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.
@lynn_olson I did just exactly that some years ago and played the amplifier at a CES in the late 1990s. The 300bs were driven by a cathode follower direct coupled to the grids of the power tubes so the bias was obtained from the driver tube which in turn ran fixed bias. In this manner the capacitance of the grids was a non-issue. |
How would you compare the sonics of your 300B amp to the the Class D amp you make now? You’re the creator of both, so you’re in the best position to evaluate and compare. I only spent a half-hour of casual listening to the Purifi at the show (and Audio Group of Denmark), so I’m hardly an expert on the subject. The thread is called "300B lovers", so tell us what you think about a 300B (of your own creation) vs your latest Class D amp. At the risk of thread derailment (I ask the forgiveness of the Audiogon moderator), and then I’ll return to the walk down Memory Lane. P.S. Karna and I actually lived in a house on Memory Lane when we were in SW Portland, up in the West Hills, just off Sunset Highway. It's a real place. |
This most genial, thoughtful, educational, respectful and generous thread of all time deserves to be a "sticky". Not only is it full of wonderful history, a person can learn a lot from it. A little ways up @donsachs used the expression "nutshell" in reference to one of Lynn’s posts. Hah! I think it is more like an advanced panel discussion between Don, Ralph and Lynn and some of our other technical gray-beards. Or maybe it can be likened to a graduate seminar in esoteric Amp design. Wonderful. My nomination for thread of the year, 2023. |
Alex, I wish you every success with your revised 300B amplifier. An isolated power supply for the input+driver, and replacing all the electrolytics with arrays of 440VAC (630VDC) industrial motor-run caps, will make a difference that will astonish you. Not joking here. It will definitely take it into the top class of SETs. Be prepared for a pretty large and heavy chassis for an 8-watt amplifier. 18" x 18" and 50 lbs or more would not be out of line. As for cap-value tuning, set the RC (or LC) frequencies between 3 and 4 Hz. The beat of most music is between 1.3 and 2 Hz, and you do NOT want any of the RC networks interfering with that. Anything slower than the beat of the music will give a kind of seasick, unsteady feeling, so don’t go there. Leave the banks of electrolytics to the DC-coupled transistor guys. A lot of their tuning (and amplifier sonics) comes down to the brand of the electrolytic. (Oops, did I let the cat out of the bag? Sorry, guys.) Don accomplished a miracle of miniaturization for the show, but we’re dialing it back a bit for the production models (to simplify assembly). We’re expecting 18" wide, the exact same width as the preamp, and maybe 16" to 18" deep. Weight ... yeah, maybe 50 lbs or so. Depends on what the transformers weigh. Specs and overall performance will be the same as the show models, so if you like what you heard, that’s what you’ll be getting.
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Actually, I have already improved the preamp considerably with a few subtle changes, and the power amps will get improvements to the power supply with the larger case, as well as higher quality and physically larger film caps in what we now know are 3 really important places. I could not fit some things in the previous case that Lynn and I agree should be added. I would expect the whole system to sound noticeably better than what was at the show. Same tonality, but a bit faster, with even better imaging and separation of elements in the sound stage, and tighter and deeper bass. Experiments are already showing these improvements. Production by the end of the year is the goal. When we have production models there will be photos posted on the Spatial Audio Lab site. I really appreciated meeting people at the show and getting their opinions! |
