I ordered a set of KT-150's for my Jolida Fusion 3502 .....

joeinid

joeinid

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Since the amp takes all tubes and came with EL-34's, I am excited to finally try the KT-150's. I ordered from Upscale Audio and hope to have them late next week. Should be a nice upgrade.
 
It should be interesting to hear how the sound of that amp changes with the big tubes in it. Let us know how they are Joe.
 
Thanks Doug. I am looking forward to it.

tungsolkt150__68256.1410739307.1280.1280.jpg
 
Very exiting Joe :exciting:

Since I have no tube experience, I'm very interested in the sound difference between tubes.
 
MDP said:
Very exiting Joe :exciting:

Since I have no tube experience, I'm very interested in the sound difference between tubes.
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Hey Mark what's interesting about tubes they all sound different. Even when comparing the same type the different manufactures sound different. I'm not a fan of the KT120 and after they were introduced it seemed as everyone loved them. I read the KT150 is much nicer sounding. Haven't tried them myself yet but someday I will. But you have to also consider the overall design of the circuit. Now add to that the speakers too. When I had the Dyn C1's the original TS 6550 black plates were the best sounding but once I got the Raidho's they sound pretty bad. Hated the KT120's with the Dyn's but better with Raidho (still don't like them). Same goes for the 'little' tubes.
 
George, it sounds to me that a person had to be patient when trying to find the right system synergy in regards to tube types. But I'm sure that's a very fun journey.
 
If you are going to use either the KT-120 or KT-150, you need have a power transformer that is rated for a minimum of 2A of heater current in order to operate the tube safely and correctly. 6550s and KT-88 tubes only draw from between 1.4A to 1.6A of heater current and many amps that use 6550/KT-88 tubes may not have a power supply that is robust enough to supply up to 2A of heater current. Also, most current amps that are using either the KT-120 and especially the KT-150 are not specifically designed to take advantage of the output power these tubes are capable of. In most of these amps, you would need both a new power transformer and output transformers and that would include my ARC Ref 75. Even the changes that ARC made with the recently introduced "SE" version does not change the amount of power output as they are not changing the power and output transformers. So even when the KT-120 and KT-150 tubes are plugged into an amp that has sufficient heater current, these tubes are basically loafing along because they are nowhere near their maximum plate dissipation. Remember that tube amplifiers that use a pair of 6550/KT-88 tubes per channel typically have a rated output of 75 watts per channel and these tubes are rated for a maximum plate dissipation of 40 watts. The KT-150 is rated for a whopping 70 watts of plate dissipation. Had the Ref 75 been designed to take advantage of the KT-150 plate dissipation, the Ref 75 could easily have been the Ref 125 (meaning the amp could output 125 watts per channel instead of 75) and still not stress the tube.

Having said all of that, the KT-150 tube still sounds like a more powerful tube even in circuits that weren't optimized for its use. I have now heard them in 3 different amps in my house and currently use them in my Ref 75 and I'm smitten with these tubes. They have the best bass detail I have ever heard as well as the best dynamics both micro and macro. They are extended at both frequency extremes and have great bass punch as well.
 
mep said:
Having said all of that, the KT-150 tube still sounds like a more powerful tube even in circuits that weren't optimized for its use. I have now heard them in 3 different amps in my house and currently use them in my Ref 75 and I'm smitten with these tubes. They have the best bass detail I have ever heard as well as the best dynamics both micro and macro. They are extended at both frequency extremes and have great bass punch as well.
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You're right. The plate and control grids have to be optimized for the tube in use to get the max. Andreas Hoffman (from Octave) said the KT150's will work fine in my Octave V110 but also said there will be no additional power. He did say you will only hear the sonic differences between the tubes and preferred the KT150 over the KT120.
 
Thanks Mark. Great information. My Jolida may provide an additional 20 wpc or more with the KT-150's. Not a tremendous amount but if I get the sonic benefits with longer tube life, I'll be ecstatic.


mep said:
If you are going to use either the KT-120 or KT-150, you need have a power transformer that is rated for a minimum of 2A of heater current in order to operate the tube safely and correctly. 6550s and KT-88 tubes only draw from between 1.4A to 1.6A of heater current and many amps that use 6550/KT-88 tubes may not have a power supply that is robust enough to supply up to 2A of heater current. Also, most current amps that are using either the KT-120 and especially the KT-150 are not specifically designed to take advantage of the output power these tubes are capable of. In most of these amps, you would need both a new power transformer and output transformers and that would include my ARC Ref 75. Even the changes that ARC made with the recently introduced "SE" version does not change the amount of power output as they are not changing the power and output transformers. So even when the KT-120 and KT-150 tubes are plugged into an amp that has sufficient heater current, these tubes are basically loafing along because they are nowhere near their maximum plate dissipation. Remember that tube amplifiers that use a pair of 6550/KT-88 tubes per channel typically have a rated output of 75 watts per channel and these tubes are rated for a maximum plate dissipation of 40 watts. The KT-150 is rated for a whopping 70 watts of plate dissipation. Had the Ref 75 been designed to take advantage of the KT-150 plate dissipation, the Ref 75 could easily have been the Ref 125 (meaning the amp could output 125 watts per channel instead of 75) and still not stress the tube.

Having said all of that, the KT-150 tube still sounds like a more powerful tube even in circuits that weren't optimized for its use. I have now heard them in 3 different amps in my house and currently use them in my Ref 75 and I'm smitten with these tubes. They have the best bass detail I have ever heard as well as the best dynamics both micro and macro. They are extended at both frequency extremes and have great bass punch as well.
Click to expand...
 
mep said:
If you are going to use either the KT-120 or KT-150, you need have a power transformer that is rated for a minimum of 2A of heater current in order to operate the tube safely and correctly. 6550s and KT-88 tubes only draw from between 1.4A to 1.6A of heater current and many amps that use 6550/KT-88 tubes may not have a power supply that is robust enough to supply up to 2A of heater current. Also, most current amps that are using either the KT-120 and especially the KT-150 are not specifically designed to take advantage of the output power these tubes are capable of. In most of these amps, you would need both a new power transformer and output transformers and that would include my ARC Ref 75. Even the changes that ARC made with the recently introduced "SE" version does not change the amount of power output as they are not changing the power and output transformers. So even when the KT-120 and KT-150 tubes are plugged into an amp that has sufficient heater current, these tubes are basically loafing along because they are nowhere near their maximum plate dissipation. Remember that tube amplifiers that use a pair of 6550/KT-88 tubes per channel typically have a rated output of 75 watts per channel and these tubes are rated for a maximum plate dissipation of 40 watts. The KT-150 is rated for a whopping 70 watts of plate dissipation. Had the Ref 75 been designed to take advantage of the KT-150 plate dissipation, the Ref 75 could easily have been the Ref 125 (meaning the amp could output 125 watts per channel instead of 75) and still not stress the tube.

Having said all of that, the KT-150 tube still sounds like a more powerful tube even in circuits that weren't optimized for its use. I have now heard them in 3 different amps in my house and currently use them in my Ref 75 and I'm smitten with these tubes. They have the best bass detail I have ever heard as well as the best dynamics both micro and macro. They are extended at both frequency extremes and have great bass punch as well.
Click to expand...

Great info, thanks Mark.
 
Joe...did you check with Jolida that you can plug in the KT-150s into your amp? Does it have an autobias circuit or do you have to rebias when you plug in the new tubes? if you have to rebias, do you have to do so at the same level as with the EL-34s or to a different point? Just making sure that you have all your points covered...:D
 
Yes it can take KT-150's. It has a switch on the back.

Bias Settings: 400 millivolts + 40 mV For EL 34s or 500 millivolts + 50 mV for 6550s

Fully Integrated Stereo Amplifier: Can be ordered with 6550, KT 120, Kt 150 or EL34 vacuum tubes.

Input 600mV driving 60 watts, maximum 85 watts output with 6550 power output tubes.

Input 600mV driving 50 watts, maximum 75 watts output with EL-34 power output tubes.
 
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