What's your OTL tube amp experience and suggestion?


Are OTL amps in general much less reliable due to their nature, or due to the implementation quality, or both?

Perhaps this has been discussed a zillion times in the past.   Perhaps, however, makers have now improve on past experience?  So it could be worth re-visiting.

My past encounters with OTL tube amps are among the most negative: Wonderful (but never great) sound during the brief period that they work.  Otherwise, major fire hazard.  Overheating, red hot plates, sparks, consistently toasted fuses, burning smell, you name it.  My past OTL amps are like crying babies on an changing table - don't you ever walk away from an arm's distance.   The used market seem to reflect such as well --- way more 'as-is for parts' or 'totally refurbished' units than reliable 'used' units that rarely need service.

Beg your pardon if it's just my poor judgement that keep getting the lemons.   What's your experience, and tips to keep OTL amps up and running happily?


bsimpson

This statement seems to be incorrect. To the best of my knowledge they only make solid state amps; I’m sure we would have heard about it if they still made OTLs.

FWIW the MA-2 Mk2.2 dates from about 17 years ago... and in the intervening time we have managed to make some progress :) The current incarnation of the MA-2 is Mk3.3. People have described the improvement as a ’transformation’.

Ralph,

Tenor makes hybrid tube amps (an update to their Hybrid 300 mono blocks I owned briefly in 2004) now. not sure about any other products. however; back in 2005 a group of investors did purchase the assets of Tenor and did redesign/update the tubed OTL amps and sell them as a current product for some years. there are still a few out there new for sale but not sure it’s a current product anymore.

regarding my personal Atma=sphere MA2 experience; if you read my post it says this happened in 2001, 16 years ago. i’ve had many positive things to say about you and your products over the years and just because i preferred the 75 watt Tenor OTL’s back then, does not change the fact you make great products and take great care of your customers. i’ve heard your more recent products many times at shows and they are as you describe.

@mikelavigne , I remember when that happened, but even back then the story I heard was they were only doing the transistor amp. In all that time, I've yet to hear about a Tenor OTL that was made after the 1st company went under. I suspect what you are seeing for sale are older amps that have been refurbished.


Yes- apparently we're on the same page here, if you'll pardon the expression :)
Simple fact is Most OTL on the market are not built Like Atma-Sphere. These companies that try to work on OTL cant seem to figure out a Stable build, Atma did this decades ago.

The Simple answer to OP issues is, If you want OTL Stick to Atma-Sphere and you will have Years of trouble free operation.

Sorry but DartZeel is not on the same league as the Atma-Sphere Amplifiers. The Atma is a lot more transparent, faster and throws a larger sound stage and does not sound like a tube nor a solid state. Should I even mention the Atma not only has better transparency it is a lot more emotional to listen too. It draws you into the music and does not sound mechanical.

DartZeel make good solid state amp but I'm sorry it cant be compared to a Atma-Sphere.