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±. With true variable gain for constant S/NR regardless of level, testing Pasithea's volume control was de rigueur. I tried it downstairs and upstairs. Either system is configured to run best with passive-magnetic preamps using multi-tapped attenuation autoformers. As one selects higher signal cut, output voltage drops but current multiplies in log fashion. Downstairs on 95dB speakers into a 25wpc amp, my standard levels demand ~30dB of cut while low SPL can want 40dB. Upstairs the room is smaller and I listen there mostly in the late PM. So I deliberately run a direct-coupled amp with high 35dB voltage gain then tap the DAC by XLR for twice the source voltage so 4 volts. At my low SPL I predominantly want here, 50dB of attenuation by autoformers benefits the sound by maximizing voltage/current conversion. As Martin Colloms put it in his review of an equivalent Townshend passive, "autoformers multiply the load impedance by the square of their step-down ratio. Thus attenuation of just ten decibels increases their input impedance by x 10. At -20dB, the reflected load is reduced by a factor of 100. At -40dB it is reduced by a factor of 10'000. The more quietly we listen, the higher that value as seen by the source. What's more, as input impedance goes up, output impedance goes down to expand bandwidth." So this type of attenuation is extra beneficial when engaged deeply.
When I bypassed Dave Slagle's downstairs autoformers at my usual SPL, lowering Pasithea's amplification factor instead behaved virtually indistinguishable. Wherever an owner prefers a system with a quality passive preamp, running Pasithea amp-direct should be as good if not better. That's especially so over XLR where its low output Ω for high current transmission is so effective. Upstairs the same exercise likely gave the nod to our autoformers because now desired attenuation hit -50dB. You might say that I had stacked the deck to favor the magnetic volume solution by combining unnecessarily high voltage gain with very steep attenuation. That's not what's usually advised. In fact, it's exactly the opposite. For my hifi whisperer applications, it's simply ideal. That Pasithea came in second was probably predictable. That said, there was none of the pronounced white-out where everything goes pale, thin and half-hearted as it does with significant bit decimation in traditional on-chip digital volume. For 95% of all usage scenarios where an amp/speaker combo already generates all the desired image density and tone weight, I predict that running Pasithea amp-direct will be the preferred mode. It's thus perfectly legit to call Pasithea a DAC/passive-pre in one small box. If a system relies on the contributions of an active preamp, the direct connection steps back. Now one simply runs Pasithea full tilt. Since that feature is built in free, it's the perfect two-step solution. Start direct. Should you subsequently feel that additive action from a separate preamp is desired, you have a fully functional solution until sufficient funds accrue to pursue your dream pre.
To summarize, let's segue back at that podcast. Its DAC tribute list came about because for 2022, John Darko swore off further converter coverage. He refers to the door wedge and its fat and skinny ends. On the fat end live room, speaker and subwoofer. In the middle live power and integrated amps. Preamps sit closer to the pointy edge, DACs still more so. They do make a difference. In terms of delta, it's simply far smaller. Being able to produce ~35 reviews/year, John feels that focusing his limited time on the thicker end of the wedge is sensible for a change. I concur with his wedging 110%. It reared its head upstairs. There Pasithea made less of a difference over a Kinki DAC; and not because the Kinki bests T+ downstairs. Not! It's because overall system res is lower upstairs where I still run a Dynaudio box sub not a smaller Ripol. Hence the earlier proviso. A single component of truly higher resolution can only show off its full advantage when the rest is fully transparent to it. The difference a Ripol sub makes to overall system resolution when run across the two bottom octaves is grossly more significant than any DAC games you could ever play. So first put such a sub in place to remove time smear and overhang caused by typical room gain (or go gonzo on room treatment that's actually effective to 25Hz). Whatever you now do upstream can't fail to telegraph more. You removed mud and blur that overlaid the midrange with bass ricocheting around the room like snookers. With that primary obstruction sorted, otherwise rather secondary moves grow in weight. Having done so downstairs, I already knew my DAC to be its weak link. Pasithea created a resolution gap which I considered significant and priced surprising given that what she beat cost virtually the same. She only looked less impressive. But my ears didn't care one wit. And what higher resolution actually meant to my pink bits rather than grey preconceptions I've already described. Just remember to do first things first.
If you can't remember Pasithea or are unsure how to pronounce it, call her Miss Peach. That'll do. And she really does wear Prada. My encounter with a goddess has proven most enlightening. I actually do need to do something about my downstairs converter now…
Cees replies: "Thank you for the positive review. Reading your last page, I see that something may have escaped your attention. To create the possibility to couple Pasithea to very sensitive amplifiers, two forms of extra output attenuation are possible. The first can be found in the menu where you can enable a -10dB cut. By doing this the scale remains unchanged but you will see that you have to increase the volume by 10dB for the same sound level. There we reduce the reference voltage by a factor of 3 which gives the -10dB attenuation. A second—and in my opinion best permanent setting for sensitive amplifiers—is a passive way which involves two internal jumpers on the output section. Here the reference voltage isn't adjusted but the output level lowered by 10dB. The result is that noise goes to an almost unmeasurable level (in the range of -170dB) and output impedance to 8Ω. A combination of both is possible and extra attenuation becomes -20dB. This is a very unrealistic situation by the way. Somewhere at page 8 in the online manual this is explained. Thanks again for this great review!"
Postscript: By February 10th 2022 so on my 60th birthday, I'd bought my Pasithea sample. Miss Peach has now upgraded my big system's digital to the next level. Going Dutch never sounded richer…
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