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THE AM BULLETIN BOARD => Technical Forum => Topic started by: WA1HZK on February 05, 2019, 07:14:45 PM



Title: Microphones
Post by: WA1HZK on February 05, 2019, 07:14:45 PM
Guys
I saw this on E-Bay and figured it could not be true so I of course ordered one. https://www.ebay.com/itm/322352317950
It came in today and I asked Brent, W1IA to test it for me.
He unplugged his B-1 and plugged this in and guess what? Worked Pissa and sounded better then the Berringer!
Under 30 bucks!


Title: Re: Microphones
Post by: WD4DMZ on February 05, 2019, 07:41:15 PM
Questions:

- As it is a condenser mic do you need to supply a power source?

- Do you use an impedance matching transformer?

I'd like to try one to use on AM with my Viking 2.

Rich


Title: Re: Microphones
Post by: WA1HZK on February 05, 2019, 10:57:17 PM
It does require a phantom power supply.
It's a low Z mic so it should drive a Viking just fine as the Viking is Hi Z. Maybe a series resistor once you figure out what phase works best for you.
We will be doing some more testing this week to get more opinions but so far we think it sounds great.
As far as the rest of the accessories, they look to be a copy of the B1 mic and decent quality.
For 29 bucks, how can you go wrong.
Keith Clark
WA1HZK

If your in the northeast give me a freq. and time and we will let you hear it.
wa1hzk@usa.net


Title: Re: Microphones
Post by: w8khk on February 06, 2019, 12:41:10 AM
Keith, I could not believe it either, when Brett, N2DTS announced that he had one.  I ordered a couple, one for the shack in the den, and one for the downstairs radio room. 

I was quite impressed.  I tried it with my Mackie 1202VLZ board which provides the requisite phantom power, and I was duly impressed.  It even came with the a cable with  XLR connectors.  How unusual!

The only thing I found a bit short was the boom, I would have liked a longer span, but considering the cost, the boom was a freebie.  Great deal!  Thanks for sharing!


Title: Re: Microphones
Post by: K1JJ on February 06, 2019, 12:10:02 PM
Wow.  That has got to be the best Chinese electronic deal I've ever seen.  The XLR cables OR the boom ALONE would normally cost more than $29..... never mind a good-sounding condensor mic, spit shield, shock mount, boom, pop filter, accessories, etc.   Slave labor or not, that is amazing.  And freeeee shipping. WTF.   (1850+ sold)

If I didn't already have an RE-20 and boom setup, I'd order one right now.   No excuse for anyone to run a Turner 2+2 anymore and complain about the high cost to upgrade. Would we call this  "simulated BC quality?"

(If I were a "high-priced" US mic manufacturer, I'd be very, very afraid...   :o )

T


Title: Re: Microphones
Post by: w4bfs on February 07, 2019, 05:14:49 PM
I'm in ....


Title: Re: Microphones
Post by: W2NBC on February 07, 2019, 06:08:36 PM
Excellent resource regarding "Large Diaphragm" condenser capsules:

http://recordinghacks.com/capsules/

Most manufacturers (with some "designer" brands included), use one of the listed capsules.. Chances are that other than Shure, Neumann, and some Russian and Australian models, almost all capsules are manufactured in China. This all means that other than the internal noise figures (self-generated by the mic preamplifier, and almost irrelevant on the HF bands), these Ebay specials probably sound just as good as the expensive "designer" ones.

 ;)



Title: Re: Microphones
Post by: KA0HCP on February 07, 2019, 07:47:39 PM
Too good to pass up!  Thanks for the tip.  bill


Title: Re: Microphones
Post by: W1IA on February 08, 2019, 07:19:55 PM
What a pleasant surprise! After complaining about my Bheringer B1 going south, Keith shows up with a gift. I plugged in the BM800 Chinese microphone and too my surprise it sounded Great!
It came with the boom, cables and computer USB dongle etc. The specs are the same as the B1. The element is the same gold sputtered design as the B1. For the whopping sum of $28, you too can have big Kung-Fu audio. HA!

Thanks Keith!

Brent W1IA


Title: Re: Microphones
Post by: w9jsw on February 08, 2019, 07:26:19 PM
Does the USB dongle supply phantom power?


Title: Re: Microphones
Post by: K1JJ on February 08, 2019, 08:42:26 PM
What a pleasant surprise! After complaining about my Bheringer B1 going south, Keith shows up with a gift. I plugged in the BM800 Chinese microphone and too my surprise it sounded Great!
It came with the boom, cables and computer USB dongle etc. The specs are the same as the B1. The element is the same gold sputtered design as the B1. For the whopping sum of $28, you too can have big Kung-Fu audio. HA!

Thanks Keith!
Brent W1IA


Yo Brent!

Yes, their Kung-Fu is exceptionally strong. I feel a tremor in the force.

But you'd think they could come up with a better name than "Voilamart."  What the heck is a Voilamart anyway -  a Chinese suburb of Walmart?      

I'd like to nominate the mic name as "GoldFinga."

Listen to this link while viewing the jpg below for the full effect:   ;D
https://www.youtube.com/watch?v=6D1nK7q2i8I

T


Title: Re: Microphones and phantom power
Post by: W4EWH on February 09, 2019, 06:49:25 PM
I saw this on E-Bay and figured it could not be true so I of course ordered one. https://www.ebay.com/itm/322352317950 (https://www.ebay.com/itm/322352317950)

I've ordered one too, but I have a question: the "you may also want" ads that came with the receipt included an offer for a 48 volt phantom power supply.

How much bias does this mic require to operate? TIA.

Bill, W4EWH


Title: Re: Microphones and phantom power
Post by: nq5t on February 09, 2019, 10:55:32 PM

I've ordered one too, but I have a question: the "you may also want" ads that came with the receipt included an offer for a 48 volt phantom power supply.

How much bias does this mic require to operate? TIA.

Bill, W4EWH

I assumed it would require 48v, and found a comment in the reviews of one that indicated it did require 48v phantom power.  Probably not a problem since it will likely need a preamp anyway.

I bought one, too, although I don't really need it.  But for the price ó what the heck :-)


Title: Re: Microphones
Post by: Steve - K4HX on February 10, 2019, 11:29:01 AM
Violamart! Trademarked no less. I ordered the silver version and it was a dollar less. Go figure.

https://www.ebay.com/itm/BM-800-Condenser-Microphone-Studio-Recording-Mic-W-Stand-Shock-Mount-US-NEW/264075497939?_trkparms=aid%3D555018%26algo%3DPL.SIM%26ao%3D2%26asc%3D20160323102634%26meid%3Db39033e242b1497bbeb0f185c8a834c5%26pid%3D100623%26rk%3D1%26rkt%3D6%26mehot%3Dpp%26sd%3D322352317950%26itm%3D264075497939&_trksid=p2047675.c100623.m-1

And there's a kit without the USB, thingie, $8.63!

https://www.ebay.com/itm/BM800-Audio-Vocal-Studio-Condenser-Microphone-Kit-Arm-Stand-Shock-Mount-SH/123539952993?_trkparms=aid%3D222007%26algo%3DSIM.MBE%26ao%3D1%26asc%3D20131231084308%26meid%3D52b8c486412841678977e590922742db%26pid%3D100010%26rk%3D6%26rkt%3D12%26sd%3D322352317950%26itm%3D123539952993&_trksid=p2047675.c100010.m2109

If you just want the mic, $8.88! They even have one in pink.

https://www.ebay.com/itm/Condenser-Pro-Audio-BM800-Microphone-Sound-Studio-Dynamic-Mic-Shock-Mount-KTV/153362737110?_trkparms=aid%3D888007%26algo%3DDISC.MBE%26ao%3D1%26asc%3D55675%26meid%3Dc07ea9ceacd44c98ab7fd770402e599e%26pid%3D100009%26rk%3D1%26rkt%3D1%26sd%3D322352317950%26itm%3D153362737110&_trksid=p2047675.c100009.m1982


Title: Re: Microphones
Post by: KL7OF on February 10, 2019, 11:48:18 AM
So what is the usb adaptor for?  can you plug this mic into your computer ?  does the computer supply the phantom voltage?
I have a couple of these Chinese condenser mics..different brands, both say "Bejing Audio" on the pc board inside..


Title: Re: Microphones
Post by: Steve - K4HX on February 10, 2019, 12:09:27 PM
Looks like it converts the mic input to digital and USB format and also provides an analog headphone monitor/output.


Title: Re: Microphones
Post by: nq5t on February 10, 2019, 01:33:00 PM
These things must be some really serious junk Ö someone else on eBay has the mic and shock mount for sale for $5.69 including shipping from China. ;D


Title: Re: Microphones
Post by: WA1HZK on February 10, 2019, 04:21:42 PM
The proof is the guys that bought the microphones.
And the fact that no one can tell the difference from the $100.00 B1.
And it now comes with a Kung Fu rating of 8.9 on the Mongo Scale.
Keith


Title: Re: Microphones
Post by: Steve - K4HX on February 10, 2019, 05:31:29 PM
I've been using these cheapie 1 inch diaphragm condenser mics for about 15 years. I bought one 10 years ago for about $30. As NBC posted, they all use the same diaphragm/cartridge. For amateur radio use, the cheapies are just as good as the higher priced mics.


Title: Re: Microphones
Post by: K1JJ on February 10, 2019, 05:42:42 PM
It's such a great deal it makes me wonder....

What if your country (China) was imposed tariffs and wanted to fight back? What would be an effective way that nobody could stop without drastic measures?  How about flooding the opposing market with tons of products that work well, but are many times below the cost of production?  Like the mic Steve highlighted...  $8 for a mic, shock mount and stand -  plus free shipping from China. Who is absorbing the loss, the gov't?

How could a competing US company possibly stay in business assuming the product quality is similar to theirs?

I wonder if there are other markets, electronics included, getting flooded right now?

Hey, intense competition is part of capitalism, so am I wrong to even consider this possibility?

T



Title: Re: Microphones
Post by: WA1HZK on February 10, 2019, 06:11:15 PM
Well you could be right.
And if you are, better grab these while they are there.
Because the new treaties are likely to change things.
Keith


Title: Re: Microphones
Post by: K1JJ on February 10, 2019, 06:23:21 PM
Well you could be right.
And if you are, better grab these while they are there.
Because the new treaties are likely to change things.
Keith


I think so.  We all know a great deal when we see one and this will be gone, no doubt.

This could also be a shot across the bow to show what they COULD do if they wanted.

Either way, the latest eBay says they have sold 98% of their $30 GoldFinga inventory...  assuming they don't have more in the warehouse.

"1,854 sold      More than 98% sold    Free shipping"

T



Title: Re: Microphones
Post by: KK4YY on February 10, 2019, 07:44:36 PM
Is there a great Chinese economic conspiracy to sell cheap microphones or is it just Chinese culture?

Check out "There is a Huge MORAL CRISIS in China"
https://www.youtube.com/watch?v=FfLnFVzfKBs (https://www.youtube.com/watch?v=FfLnFVzfKBs)
YouTube has 'age restricted' the video since I first saw it.
But it can also be directly viewed here:
https://www.reddit.com/r/China/comments/acx6n6/there_is_a_huge_moral_crisis_in_china/ (https://www.reddit.com/r/China/comments/acx6n6/there_is_a_huge_moral_crisis_in_china/)

More videos from this YouTuber can be seen here:
https://www.youtube.com/user/serpentza/videos (https://www.youtube.com/user/serpentza/videos)


Title: Re: Microphones
Post by: Steve - K4HX on February 10, 2019, 08:45:26 PM
Not sure who they would be putting out of business. Those buying Electro-Voices, Neumanns, AKGs and the like won't be being the Gold Finga.


Title: Re: Microphones
Post by: WA1HZK on February 10, 2019, 10:00:57 PM
Yup, just bought another for myself.
This year, small upstairs station.
:)


Title: Re: Microphones
Post by: K1JJ on February 10, 2019, 10:21:43 PM
Not sure who they would be putting out of business. Those buying Electro-Voices, Neumanns, AKGs and the like won't be [buying] the Gold Finga.

Yep, the USA mic companies building high quality, getting a fair price and paying their workers a fair wage are probably safe. But what happens when the Chinese products are eventually as good for 1/2 or 1/4 the USA price?  

Let's just say for now, if there were any US GoldFinga manufacturers, they're gone. If there were any planning to go into biz, they better can those plans. Those type of low quality product companies probably never existed in the US in the first place.

Imagine building GoldFingas in the US - the whole shebang for $30 and shipping it free.   Even a full profit of $30/ mic would probably not even pay for the typical executive and staff salaries, insurance and 401Ks never mind the endless expenses of producing and marketing.

It's like we have been taught a lesson on advanced alien business efficiency or something like that.  Imagine creatures from Uranus sending down auto-factories that auto-assemble themselves,  auto-mine the raw materials and auto-assemble the products for pennies.  They even do the eBay listings and shipping by auto-robot.  They make a $29.95 profit selling brand new Kia-Rio cars for $30 each.  Everyone in the world buys three each. I sell short Tesla, Ford and GM stock.  Then I wake up.    ;D

T


Title: Re: Microphones
Post by: WA2SQQ on February 11, 2019, 08:16:46 AM
This isn't any different than the flood of Chinese handy-talkies. How can you sell a dual band radio, and make a profit for $35? Granted, they may npt be the most spectrally pure radios, but they do work.


Title: Re: Microphones
Post by: Todd, KA1KAQ on February 11, 2019, 10:07:19 AM
How can you sell a dual band radio, and make a profit for $35?

Cheap labor.


Title: Re: Microphones
Post by: K8DI on February 11, 2019, 10:42:14 AM
First, being open/transparent:  I've spent the majority of my adult life working in professional audio, from studio to concert stage to high end commercial audio installs in churches, colleges, and theme parks.

There's a misconception here that old American companies like Shure and Electro-Voice, Crown and JBL, still have any significant US manufacturing. They don't. Shure makes almost everything in Mexico. JBL and Crown, AKG too, mostly in China. Harman, the parent of AKG/JBL/Crown/and a bunch of others, is owned by Japan's Samsung. Behringer is also made in China; they were never American.  They're part of Music Group, who own legendary audio brands Klark, TurboSound, Midas, Tannoy, and others.  

Professional Audio is Chinese already.

However, there's also a misconception that this cheap mic direct from China is anywhere near the build quality of pretty much any real microphone. It's like everything else: you get what you pay for.

FWIW, I use a Shure SM58 for my station. I can't justify the $300+ dealer cost for an SM7B when I've got a dozen  '58s in my rental PA stock to swipe from. It sounds fine, it's dynamic, RF shielded, simple, reliable, has a warranty. The Gold Finga, none of those things.

Ed Walters


Title: Re: Microphones
Post by: KD6VXI on February 11, 2019, 10:58:30 AM
I've extolled cheap chicom miles and usb professing for years here.

I used a Sony Playstation Band Hero microphone and USB interface.

I replaced the mic, as it didn't sit nicely in my cheap chicom arm


These have been around for a long time. 

Welcome to the 21st century.

--Shane
KD6VXI


Title: Re: Microphones
Post by: W1AEX on February 11, 2019, 11:16:50 AM
I've heard a few of the BM800 condenser microphones being used on the air and they do sound fine. That being said, after viewing a video showing the disassembly of two different versions of the BM800 "large condenser microphones" I had to laugh at the electret elements used in both. One had a built-in FET and the other did not, and they looked very similar to the little electret elements sold by Radio Shack and other vendors for a couple of bucks. Both microphones used the same general purpose circuit board which can be wired to support an element with a FET or one without a FET. One of the mics in the video had a 16mm element and the other was almost 10mm which is pretty far from the description as a large condenser microphone:

https://www.youtube.com/watch?v=KoGZagzhWac (https://www.youtube.com/watch?v=KoGZagzhWac)

I received an email from a guy who took his apart and then re-mounted the element so that the microphone could be used as an end-fire rather than side-addressed microphone and that seemed like a pretty good idea.

At any rate, the price makes these things a lot of fun to mess around with. I bought a black Neewer NW800 priced at 20 bucks for my own personal amusement.

Rob W1AEX


Title: Re: Microphones
Post by: WD4DMZ on February 11, 2019, 12:35:49 PM
Interesting thread. I use a Viking 2 on AM usually with a non-amp D104 and have been looking an inexpensive broadcast mike to try. After checking ebay I looked on Amazon for options. The mics in question need the phantom power supply and I found the full package for about $42. While reading the specs a $10 discount offer popped up so I ended up buying the package with the PS for about $32.

To use it on the V2 I will use a Shure matching transformer as well.

It should be here in a week and will report back on how well it functions.

Rich


Title: Re: Microphones
Post by: K1JJ on February 11, 2019, 02:54:55 PM
I wonder how Bob Heil handles the competition?  The web says he assembles Heil mics in Indiana.  It's not clear to me if these are outsourced, pre-made parts from China or is everything manufactured by Heil - or from the USA made from scratch, from raw materials?  More power to him if he is able to do it all here.  Probably one of the few left, if so.

He frequents this BB, so maybe he can drop by and tell us what's really happening out there in the world microphone market.

T


Title: Re: Microphones
Post by: W1RKW on February 11, 2019, 05:06:51 PM
Heck, if it sounds good, go with it.  Question is, how long will it last? If it last a couple of months, not so good. If it lasts several years. What the hell. Whatever floats the boat so to speak.



Title: Re: Microphones
Post by: KL7OF on February 11, 2019, 06:53:43 PM
https://microphone-parts.com/


Title: Re: Microphones
Post by: W2NBC on February 11, 2019, 07:15:43 PM
"Heck, if it sounds good, go with it."

TRUE!!

Almost all condenser mics (large capsule or not), inherently have a flat frequency response. The audible difference is mostly in the circuit boards (guts) of the microphone. That includes if it's transformer-coupled, quality of the caps, etc.. This translates to self-generated noise that is important for actual studio voice-over work in a quiet studio.

As I mentioned in an earlier post, for HF Ham use, the noise figures are almost irrelevant due to the signal to noise ratio of ANY audio introduced in the HF spectrum.

The pick-up PATTERN of a flat condenser or any wide frequency response microphone is much more important! In our ham shacks with fans blowing, transformers humming, and furnaces firing up, having JUST your voice heard at the receiving station is important.

Side-rejection, and front to back figures are the features to look for. The best way is a multi-pattern mic which basically has two capsules back to back that would introduce 3 distinct polar patterns: Figure 8, Omni, and Cardioid.

As for great sounding audio on the cheap, here is an example of a Radio Shack electret element in use from W1AEX (less than $10 total), that proves this all out:

http://www.w1aex.com/mic/mic.html

Here is Rob, W1AEX proving how a CHEAP mic can sound:


Title: Re: Microphones
Post by: WD4DMZ on February 11, 2019, 08:53:26 PM
Good circuit. I have a couple of the RS mic elements in my parts bin. Should give that a try.

What sort of impedance will my radio see? My Viking wants a hi-z so would likely need to use a matching transformer.

One old mike head I had needed an element and I used a RS condenser element. For power I simply attached a 9V rectangular battery on the plus lead and it worked just fine.

Rich


Title: Re: Microphones
Post by: KK4YY on February 11, 2019, 09:40:32 PM
With the recent interest in cheap condenser microphones I thought I would relate a problem, and the fix, with my Marshal MXL-770 microphone.

The microphone worked fine, most of the time, but would develop a pronounced hum on occasion. Fiddling with it would make it clear-up so I suspected some sort of poor/loose connection. And it took me a while to find it.

The poor connection was paint on the grounded body parts that form a shield around the electronics. Disassembling the microphone and scrapping the paint from the mating surfaces completely cured the problem.

I suspect other microphones may have a similar issue. The fix is an easy one.

Of course I wish I had done a web-search first, because I subsequently found this page:
http://www.mikeperalta.com/blog/3I2O10OA0DK4/How-to-Fix-Hum-Radio-Inteference-in-the-MXL-770-Condenser-Microphone.html (http://www.mikeperalta.com/blog/3I2O10OA0DK4/How-to-Fix-Hum-Radio-Inteference-in-the-MXL-770-Condenser-Microphone.html)


Don


Title: Re: Microphones
Post by: KD6VXI on February 12, 2019, 12:46:52 PM
The painted ground screw is so common in audio and other equipment it's always worth looking into and at.

Astron is HORRIBLE about this, with trip lite coming in a close second.

Ground screws on a painted surface with no lock or star washer to make ANY bite.

I bought a used Astron 20.  Ten ohms of resistance from ground pin to the case.

My brand new trip lite pr60 had 3 ohms.

Worth looking at.

--Shane
KD6VXI


Title: Re: Microphones
Post by: WA2SQQ on February 13, 2019, 01:19:39 PM
I received an email from a guy who took his apart and then re-mounted the element so that the microphone could be used as an end-fire rather than side-addressed microphone and that seemed like a pretty good idea.

At any rate, the price makes these things a lot of fun to mess around with. I bought a black Neewer NW800 priced at 20 bucks for my own personal amusement.

Rob W1AEX
Rob, I recall when I first discovered that Radio Shack element project on your web site. I built it and used it with my Flex 5000. It sounded very good, and it's still in use on another radio. I suspect that my PR-40 also has a Chinese made element that Bob Heil found or has manufactured for him in China, for a lot less than what the mic sells for. I judge the end result, and that's why I like my PR40 regardless of its DNA. I just got my GoldFinga mic in the mail yesterday and plan to do some A/B comparisons tonight. I also use a cellular headset I picked up in the local "dollar store". I've received many "great audio" reports while on SSB. It makes you wonder if a lot of the expensive mics are just repackaged and rebranded.


Title: Re: Microphones
Post by: WA2SQQ on February 13, 2019, 02:02:07 PM
I can see where this discussion can evolve into a lot of hacking! Interesting video discussing some simple mods to improve the noise floor. It also shows the schematic for the PCB.
https://www.youtube.com/watch?v=0lpQ0BpjUtg


Title: Re: Microphones
Post by: WD4DMZ on February 13, 2019, 04:46:49 PM
The $31 Neewer (via Amazon, not ebay, but looks to be the same thing with a different nameplate) package I ordered last Thursday arrived today. All components shown in the ad were included including all of the mounts, 2 cables, phantom PS, wind screens and flexible desk mount. First test into a dummy load sounds good on both the old Kenwood TS930 I use on AM and also on my Viking 2 using a Shure inline matching transformer.

Tomorrow I'll put it on the air to see what kind of reports it gets.

Rich


Title: Re: Microphones
Post by: WD4DMZ on February 14, 2019, 02:14:13 PM
The Neewer condenser mic package does work on my Viking 2. I used it on today's AM noontime forum on 7295 and asked for honest reports, no fudging. It gets an OK and sounds about the same as the old Shure controlled magnetic hi-z mic I usually use. It definitely looks cool and is no hands with the mounting package it came from... a definite plus.

A big improvement in audio? No.

Worth $31? Yes.

Rich


Title: Re: Microphones
Post by: K1JJ on February 14, 2019, 04:17:05 PM
The Neewer condenser mic package does work on my Viking 2. I used it on today's AM noontime forum on 7295 and asked for honest reports, no fudging. It gets an OK and sounds A big improvement in audio? No.
Worth $31? Yes.
Rich


Hi Rich -

The difference may be too subtle to hear on the air. Try a comparison between the Neewer and the Shure mic into a local hi-fi amplifier using quality stereo headphones.  Or better yet... make a good local recording to avoid bone conduction and listen in the headphones.   That may show the difference, if any.

Going into a Viking 2, over the airwaves, into a receiver - with human ears and human opinion may not show you what you want to hear...  ;)

T


Title: Re: Microphones
Post by: W1AEX on February 14, 2019, 05:06:49 PM
My 20 dollar NEEWER NW800 arrived today and I had a chance to play around with it on 75 meters this afternoon. I swapped it out with my MXL-770 condenser mic and ran it with exactly the same CFC voice processor settings in the Thetis software that runs my ANAN-200D SDR. The MP3 file below is a recording of the ANAN-200D running AM with a 12K wide transmit filter. The output level of the NEEWER is 10dB higher than the MXL-770 and it has quite a bit of roll-off on the low end but it does seem to offer pretty good clarity.

The sales pitch at Amazon indicated that this has the "new and improved" circuit board. The pictures below of the disassembled mic indicate that it looks the same as the boards I have seen on various mod pages but I suppose there might have been some component changes. I did not notice a high level of background noise which was a complaint of earlier models so perhaps they addressed that.

It should be good nerdy fun to play around with and modify. Definitely worth 20 bucks as a standby mic.

Rob W1AEX


Title: Re: Microphones
Post by: W1AEX on February 15, 2019, 11:43:03 AM
One last comment regarding the Chinese NEEWER NW800 is that the phase of this mic was opposite every other mic at my station. It was only a 3 minute job to warm up the soldering iron and open the mic up to flip the connections at the XLR connector. This morning I got decent audio reports on AM but as expected, it was noted that the low-end was lighter than the the MXL-770. The picture below shows it on the boom with the suspension mount and foam windscreen that came with the package. Not too shabby for 20 bucks!

73,

Rob W1AEX


Title: Re: Microphones
Post by: KQ6F on February 15, 2019, 01:59:43 PM
I wonder if the low-end rolloff is due to the electret or to the amplifier circuit.  Rob's circuit board appears to be different than the one shown in earlier posts and the circuit may not be the same as shown in the youtube video.  Too bad...I could run Rob's circuit through LTSpice if I had the schematic...

Rod


Title: Re: Microphones and phantom power
Post by: W4EWH on February 28, 2019, 02:26:57 PM
I saw this on E-Bay and figured it could not be true so I of course ordered one. https://www.ebay.com/itm/322352317950 (https://www.ebay.com/itm/322352317950)

I've ordered one too, but I have a question: the "you may also want" ads that came with the receipt included an offer for a 48 volt phantom power supply.

How much bias does this mic require to operate? TIA.

Bill, W4EWH

My kit just arrived, but the 48v power supply I ordered is a week or two away. If you've been able to run the mic directly from the input of an Icom rig, or with a lowered bias voltage, please tell me how it worked and how you set it up. TIA.

73,

W4EWH


Title: Re: Microphones
Post by: WA2SQQ on March 02, 2019, 06:34:14 PM
Has anyone ever considered that these well known microphone manufacturers are also buying from China? Their ideas, made in China - itís known as an ODM product.


Title: Re: Microphones and phantom power
Post by: W4EWH on March 02, 2019, 11:16:41 PM
I saw this on E-Bay and figured it could not be true so I of course ordered one. https://www.ebay.com/itm/322352317950 (https://www.ebay.com/itm/322352317950)

I've ordered one too, but I have a question: the "you may also want" ads that came with the receipt included an offer for a 48 volt phantom power supply.

How much bias does this mic require to operate? TIA.

Bill, W4EWH

I put my kit together today, and have this report:

  • There wasn't much output: less than half of what I get from my USB headset that I use for Skype and Hangouts.
  • The mic appear to be unidirectional. I tried speaking into the "front," the "back," and the "top," and I couldn't see any difference on the PC sound meter, nor hear any change in level when I rotated it while speaking. The usual caveats apply.
  • The mic works fine with the USB dongle provided, and when plugged directly into the red jack on the computer sound card.
  • The power supply also arrived, and it does indeed put out 47.5 volts. It comes with a robust wall-wart rated at 18V AC. I don't know why such a high voltage was used, given that the mic works fine with the 2.8 volts my sound card provides for bias.

So, i'm wondering if it's actually a condenser mic, or just a dynamic one with a preamp. FWIW I agree with other opinions: counting the accessories, it's a good deal.

W4EWH


Title: Re: Microphones
Post by: MikeKE0ZUinkcmo on March 03, 2019, 04:10:19 PM
Mine arrived  a couple days ago.   Looks pretty good for thirty something bucks.   Haven't fired it up yet because I've got to come up with 48 Volts for the mic, and isolate the DC from the Mic amp.

Although I'm certainly impressed with the usual extremely detailed "installation instructions", I have to admit their English is much better than my Mandarin, or Cantonese, as the case may be.   


Title: Re: Microphones
Post by: ka8gef on March 11, 2019, 09:47:26 PM

I bought one a few years ago, ran it into a Behringer Xenyx 1280 (48 phantom power and audio tailoring), through an inline impedance transformer, into a DX-100.

Within 5 minutes, I forgot all about the pile of D-104 heads that I have, each one with a degraded crystal cartridge and no hope in sight...

ka8gef



Title: Re: Microphones
Post by: W4EWH on March 12, 2019, 07:43:46 PM

... I forgot all about the pile of D-104 heads that I have, each one with a degraded crystal cartridge and no hope in sight...

ka8gef


Why no hope? Are there no replacements to be found?

Bill, who has a few D-104's himself


Title: Re: Microphones
Post by: KA0HCP on March 12, 2019, 08:35:08 PM

... I forgot all about the pile of D-104 heads that I have, each one with a degraded crystal cartridge and no hope in sight...

ka8gef


Why no hope? Are there no replacements to be found?

Bill, who has a few D-104's himself
A major manufacturer of crystal elements in Japan was closed by the tsunami disaster.


Title: Re: Microphones
Post by: W4EWH on March 13, 2019, 05:04:44 PM

... I forgot all about the pile of D-104 heads that I have, each one with a degraded crystal cartridge and no hope in sight...

ka8gef


Why no hope? Are there no replacements to be found?

Bill, who has a few D-104's himself

A major manufacturer of crystal elements in Japan was closed by the tsunami disaster.


Sorry to hear it. I know another ham who is looking for one: he says they're very popular with Blues harmonica players, but that he couldn't find any elements. He said he's going to try using a phonograph pickup with the diaphram glued to the needle, but I haven't heard if that did work.

This might be a chance for a cottage industry: does anyone on here know how to make these?

73,

Bill, W4EWH



Title: Re: Microphones
Post by: WD4DMZ on March 13, 2019, 05:48:13 PM
Kobitone used to make a hi-z crystal element. I used the one I had in my drawer to replace a bad D104 element on an amp stand and it works pretty well. It is a 25,000 ohm element and sounds similar to an original D104 I use regularly.  Also used one in an old hand mic to partner with my Collins KWM 2A and it works well.

When I went to the Mouser site to buy a few more they were gone. Too bad as they were very inexpensive. Kobitone must have been the last producer of hi-z crystal elements.

Rich


Title: Re: Microphones
Post by: ka8gef on March 14, 2019, 09:08:35 AM
I wish I could find a few (the Astatic crystal cartridge part number was  MC-320) that still deliver the response as designed. The rochelle salt crystal deteriorates and typically low end response disappears as a result. All of my crystal D-104 mic heads suffer from this.

The Kobitone does not come close to the performance of an Astatic MC-320. During the time it was available, it was the only choice as a replacement.

...regarding a properly functioning D-104 head/MC-320 element, of course you can take your chances with e-bay or the guy at the hamfest who claims 'it sounded fine the last time I used it'...no thanks.

I spent a reasonable amount of time going through the Astatic patent docs. Frankly, there is not enough information to warrant effective experimentation and results, without finding/employing someone who has significant expertise with the crystal development, shaping etc.

Still hoping...

ka8gef

AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands