The new SB-LAB Taygete is the natural evolution of the Merope project, from which it inherits philosophy and voicing, bringing them to a new level of power and authority. If Merope was a refined push-pull of EL34 in triode connection delivering about 10 watts per channel, Taygete is its elder sister, capable of 20 real watts in class A, thanks to the adoption of a pair of EL34 per side in a parallel push-pull configuration.
The choice to keep the triode connection is not a nostalgic whim, it is a precise intent to pursue maximum sound quality instead of mere power. In this mode, the tube works on a more linear curve, reducing distortion and delivering a more “true” sound, rich in micro details.
Choosing class A is pure audiophile orthodoxy. It means the tubes conduct current for the entire signal cycle, eliminating any form of crossover distortion. The result is a smooth, continuous presentation rich in natural harmonics, with dynamics that do not jump out artificially, they grow fluidly and proportionally like in a live performance.
With Taygete, SB-LAB consolidates its view of tube amplification as the art of balance. Power without aggressiveness, detail without harshness, and above all, authentic musicality, the fruit of design that joins rigorous engineering with listening sensitivity.
Rebirth from a wreck: how Taygete was born
The story of Taygete began almost by chance, one of those moments when a failure becomes an opportunity to create something new and better. A few months ago, a long-time customer brought me back for the umpteenth time a Sigma Elettroacoustics EL34-PPP, a unit I had already repaired and serviced several times over the years. This time the symptom was unmistakable: a bang, smoke, and a “fart” in the loudspeaker, as he described it.
Once I opened the amplifier, the diagnosis was clear. A capacitor had exploded and some resistors were burned. The real problem appeared shortly after. One of the output transformers was compromised. Primary inductance readings were abnormal, and insulation toward the secondary proved insufficient. At about 700 volts it already started discharging internally, while its twin easily withstood 3 kV. The transformer was irreparably faulty.
The repair would have been expensive. A new pair of output transformers had to be rewound and the damaged circuit restored. Faced with that prospect, the customer was seriously considering scrapping the unit, by then dated and no longer fully satisfying. He described it like this: “Yes, silky mids and highs, but the bass is soft, weak…”, the typical behavior of a zero feedback circuit with all the dynamic limits that entails.
At that point I proposed an alternative. Instead of throwing everything away, we could recycle the massive stainless steel chassis of the Sigma, an already finished, quality mechanical platform, saving many hours of work. The idea was to build a completely new amplifier inside, starting from the proven Merope circuit, with a PCF80 and an ECC82 per channel driving a push-pull of EL34 in triode connection.
The project did not stop there. Doubling the output tubes was not a big technical problem for the driver, and the new parallel push-pull setup would bring concrete advantages. With more tubes in parallel, the internal resistance seen by the transformer is halved, improving the natural damping and allowing the use of less feedback, gaining quality without giving up bass control, exactly what the customer wanted.
Finally, on request, I made Taygete usable without a preamplifier by adding a motorized volume control with remote. For aesthetic and functional reasons I placed the knob on the rear panel, keeping signal leads as short as possible. In practice, you control everything comfortably by remote.
The customer, enthusiastic about the idea, accepted the proposal. Thus, from an amplifier that had become a wreck, Taygete was born, a new unit that is elegant and powerful, finally capable of delivering firm bass, natural dynamics, and satisfying musicality, while preserving the purest tube spirit.
From simulator to workbench: building Taygete step by step
The construction process of Taygete began, as with all my projects, with the LTSpice simulation phase, where I finalized the schematic and verified correct electrical behavior under all operating conditions. Once the operating points and supply voltages were established, I moved on to calculating the output transformers, the power transformer, and the filter choke, then I commissioned their winding to my specifications.
With the theory complete, I tackled the practical side. I completely disassembled the old Sigma Elettroacoustics, bringing the large stainless steel chassis back to its original state, completely empty.
I created a new graphic for the aluminum front panel, which had faded over time. The artwork was printed on vinyl film and then applied to the panel, giving Taygete a clean, elegant, modern look.
I then mounted the new transformers, designed specifically to fit the existing holes in the chassis, with no need for new mechanical work. At this point the assembly of the new circuit began, step by step, with the usual artisanal care.
The first serious problem to solve was the heater voltage distribution. With eight EL34 to feed at 6.3 V for a total of about 12 A, the classic twisted pair wiring was not feasible, since the conductors would have been too thick for the sockets and the voltage drops would have created imbalances between tubes. After some thought, I built a system with solid copper bus bars, fixed with nylon insulators and fed at the center, from which I then took the voltage for each tube. A solid, clean, perfectly balanced solution.
I also reprinted two replacement insulators for the speaker binding posts, since the originals were cracked, yet they were essential to keep mechanical compatibility with the existing rear panel holes.
The rest of the wiring reused some original anchors from the Sigma, carefully cleaned. The electronic parts were chosen with care. All new, except for a few high quality components salvaged from the previous circuit, such as the two 680 µF Kemet electrolytics, the tube sockets, and a couple of non polarized capacitors that were still perfectly good.
As in Merope, Taygete adopts the Blumlein self bias and self balancing system, which allows each pair of EL34 to self equalize and completely cancel DC in the output transformers, with no user adjustment required. This calls for 16 cathode resistors and 8 electrolytic capacitors with their respective polypropylene bypasses, all hand selected on an LCR bridge to ensure perfect balance between sections.
Performance and bench measurements of Taygete
Bench tests of Taygete fully confirm the soundness of the design and the quality of the transformers used. The amplifier delivers 20 watts RMS per channel, perfectly clean and free of audible distortion, for a total of 40 watts. In clipping, the peak reaches 26 watts x 2, with soft, progressive saturation, so any distortion remains hard to notice if it occurs briefly during dynamic peaks.
The damping factor (DF) sits at 6.2, an excellent figure for a class A triode amplifier, ensuring firm woofer control and precise low frequency response. In the bass range Taygete surprises. The bandwidth extends from 5 Hz to 55 kHz (?1 dB), even at full power, thanks to output transformers with an oversized core compared to the nominal power.
Total harmonic distortion (THD) measures just 0.22% @ 1 watt, a value that confirms the circuit’s high linearity and the excellent symmetry of the push-pull. Square waves are also exemplary, with very low ringing and no hint of instability or abnormal phase shift.
For those interested in technical details, Taygete’s output transformer has a primary impedance of 2 kohm and is identified by the SB-LAB PP2K (PPPEL34T) code. It is also available separately, on request, with or without shielding covers.
Taygete takes shape
After weeks of work, Taygete is finally ready. Here are some images of the finished unit that show in detail the result of this long work of precision and passion.
With Taygete, the path started with Merope reaches its natural fulfillment. More power, greater control, and an even more mature sonic performance, without betraying the refined soul of the triode connection in class A. It is an amplifier born from a recovery idea, grown into a completely new project, where every choice, from the oversized transformers to the solid copper bus bars, follows a logic of absolute quality and long term reliability.
The result is a unit with a dense, controlled, transparent sound, naturally uniting power and musicality. An amplifier built with the care of a craftsman and the precision of an engineer, designed for those who seek not only power, but sonic authenticity.