Ultralinear vs. Triode vs. SET


I currently have a Rogue Cronus that I have been quite satisfied with, but I am intrigued with the possibility of a SET amplifier. From both a technical and sonic perspective, what are the differences between a tube amp with switchable ultralinear and triode mode vs. a true SET amplifier?
droz

Showing 7 responses by charles1dad

Hi Droz,
I was in your shoes about 14 months ago. I prefer tubes over SS amps and had been using push-pull(PP)amps with mcuh satisfaction. These amps were pentode/triode switchable and were El34 or KT88/6550 based. Well after reading reviews and articles concerning SET amps my curiosity got the best of me and I purchased the CoincidentMK2 300b monoblocks.I`m absolutely hooked on these amps they`re just fantastic. As other posters have said above a good quaility-well designed SET amplifier just sounds so naturally real and live. The tactile and palpable presence is the best I`ve heard compared to SS amps and even very fine sounding PP amps. The sound is very organic, fast and dynamic, yet it retains such a relaxed musical flow.
I disagree with those who say you give up upper and lower extension for sake of a great midrange NO YOU DON`T! This is a misinformed stereotype Droz. The key to sucess is matching to a appropriate speaker(high effiency and favorable load-ohms). You do not have to settle for rolled off highs or soft/flabby bass. You will have many choices in different DHT tube types and also various speakers. Just be patience in your search and read many reviews of SET amps to increase your knowledge base. The world of SET can be wonderful with the proper approach. I hear nuance harmonic overtones and micro detail that were hidden with my PP amps.
Droz,
If you have not done so already, search the site for high effiency speakers this topic has been well covered on audiogon. The old threads contain much information and many good suggestions, there`s no shortage of very good speakers of this type.In contrast to Sparky`s statement above, in my experience the high effiency speakers sound more real/natural and less HiFi in many cases.
Droz,
As predictable many opinions and experiences expressed here, as each type of amp design has some level of compromise(SET,PP,OTL,etc.) The 300b PP route is ok but won`t offer anymore speaker flexibility than say a 845 or 211 tube used single ended. There are`nt extreme limitations of speaker choices either( even if you choose a 300b SET). With a PP 300b you will gain power, but now you`ve introduce phase splitters to the circuit. The SET approach will generally sound purer and even more natural(very simpler circuits tend to sound more natural) Since the original post was an inquiry of SET AMPS i sincerely hope you have the chance to hear them in a well thought out system and judge with your own ears. Just for the record I can play any type of music I want with my 8 watt Coincident Frankenstein. Don`t think you have to limit your music selection at all.
Best Wishes
Hi phaelon,
No real disagreement actually, Droz said he wanted comparisions with his switchable PP tube amp and a "true SET"amp. If he wants to expand his options, a 300b PP amp would be a good way to go i.e. the beauty of DHT tube vs a pentode indirectly heated tube. Many opinions is what I`d expect on a open forum that`s all. Regarding speakers , yes theh`re some restrictions but Droz has a lot more choices available then some would lead him to believe. Zu, Tonian Labs, Coincident,Horning,Audio Note, Living Voice, you get the idea as the`re many more.On the other hand if he was basing a system around an inefficent speaker he would then have to deal with limiting the pool of amplifiers( always some compromise is`nt it). Phaelon you have the NAF amp from Italy correct? I`ve never heard one but love the look of them.

Take Care
Sparky,
I agree, the SET experience most certainly is`nt HiFi it`s music presented naturally.
Sparky relax! it`s just a hobby we both enjoy but with different taste and perspective. In my audio evolution over the past 22 years I`ve gone from SS amps( Symphonic Line was my best in this catagory) then various PP tube amps(which I liked more than the SS amps). SET amps for me were a significant step above the former amps because they sounded much more like the sound I hear at the local jazz clubs(unamplified and acoustical) I visit quite often. It was a revelation for natural sonic realism. I used to play trumpet and man, my 300b amp is spooky close with the tone, power and the brass body reproduction. But that`s me , you obviously simply prefer something else and that`s perfectly fine. The orgin of this thread was based on an interest in SET amplifiers, I was happy to share my own very deep joy with this type of amp, nothing more nothing less.