Sophia Electric Coke-bottle KT88-ST Tubes (long life version)
This patented Sophia Electric coke-bottle KT88-ST (long life version) tube has the most refined sounding with best high frequency extension, a cure for the dark sounding KT88 amplifiers.
Positive Feedback Online Review: "The Sophia Coke Bottle KT88-ST's easily bested my modest collection of glass bottles. These tubes brought to my system clean and detailed high frequencies, round, dimensional, realistic midrange, and full, rich, and taut dynamic bass. This is a very coherent, highly musical tube." -- Francisco Duran
Darren Henley: "The tubes sound so good, that I find myself pulling up track after track. Addictive audio. The most remarkable part of their performance is the seemingly grain-less flow that isn’t limited to the mid-range, but extends in both directions out from center. There is such ease to the sound that I am listening more to music than the sound." -- Full Review
Not all tubes are created equal.
- Option 1: Grade A (top 10%): $175 per tube (or $350 per matched pair) with one year warranty
- Option 2: Grade A (top 10%): $150 per tube (or $300 per matched pair) with 30 days warranty
- Option 3: Grade B (top 25%): $150 per tube (or $300 per matched pair) with one year warranty
- Option 4: Grade B (top 25%): $125 per tube (or $250 per matched pair) with 30 days warranty.
For U.S. domestic, we use USPS priority with insurance -- $15 for up to 4 tubes. Express shipping is also available at higher cost.
For international, we use either DHL or USPS express. Please email us your country and city, so we can find out the shipping cost for you.
Hello Sophia Electric
I have an update of my review from March 2019 on the EL34's. The EL34's are a beautiful sounding tube. The best sounding EL34 I have tried. I now have had the pleasure to listen to your KT88's in my Aric Audio amplifier. Fantastic is all I can say. The KT88's bring the level of music up quite a bit. The highs,mids and lows are better. Don't get me wrong your EL34's are sweet but the 88's bring more to the table. I have tried EAT, Gold Lions, Shuguang, Psvane, EH and Northern Electric. The Sophia's to me and my ears just do it all just right. After 50 hrs. they continue to sound better and better. Thanks again.
Dear Sue and Richard:
I am writing to inform you how delighted I am with the sound of your KT-88 Coke Bottle power tubes in my VAC amplifier. I have tried many varieties of KT-88s and many are quite competitive in excellent extension and detail. What makes the Sophia stand out is their musically natural presentation. This is the result of their even and seamless response throughout the frequency spectrum, with nothing diverting my attention from the music and the artist. I highly recommend your KT88's to all audiophiles seeking a life-like natural presentation. Thank you for your wonderful products and customer service...outstanding!
Dear audiophile friends,
Sophia Electric tubes are my best choice after comparing with all new product tubes on market today, especially on KT88 tubes I bought. After 35 hours burning-in, they sound incredible. I also bought the 12ax7 (driver tube). They totally changed the sound of my system (new McIntosh 275 mark 6). I'm very happy with Sophia tubes.
Just want to thank you for super service seldom seen…
Tubes in five days in my set playing and burning in, truly great.
And the early sound is so delicate and detailed, full of air I hardly can believe it is the same set of McIntosh 75 monos I have. KT88s are definitely redefined by you.