I've been happily listening to my TAD-60 amp driving the Silver Iris OB speakers for a couple of months now. The amp came with EL34 (Svetlana) tubes. Running them 8-16 hours a day, it's just a matter of time before needing replacements. The amp is set up to take EL34, KT88 and 6550 tubes (triode and ultra-linear mode.) I'm looking for opinions on which way I should go. This is a bit of a major purchase for me these days, so I could use some experienced guidance here. Things to consider include longetivity under long hours of playing, non-fatiguing high end, taunt bass and good midrange for acoustic instuments. I'll be listening mostly in triode mode (unless one of the other tube types proves to sound better in ultra-linear mode.) I listen mostly to jazz and folk with some classic rock thrown in quite a bit.

Here's the amp I use.

http://www.angelfire.com/biz/bizzyb/TAD-60.html

Here's the speaker drivers used (mounted on open baffles.)

http://www.hawthorneaudio.com/drivers.htm

Let's hear what you experienced tube rollers have discovered with amps that can do this type of conversion.
Thanks.

Dave

• my amp

As well as EL34, KT88 and 6550, there's also 6CA7 and KT90 to consider. If no clear winner comes from these discussions, I'll probably stick with EL34 as a known quality. Leaning toward JJ's. The JJ EL84's I had running in a Scott integrated were substituting for 7981's and held up great. That's quite a feat.

I've never heard a KT88, and only heard 6550 in guitar amps, so don't know anything about them. Heard a pair of 6CA7's several years back, but was to long ago and in old vintage amp, so can't make any meaningful conclusions there, either.

Dave

Thanks guys!

Dave