I can’t say that I was in any way “unhappy” with the sound of my rig with my prior amps – a pair of Manley “Mahi” mono-blocks and a “Shrimp” preamp. The Mahi’s are a push-pull affair that pump out a respectable 20 W per channel in triode mode and 40 W per channel in ultra-linear mode. When I first purchased them, I was so thrilled with the improvement over the “class D” amplifier that they replaced, that I never went any further. At that point, I just thought that “tubes are tubes” and didn’t understand anything about the variety of topologies out there. Then, as I had done with my Reference 3A Dulcet’s, I posted a review of my upgraded Reference 3A De Capo’s. In response, someone on Audio Asylum wrote that if I really wanted to hear what the De Capo’s could do, I should hear them powered by a SET – or “single ended triode” amp. Looking through the De Capo’s owner’s manual, one finds the following assertion:
Although 92 dB rated efficiency is not considered to be very high, the MM De Capo iA with its direct coupled driver topology (no crossover) does not waste amplifier power. It also presents very easy impedance loads to amplifiers. They can work very well with low powered purist design amplifiers of both tube and solid state types. Well designed SET tube amplifiers with only 5 or 8 Watts of output power are often used with excellent results…
This got me reading up on the virtues of good SET amps – tonal purity, great midrange, “vocals to die for,” holographic imaging and sound staging – and the more I read, the more I wanted to try one.
This prospective change also opened the possibility of simplifying my rig, moving from three separate pieces of amplification – two mono block power amps and a preamp – back to the convenience of an integrated amp. I was starting to tire of having to flip 5 switches just to listen to a CD! 😉
As mentioned earlier, I started a thread on Audiogon called “What’s the Greatest Bargain in SET These Days?” It eventually ran to over 400 posts and taught me a lot (as I hope it serves in the future as a useful resource for others making similar decisions). The thread itself is worth reading and I won’t try to rehash it here.
What I will say is that among many other things, the thread convinced me to spend more money (which was possible because I got more for my Manley gear than I’d anticipated) and go for the classic, “directly heated triode” (DHT) sound of the 300b tube, rather than a less expensive EL-34 pentode tube “strapped” in triode mode. (If this is “Greek” to you, don’t worry! It was Greek to me, as well, until I started that thread and did some research!)
Well, it’s late… time to put this blog to bed. My Kit 1 is due to ship tomorrow from Canada. it’s only a matter of time, now…