lynn_olson
Responses from lynn_olson
| 300b lovers Although a glance at a schematic might lead you to think it is simpler than a classical (Golden Age) PP KT88, the parts are more expensive. Way more expensive, just as 300B’s (as a group) are more expensive than KT88’s (as a group). Another facto... | |
| 300b lovers I agree with Atmasphere. Some things cannot be accurately modeled. Put it on a bench, attach a dummy load, light it up, and measure square waves. Tune for nice-looking leading (and trailing) edges. Measure both low-level (below 1 watt) and also ju... | |
| 300b lovers Very good article about how the brain distinguishes between reality and imagination. Since audiophiles are endlessly arguing about perception and reality, this is a useful read: Quanta Magazine | |
| 300b lovers Not going anywhere near an 833 or those Eimac transmitter tubes. No thank you. Those things light up a room with a dazzling white light and get serious, room-heater hot. They are designed for transmitter use, with forced-air cooling that ducts to ... | |
| 300b lovers If a cool room is important, you want Class D (90% efficient or better) and speakers that are more than 1% efficient (a true Theile/Small 92 dB/meter/watt), as well as switching (not linear) supplies for all the other audio components. That’ll mak... | |
| 300b lovers Pindac has described the stage Don and I are at now: tuning the subjective balance ... there are a couple of nodes in the circuit where parts selection is quite audible, and we’re fine-tuning that. I wrote an email to Don a couple of days ago tha... | |
| 300b lovers I was there. Thom’s amps did not use interstage coupling (at the time), so 8 watts is pretty much all she wrote. Frankly, I was kind of surprised ... I knew Thom’s NiWatts were maxed out for all they were worth, but audibility was surprisingly low... | |
| 300b lovers It is difficult to predict real-world distortion from idealized triode or pentode models. The models assume tubes with perfect physical assembly and ideal emission characteristics. In practice, grid windings are not evenly spaced, grids are tilted... | |
| 300b lovers Hi, CuriousJim! I am kind of dubious about any KEF speaker being really 91 dB/meter/watt. That’s almost 1% conversion efficiency, and believe it or not, that’s quite high for the mainstream market, and especially KEF. True efficiencies between 85... | |
| 300b lovers A good way to visualize the difference between even and odd-order distortion harmonics is to imagine a sine wave ... a perfect, happy little sine wave. That's the original signal. * Now, use a single diode to clip one side of it ... say, the posi... | |
| 300b lovers The house I lived in back when I was in Portland had a ceiling like that, with a panoramic picture window overlooking the Oregon Coast Range behind the speakers. The very first PP 300B amp, the Amity, had a vast, CinemaScope soundstage. Once I hea... | |
| 300b lovers What’s odd is that I have trouble describing the sound of my own gear ... this applies to Shadow Vector, my loudspeakers, and my electronics. I aim for natural, open sound that is free of electronic artifacts. If there is a residue of coloration, ... | |
| 300b lovers Well, I tried that with an amp I once called the Aurora. SE input, and if memory serves, the conversion to PP prior to the driver, which was PP. The problem is the input tube has a high output impedance, which enormously complicates the transforme... | |
| 300b lovers Let’s talk a bit about distortion, particularly in a DHT driver. It defeats the purpose of using a very low distortion 45, 2A3, 300B, or 845 if the driver has more distortion than the DHT itself. You might as well use a much cheaper power pentode ... | |
| 300b lovers The Statement ... or Blackbird ... or whatever it’s called, is pretty sensitive. Don told me 1.5 Vrms to full clipping, and my gain calculations indicated a bit more sensitive than that. Since there is no RC loading anywhere, and all the cathodes ... |