At Silbatone Labs, we engage in a lot of experimentation and exploration to discover new things that work. Our patented NeoHyb current multiplier circuit is one of our best innovations yet.
Although we use mosfets in this topology for their awesome current delivery capabilies, this is completely unlike previous “hybrid” attempts, which usually involved a tube driver slapped onto a transistor output stage, the worst of both worlds, and never a high performance solution. This is why we call it NeoHyb. It has nothing to do with 1980s style hybrid amplifiers. NeoHyb is a whole new direction.
Our NeoHyb circuit uses parallel mosfets to enhance the current delivery of vintage triodes, yielding greater power and allowing for more conservative tube operating points at the same time. The mosfet is completely locked to the plate of the tube and adds no measurable influence, except greater current swing. The musical performance and distortion spectra are pure triode. All signal current passes through a Silbatone foil output transformer. It acts and sounds like a pure tube stage, only boosted in output power.
One use for this technology is that we can adapt very low power tubes, some ancient antique tubes, even preamp tubes, to play loudspeakers so we can learn and understand what they can do, often with very impressive results. We can take medium output tubes like our standby 300B and shake the walls with power. And we are able to dial down the dissipation in tubes for both great longevity and the often higher quality presentation they can provide when operating at more moderate levels.
One lesson in our NeoHyb project is that what makes these tubes so great has nothing to do with low power output, per se. The struggle with low power output of so many of the best sounding tubes does not have to be obstacle to enjoyment. NeoHyb will satisfy with a wide range of popular speaker types, not only 110dB+ theater horns! And even with the most sensitive horn speakers, the headroom and drive created by our current multiplier technology opens new doors for old favorites,45, 71A, 275A, 2A3,, and many other great tubes not given the respect and wide use they deserve.
This is what we have accomplished in the new P106 NeoHyb amplifier. A single 45 amp that can really drive a practical speaker, finally!
The NeoHyb P106 plays with all of the grace, dynamics, and musicality we know from the legendary 45 triode, but with a magnified power output that is far more useful in the world of practical speakers. Thanks to the high current output stage and low ratio foil transformer, the P106 will demonstrate more drive and punch than expected from an 8 watt amplifier.
Although it works great with super-high efficiency horns, the P106 can play many dynamic speakers with satisfying weight and authority.
We love to fit this amplifer with beautiful antique globe shaped 45s from the 1930s, not only because they are very great sounding tubes but they also symbolize the marriage of old and new that is at the core of the Silbatone NeoHyb project. This is no vintage style amplifer, being very low noise, wide bandwidth, and dynamic, yet it evokes the dream of the golden days when musical electronics were new and the triode amplifer ruled the empire. Those days are back with Silbatone NeoHyb!
P-105 WE275A NeoHyb Power Amplifier
Silbatone has always been a great champion of the Western Electric 300B tube and many of our highest aspiration amplifiers have been based on this ancestral triode. It is no exaggeration to say that the triode revival and the rise of single ended amplifiers over recent decades was built on the reputation and outstanding performance of the famous and fabled WE 300B.
One factor in the success of the 300B is that it can provide eight watts, enough to play many speakers for home listening...or fill a movie theater, with appropriate speakers, of course. Beyond that, the musical balance of a good 300B tube has been a great education for music lovers. It is natural but animated, detailed yet lush when it is supposed to be. Organic sound that captivates the ear and brings the musical message home. Yes, we love the 300B.
Naturally, when we developed the NeoHyb circuit, a voice from somewhere above began “What would a 15 watt 300B amp sound like? How about a 30 watt SE 300B amp??” We had to try it, and the results were very rewarding. NeoHyb boosted the power as expected and the familiar 300B flavor was retained, one could even say enhanced in some ways. Dynamics, low frequency drive, and midrange speed were magnified. The harmonic structure of the NeoHyb measured on our Audio Precision workstation was extremely close to or Reference 300 stand-alone 300B amplifier. It worked better than we hoped!
We decided to create two new reference grade models to showcase this new accomplishment in the historical development of 300B amplifiers, The Mono RP-30W and the fifteen watt Stereo RP-310. The 30 watt version had to be made in mono block format due to the size of the required transformers and the heat management issues of a 30W Class A amplifier.
When we say “Reference Grade” that means we put everything we have into the design: our finest chassis construction and our best transformers. These amplifiers use a pure silver input transformer, then a particular selected 1950s era 12AY7 voltage amplifier into a 7044 in our very strong, ultra low distortion current amp driver topology, genuine NOS WE 300Bs, and silver wired pure silver output transformers on Hitachi Finemet double C cores. The build quality is reflected in the peerless performance of the amplifiers, which we think will surprise even the most experienced triode listeners.
If you think you already know 300B amplifiers, prepare to be amazed!
RP-310 MkII shown with globe mesh WE252A tubes