Turmoil In The DIY Microphone Forum

There is definitely something going on within the PSU that influences the overall tonality of the mic and it isn't whether its vintage or not. Unfortunately I haven't figured it out yet either but I have multiple copies of the same design that influence the mic to sound/behave differently. If one of them sucked I'd just say there was something wrong with that one but dammit they both sound killer for different reasons. Jess Jackson experienced the same phenomenon but his first mistake was to pretend he knew what the difference was. He claimed that his original was a passive supply and the clone's was not. The Matachung supply differs in that it is full wave rectified vs half-wave for the original C12 supply and while they both used regulation for the heater voltage the Matachung PSU uses an IC while the original used discrete regulation. They are both passive, self biasing circuits. I can't imagine that how you light the heater would make any difference, but I do know several people who have experimented with under-volting tube heaters to influence performance (as well as tube life). Perhaps in their age the original supplies have dropped a few volts on the heater rail and this is causing the difference Jess hears. As far as the half vs full wave aspect of the PSU, I can't say I'm sure it isn't a factor but Matador has suggested not. The two power supplies I have that differ from each have different value transformers - one being 175V and the other being 200V. I used different dropper resistors to derive the same 120V B+ voltage, and -1.1V bias voltage so in theory it "shouldn't" make a difference.  The voltage going into the mic is identical regardless which PSU I use. In actuality, something is making a difference and it'd be great to know what. Matador has suggested to me it could be the value of the first PSU capacitor the mic sees, since the tolerance of 20% really allows for up to 40% differential between 2 "in-spec" parts. Maybe one day I'll dive deeper into that possibility.  I know Kidvybes has experienced the same phenomenon but I haven't examined his PSUs so I don't know how similar they are or not.

It still stands that the capsule, tube, and mic placement all make WAY bigger differences than I have ever experienced by varying the PSU, so time might better be spent optimizing those variables. Even the three CT12s I have show differences between them. I like to think of them as three individual pieces of the same type of wood. Certainly they sound the same, but each is unique in it's fine character.

As for Jess Jackson vs GDIY, I think he approached his hypothesis carelessly and in a mildly offensive stance, and when Matador engaged defensively he turned it into a pissing contest. I think both of them would probably take it all back if they could. The fact is that the ear is a horrible and un-reliable measuring device. Without some kind of measurable evidence it really becomes pointless to say PSU A is better than B because... Even with controlled comparisons and testing it may turn out that differences which appear audible are not measurable.

Rare is an internet forum without some kind of drama.

So you have tested the two PSUs in the two clones to determine the difference was the PSUs and not the capsules/mics themselves? Sorry - I would assume you have, but you didn't mention it specifically, so I have to ask. I think there is a bigger discrepancy between capsules than people realize/assume. For example, unless something is wrong with my circuit, PSU, or something else, even the front and back of my CT12 sound relatively different.