I'd love to hear you elaborate on this!
Craig
I'm not feeling very well today, so I won't go into great detail, but off the top of my head:
6072 tube (12AY7). Not the greatest tube for a microphone. I didn't realize that until one of my more learned colleagues pointed it out. Yeah AKG picked it, but really there are way more exciting tubes out there. I really knew what he meant after trying it out for myself. Plus with this tube's impedance you have to use a higher turns ratio transformer which means you hit the transformer hard and you also end up with lower output. Everyone (including me) jumped on that Cinemag transformer. BO-ring! Not to mention a transformer that small it has a low over-load point on the low end. A tube with lower impedance would be great and I'm about to try that right now in a Nady TCM-1050. It meant re-wiring the socket. No biggie. I can also use a better and larger transformer with a lower turns ratio. And believe me, the type of transformer you use, how its made, the winding method, the lamination metal types and density of the stack has a LARGE influence on the texture and presence of the sound. Bigger than I had imagined. Marik is making some transformers now that KILL!
There are also capacitors that were swapped out or removed that should be left there, and ones that were not taken out that should be. Not to mention what type should be used. Certain resistors should be changed as well. The HF peaked could have easily be compensated for or subdued! So many ideas were missing or not even tried!
Also, when you lower the voltage in the power supply it means you have to re-bias the tube circuit at both the cathode and capsule. Not many people know how to do this or what to look for. No one even made mention of that on any of the forums I read. A class A tube circuit can really be messed up sound-wise by incorrect biasing.
Capsule choices and grill mesh are another story. Removing the mesh should only be done if you know what sound you're going for, and a lot of that depends on the type of capsule/tube/transformer configuration. Changing the wire mesh SIZE may be more important than how many layers the grill has.
How you solder, connect and arrange components and clean the boards are often over-looked issues. There should be stand-offs used and special insulation where the wire passes through the grill plate to the circuit! These are high impedance circuits and electricity always takes the path of least resistance. Sometimes that means right through the insulation (Can you say "capacitance"?) Even the wire should be treated a certain way to avoid that. Have you looked at how much wire is between the boards on the 460 style mics? Very bad idea!! Even MXL made one of the biggest microphone no no's in how they made the V69!
There are reasons why skilled mic techs charge a lot and take time to do their work. They have a great deal of knowledge! Knowledge that shouldn't just be surrendered on the web, which is why I'm going to limit my detail. The information is out there if you spend the time and get educated. Some tidbits are free though. Did you know you shouldn't touch resistors with your hands unless they're really really clean? Even then cleaning them afterwards (and the board and other components) is a good idea. I wonder if the Chinese manufacturers do this after remembering reading so many posts about the "ocean" noise. You've got people out there soldering away with no real soldering skills and have no idea what flux left on a board can do. And don't even get me started on too much solder or bad solder joints!
Over-all, that mod could be made way better than what's all over the web right now. Pity, because so many people are doing it without continuing to learn what makes great mics great. I'm still a perpetual student myself, but the revelations for me lately are quite eye opening.
Sorry I'm editing this so much. I want to make sure I'm being as clear as possible.