Exporting mics to China? FAIL!

mshilarious

mshilarious

Banned
Sounds kinda backwards, eh? But we're all into free trade, right? So I had somebody ask me about it, and I looked into it, and this is what USPS says the restrictions are--I included a few other bits of interest:

Prohibitions (130)


Manuscripts, printed matter, photographic negatives, gramophone records, films, magnetic tapes, video tapes, etc., which could do political, economical, cultural, or moral harm to the People’s Republic of China.

Radio receivers, transmitters or receivers of all kinds, walkie-talkies and parts thereof; valves, antennae, etc.

Wrist-watches, cameras, television sets, radio sets, tape records, bicycles, sewing machines, and ventilators.

Restrictions

The importation of personal articles is limited to those intended for personal use and imported in reasonable quantities. The value of the items contained in each shipment must not exceed RMB (renminbi) 100 yuan and the total value of the shipment received annually by each family may not exceed RMB (renminbi) 800 yuan.

100 yuan = $14.

So it's pretty much impossible for me to sell into China . . . can't even send a single valve, and strictly reading that provision on radio equipment, even a single transistor.
 
And now you understand why we have a permanent trade imbalance with China.... It just goes to show that if you give politicians the right to set statutory limits on free trade, they'll find a way to screw things up. :)

The short form is that AFAICT, only businesses in China can import anything of value into China. If you want to sell in China, you would need to get someone there to create a business to sell them locally, at which point, I believe that person would be able to import them and sell them in China. I could be wrong, though.
 
That's pretty much it - you have to partner up with a Chinese company (or buy one - but that's even more complicated than those restrictions :D)
 
I dont think you can sell any finished goods there unless they had a part in making them...My company had to purchase a plant there to assemble parts that I make at my job. We had to ship over equipment so that they could take the parts that we have ALMOST completed....then they finish them so we can sell them in china....we could not ship over finished product to sell....
 
That's easy enough. Have them put the case on the mic and tighten the set screw. Done. :D

Besides, I'd imagine the condenser elements are all made over there, and probably half the other components as well, statistically speaking.... :D
 
dgatwood said:
That's easy enough. Have them put the case on the mic and tighten the set screw. Done. :D

Besides, I'd imagine the condenser elements are all made over there, and probably half the other components as well, statistically speaking.... :D
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Most of my components aren't. The Pana capsules and resistors are all Japan, so are the Pana film caps and Nichicon electros. Transformers are Malaysia. Diodes are Chinese, and some of the Neutrik parts (although a big chunk of those are Liechtenstein). Transistors, I forget. Somewhere random in Asia though I recall, but not China. The capsules I get from Transound are Chinese. I can't remember where the ICs are from either, I should start recording this stuff in my inventory sheet. TI makes stuff all over the place, so it's hard to remember.

PCBs, tubes, and windscreens are definitely USA :cool: Although I dunno where the PCB substrates are made. Sub-component level, I give up :confused:
 
Wow. Non-Chinese resistor/capacitor manufacturers actually still exist? :D

I kid, I kid. Sounds like you're sourcing some decent components. Wait... you're doing tube mics again? Cool! I love my 4s. How does the X-V compare with them?
 
dgatwood said:
I kid, I kid. Sounds like you're sourcing some decent components. Wait... you're doing tube mics again? Cool! I love my 4s. How does the X-V compare with them?
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It's a Great Leap Forward! (sorry, couldn't resist). I have cultivated the ability to do SMT all year long, and it's really starting to pay off. I can now fit circuits of much greater complexity than I could before. I actually even designed a stereo USB mic, until I realized that I could never afford to pay for the FCC compliance testing.

Anyway, starting with the same basic "tube sandwich" circuit, first I added the "X" circuit, which is just a simple power regulator FET that nearly all the X mics use. This is the typical zener-reference circuit, but by using a FET, I avoid the diode drop of a BJT, which allows the mics to keep working down to very low voltages. I get better filtration of zener noise too, as that part of the circuit is high-impedance. It's a simple idea but it has worked really well for me.

Previously I didn't use power regulation on the tube, because I needed every scrap of power possible from phantom. That's no longer true--I was dependent upon the voltage drop of standard phantom power to set the operating level of the tube. Now, I regulate that down to 12V, and set the plate supply resistor lower, which keeps plate current unchanged, albeit at less gain. The result is the mic will work with slightly less than compliant phantom power supplies, and power consumption is down from 9mA to a little under 8mA. In theory, that would mean +40V across 6.8K resistors, or +48V with a net power supply resistance of 4.5K. Or even something like +18V across 1.5K resistors. I use the center tap of its output transformer for the supply, so there is only about 100 ohm resistance for the power supply internal to the mic (down from 500 ohms in the MSH-4).

With trimpots on both plate and cathode, I can dial in a low-current, low-distortion operating point for each tube/FET combination. Distortion will be dramatically lower as a result. Although I am considering an option to set a higher level of second-order distortion, if I can figure out how to pitch that. That is probably what was popular with the MSH-4.

Another change is the capsule, which is a Transound 16mm unit. I put in it an unvented case and correct the resulting resonant peak with an active notch filter, which yields a net improvement in low-frequency performance vs. the free-field cardioid response, and a rather flat microphone overall.

Probably the biggest improvement from my point of view is the longer case (still shorter than the X-M!), which will improve isolation of the tube from vibration. That was the Achilles' heel that killed the MSH-4. When I started out, I dunno, I must have gotten lucky with my tube supply early on, because I used about 70%. By the end of last year, that had declined to about 30%. I am still being very selective and rejecting over 50% of my supply, but this mic will suffer from vibration much less than earlier versions :)
 
mshilarious said:
Probably the biggest improvement from my point of view is the longer case (still shorter than the X-M!), which will improve isolation of the tube from vibration. That was the Achilles' heel that killed the MSH-4. When I started out, I dunno, I must have gotten lucky with my tube supply early on, because I used about 70%. By the end of last year, that had declined to about 30%. I am still being very selective and rejecting over 50% of my supply, but this mic will suffer from vibration much less than earlier versions :)
Click to expand...

I'm guessing you're referring to a microphonics problem with the tubes? Would there be any advantage to isolating them with wires acting like springs on one end pressing the top of the tube into a rubber boot kind of like the group buy 6802T tube mounts do?
 
dgatwood said:
I'm guessing you're referring to a microphonics problem with the tubes? Would there be any advantage to isolating them with wires acting like springs on one end pressing the top of the tube into a rubber boot kind of like the group buy 6802T tube mounts do?
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The big issue with 6418 is there is no separate cathode; the filament is all there is. So any vibration in the filament goes straight to the signal. It resonates around 4kHz, so it's quite noticeable.

Sure, it's a great idea to shockmount the tube in some manner; the problem with the MSH-4 was there was no space inside the case, so the tube was touching the chassis. Therefore, only the quietest tubes could be used. With a larger case, it has better isolation, plus I have some space for dampening.
 
mshilarious said:
The big issue with 6418 is there is no separate cathode; the filament is all there is. So any vibration in the filament goes straight to the signal. It resonates around 4kHz, so it's quite noticeable.

Sure, it's a great idea to shockmount the tube in some manner; the problem with the MSH-4 was there was no space inside the case, so the tube was touching the chassis. Therefore, only the quietest tubes could be used. With a larger case, it has better isolation, plus I have some space for dampening.
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Oh. Bigger in diameter. I thought you meant length. Cool. :)
 
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