The most musically involving and naturally sounding amplifiers are those of single-ended topology. Single-ended triode (SET) amplifiers are usually low powered. There is also a question mark concerning the reliability and sonic signature of the output tubes. SETs also suffer from a high output impedance (between 1.5-2 ohms if no feedback is used). In most cases, at least 3 gain stages are required in order to achieve adequate overall gain. A consequence of this is that there are more capacitors or interstage transformers in the signal path.
Ypsilon’s aim in designing the SET-100 was to produce a single-ended amplifier with only two gain stages, and having output power of around 100 Wrms with low enough output impedance. Their aim was not only to capture the magic of the midrange, so typical of a small power SET amplifier, but was also that it should be able to reproduce the realistic scale and authority of an orchestra in full flow (for example the finale to the organ symphony by Saint-Saens), which has so far escaped all the other SET designs of the past.
The result is a single-ended amplifier of 120 Wrms/8 ohm output power with
relatively low distortion
no overall feedback
low output impedance (around 1 ohm)
two gain stages having an overall gain of x34 times (30db)
Compared with state of the art single-ended triode amplifiers, the Ypsilon SET-100 ULTIMATE is more direct sounding, more musical and with more instrument body, lower frequency extension, frightening dynamics and, most of all, magically three dimensional.
Any comparison between the Ypsilon SET-100 ULTIMATE and all types of push-pull amplifiers is like comparing a Grand Master’s original with a faked copy.
SET 100 ULTIMATE is a 120W single-ended class A hybrid amplifier with a magic midrange of a small Single-ended triode (SET) amplifier, the scale, authority, macro and micro detail that no amplifier has ever achieved until now, combining power and drive with transparency, musical involvement and above all with music sounding naturally. Also, direct sounding, musical, with more instrument body, lower frequency extension, frightening dynamics and most of all magically three-dimensional.
SPECIALLY DESIGNED SINGLE-ENDED MOSFET OUTPUT STAGE
FIRST STAGE SIEMENS C3g
TUBE RECTIFICATION AND CHOKE REGULATION
INTERSTAGE C-CORE SILVER TRANSFORMERS
4-POLE ELECTROLYTIC CAPACITORS
HARD WIRED WITH CUSTOM MADE SILVER WIRE
2 POWER STAGES
SEPTEMBER 2012, Seite | Page 72: Ypsilon SET 100 Ultimate Monoblock Power Amplifier
It sets a high bar to denominate a product «ultimate», but in the case of the Ypsilon monoblocks the moniker is more than justified. What does $125,000 (€ 75,000 in EU) buy you? Lightning-fast transients, an exquisitely refined treble, and a seemingly endless reservoir of power. The SET 100 has only one output transistor, a tubed input stage, and 140 watts into a 5-ohm load. Don’t be fooled by the power rating. It can deliver crushing hammer blows on drums and tympani and effortlessly reproduce an orchestral climax without any sense of strain. The notes simply pop out of the loudspeaker coupled with the Ypsilon. Based on a highly inventive all-transformer-coupled design devised by Ypsilon engineer Demetris Baklavas, it is a true boutique product, featuring point-to-point wiring and nary a circuit board. It is the ravishing purity and jet-black backgrounds of the SET 100 that will ultimately seduce all but the most obstinate listeners.
THE ABSOLUTE SOUND | AN YPSILON VISIT FROM ATHENS
I can’t say whether or not the Greek Gods remain in action, but Ypsilon does appear to be performing heavenly work | Jacob Heilbrunn
SET 100 TUBE AMPLIFIER (Discontinued Model)
The Ypsilon represents the ultimate SET solution. Constantine Soo | dagogo.com
Now, for the privileged few who can afford the Ypsilon SET 100, with the attendant listening space and a central AC, the Ypsilon represents the ultimate SET solution that will not only show you what your horn speakers can do with 100 SET watts, but it will also free the rest of us from the meager lineup of high-efficiency loudspeakers. Only then will the SET 100’s virtues be fully appreciated.