The statements regarding the Otl not working well with "low ohm headphones" such as Utopia or even Fostex Tr x00,Th900 are pure speculation.
There are simply a few things that need to be taken into account regarding the OTL amplifier and that is not very much.
Otherwise I see no reason why a Utopia, Fostex or Denon wouldn't work. Fostex and Denon are even lower ohmic and are quite powerful and for some listeners a miracle if the amplifier plays along.
I am a bit more cautious with planar headphones - it is possible, but there too, things have to be right.
On my Feliks Euforia it was still possible to get an Lcd 2 C to work, even though the amplifier would be capable according to the description but is quite limited.
It was still possible to give the Lcd 2C more bite by changing the tubes.
And it's no secret that planar headphones work better with hybrid amplifiers, but not everyone does.
The Patos Aurium for example was a prime example for me to screw up the Lcd2C.
Even with a hybrid amplifier, things have to be right, just like with an OTL amplifier.
As a beginner, you are better off with Little Dot products Mk2 Mk3se. it is very good to get a feel for them until you have an idea.
There are also interesting Otl amplifiers from Poland that are currently inexpensive, of very good quality and really make an alarm.
Depending on the length of time you have to wait for them to be built, but otherwise they are top quality and better than Made in China.
Eufonika on Ebay is worth a look, solid construction and could keep up with the popular Bottle.
Otherwise, Woo Audio Wa6 or Quicksilver tube amp could be interesting as a good but still homogeneous entry, and there is still some money for a tube exchange.
Feliks Echo 2 would also be an option.
What you have to make sure is that the amp has enough bite for your Utopia and that it can handle low ohm headphones in the future (like the Woo Audio wa6).
And generally has enough power.
If it can deliver a good 500 mw-800 mw then that's fine, more is always better of course.
The same applies to the use of a planar.
My example above with the Lcd2C and Euforia can also be argued that the Euforia was not really built for this and the power is more limited in that respect to drive an 80 Ohm Lcd 2c.
The other tip i can give is to ask the manufacturer if necessary.
Feliks was so open that they didn't recommend the Echo 2 but the Euforia for my needs.
Taga Harmony and their amplifier said that the Aeon R/T would not work.
Apart from that, there are other things you should consider when buying a tube amp.
How is the price of the tubes for amplifier Yx, the availability. It give good and badly Tubes on the Market.
It takes a while until you have familiarised yourself with them.
Therefore, if you want to try out Little Dot first, it makes sense to save the money for what you really want later and also have an idea of what you expect from a tube amp.
This will save you from buying frustration, as well as from buying the wrong thing, where you might be stuck with it for a long time.
This much I can give you as tips for beginners.unfortunately I didn't have these at the beginning and came into the world quickly.
The Euforia was therefore not a bad buy, I quickly found tubes that were worth the price to reach the desired goal.
Unfortunately it cost a bit more than I wanted in the end because of the tubes.
But that's how you learn again.
