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. 




As I said above, there are little tricks to regulated DC filament supplies on DHTs....

Post removed 

But there are choices that affect the sound.  If you need a 1 watt 1K resistor you can use any type on a cathode, but different types have different sounds.  The cathode bypass cap might need to be 100 uF.  Different 100 uF caps sound very different.  All will satisfy engineering standards, but parts and layout choices have profound effect on the final sound. 

When you run zero feedback, the circuit has no ability to reject things like this. So everything makes a difference. However, for something like an electrolytic bypass, I think you'll find that as long as the part is good quality, the big differences you hear will be more about the part forming up over time: they will arrive at the same place sooner or later.

For reasons that are not clear, various brands of metallized polypropylene capacitors sound quite different from each other, and there is little correlation with DA and DF parameters. Based on measurements, they should all sound the same.

Sometimes you have to do your own measurements because the specs of the manufacturer don't always tell the whole story. If you use a precision differential amplifier to drive the caps in question, you can measure how they behave and differ from one another while in circuit.


@atmasphere First off, this thread was started by a fellow who has a rough first prototype of a zero feedback push pull 300b amp, so of course we are discussing that.   I agree that in that circuit you hear everything.   I will tell you that even in circuits with feedback I will not use electrolytic caps in the signal path.  I also do not use them in my power supplies, but only in the filament supplies.  In my experience electrolytic caps make circuits sound grey and hazy compared to a very top quality film cap.  You can wait forever for a lytic to run in, you can bypass it with small film caps, and whatever else.  When I replace them with a very good film cap I hear the difference.  To each their own.  I also hear differences between resistor types in key spots in circuits, whether the circuit has feedback or not.  Again, my experience, so I build amps with the parts types that I favor.

@donsachs FWIW I was referring to an electrolytic cathode bypass cap. I wasn't very specific about that in my last post.