Could you clarify your question a little more? My reply may answer your question or maybe not? The Spark sounds better. The hybrid amps are not what I consider a tube amp. Hybrids have a SS output stage driving the headphones. So, they run into the same power limitations with high impedance headphones that any SS amp does. The tube adds a little character but does not make a hybrid better at driving a 300 ohm senn 650. The other tube amps are transformer coupled and one has a tap for high impedance headphones and they sound really good with all my phones. But the Spark does everything right per my preferences = more musical and enjoyable. All the other amps I still have, except the Millet max, were much more expensive and if I remember correctly even Millet Max's were 2-3 times the Spark's cost unless they were DIY builds. I have had so many really good sounding tube headphone amps over the years .... Singlepower PPX3/ MPX3 /Extreme,/ SLAM, DV 336, Eddie Current, heavily modded Doge 6210, Cavalli hybrid built by dbel84 (most amazing hybrid amo I ever owned amp but best with lower impedances) and a bunch of Millet Max types. A good sounding amp just sounds right and the Spark sounds very right. The Spark is the best sounding pure SS amp I can remember hearing. I have had the Gilmore amps (probably my favorite SS but still a touch sibilant/ much more expensive) and many others I soon dismissed in favor of the tube or hybrid amps. The Spark is a great listen. I have not heard the more expensive Cavalli liquid carbon but I do not care enough to buy one because the Spark is so good. For pure musical enjoyment the Cavalli Spark with the headphones I mentioned is as good sounding and enjoyable as anything I have owned. For $99 this amp is crazy good. One more thing .... the Spark is the only SS amp I have ever preferred to use over my tube amps for any length of time. This little amp shocks you how right it sounds.