are easily measurable.

 

[DonH50]

+1.

Hard to believe cryogenic treatment, which is used for some things, benefits tubes since they run hot and thus anneal anyway. Metallurgy is far from my area of expertise, however.

Given the same cathode/plate bias current, the biggest issue I see for swapping KT150's into non-KT150 amps is that the filament current is significantly higher so you may stress the filament power supply of your amp. I am sure it will work, for a little while anyway, but personally I would double-check with the manufacturer to ensure the LV filament supply has enough margin for the KT150's. Of course now I'm thinking there's a new niche for supplying after-market high-current filament transformers... Catch is the filament supply is probably just a tap on the regular (single) transformer. I suppose a market for new power transformers could be even more profitable... Or the market for new filament supplies wedged into existing amps.

Switching from LV AC to regulated DC made a difference in my old ARC preamp. Noise floor went down a little, but more HF hiss evident so I was never sure if I liked the change or not.

 

[Priaptor]

Well with close to 20 hours of playtime I can only state Carl hit the nail on the head. "RUN" don't walk to replace the KT120s with the KT150s in the REF75.

It's really hard to believe this is a "cheap" 75 watt amp.

Best 370 dollar upgrade I ever made!

 

[MylesBAstor]

+1.

Hard to believe cryogenic treatment, which is used for some things, benefits tubes since they run hot and thus anneal anyway. Metallurgy is far from my area of expertise, however.

Given the same cathode/plate bias current, the biggest issue I see for swapping KT150's into non-KT150 amps is that the filament current is significantly higher so you may stress the filament power supply of your amp. I am sure it will work, for a little while anyway, but personally I would double-check with the manufacturer to ensure the LV filament supply has enough margin for the KT150's. Of course now I'm thinking there's a new niche for supplying after-market high-current filament transformers... Catch is the filament supply is probably just a tap on the regular (single) transformer. I suppose a market for new power transformers could be even more profitable... Or the market for new filament supplies wedged into existing amps.

Switching from LV AC to regulated DC made a difference in my old ARC preamp. Noise floor went down a little, but more HF hiss evident so I was never sure if I liked the change or not.

Seems cryogenic treatment of musical instruments is even a bone of contention among musicians.

http://www.nytimes.com/2003/11/18/s...cold-trumpet-cryogenic-theory-falls-flat.html

 

[Priaptor]

Seems cryogenic treatment of musical instruments is even a bone of contention among musicians.

http://www.nytimes.com/2003/11/18/s...cold-trumpet-cryogenic-theory-falls-flat.html

What are the "theoretical" benefits to begin with?

 

[DonH50]

Seems cryogenic treatment of musical instruments is even a bone of contention among musicians.

http://www.nytimes.com/2003/11/18/s...cold-trumpet-cryogenic-theory-falls-flat.html

Yup. I have actually participated in one of those studies (not the Tufts one, a different one; there were several around that time as it was all the rage). No change in the trumpets tested. Cryogenic treating of some metals is well-known and in some cases beneficial, but as far as altering the tone and other characteristics, just ain't gonna' happen. Cryogenic cycling has also been known to cause problems in the metal, weakening it instead of strengthening. The worst cases are when thermal cycling is too fast and/or simply too stressful for parts of the horn, such as when solder joints break apart from the brass or stress fractures develop from plating due to different thermal expansion coefficients. Rare but did happen. Annealing (heat treatment) and quenching is far more common (and effective). All that said, all I really know are the conclusions, as I said metallurgy is far from my field of expertise.

Problem with the cryogenics thing, as well as many other things, is expectation bias. For cryogenics, you either buy a pre-treated instrumented in which case you have no basis for comparison, or send a horn away for a week or three and then "find" small differences more likely due to the joy of getting your main horn back. Day-to-day variations in physical and mental state have far more effect IMO. That is one reason I remain skeptical of many such claims (trumpet and audio). Of course, there is always the one tweak that actually does make a difference, and IME those turn out to be measurable. I've a list of them (working tweaks) based on my experience & measurements, including a few that, while I have speculations, I don't really understand. Measurements do not always yield understanding.

The brass technician in that article, Wayne Tanabe, is a great guy though he has since moved on. We may disagree on cryogenics (don't know if he is still an advocate) but he is widely regarded as one of the best techs in the country. We are very fortunate to have another great tech and player from that shop who moved to Colorado Springs. I have played with him and taken instruments for work.