Good quality KT88 power tubes?

I suggest you check with the designer of your amp, and see if you can substitute other tubes in place of the KT88. Possible alternatives (beyond the KT90 already suggested) are, 6550, 5881, and 6L6. Old stock American tubes (used, good) are superb, such as the Tung Sol 6550 and 5881. Many designs that use KT88 can use these tubes. Old stock American tubes can often be found at Antique Electronics in Arizona. The comments about the Genelex Gold Lion are absolutely correct, but they will be (probably) over $150.00 each tube, maybe much more. Good used US Military 5881 show in Antiques catalog at only $17.00. If you must only use KT88, listen to the Tesla KT88, or even the Svetlana 6550, I think that both of these are better than the Sovtec.

Albert, your right about checking with the manufactuers on what tubes can be used with there amps. my amp can use the the kt88 6550 kt90 kt100 [Rogue 88 ] they use the sovtek kt88 because it a good tube thats reliable, but they do like the sound of the tubes from Penta labs kt 88, they sound WAY better than the sovtek, Also Svetlanta has a new kt 88 comming out too! greg

I have only tried three different sets - Sovtek, JJ Tesla and Golden Dragon Classic. Of these the JJ Tesla is best, being neutral and dynamic. The Golden Dragons are softer and lacking in dynamics, but very listenable. The Sovtek's are reasonably dynamic but have an irritating sound, akin to a ringing in the upper mids - also lacking in transparency, probably related to the ringing - microphonic?

Gold aero does not make tubes,there tubes are nothing but relabled sovteks,Tesla or china etc, that have been tested and stamped with there name.

I am now using the new Svetlana KT 88 tubes for my Melos 11 ST 90 amplifier and it sounds better than my former GE 6550A, Svetlana 6550C, Sovtek KT 88 and Tesla KT 88. Regards. Slore