300b lovers

@whitestix 

I make a change and live with it for at least a few days or a week before deciding.  Yes, the film caps have to run in.  With this amp project I built a stereo version first because I had a few of the Kootenay amp cherry cases laying about.  So I made it all fit.  There are different topologies to try.  The first was full "silicon assist" where the driver tubes each have a CCS on the plates.  I took this version to Spatial Audio a year ago and we all agreed it was the best amp any of us had heard.  But then I tried LC coupling and it was better to my ear.  So then I had Dave Geren of Cinemag design me a custom interstage transformer for just this circuit.  As Lynn said above, the 300b is a hard tube to drive.  Dave likes a challenge, and his interstage transformer sounds better than either previous version.  The IT version is more "musical" and "relaxed" sounding, yet has an insane level of detail.  Then we decided to go to mono blocks because we could improve the power supply considerably with more space to play with.  So my point is these things evolve over a year or more and I listen to each variation for quite a long time.   The mono 300b amps going to Seattle for the show are the result of a year of listening to different ways to build the circuit.  You have a pair of them and they are pretty special to my ear.  It took a lot of experimentation, guided by theory to get to this point.  That and patience of course....

Guys,

Just love reading about different type topologies that went into this 300b design and it’s quite amazing the time, effort and dedication it took to come into fruition...

I know this is going to be a special 300b as I am a current owner of Don’s Kootenay 120 ...😁

Wig 👍

Gents,

This was an excellent glimpse in to the design process, voicing the sound of the electronics, that has always mystified me.  Since getting Don's first preamp many years ago, he did improve upon the sound of the preamp with a few capacitor upgrades... not rushing right to the very pricey Dueland caps, but sleuthing out caps with similar SQ characteristic at affordable prices to the benefit of his customers' pocketbooks.  V-caps in the DS2 are very nice improvement.  As Lynn mentioned and I am sure Don agrees, there are go-to components for the gear.  I know from visiting with Don how much of a revelation it was to get the Cinemax transformers which is proof positive of his relentless search for excellence.

I always think that Don's prime aim was designing his gear for his own listening pleasure, and after 15 years of knowing him, I trust in his ears and know that others enjoy the fruits of his labors.  That you two collaborated on these 300b amps indicates to me that he is willing to stretch out with his designs, involving Lynn and working with Cinemax to get the properly designed components.   Often one doesn't see the whole picture and two heads are often better than one.

I have had your mono's running since dawn and I am inclined to wonder if my Spatial Audio Triode Masters have somehow been swapped for the excellent MBL speakers that I hear at every audio show... providing a holographic sound image, with amazing inner details and significant heft in the LF... and of course the HF is ethereal. I suppose I exaggerate to my peril, but the presentation of the music is just 3-D remarkable.   The sound is neither warm nor cool tonally, it is just true to the source. 

@whitestix 

When I "voice" amps and preamps I am always trying to make them sound like they are not there.  I have a Lampizator Pacific DAC so the front end is killer.  I am always trying to have the amps vanish.  That is the goal.  They should just sound like music and not be warm or cool or anything.  Lynn's circuit is amazing.  If you put a really good power supply in front of it and really good output transformers behind it you get the vanishing act......

I "voice" things mostly with recordings of acoustic instruments and vocals of course.   Does the piano or mandolin sound real?  So I have my favorite 100 test tracks.  Of course I enjoy Pink Floyd or a live Dead show, but you don't really know what the electric guitar is supposed to sound like. That sort of music will tell you if your amp rocks, but not if instruments sound convincing.  I know what a mandolin or stand up bass sounds like.  I love David Grisman's acoustic disc label.  I love the last recording of the Goldberg variations that Glenn Gould made.  If I can easily follow the left and right hands with no strain, then the amps are good.  I really like Myriam Alter's compositions.  She plays on some of them, but they are always interesting music with hints of Klezmer and all sorts of other influences.  They are usually 3 to 5 instruments, like piano, clarinet, bandoneon, and interesting percussion.  If you can easily follow an individual instrument or switch to listening to the whole, then the amp is good.  I find this circuit to be FAR better than any amp I have ever heard.  The reason is that it avoids many sorts of distortion that plague other circuits.  You don't really know you are listening to all of that until it is gone, or at least very minimized.  So what you hear is really the lack of all the other things you usually hear in other amps.  That allows only the music to remain, floating in the air in your room.  I find it quite astonishing after all the years of restoring classic tube amps, and then building my own, to hear what this approach brings.  Very enlightening.

Wish  the amp was going to be at T.H.E. Show in SoCal as i would love to hear it.