Home » Audio » Thermionic Emissions » Sonic Difference between New Tung Sol 6550 vs KT120 vs KKT150 (Do they sound exactly alike?)
Sonic Difference between New Tung Sol 6550 vs KT120 vs KKT150 [message #97899] Sun, 21 July 2024 23:49 Go to next message
positron is currently offline  positron
Messages: 112
Registered: May 2020
Viscount
Has anyone performed a sonic comparison between the three tubes?
Do they sound exactly alike, or sonically different? If different,
can you explain the differnce? If not, that is ok.

What about longevity?

Thanks

pos
Re: Sonic Difference between New Tung Sol 6550 vs KT120 vs KKT150 [message #97900 is a reply to message #97899] Mon, 22 July 2024 09:18 Go to previous messageGo to next message
Wayne Parham is currently offline  Wayne Parham
Messages: 18774
Registered: January 2001
Illuminati (33rd Degree)

I don't know about the KT120 or the KKT150, but I do know about the KT88 in an Audio Note Kit 2. It doesn't last nearly as long as a 6550. This is true of all brands, but JJ has been worst for me, sometimes lasting as little as just a few months.
Re: Sonic Difference between New Tung Sol 6550 vs KT120 vs KKT150 [message #97901 is a reply to message #97900] Mon, 22 July 2024 22:34 Go to previous messageGo to next message
positron is currently offline  positron
Messages: 112
Registered: May 2020
Viscount
I run my monoblocks fairly easy, 29 watt plate dissipation,
20 watts output PP triode, and only one highly used Sovtek
and SED tube has failed, both old but I don't the hours.

Among the new Tung Sols I saw just a $7 difference between
their 6550 and the KT120. If they sound the same, why
not purchase the KT120. Fil no problem. I could jack
the plate voltage for a little more power output for
better side getter gas absorption.

That is if they sound the same.

cheers

pos
Re: Sonic Difference between New Tung Sol 6550 vs KT120 vs KKT150 [message #97906 is a reply to message #97901] Tue, 23 July 2024 21:52 Go to previous messageGo to next message
gofar99 is currently offline  gofar99
Messages: 1944
Registered: May 2010
Location: Southern Arizona
Illuminati (5th Degree)
A can of worms. I find the JJ KT88s to last forever. The ones in my original amps (2009) are still fine. I run them in class A at 85% dissipation U/L mode. I do the same with KT120s in the bigger amps. None have ever failed. YMMV as always. There was a bad batch of TS KT120s about 6 years back. They would red plate at less than 50% dissipation. Since then I have not heard of any problems from folks using them. Now I use different settings in my main amps (don't need the power)I personally like the KT120s in U/L class A set at 62ma each and 450 B+ with an 8K load. It is really a sweet spot and produces the best sound of all the tube combinations I tried. A fairly close second is running them at 135ma and 500 B+ into a 4K load. Low level output is nearly in the distortion range of preamps. For an amp that uses essentially no NFB (2.5db above audio at 35KHZ for stability) a 0.1% distortion at 1watt makes for a really special sound. I have never tried the 6550 though. Everything from KT77 to EL34. Several brands all do seem to have a sonic signatures that are (IMO) likely hidden in most amps by the use of fairly large amounts of NFB. All Oddwatts (3 watt to 45 per ch) will run fine without any. I just wanted to avoid anything that might excite a 70KHZ resonance that is common to the configuration and selected components.

Good Listening
Bruce
Re: Sonic Difference between New Tung Sol 6550 vs KT120 vs KKT150 [message #97908 is a reply to message #97906] Tue, 23 July 2024 22:41 Go to previous messageGo to next message
positron is currently offline  positron
Messages: 112
Registered: May 2020
Viscount
gofar99 wrote on Tue, 23 July 2024 21:52
A can of worms. I find the JJ KT88s to last forever. The ones in my original amps (2009) are still fine. I run them in class A at 85% dissipation U/L mode. I do the same with KT120s in the bigger amps. None have ever failed. YMMV as always. There was a bad batch of TS KT120s about 6 years back. They would red plate at less than 50% dissipation. Since then I have not heard of any problems from folks using them. Now I use different settings in my main amps (don't need the power)I personally like the KT120s in U/L class A set at 62ma each and 450 B+ with an 8K load. It is really a sweet spot and produces the best sound of all the tube combinations I tried. A fairly close second is running them at 135ma and 500 B+ into a 4K load. Low level output is nearly in the distortion range of preamps. For an amp that uses essentially no NFB (2.5db above audio at 35KHZ for stability) a 0.1% distortion at 1watt makes for a really special sound. I have never tried the 6550 though. Everything from KT77 to EL34. Several brands all do seem to have a sonic signatures that are (IMO) likely hidden in most amps by the use of fairly large amounts of NFB. All Oddwatts (3 watt to 45 per ch) will run fine without any. I just wanted to avoid anything that might excite a 70KHZ resonance that is common to the configuration and selected components.
Thanks for the heads up on the KT120 problem and it being fixed
Bruce. I idle the TS 6550s and JJs at ~68ma. or so, so we are
pretty close.

I was able to test my monoblocks via specialized listening tests
and with the new Tung Sol 6550 sounds extremely accurate compared
to the input signal.

I need the TS KT120 to be as descent as their 6550s. I have several
other quads that did not cut the mustard, just sitting. Hate to
have the KT120s in the same boat, money lost.

I am hoping some others might have compared the two TS tubes in
the same system since the tubes have similar specs, except the
plate dissipation.


cheers

pos

Re: Sonic Difference between New Tung Sol 6550 vs KT120 vs KKT150 [message #97910 is a reply to message #97906] Wed, 24 July 2024 08:23 Go to previous messageGo to next message
Wayne Parham is currently offline  Wayne Parham
Messages: 18774
Registered: January 2001
Illuminati (33rd Degree)

gofar99 wrote on Tue, 23 July 2024 21:52
I find the JJ KT88s to last forever. The ones in my original amps (2009) are still fine. I run them in class A at 85% dissipation U/L mode.

Seems like I remember you saying this on another thread, or might have been in person at one time, probably at LSAF one year.

I thought it was likely that the differences in what I got out of my JJs and what you did was the circuits they were being used in. That Audio Note SET circuit definitely eats JJs so maybe they run more quiescent current or something.
Re: Sonic Difference between New Tung Sol 6550 vs KT120 vs KKT150 [message #97911 is a reply to message #97910] Wed, 24 July 2024 18:37 Go to previous message
positron is currently offline  positron
Messages: 112
Registered: May 2020
Viscount
Wayne Parham wrote on Wed, 24 July 2024 08:23

gofar99 wrote on Tue, 23 July 2024 21:52
I find the JJ KT88s to last forever. The ones in my original amps (2009) are still fine. I run them in class A at 85% dissipation U/L mode.
Seems like I remember you saying this on another thread, or might have been in person at one time, probably at LSAF one year.

I thought it was likely that the differences in what I got out of my JJs and what you did was the circuits they were being used in. That Audio Note SET circuit definitely eats JJs so maybe they run more quiescent current or something.
I agree Wayne and would guess running a condition, such as plate
voltage, at maximum rating.

I have had my JJ KT88s for years now and not a single issue. But at
29 watts plate dissipation and ~450 plate volts, I am running them
pretty easy.

Right now, I am testing my JJ E88CC tubes at lower filament voltage
to see how they act, their longevity.

cheers

pos
Previous Topic: Class A, AB1, B, C Operation/Modes
Next Topic: New Production Tung Sol 6550, Penta KT88s
Goto Forum:
  


Current Time: Fri Oct 04 12:16:46 CDT 2024

Sponsoring Organizations

DIY Audio Projects
DIY Audio Projects
OddWatt Audio
OddWatt Audio
Pi Speakers
Pi Speakers
Prosound Shootout
Prosound Shootout
Miller Audio
Miller Audio
Tubes For Amps
TubesForAmps.com

Lone Star Audiofest