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. 




Unlike the 845, which relies on voltage to deliver more power, the super tubes provide more current thanks to higher emission, and plates are more

Thank you Lynn for your reply.

The EML tubes are a bit larger and heavier compared to my other 300b tubes. The glass envelope is thicker as well. It does possess a heavy duty aura and appearance.


What separates the Euro super tubes is massively higher electron emission. For example, what separates the EML 320B XLS from the EML 300B XLS is 50% greater heater current, with correspondingly higher emission. But even the EML 300B XLS, although consuming the same heater current as a standard 300B, has significantly higher emission.

Same story for the thoriated-tungsten Elrog tubes. Thoriated-tungsten is used in high-power transmitter tubes, not "radio tubes" with the typical coated filaments. The peak emission characteristic will sound more like the Eimac giant transmitter tubes than a 2A3 or 300B.

What’s fun about these is they are plug and circuit compatible with classic 300B’s, but they are not replicas. Not at all. They are modern high-power designs, optimized for both linearity and peak emission. And they sound like it ... powerful and blazing fast.

But ... the amp circuit has to match the peak power and speed, or you never hear what they can really do. They sound like just another 300B with generic RC-coupled drivers, for example, and the potential is mostly wasted. Give them a driver that is a powerful Class A amplifier that is transformer coupled, and whoa, stand back. It’s not a meek little flea-power amp any more; put on Mahler or Mastodon and frighten the neighbors.

One unique feature with transformer coupling is 97~98% of the plate power is presented to the following grid. The plate power doesn’t disappear into a resistor, choke load, or MOSFET transistor current source, or jump through a plastic-film dielectric in a capacitor. It’s right there at the grid, with only tiny losses in the transformer.

This is audible as vivid and tactile tonality, speed, and power. Basically, less electronic cruft in the sound, which is what you’d expect. Don and Whitestix will attest to that.

The regulated filament supplies for each 300b can deliver 3 amps, and the tubes draw 1.2 amps, so they are coasting along, like the B+ supplies.   As Lynn described, the amp is lightning fast.   I would love to audition the Elrog 300b in it.  I have to admit the Linlai replica WE300b is just superb though.  I cannot imagine it needing more slam, but my speakers are 97 dB and an easy load, so the amp is just cruising along and is really not stressed.   Whitestix told me he tried a pair of Dynaudio C1 on his shoebox earlier edition amps and they drove them with no trouble at all in his smaller room.  That is the third or fourth time someone has put a more difficult speaker on the mere 27 watt amps and they had no trouble.  I don't suggest you power some horribly inefficient speaker with these amps, but don't let the 27 watt rating fool you.  Any rational speaker load is fine.

I suspect any electrostat is fine. The weird capacitive/inductive load will not bother a zero-feedback amplifier.

What will not work is something like Wilson Audio or B&W speakers, with low efficiency, a band split into three or more drivers, complex crossovers, and big woofer arrays. Or MBL. They really do need 200 to 500 watts with a high damping factor (lots of feedback). Transistor amps, in other words.

Hi @lynn_olson ,

According to your comparison between RC coupling and IT coupling, IT coupling between input and driver stage should increase slew rate (dynamics, trancients, speed) similar as it does between driver and output stage. Isn't it?
On the other hand, the input stage doesn't have a big voltage swing, and as result of it a linearity issue. It shouldn't drive the driver stage in class A2. 6sn7 with IT has less wide bandwidth compared to 6v6, 6f6, 45 that can be used in driver stage (in my amplifier 6sn7 18Hz-35KHz vs 6f6 6Hz-95KHz -3db ).
Is It wars to try interstage transformer after the 6sn7 input stage in my 300B SET?