OTL amps

Philefreak, no I have not had the opportunity to listen to any other OTL's. A friend of mine gave me a very strong recomendation for use of the David Berning ZH-270. He had used other OTL's before and said this one is one to have period. His strong opinion of this particular OTL stems almost exlusively from the amps excellent sonics and the ability to handle various impedance loads with high current (and runs cool!!). Often times other OTL's are limited for use with speakers with a flat impedance curve and relative sensitivity. This little monster is a high current musical animal with the most controlled, taught bass I have ever heard. The ability to control and convey dynamic passages within the music are unparalleled by no other amp I have used. Seriously, this ugly little 10 pound amp will knock you silly with dynamics and musical ability. For technology information check out the David Berning website. No other OTL uses this kind of advanced technology.

Pjilefreak, I don't have detailed specs for my CLS's (original version), but the guys at ML say that the impedance drops to 1.5 ohms at high frequency and increase to 32 ohms in the mid-bass. I know that the next incarnation (CLSII's) dipped to about .5 ohms but didn't swing nearly as wide in the other direction. The IIz electronics ,ake the speakers a bit tamer all the way around. Again, I have the original version which always did well with tube amps.

I have quite a bit of experience with the David Berning ZH-270 and I whole heartedly agree with Thorty40. From reading all of the posts on this thread, one of the biggest concerns with OTL amplifiers is there ability (or in some cases inability) to drive certain speakers due to impedance requirements. Just in a technological aspect the Berning is different from ALL other OTL's. The Berning is based on an impedance matching system which automatically matches the output impedance with that of the speaker. So it then all comes down to power requirements. The Berning creates 70 of the most powerful watts I have ever heard. Of course there are just some speakers that will just suck the life out of this amp, but not most. As far as sonics are concerned this amp is truly special in many ways. I have never heard an amp with more inherent speed and control over the music. Period. The midrange is silky smooth and more alive than I had ever thought possible from an amp, with highs to match. The bass is something which, put simply, must be heard to believe. If you think that tube bass can't ever match solid state, be prepared to be disappointed. I have owned many solid state amps and the bass can not even compare to the Bernings. All of the other OTL's mentioned above are all very respected names, and I am in no way implying otherwise. What I can tell you is that the Berning is a new kind of OTL which does not suffer from some of the problems that the aforementioned amps do. Put simply the David Berning ZH-270 is the most sophisticated amp in the world. A stroll through the David Berning website will confirm this as there are not many designers who can even decipher Davids theories and topology schematics. The Berning tips the scales at a mighty 10 lbs., runs cool enough that you can place your hand directly on the amp anywhere, indefinitely. Idles at one hundred watts and has a peak consumption of about 300watts. And yes, it only uses 4 output tubes! The most striking quality though, is the amps ability to effectively match the impedance of the speaker at any given time. It does all this, while maintaining a superior musical quality which at times is truly hypnotizing. By the way the Berning automatically bias's tubes on a cycle by cycle basis at all times. If you are in the market for an OTL amplifier(or any amplifier for that matter)make sure to put the Berning on your very, very short list. The Berning is an investment which will give its owner many years of enjoyment(there is a manufacturer claim of 20 years on the tubes)which will NEVER disappoint.

After listening to a pair of Transcendent mono's a month or so back, I knew I had to go OTL. I just received mine a few days ago and to say that this amp "transcends" any type of electronic signature is about the most apt description I can give. Just music; pure, ultra low noise floor, natural, dimensional and real. I can't imagine it can get too much better than this providing you have the right speakers. OTL's must be the best kept secret in high end unless maybe folks are too concerned about their less than dependable reputation. If you have the right speakers, love music and want to forget about the upgrade train, an OTL amp ANY OTL amp is a MUST audition. Another thing, this amp actually runs cooler than the ARC it replaced.