KT88 or EL34 based tube amp for Titus ES

Srmax,

If you are talking about about a runaway output tube, I had that happen with an Audion Sterling ETSE integrated EL34 tube and there was never any danger of damage to my speakers. Most well-built amps have a resistor or thermister, etc. to protect speakers from damage in this situation.

As for 6C33C-B sources, you can always get them from Alamarro reps or the company directly.
Also, the Tubestore.com sells 6C33c's.

I have traded emails directly with the owner of Almarro, Mr Muramatsu, and he goes out of his way to make customers are well taken care of. Both he and his son (along with Brian @ Venus HiFi) helped me replace a defective A318A that an unscrupulous (potential)dealer sold which was never meant for commercial distribution.

And, Maxmad makes a very good point, the A318B is not the type of amp you want to put in tight equipment rack or anything closely above it. Those 6C33C's put out a lot of heat.

If I could toss a seemingly odd suggestion, but it might be worth checking out the 18wpc Almarro A318B Single-Ended/Class A integrated that uses 6c33c output tubes. It is a phenomenal amp with power, tonal purity, and silken highs. It seriously equalled my much more expensive high-end amps in musical satisfaction.

It was able to drive 90dB/4ohm Jean Marie Reynaud Twins mkII monitors beautifully. There are a few, simple, aftermarket upgrades(coupling caps) by response Audio that take the amp to a whole 'nother league - 2 V-cap coupling caps; 2 Black Gate cathode bypass caps; 2 Elna Cerafine cathode bypass caps; a Sonicap power supply bypass and a Noble volume control pot.

Also check out the JAS Audio Bravo 2.3 Integrated Amplifier , like the reviewer in the link, I also owned the reference level $8k Art Audio PX-25 and found the Almarro to be nearly equal in many ways.