Yes, Don and I are working on a medium-price (by high-end standards) amplifier, most likely a stereo integrated amp. Not much to say about it now, since it's mostly conceptual at this point. If people are looking for value, I think Spatial may still be making Don's previous Kootenai amp, which is a superb amp.
300b lovers
I have been an owner of Don Sachs gear since he began, and he modified all my HK Citation gear before he came out with his own creations. I bought a Willsenton 300b integrated amp and was smitten with the sound of it, inexpensive as it is. Don told me that he was designing a 300b amp with the legendary Lynn Olson and lo and behold, I got one of his early pair of pre-production mono-blocks recently, driving Spatial Audio M5 Triode Masters.
Now with a week on the amp, I am eager to say that these 300b amps are simply sensational, creating a sound that brings the musicians right into my listening room with a palpable presence. They create the most open vidid presentation to the music -- they are neither warm nor cool, just uncannily true to the source of the music. They replace his excellent Kootai KT88 which I was dubious about being bettered by anything, but these amps are just outstanding. Don is nearing production of a successor to his highly regard DS2 preamp, which also will have a unique circuitry to mate with his 300b monos via XLR connections. Don explained the sonic benefits of this design and it went over my head, but clearly these designs are well though out.. my ears confirm it.
I have been an audiophile for nearly 50 years having had a boatload of electronics during that time, but I personally have never heard such a realistic presentation to my music as I am hearing with these 300b monos in my system. 300b tubes lend themselves to realistic music reproduction as my Willsenton 300b integrated amps informed me, but Don's 300b amps are in a entirely different realm. Of course, 300b amps favor efficient speakers so carefully component matching is paramount.
Don is working out a business arrangement to have his electronics built by an American audio firm so they will soon be more widely available to the public. Don will be attending the Seattle Audio Show in June in the Spatial Audio room where the speakers will be driven by his 300b monos and his preamp, with digital conversion with the outstanding Lampizator Pacific tube DAC. I will be there to hear what I expect to be an outstanding sonic presentation.
To allay any questions about the cost of Don's 300b mono, I do not have an answer.
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HI No Spatial is currently only making the Raven and Blackbirds... @yoder I have played the mono 300b amps with 86 dB speakers and it drove them with no issue. I am sure your 93 dB ones will be just fine. It sounds like a 100 watt tube amp really..... Yours runs a bit hot as it was the first build for proof of concept. The final versions.. well they can play all day long at the show and you can put your hand on any transformer or the top panel and it is barely more than warm. Lots of improvement since the first prototype build. If you ever have trouble with that prototype send me a PM and I will of course try and help you. |
I would suggest that this thread has planted a seed that has now become a seedling. Between my last post and very recently I have become the owner of a SE 300b Power Amp. I am yet to fire it Up as it was purchased without Tubes, but am very close to having the first experience. A dual concentric Speaker is also a new addition at 96dB efficiency, these are superb driven by the PP 845's and know they are going to work with the 5W 300b just fine. Within my Local HiFi Group there are Six Brands of 300b able to be tried inclusive of my recent purchases of Two Brands of 300b. What is very interesting is that there is a good selection of Driver Valves up to approx' 70 years vintage to be used in conjunction with 300b's. The anticipation being, but also founded from prior experiences had, something will connect as a more than perfect synergy and be a Super Combo. A lot to look forward to, the mould is broken, the new outlook is quite different and removed from my long term maintained Audio Ideals, where I have been very very committed to maintaining my choices made. |
Don and I wanted to avoid unobtanium vacuum tubes, while leaving the option of "tube rolling" up to the owner. All we ask is the owner uses matched pairs, whether vintage or modern. This retains DC balance while keeping distortion low ... with typical matched pairs, the dynamic gain-match is usually within 3% of each other, which gives a 30 dB distortion reduction compared to an equivalent SET circuit. All without using either local or global feedback. The high-power Class A balanced drive for the 300B grids is a big part of the Blackbird’s sound. This is a sharp departure from "Golden Age" practice of the 1950’s and 1960’s, which used low-current "concertina" drivers for the output tubes (Dynaco circuit, also widely used in vintage receivers), or a differential long-tail pair (Mullard circuit). These are (barely) acceptable for pentodes and beam-tetrode tubes, but not very good for triode output tubes. The designers of the "Golden Age" amplifiers were struggling for every single watt, which is why Class AB was universal for these amps, to maximize power output and efficiency. Watts were very expensive back then, and power transistors were notoriously unreliable. (Partly due to lack of understanding of Secondary Breakdown and stability issues with full-power oscillation, and partly the devices themselves.) This is why the transistor conversion, which began around 1964, took about five to ten years. Transistor amps didn’t really become reliable until the mid-Seventies, while they passed tubes in the watts-per-dollar competition a few years earlier. It wasn’t until the late Eighties and early Nineties when tubes started to ascend in the North American high-end market. By then, the tube factories in North America, the UK, and Western Europe had all closed ... but Russian, Czech, and Chinese tubes appeared on the market to replace them. |
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