Challenge for Objectivists: Bottlehead crack emulation (w/ Sennheiser HD6XX)

[captainbeefheart]

Hi Captain,
Your trout mask looks dapper, (even if it is a mere replica...)!
I have certainly heard that some (usually very expensive) tube amplifiers can sound identical to SS, but had not head that triodes were inherently less distorting... although I was aware that SS use negative feedback to reduce distortion, so I guess that makes sense. Would I be correct in assuming that the inherent variability of different tubes, their changes as they age, etc. are the reason why, nonetheless, we are currently able to produce SS amplifiers that measure below anything that was available in the old tube days?

Hahaha I love the trout mask references! Someone knows their Captain Beefheart

SIY basically hit the nail on the head. Transistors have NPN and PNP devices where tubes are all "NPN" devices, they allow current to flow in one direction only. With SS the two types of devices are called "complimentary" which is one major advantage to circuit design. The other aspect I initially brought up is that SS amps use a lot more negative feedback compared to tube amplifiers which is a big reason they have very low distortion. My example with the 12AX7 tubes having solid state like distortion is because the topology is like modern opamps, differential pairs are used and the open loop gain is very high allowing a lot of feedback to be used. Honestly at that point people say why not just use transistors then and that's sort of accurate due to tubes inefficiency from needing heater power. But to my point in that if you were to run a triode and a transistor in open loop and similar configuration (common cathode/emitter) the triode will have less distortion but to be fair the transistor will have more gain. The reason I say triodes and not tubes is because a triode and pentode have very different characteristics which is another reason it's inaccurate to compare tubes vs solid state because there are big differences within each category. A pentode is actually very similar to a Mosfet, they are both voltage controlled devices where a BJT is a current controlled device, and both a pentode and a Mosfet have very similar output characteristics. The simplest way to look at it is that a pentode's plate current is independent of plate voltage, so the output curves look horizontal just like a Mosfet. A triode has internal feedback, the plate voltage directly affects plate current so it's output curves are more linear and look more vertical on the output characteristic graph. We have circled right back around to feedback again, a triode is only linear because of it's intrinsic feedback mechanism, we don't need to externally add a feedback loop. So even though we can get low distortion with a triode without external feedback it's still feedback that creates the linearity. I will not get into power laws and such but I think I scratched the surface enough to get the gears moving.