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. 




You want a technical presentation, here’s my talk at the 2004 European Triode Festival:

2004 ETF Presentation

As for the lengthy previous post, I am not sure about the impact of dynamic variations in output impedance. One way to measure the impact would be to measure distortion harmonics at a constant voltage output, compare 4 and 16 ohm loads, then repeat again into a reactive loads.

The key point stands: Push-pull Class A triode has the most linear interface to loudspeakers. Nearly all loudspeakers generate significant back-EMFs, which are resonant in character, that reflect back into the output devices. Other topologies have nonlinearities or discontinuities that interact with these resonances, which exaggerates speaker coloration.

There are planar-type speakers that present essentially resistive loads, but the reason for this flat impedance curve is very low magnetic coupling between the diaphragm and the magnetic system. As the magnetic coupling (BL product) becomes more intense and efficiency increases, resonances appear in the impedance curve, as well as smaller narrowband divots that reflect stored energy. Regrettably, speakers are inherently resonant, particularly as efficiency goes up. It has to be kept in mind that most speakers are stupendously inefficient, ranging between 0.3% and 1.0%.



FYI,  the guy who published DH tube comparison more than 20 years ago uses the same driver and same speakers as well the same signal source during his blind listening tests.

I can confirm his report that PX25's bottom is much solid and deeper than 300B. 300Bs could not even match 7A1's deepness.  The common sense is 300B could not be driven into A2 region w/o distortion, so I consider 300B is a good candidate for pre-amp/headphone amp which always worked at A1 region.   Also, the measurements of output impedance from 300Bs is way higher than PX25s.  FYI, my 6336 SE amp beats my 300BXL (beefed up 300B) amp hands down at bottom spectrum.

You are right about driving stage quality is the bottleneck of MOST commercial SE DH amps.  but the reason is not what you stated.  The real secret of making best SE amplifier is to SHUNT REGULATE POWER SUPPLY for the driving stage. Push Pull amps are less critical of regulated power supply for its driving stage.


Many roads lead to Rome...

As to DHT shootout, using the same driver may suit certain output DHT tubes better than the other ones. Different DHTs also need different output transformers, different B+ voltages and filament supplies, etc. So AB test is not that easy as more than one elements have to be changed for each DHT output tube to have a chance to perform at its best potential. That said, there is no bad DHT in my personal view - assuming adequate power output. So, many good choices are around!


Oh my, I was not aware that I had the good fortune to be the first in line for the mono's, but I do recall that I was a very early owner of your first preamp as well your DS2 preamp, both remarkable preamps.  I am gratified to see revealed on this thread the thinking that went into the creation of these stellar monos and the collaboration that brought it about.  The participation of Ralph and other knowledgeable audiophiles, along with Lynn for sure, has given us all an appreciation for the bounds of your joint inquisitiveness that has wrought such a stellar component.  Obviously, it like nothing I have ever heard before, just as you said it would.  The Spatial Triode Masters (which you encouraged me to buy nearly 6 years ago before you yourself had your own pair which was a stellar recommendation as all owners of them know) sound amazing with your amp and my soon-to-be-delivered Cube Audio Jazzon speakers clearly will love to be driven by your monos so expect a report back on that soon.  

Finally, as others have said, this has been among the most informative and civil threads I have ever participated in on the forum and I am among many who are excited to hear your room in Seattle next month.  

This place needs more info like this, I almost resigned sludging through some pretty pathetic posts that all went south and should have been erased.