Auuugh! apl taunts me as much as you. Why, who knows? That's apl. Carvin, ES57s, DavidK's CD, and me. Go figure.
OK, here is ONE MORE POST! LAST TIME! I MEAN IT! I have an email address you know!
The 1O is essentially replaced by the 2, however note the customization section on the 1 page. I will still make one if you beg me to, but I felt that the 1O needed a metal case and an extra component (note the 1O noise rating was 22dBA), and I had already maxed out on space inside the XX connector.
The 1 design doesn't suffer as much from the plastic boot because it is a fully balanced design from the capsule on through. On the minus side, that also limits its SPL performance.
The 2,4,5 also had to use a 10mm capsule to work mechanically inside the new case. Therefore, they aren't quite as flat 20-20k as the 1 is (the 5 isn't flat at all), but then again I've had some customers say they thought the 6mm omnis were too accurate
Why is the 5 so noisy? Because of the optocoupler. Probably only I am crazy enough to run signal (rather than a sidechain) through an optocoupler, but it sounds too cool! (PS optocouplers have LEDs, of course I used a LED too) With a harp 1mm from the capsule, it is not a problem. You need to push the volume up over 100dB to get into overdrive anyway. I have largely pitched this thing as a stage mic, since I doubt it would replace a tube amp in a studio, at least for a real serious harp player. I mean does any guitar pedal really replace a good tube amp? Other applications, I have no idea.
Someday, soon I hope, LETs will be commercially available
Phantom blockers: gone for good. They were a bitch to make, and ultimately I think the circuit still fell a bit short of full protection. I mean it stopped ribbons from popping, but when I cycled through 100 shorts, in some cases I could stretch the ribbon enough that I felt performance of the mic could be affected. The real solution is an active circuit, but that would require phantom power rather than just tolerate it like the passive circuit did (that is, the passive circuit passes signal whether or not there is phantom). Also I don't think I could fit my version of an active circuit inside the connector.
Here is the circuit for anyone interested in taking it up, I think I advanced it quite a lot from the idea I picked up. How it works: what happens when you turn on and off phantom voltage: most often, nothing, because there is no difference in voltage between pins 2 and 3. However, if you manage to short either pin, or only connect one pin (which can happen when patching or unpatching cables with phantom on, especially but not exclusively through a patchbay), you will get a nasty pop headed for the ribbon. I have measured that pop to be in the neighborhood of 2VAC, and it will usually destroy a ribbon quickly and mercilessly. You don't hot patch cables, you say? I believe you, as long as you don't let any oafs into your studio who trip over cables.
So we have to stop an incoming surge. R1 and R2 just serve to drop the voltage a bit, makes life a little easier on the cap ratings which means smaller size. What does the bulk of the work is D1 and D2, which are Schottky diodes. They have a couple of nice features: very low forward voltage, and they are very fast. However, unlike most diodes, the forward voltage is dependent on current, at phantom currents, it's very small, 0.2-0.3V. That voltage will *usually* not damage a ribbon, but ribbons with low impedance transformers (50 ohm) can still be damaged. So that limited voltage needs to be dropped again by R5 and R6. The values are R5 and R6 here are rather conservative, if you are using a normal medium impedance (150 ohm) ribbon, 220 will probably do. In the forward direction, well we've just built an attenuator circuit so higher values here will protect the ribbon better, but cost you more dB of signal, depending on the input impedance of your preamp, but generally something like 2-3dB.
Lastly, R3 and R4 serve to protect the ribbon in case something crazy happens like AC voltage is applied at line level (or through a headphone amp, in my case
). Because the forward voltage of Schottkys increases with current, R3 and R4 limit current to prevent that from happening.
You know, everyone's initial reaction is to use caps to block DC (which doesn't work in this case), but in the end, I don't even think C1 and C2 are necessary. But I never tested the circuit without them.
I hope 
