Need help : Single ended, Low power, SET amps..


Can someone help me to understand the + and - of Low Power? SET? Single Ended? And a few examples of some models would help.
tweekerman

Showing 4 responses by twl

Tweek, the plus is that they have low power. The minus is that they have low power. Low power sounds better because of less gain stages, tubes, and complexity.(All else being equal). Low power cannot drive most of the available speakers to a reasonable level, hence the minus. The art is to assemble a SYSTEM that will work to provide both sound quality and reasonable SPL.
Single-ended is generally preferred for great midrange. Since most SETs have output transformers, they suffer from transformer related problems like rolloff and bloat. The best transformer SETs do a very good job at minimizing this and sound absolutely phenomenal. OTL SETs of which there are very few, can be even better, since there is no output transformer. It is generally conceded that SET is superior in the midrange to push-pull. These are all generalizations and each type can be very good depending on the execution of the design. The sound of SETs like all tube amps is very dependant on the type of tubes used. 2A3 is different than 300B. NOS tubes sound different than Russian or Chinese. Etc. Speaker matching is especially critical. Load must match amp well or you will lose some of the little power you have, and impedance matching is also critical for some of the same reasons. If you get it right, the sound quality will be about as good as it gets. And you will get reasonable listening levels with higher efficency ratings of the speakers. A system like this provides enough detail to be ruthlessly revealing of any flaws in the system or recording. If you don't get it right, you WILL hear it. Many people cannot tolerate this level of detail because of this ruthless revealing nature. It can spoil your enjoyment of lesser recordings. But it will greatly enhance your enjoyment of the great ones. Nothing is perfect. This type of system has its strong and weak points. You will never get "rock show" volume levels. You will get awesome small scale sound. Whatever floats your boat.
Tweek, Single Ended Triode is what SET stands for. S is for Single, E is for Ended, and T is for Triode. A good example of one is the Sun 2A3. Another is the Golden Tube 300B. An example of a SET OTL is the Berning Siegfried. An example of a push-pull tube amp is a Marantz 8B(I think?). An example of push-pull OTL is a Berning ZH270 or a Berning MicroZOTL. Regarding the trade-offs, there is a trade-off in every choice that you make in audio no matter what. Everything has its strengths and weaknesses. No product is perfect, even the megabuck ones.
Tweek, check out the Lowther America website. They have improved the Lowther drivers with a re-designed whizzer cone that has a rolled edge. I supposedly eliminates the midrange resonance peak that previously plagued Lowther drivers. They also changed the suspension ring from a rolled out to a rolled in. Smoothed out response there too. New,optional phase plug design is questionable but new just the same. Old one still standard. I just ordered a pair of new DX3 with all the mods. I am making a set of Voight Pipe enclosures to start with and may go to a somewhat more exotic enclosure later. Their new "Big Fun Horn" looks pretty good as a back loaded bass horn design which extends the full-range Lowther down to 32HZ on the low end. Even if it rolls off at 12db from there, it will still only be about 6db down at 24Hz. Not bad for a single driver. Goes to 22kHz at the high end. 98db at 1watt input unloaded. About 100db at 1watt in a cabinet. Not sure if I am all that wild about a corner horn though. Still researching. In any cabinet you choose, though, the Lowther is a great choice for a SET amp. You get great sound with great efficiency and detail with decent accurate bass depth and maybe real good bass depth with the corner horn. Front wave is not horn loaded so it does not "honk" in the mids. How's that? New improved Lowther + Big Fun Horn Cabinet + SET = WOW!! Nothing can touch it! :-) Have fun.
John, welcome to our world. Now, the next step is to get that magic into the rest of the frequency band too. This is what we are all working on. Not easy, but fun.