Tube amps - what 3 things…


Hello all,
 

I am close to purchasing a tube amp moving away from SS. So far I have listened to a pure sound, PL, and allnic. 


Question for all you experienced owners - if you could do it all over again, what 3 things/features would you look for in an amplifier and what 3 things/features would you not invest in again?

 

thanks

mpoll1

ralph, curious to know what is your take on auto biasing... now increasingly employed in high level tube amps, audio research’s newer amps for instance

the feature certainly offers a major convenience factor for users, but what do you see as the tradeoffs or downsides sonically or operationally, if any? (of course we note the obvious add’l cost and complexity of the feature)...

also, does auto biasing get the power tube biasing as precisely correct as manually biasing via multi meter (as arc used to do it for years?)

I see automatic bias as a good thing. The less the user has to fiddle with the amp the better- makes it easier to live with.

If designed right there's no downside except the additional circuitry itself. How precise it is depends on the design; in some circuits the precision is more important than others. So its a case by case basis.

The downside of manual bias is the tube can drift while you're not looking, assuming you got it right in the first place. An auto bias system takes care of that. FWIW, cathode bias is a form of automatic bias. This can makes things confusing, because many autobias systems typically use some sort of monitor on the tube and adjust the bias via the grid rather than the cathode of the tube. For this reason, most modern autobias systems are considered 'fixed bias'.

Well designed autobias is precise. The tubes idle @ the setpoint very shortly after turn on and after several hours of robust use. It's probably an order of magnitude more precise that a pot and resistor in fixed bias designs.

The biggest advantage with a quality CT OPT is both halves idle identically, thus reducing distortion and noise.

In general, power supplies are important on all pieces of equipment. I think point to point wiring helps determine quality of build and sound. I believe separates are critical for improved sound, so mono blocks would be part of my choice. Past these few generalizations you then need to figure in the room size and acoustics along with the efficiency of your speakers, then you could begin to narrow the choice down.

I’ve owned several ARC power amps Classic 120 monos were awesome except when they blew a tube.

My recommendation is the Ayon Spirit V I had the Spirit lll the Ayon amps are exceptionally well made. Auto bias, beautiful looking, top notch parts. Excellent protection circuitry. Not sure how much power you need. If you need more the Ayon Triton is a 120wpc in pentode and 70wpc in triode, it’s a beast!

I wanted to mention Ive been using a Aestheix Mimas for a couple of years now. It has a tube preamp with a solid state power amp. It’s an awesome integrated amp. Lots of features great metal remote, tons of power but it can sound really delicate if the music calls for it. Great reviews out there: