Questions on KT150 tubes

I guess I'm lucky…no, wait…I know I'm lucky.

I too have the Jolida Fusion 3502  
Bass on el 34 is tight and punchy,image depth and natural rich midrange without 
Question best with el 34  tube very important for top shelf input tubes
I use 50s black plate Raytheon 12ax7,and GE 5star phase splitter 12ax7 50s tubes
Much better then current made crap. Also Cryo ed tubes EL34 from tube man 

Same Chinelse company that make black treasures which are even better with exceptional Bass. I like a tube that does everything well including natural tone 
And image density the kt 150 can never do.one Big thing to remember Your Loudspeakers and ease of signal I have 94 dB Spatial audio  Hologram-3 
Using top Mundorf caps, reference compression driver with dual 15 inch drivers
Very Easystem load .lowest Xover800hz seamless. That is the key 
And EL34 bandwidth to 28hz with this speaker a exceptional match.
Your speakers efficiency ,and Xovers efficiency will dictate this. 

Just googled ~~KT150 Review~~ and brought me here, read through the posts. 
Only confirms what i figured out on my own reserach independent of the comments/experiences posted here.
I listened to the YT vids of the few 150's uploads( sure sound is compressed etc) still I can detect  that the 150 is the tube i want to roll next in my Defy7. I bought it with 6550's and never listened to it with that tube, as i had no preamp,,,yrs later i boughta  pre and decided to get the Defy up N running with KT90's, as i recall fond memories of that tube in my jadis Orch Refer,, the EIKT90's are over rtaed as mentioned by a  jadis expert here on audiogon.
So I just sold off at 1/2 price the 12 EHKT90's and am running the KT88, labeled ARC,,,a  bit superior to the 90. So I am looking for a  bit more soundstage for my full orchestra muisc.
I thought maybe the KT120;s..then I thought through a bit more carefully, as i do not want to make  yet another costly error,,,so i thought ~~~why should i even consider the1 20's, when fora  bit more i could get the 150's. 
After hearinga  few YT vids of the 150's. its certain its my next upgrade.
Sure the 88's are really nice. But since i am looking for ~~Nirvana~~ the 150 will voice the Defy's raw power and dynamics more than the 150's smaller brother, the 120.
The prices are stable at near $400 Sextet from 1 ebay seller. 
btw I have my cayin cd17 Mark1 in the shp/installing twenty  M SGO caps, the white  casing. Can not afford the much larger sized  Supremes, nor would they fit,,,,,even the whites are going to be jammed in/but doable,,,I will return to the shootouts twix top dog AX's and also  the AU's vs the E80CC's. ...back to subject,
The KT150;'s. ,,,,,,you do not see any used/good bargains on ebay,, = ~~a  keeper~ = ~~A winner~. could we say the 150 tube is ^^almost^^ approaching a  single ended tube sound, the 300/805/845 sound imaging?. 

@mozartfan
02-02-2020 2:22pmJust googled ~~KT150 Review~~ and brought me here, read through the posts.
Only confirms what i figured out on my own reserach independent of the comments/experiences posted here.
I listened to the YT vids of the few 150’s uploads( sure sound is compressed etc) still I can detect that the 150 is the tube i want to roll next in my Defy7. I bought it with 6550’s and never listened to it with that tube, as i had no preamp,,,yrs later i boughta pre and decided to get the Defy up N running with KT90’s, as i recall fond memories of that tube in my jadis Orch Refer,, the EIKT90’s are over rtaed as mentioned by a jadis expert here on audiogon.
So I just sold off at 1/2 price the 12 EHKT90’s and am running the KT88, labeled ARC,,,a bit superior to the 90. So I am looking for a bit more soundstage for my full orchestra muisc.
I thought maybe the KT120;s..then I thought through a bit more carefully, as i do not want to make yet another costly error,,,so i thought ~~~why should i even consider the1 20’s, when fora bit more i could get the 150’s.
After hearinga few YT vids of the 150’s. its certain its my next upgrade.
Sure the 88’s are really nice. But since i am looking for ~~Nirvana~~ the 150 will voice the Defy’s raw power and dynamics more than the 150’s smaller brother, the 120.
The prices are stable at near $400 Sextet from 1 ebay seller.
btw I have my cayin cd17 Mark1 in the shp/installing twenty M SGO caps, the white casing. Can not afford the much larger sized Supremes, nor would they fit,,,,,even the whites are going to be jammed in/but doable,,,I will return to the shootouts twix top dog AX’s and also the AU’s vs the E80CC’s. ...back to subject,
The KT150;’s. ,,,,,,you do not see any used/good bargains on ebay,, = ~~a keeper~ = ~~A winner~. could we say the 150 tube is ^^almost^^ approaching a single ended tube sound, the 300/805/845 sound imaging?.

IF it’s an older Jadis Defy7, I’d call Jadis Electronics first and ask if your amp can effectively drive KT150s to operate properly. It’s possibly going to be a waste of money to buy KT150s if it’s not designed to run enough plate voltage to properly run KT150s. Just went through this with a friend. His amp was like 500v at the plate, and KT150s were tested up to 900-1100v at the plate with the same manufacturer, was told to go back to KT88s. It proved out to be correct.

He bought an amp from a guy removed 6550s from, former owner put in KT150s and it never quite sounded right. We put some PSVane CV181s (KT88s) in and it completely woke the amp up, resulting in what was equal to a complete system upgrade and then some. Quite surprising, proof is three of the KT150s are for sale right now on USAudioMart for cheap. Great tube, wrong amp for them.

My other brand mono block amps run KT150s and they are great, however the amps are designed to run KT150s, I cannot go back to KT88s or EL34s even if I crank he bias down. Different design in my case for KT150s. Some will actually report they like GLKT88s or PSVane CV181s better than KT90 or KT120s. I tried KT120s in my mono amps and much prefer the CV181/KT88 in some amps -or- KT150s only in a KT150 circuit designed amp. It makes a difference.

Doing some quick checking for ya, I noticed this footnote on the Jadis site for the current JA80 MKII mono amp, further hints that Jadis does design their circuit around KT150s too for their newer amps, fwiw, quote:

"When switching from KT150 to another type of power tube such as : EL34, 6CA7, KT88, KT90, KT120 & 6550 a small modification has to be made inside the unit."

Upscale Audio comes though …. kudos!!

This is an update to some old posts about sourcing KT-150s from third party tube vendors.  Just bought 2 quads of KT-150s from Upscale Audio.  I had several telephone conversations with Kevin Deal and a UA service tech about the tube matching challenges I experienced in the distant past with my ARC amp.

Kevin and the tech explained that UA is using a third testing device (an Amplitrex or something like that??) that is set to ARC amp operating parameters.  Extra care and time is taken with matching ARC amp tubes.
  
So I tested UA out by buying a matched pair of KT-150s.  First set, … ok.  The tube biases in the set were within 2 or 3 mVs, which is as good as ARC matched tubes.  Second set, … the same.   Excellent.

I bought a 3rd pair.  The bias delta was outside ARC spec.  Called Kevin.  He said that it is best to order KT-150s in matched quads. UA can do a better job matching that way.  So I did.  Kevin kindly took the 3rd set back and refunded my money, … promptly.

I got the quad last week.  I was and am stunned.  The tube pairs match as close as or better than ARC matched tubes.  So kudos to UA and Kevin Deal for making me a satisfied customer.  

BTW, UA increased its price a little for ARC matched tubes.  UA spends a lot of time with ARC tubes and I do not blame him.  The price increase is de minimis for what we get in return. Just be sure to let UA know about tube matching concerns in the comment section of the online order form. Based on my experience, I am confident UA will get it right. 

Bottom line:  kudos to Upscal Audio and compliments to Kevin Deal.