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. 

 

 

whitestix

@donsachs 

The prototype amps along with their matching preamp will be demonstrated at the Spatial Audio Labs room

This sounds like a very exciting venture. 
What is your preamplifier tube?

Do you prefer the LampiZator Pacific DAC with preamplifier or direct into the 300b mono blocks?

Best wishes for the upcoming audio show.

Charles

 

HI

My Pacific is XLR out with no volume control so have not tried direct to amps, but I build a really good preamp so I will continue to use it. The prototype preamp is essentially a circuit that was a thought experiment of Lynn’s for a fully balanced design that has been around for years and no one ever really tried to build and perfect it.  So we did for this project. Like the amps it is conceptually simple, yet has subtle complexity.  It is transformer coupled on both inputs and outputs and uses the same Khozmo 64 step remote attenuator with relay input switching I have been using, but set up as dual mono. This allows me to switch a balanced signal on both channels, plus you get a balance control if you need one. Main tube is 6SN7 and it is transformer coupled to the output with custom wound iron from Dave at Cinemag for just this circuit. I have tried ECC99 and 6H6P with adapters and they also sound good, but I always pick the 6SN7 in a shoot out, so it has octal sockets. The power supply features damper diodes into a CLC and that drives a custom regulated supply which then feeds gas regulator tubes. Because of the output transformer it can easily drive RCA or XLR outputs and headphones. It has no caps in signal path and of course no feedback or anything like that. If you use the preamp xlr outs you can drive the amp input tube grids directly. It has a level of clarity that has to be heard. Quite astounding. The prototype works well and I am working on the "real" one for the Seattle show. Dave’s iron is just superb as it always is and response is dead flat from below 20 Hz to way out there beyond 20KHz. Just having fun and we will see where it all goes. Honestly I have never heard anything like this setup.... fun.

The prototype preamp is essentially a circuit that was a thought experiment of Lynn’s for a fully balanced design that has been around for years and no one ever really tried to build and perfect it. 

@donsachs I'm curious what is meant by this. We've been working on a fully balanced design since the mid 1980s, which started selling in 1989. Is it the use of transformers in the circuit path?

HI

It is really not my intent to get into detail here for something that is in prototyping.  Yes, there have been many balanced tube preamp and amplifier circuits around for years, and I have absolutely no doubt you build an excellent balanced preamp as I know you guys build really good amps as well!   This is a slightly different approach to a traditional tube circuit, and yes the transformer coupling is part of it.  

Also, as you well know, the quality of whatever attenuator you use is critical, and of course the power supply.   Anyway, I think I am going to bow out of this thread because it was never my intent to do business here.  That is inappropriate and there is nothing to sell yet anyway!  Just was commenting to tell folks what I was up to in my semi-retirement.  See anyone who wants to chat in Seattle!

Don and Ralf,

 

both classy members of the community contributing their know how. Stay around to educate us!