KT150 v KT120 Tubes

[mep]

What are the "theoretical" benefits to begin with?

Cryongenic treatment was (and is) mainly used for tool steel to reduce wear and there is an additional annealing process that usually takes place after the cryogenic treatment. Vacuum tubes and musical instruments are not going to be annealed after the cryogenic treatment. It's a fad that has caught on in the audio industry because audiophiles buy into fads and sometimes plain nonsense. If someone spun a story that sticking your cables under a pile of dog sh*t from a purebred dog under the hot sun for 36 hours caused a permanent change to the metal used in the wires and 10 other people swore to it, we would have people that specialized in putting your cables under a pile of purebred dog sh*t for 36 hours.

Back to the topic at hand, Priaptor, it didn't take you long to come to the conclusion that using KT-150 tubes in place of KT-120 tubes resulted in a significant improvement. Based on my limited experience, I can't say I'm surprised.

 

[DonH50]

I got curious and checked the Tung-Sol data sheets for their KT120 and KT150. The good news is that the specs, including filament and normal operating bias currents, are almost identical. So swapping them into an amp that can handle KT120's should be benign. That was my reason for looking, concern people might be stresing parts of their amplifier's power supply by swapping them in. Interestingly, from the specs there is nothing in their performance parameters (gain, power output, linearity, etc. or even plate voltage and such) to indicate they are worth twice the price or would even provide a significant improvement over a KT120. I am certainly not going to deny listerner's impressions, but find it curious (and surprising) that on paper the KT150 appears to offer little if any benefit over the KT120.

 

[microstrip]

+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.

It is neither my expertise but as far as I know cryogenic treatments afect the surface of materials, and cathode materials, that have complex compositions, could show some sensitivity to these treatments. Burn in of tubes is a well studied effect since the forties - use will destroy whiskers and other similar irregularities responsible for unwanted emission resulting in noise.

 

[Priaptor]

Cryongenic treatment was (and is) mainly used for tool steel to reduce wear and there is an additional annealing process that usually takes place after the cryogenic treatment. Vacuum tubes and musical instruments are not going to be annealed after the cryogenic treatment. It's a fad that has caught on in the audio industry because audiophiles buy into fads and sometimes plain nonsense. If someone spun a story that sticking your cables under a pile of dog sh*t from a purebred dog under the hot sun for 36 hours caused a permanent change to the metal used in the wires and 10 other people swore to it, we would have people that specialized in putting your cables under a pile of purebred dog sh*t for 36 hours.

Back to the topic at hand, Priaptor, it didn't take you long to come to the conclusion that using KT-150 tubes in place of KT-120 tubes resulted in a significant improvement. Based on my limited experience, I can't say I'm surprised.

Now that I stopped LMAO about the purebreds I was just thinking if I should try it with my Golden Retrievers.

Yes it is like a new amp. Carl told me out of the box it was better but I thought it lacked upper octave clarity of the KT120 but better in every other aspect. After 20 hours all is better. I see you have a REF75. I recommend this upgrade. I also see you have a pair of KOs coming. Amazing speaker and clearly the best bang in the Nola line.

I have gone from Micros to Baby Grand to Series II Baby Grands and finally to his Concert Grands. His speakers are really wonderful and the CGRs sing with REF75 and now really kick ass with the tube change.

 

[DonH50]

Hey microstrip,

I agree that tube burn-in is very useful and accomplishes several things, but that is a far different thing than cryogenically treating the tubes. I know enough to know the way it affects materials is much different than heat treatment, with a different set of trades and benefits. I did a bunch of research as part of the trumpet experiments, including talking to real materials folk, but unfortunately it has been 10+ years and I have forgotten most of it.

...

Dog poop, blah, dealing with a dog that just went through surgery and is having complications, I am immersed in various dog excreta. Should anyone desire some for audio experiments I am more than willing to provide. Full disclosure: she is a mix, not pure-bred, so I imagine beneath the dog poo WBF'rs would use in their systems.

 

[mauidan]

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!

Mahalo for sharing your experience with the KT-150s. I'll be ordering KT-150s for my REF 75.

So, what REF 75 improvement was larger, the KT-150s or the Odin PC?

 

[MylesBAstor]

http://www.positive-feedback.com/Issue21/goffinterview.htm

 

[mep]

Mahalo for sharing your experience with the KT-150s. I'll be ordering KT-150s for my REF 75.

So, what REF 75 improvement was larger, the KT-150s or the Odin PC?

Please let us know what you think of the KT-150s after you have some time with them in your amp.

 

[joeinid]

Thank you so much Myles for this informative link. I sincerely appreciate it.

http://www.positive-feedback.com/Issue21/goffinterview.htm

 

[Priaptor]

Mahalo for sharing your experience with the KT-150s. I'll be ordering KT-150s for my REF 75.

So, what REF 75 improvement was larger, the KT-150s or the Odin PC?

Unquestionably the tubes especially when price is considered. Having said that only a lunatic (guilty as charged) would spend the kind of $$ that an Odin costs which is more than the amp it is supplying power to. I tried many cables including Sain's fabulous PC. I was quite surprised at how good the Odin and even more surprised when I went direct with it into the wall bypassing my Silver Circle.

 

[Priaptor]

http://www.positive-feedback.com/Issue21/goffinterview.htm

Great article explains the physics and it makes sense. I guess one issue specific to tubes that are treated is given how hot they run does the temperature the filaments are reaching close enough to the material's "critical temperature" to negate the "benefits"

 

[mep]

It's a waste of time and money. Send your tubes to me and I will pile dog sh*t on them from my purebred boxer for 36 hours in in the hot sun and then return them to you.

 

[DonH50]

That article doesn't do much for me but to each his own. If I remember I'll try to dig up some of the materials papers I found.

 

[zztop7]

It's a waste of time and money. Send your tubes to me and I will pile dog sh*t on them from my purebred boxer for 36 hours in in the hot sun and then return them to you.

Can I send my CDs for the the upgrade.

zz.

 

[rbbert]

That article doesn't do much for me but to each his own. If I remember I'll try to dig up some of the materials papers I found.

It read like a simplified "white paper"

 

[mep]

Can I send my CDs for the the upgrade.

zz.

Sure. I need to scoop my yard anyway. Might as well just pile it up until your CDs arrive. The good thing is that if someone comes to your house and hears one of the CDs that I 'treated' for you and they look at you and say, "Man, that CD sounds like sh*t!", you can respond, "Well, there is a reason for that..."

 

[mep]

It read like a simplified "white paper"

It read like a marketing paper and not a scientific paper.

 

[mauidan]

Unquestionably the tubes especially when price is considered. Having said that only a lunatic (guilty as charged) would spend the kind of $$ that an Odin costs which is more than the amp it is supplying power to. I tried many cables including Sain's fabulous PC. I was quite surprised at how good the Odin and even more surprised when I went direct with it into the wall bypassing my Silver Circle.

Seems there are lots of happy lunatics on WBF that spend big bucks on PCs and PLCs.

Still using the stock PC on my REF 75, and like you, bypassing my Silver Circle 5.0SE and going direct into a Furutech GTX-D outlet.

 

[zztop7]

"Man, that CD sounds like sh*t!", you can respond, "Well, there is a reason for that..."

No wonder I gave away 90% of my CDs .

zz.

 

[mep]

Seems there are lots of happy lunatics on WBF that spend big bucks on PCs and PLCs.

Still using the stock PC on my REF 75, and like you, bypassing my Silver Circle 5.0SE and going direct into a Furutech GTX-D outlet.

I'm still using the stock PC on my REF 75 too. Mine is plugged into a dedicated 20A outlet with an Albert Porter outlet. At some point I do plan on trying a Shunyata PC just because of all of the positive buzz their products have on this forum.