Dfrigovt, it would be a shame if you concluded that these OTL amps are troublesome or finicky or are only good for "optimal" setups with "perfectly matched" speakers. Proper amplifier/speaker synergy is something you need to concern yourself with regardless of what type of amplifier you choose. When I read comments from people warning of the need to "change tubes as often as they change the oil in their car" or other critical remarks, I have to wonder if this is coming from someone with personal experience with OTLs. As a Joule VZN80 owner I can tell you that my personal EXPERIENCE with this amp over the last few years shares nothing with the comments from Marakanetz. It has been nothing but a pleasure and, next to my speakers, is the smartest purchase I have made in audio. With respect to my amp, the idea that you need to frequently change tubes is absolute baloney. Quite frankly, it's a bit annoying to read comments that broadly label OTLs as having that problem. After three years I am still using the original tubes in my amp with absolutely no problems.
As for speaker matching, one thing to keep in mind (with respect to the Joule at least) is there is no problem using the Joule OTL with 4ohm speakers. In fact, Joule provides power ratings for both 4 and 8 ohm speakers. In fact, Jud Barber of Joule designed the amp to be capable of running his own speakers - Duntech Princess. Those speakers go below 4ohms. One nice thing about the Joule is that the feedback is variable - each channel, progressively. So, that means you can dial in the amount of feedback to suit your tastes - and the damping that your speakers seem to match well with.
As far as being "finicky" I will tell you this. I have had absolutely no problems with my Joule. Zero. From a practical use standpoint this is the way it works. You tell me if this is too finicky for what could be the best, and last amplifier you will ever need to buy... I take 30 seconds to turn a dial up (Variac) to operating voltage which you can read on a built in multimeter. It starts making music right away. 10 minutes later I get off my butt to tweak the voltage (once the tubes heat up). That takes about 10 seconds. That's it. Every half hour or so I may peak at the voltage while I change records. Sometimes I do. Sometimes I don't. No big deal.
In my opinion, saying an OTL amp is finicky is like complaining about engine noise from a V12 Ferrari.
I won't even get into the fact that the amp is built like a brick house, etc. I fully expect it to outlive me (I'm 31). Eventually I will have to replace tubes I guess. I don't view replacing tubes every 4 or 5 years as being a problem.
BTW, I have Merlin VSMs. You owe it to yourself to hear an OTL. I suspect many have no idea what they are missing.
Best wishes.
Jim
