The overall sound of the KT150 is thunderously powerful. The bass is tight, full, and precise with a neutral midrange and transparent high end clarity. The dynamics are unlike anything we have ever heard before. This is truly the Tyrannosaurus Rex of beam tetrodes.
What the manufacturer says: "With the new KT150, Tung-Sol continues to lead in the audio power tube, power game. After the introduction of the highly successful Tung-Sol KT120, Russia's premier vacuum tube inventor, Valery Krivtsov, in collaboration with Irusha Bitukova and a team of ExpoPUL tube designers, set to work in our laboratories to develop an even more powerful audio output tube.
With a massive plate dissipation of 70 watts, the Tung-Sol KT150 is the most powerful octal beam tetrode ever produced. The Tung-Sol KT150 glass envelope is a special egg shaped balloon that was developed to improve thermal dissipation and maintain a superior vacuum for the best sound. The fact that the glass envelope has no flat sides means the Tung-Sol KT150 has no problems with microphonics.
All power tubes are Platinum Screened & Tested to the highest standards, including a 72-hour burn in process, and testing at real-world voltages.
Because each KT150 consumes 2.0A of filament current (more than the KT88 and 6550), we recommend contacting your equipment manufacturer to ensure your power supply is capable of powering this tube.
Additionally, this tube is 5-1/2" from bottom of base (not including pins) to the top of the glass. Make sure your amp has at least 6-1/2" of clearance from top of the tube socket to the overhead limit. There must be room allowed for both tube installation and cooling. Also please understand that the plate structure of this tube is such that it almost completely obscures the heater element of the tube from view... so you will most likely not see these tubes glowing; this is normal.
Every power tube is different. This applies especially to power tubes like EL34, 6550, KT88’s, etc. Two tubes can be brand new in the original box, with one testing at, as an example, 6500 micro ohms, the next one at 8600 micro ohms. Both tubes would be considered "new" by the factory, and not defective. While the weaker tube isn’t "defective," it will certainly have a shorter life. So if you pay 10% less, you might get a tube with a significantly shorter life. The big lie from manufacturers of tube equipment and tube dealers themselves is that they “reject” these tubes. It’s not true. You can imagine the nightmare that would create for the tube factory if people are sending back 50% - 80% of the tubes that get shipped, coming back in all kinds of condition.
As the owner of Upscale Audio, a company that has supplied tubes into over 50,000 components, and someone obsessed with treating your amp like it’s my amp, I can tell you in no uncertain terms the factory doesn’t take them back. The only tubes they will take back are tubes that have shorts, gas, or measure BELOW the minimum number they assign for that tube type (it varies from type to type, so don’t bother trying to figure that out).
I’ve overcome that issue for you. I can say with calm assurance that we pay the factories more for our tubes than any other tube seller, and we ensure that we receive the absolute cream of the crop. This flies against the logic of how to run a business: The way you make money is to pay less for the goods you sell! That’s what most ANY business owner will tell you. We also don’t sell certain brands of tubes because while they might be cheap and sometimes good, they can be more trouble than they're worth. We pass on a lot of money as a result.
Upscale Audio is the only dealer that does what we do on a grand scale, and have a deep understanding of high end tube electronics. We’re the only dealer that manufacturers give a thumbs-up to, and recommend to their customers. And I promise you only the best.
- Kevin Deal
A nice note from our customer, Jeff Wheaton
Greetings, I am sure you are aware the KT150 drifts, when new, even after "alleged" matching by other sellers AKA ebay or other. Your burn-in solves this problem.
Prospective kt 150 buyers know this....many of the KT 150 Quads bought from small time operations cannot be used....they won't balance. I work at a custom tube amp builder. We now are ONLY buying your tubes or our customers MUST buy your KT 150'S or we won't set the AC/DC balance for them. Several customers have brought unusable "new KT 150" quads to us which after 10 hours, drifted so far, they would not balance....now unusable......and they saved 15.00/tube. Share this and save philes some money, and they will get longer tube life, and better sound.
Audiophiles, believe Uncle Kevin...his tubes are better. The 150's match so nice now......Only get "Real Matched tubes".........Jeff