KT120's in new Classic Sixty SE ...

[joeinid]

According to the Spearit web page on the Classic Sixty SE, they are using KT120 tubes. I pretty much know what to expect with EL34's and to a certain extent 6550's. Can anyone say what to expect with KT120's? Are they more or less sweet as compared to other tubes? I would expect a firmer, more solid base and at 60 wpc, longer tube life. Anything else? Do you expect more C-J amps to be built around this tube?

The Classic Sixty SE builds on the very high standard set by the Classic Sixty. The Classic Sixty SE enjoys a number of upgrades that enhance the already stunning performance of the Classic Sixty. The Classic Sixty SE replaces the high quality polystyrene coupling caps (inverter to output tubes - one per each of the four output tubes) with Conrad-Johnson design (CJD) Teflon Capacitors. The inverter grid to ground capacitor is bypassed with CJD Teflon cap (one per channel). Critical resistors are upgraded to Vishay (input to grid, input tube grid load, input tube plate, input tube cathode and feedback). Output tubes are upgraded from EL34 to KT120. Output binding posts are upgraded to special Cardas binding posts. The result of all of these parts changes is an amplifier that sets a new standard for dimensionality, musicality, detail, and top to bottom harmonic "rightness" in a power amplifier that sells anywhere near its price. Audition this great amp and rekindle your passion for enjoying great music in your home.

Specifications Conrad-Johnson Classic Sixty SEPower: 60 watts per channel RMS both channels driven into 4 ohms from 30Hz to 15KHz at not more than 1.5% total harmonic distortion or intermodulation distortion (can be re-connected internally for 8 or 16 ohm loads. 4 Ohm wiring is recommended for most loudspeakers.) Sensitivity: 0.7 V RMS to rated power. Frequency Response: 20Hz to 20 kHz +0/-.3 dB. Hum and Noise: 96 dB below rated power output. Phase: phase correct. Input Impedance: 100 kOhms Tube Complement: 1 x 6189 (12AU7), 2 x 6922, 4 x KT120. Bias adjustment: built in LED indicators. Dimensions: 13.375”D x 17.375”W x 6.625”H.

[ronenash]

Its looks lke CJ are moving to the KT120. The new LP125SE also uses KT120. Now that the 6550C are no longer available in the US CJ changed their tube of choice.

[Rafale]

No news about the compatibility of the KT120 on amplifiers using 6550?

[Rafale]

any feedback from c-j about the 6550/KT 120 swap ?

[joeinid]

any feedback from c-j about the 6550/KT 120 swap ?

I have not really looked into it but I think they are starting to switch over for supply reasons and I am sure better sound. :thumbsup:

[Rafale]

Did anybody try KT120 on one Prem11 / MV60SE / LP series?
Is a modification of the circuit necessary?

[Coppy]

Did anybody try KT120 on one Prem11 / MV60SE / LP series?
Is a modification of the circuit necessary?

Okay Folks,

As it happens i was just talking to Ed at CJD and he tells me that the issue with the 6550s is availability in volume from the Russians. The fatcory is shutting down. So, they are switching to the KT120... even in the ART Amps. I believe them to be directly interchangeable. You should verify that with CJD before changing in your equipment, but I'm told they are a simple substitution... except, they are taller... and in my case it means the tube covers will no longer fit. Hmm... to buy eight of the Wing C 6550s from them would be $800. Maybe I'll wait until something blows. I did put a pair of NOS Mullard E88CCs in Mr. GAT and they sound great. Maybe a bit better than the EH 6922s. A bit smoother. Maybe less peaky in the highs which is okay with my Sashas.:music:

Bob

[joeinid]

Thanks Bob!

I appreciate the info. :)

Joe

[Rafale]

Okay Folks,

As it happens i was just talking to Ed at CJD and he tells me that the issue with the 6550s is availability. So, they are switching to the KT120... even in the ART Amps, which I believe to be directly interchangeable. You should verify that with them before changing in your equipment, but I'm told they are a simple substitution... except, they are taller... and in my case the tube covers will no longer fit. Hmm... to buy eight of the Wing C 6550s from them would be $800. Maybe I'll wait until something blows. I did put a pair of NOS Mullard E88CCs in Mr. GAT and they sound great. Maybe a bit better than the EH 6922s. A bit smoother. Maybe less peaky in the highs which is okay with my Sashas.:music:

Bob

Thanks Bob
Do you know what brand of KT120 they recommend?

[turntable]

Okay Folks,

As it happens i was just talking to Ed at CJD and he tells me that the issue with the 6550s is availability in volume from the Russians. The fatcory is shutting down. So, they are switching to the KT120... even in the ART Amps. I believe them to be directly interchangeable. You should verify that with CJD before changing in your equipment, but I'm told they are a simple substitution... except, they are taller... and in my case it means the tube covers will no longer fit. Hmm... to buy eight of the Wing C 6550s from them would be $800. Maybe I'll wait until something blows. I did put a pair of NOS Mullard E88CCs in Mr. GAT and they sound great. Maybe a bit better than the EH 6922s. A bit smoother. Maybe less peaky in the highs which is okay with my Sashas.:music:

Bob

Thanks for that Bob. Sounds like cj don't like any other production 6550.

Could be time to start stockpiling svet winged c 6550's

[ronenash]

Thanks Bob
Do you know what brand of KT120 they recommend?

There is only one brand of KT120 and that's Tung-Sol. They developed the tube and are the only ones manufacturing it. I guess patents will leave it that way for some time to come.

[Coppy]

I don't plan to buy any backup 6550s. Remember CJD's problem is that they need to buy in quantity... enough for current product equipment and to have them in the future for customers who need replacements. They may need to order 1000 or more at a time, and have the assurance of even more future stock. As I look at the market now, there are sources (Tube Depot, etc.) of 6550s in the smaller numbers we might require. Although by the time we need them they may be expensive. :tears: