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. 




Regulated high voltage supplies are also a very hot button issue.   I know what I prefer from having built the same circuit with multiple power supply topologies and critically listened to each.  The way I do it costs more money and certainly has to be worked out so that it is very reliable, but once you get to that point....  As I said, I value absolute blackness between notes and very fast transient response delivered by supplies that are grossly over rated for what they have to deliver.  Other people value other things..... to each their own path.

@alexberger  Hi.   I just tried schottky diodes maybe 5 or 6 years ago and I liked the sound.  They have a fast recovery time.  They also have very low voltage drop so are good for small filament supplies, but the main reason is the fast recovery.   I didn't hear any difference compared to the super high priced hexfreds or other types in the sort of supply I build.   The automotive schottky diodes are not expensive and they are available in voltage and current ratings that far exceed requirements of the circuits I am building so there is plenty of headroom, and you can get to-220 versions that fit everywhere.   So basically, they work well, sound really good, and are readily available.   

For DHTs such as 300B, AC at main frequency is hard to be hum free. But some have tried AC at a high frequency well above human hearing limit with decent result. Sadly this is mostly in DIY world, hence very few commercial offerings with high frequency AC DHT filament supply.

I don’t think DC, IF well done, is any inferior to AC in DHT though. But there are many ways to get DC done. So it gets down to implementation at the end.





I don’t think DC, IF well done, is any inferior to AC in DHT though. But there are many ways to get DC done. So it gets down to implementation at the end.

The commercially available 300b amplifiers seem to bear this out. By a wide margin they are DC heated rather than AC heated. AC is utilized by the DIY crowd more (Relatively speaking)  than commercial manufacturers.


There are a lot of little tricks to DC filament supplies that make them sound better too.  It isn't rocket science, but you can get a bit more performance and noise rejection by connecting them properly:)