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. 





 So if done right, there are lots of advantages to a transformer coupled preamp.  I can say that I don't miss coupling caps at all, note even the really good ones I was using previously.  So again, for me it is about seeing what was possible and then refining it.

This has been a topic of long standing discourse. Premium grade coupling capacitor versus high quality interstage transformer.


Yes I am well aware of the debate and tradeoffs in interstage coupling in amps, but I am talking about the output transformer in a preamp here. It has numerous advantages over cap coupled output provided the transformer quality is superb and the turns ratio and design is well mated to the circuit.

I prefer preamps with output transformers too. Luckily, there are decent line output transformers around that are not too expensive, certainly cheaper than exotic caps. But sadly preamps with output transformers are not often offered by preamp manufacturers.


Weirdly enough, both Thom Mackris and Don Sachs came up with the 6V6 driver within hours of each other. Thom was hacking around with his SET 300B amp and swapped in the 6V6 driver and was jumping up and down about it, and Don calls the same day. OK guys, you win, tell me how it’s going.

Thom plays electric guitar and has built his own guitar amp, as well as his 300B SET for his hifi system, so he’s really into tone. The 6V6 is famous throughout the guitar community for its tone. And Don’s a big fan of the 6V6 too. I’d been casting around for a replacement for the unobtainium 45 (in matched pairs no less), and both my friends say the same thing on pretty much the same day. And yes, Don and Thom chat on the phone on a regular basis. I think they have an ESP thing going.

My NiWatts started off as 6SN7 --> 6SN7 --> 300B.  You could think of the Reichert as being the launch point, although through the years, the only remaining similarity between the two designs is two tubes (the 6SN7 input and the 300B).

I was pondering switching to a 45 for a driver for quite some time, and thought, why not start with a 6V6?  I have to say that I can't find a compelling reason to change.

I let this amp sit in a 90% state of completion for several years.  I had too many irons in the fire. 

Anyhow, Lynn's conversations with Don motivated me to pop the hood and finish the job.  The spooky thing about this process is how many things the two of us discovered in parallel, and even more spooky - within days of each other.

I could swear that an audio muse was injecting thoughts into both of our heads.

The fact that we settled on so many similar design concepts (while the two designs are so radically different) still has me shaking my head.

The most recent "coincidence" occurred last Friday (literally within hours of each other, according to Lynn), where we made parallel revisions to our 300B cathode's circuit.

... Thom @ Galibier

The most recent "coincidence" occurred last Friday (literally within hours of each other, according to Lynn), where we made parallel revisions to our 300B cathode's circuit.

... Thom @ Galibier

Long live the 300b! 😊