Taperssection.com
Gear / Technical Help => Microphones & Setup => Topic started by: afri-cola-man on June 24, 2007, 10:19:17 AM
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If you can't run an open rig and size of gear is an issue, the Greenmachine GM standard Microphones are worth consideration. Greenmachine web site is here (no affiliation whatsoever/ sorry only in german): http://www.geocities.com/greenmachine_audio/de-mic.html (http://www.geocities.com/greenmachine_audio/de-mic.html)
Specs given: range 20 - 20.000 khz, pressure up to 115 dB, mic diameter 7 mm
Greenmachine also offers a battery-pack. I hooked it up with the iRiver 120 and it makes a really nice combo. The batt-pack is velcroed to the back of the iRiver and can easily be stored in a shirt pocket for example. Fix the mics whereever you like, but be careful of shock transfer.
A mp3 sample (Taj Mahal Trio - Sanzibar - 2007-06-17 [gm >gm bb > iriver120rb] is here: http://www.mp-acm.de/greenmachine_2007-06-17/mahal_taj_2007-06-17_sanzibar_greenmachine.mp3 (http://www.mp-acm.de/greenmachine_2007-06-17/mahal_taj_2007-06-17_sanzibar_greenmachine.mp3)
I posted two complete shows recorded with the Greenmachines at etree. Please note that the volume at the shows was extremely loud and the bass was massive (shirt wavered from sound pressure). For these conditions the little gadgets did extremely well, imo. [My Church-Audio cards were too large to bring into the venue ...]
Honeytribe, Cologne - 2007-06-10: http://bt.etree.org/details.php?id=507383 (http://bt.etree.org/details.php?id=507383)
Gov't Mule - 2007-06-10 http://bt.etree.org/details.php?id=507363 (http://bt.etree.org/details.php?id=507363)
And here 2 pictures of the mics, batt-pack and the piggy-back-iRiver-combo:
(http://www.mp-acm.de/greenmachine_2007-06-17/greenmachine_2007-06-21_015.jpg)
(http://www.mp-acm.de/greenmachine_2007-06-17/greenmachine_2007-06-21_024.jpg)
Cheers from a hot Germany
Ulrich
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For those of you with a mind to, here is the link to greenmachines step by step instructions for building these mics and battery boxes:
http://forums.minidisc.org/index.php?showtopic=11254
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wow those dont sound bad at all!
but isnt the Panasonic WM61A - cards?
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wow those dont sound bad at all!
but isnt the Panasonic WM61A - cards?
They are omni and when you do my 4.7k mod to them look out :) they sound great.. Thats a good capsule still available at digikey... I cut the trace between the ground and the negative pad then solder a 4.7k 1/8th watt resistor I then connect the output to the + terminal and the ground to the case side of the resistor you have a reduction in distortion from 1.5% @ 114db to just under 0.3% @ 114db @ 1k.
The key to my mod is making sure the resistors you use are exactly 4.7k.. if they are not your distortion figures will suffer.. I also make sure both capsules are matched at 1k. for output and distortion then I measure the resistors and match them.. After all that's done you have a well matched set of mics with high spl handling good frequency response.. I then coat the back of the capsule in epoxy because any air leak in the back of the capsule will cause low end distortion to increase. After that I heat shrink the capsule wires to the back of the capsule, then I use a copper foil tape to sheild them then I put the mics in a brass tube and fill that with epoxy and heat shrink over that. You then end up with a very nice looking mic that will handle all kinds of abuse.. Just heat shrinking the capsule alone does not decrease the noise floor you must have good shielding at the back of the capsule imo...If you really want to sheild the capsule well I also use a fine brass mesh screen over the front of the capsule this further eliminates inducted RF and EMI from getting into the capsule...
Chris
PS... I am not trying to sell anything here this is simply just how I make a omni panasonic mic...
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I made my DIY mics and BB following those greenmachine instructions. I cut up a bic
pen for the housing, next time I'm trying some 9mm brass casing.
of course, when I get my act together, I'm buying Chris's stuff.
Fine Brass screen? you mean like those found with some smoking pipes?
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wow those dont sound bad at all!
but isnt the Panasonic WM61A - cards?
They are omni and when you do my 4.7k mod to them look out :) they sound great.. Thats a good capsule still available at digikey... I cut the trace between the ground and the negative pad then solder a 4.7k 1/8th watt resistor I then connect the output to the + terminal and the ground to the case side of the resistor you have a reduction in distortion from 1.5% @ 114db to just under 0.3% @ 114db @ 1k.
The key to my mod is making sure the resistors you use are exactly 4.7k.. if they are not your distortion figures will suffer.. I also make sure both capsules are matched at 1k. for output and distortion then I measure the resistors and match them.. After all that's done you have a well matched set of mics with high spl handling good frequency response.. I then coat the back of the capsule in epoxy because any air leak in the back of the capsule will cause low end distortion to increase. After that I heat shrink the capsule wires to the back of the capsule, then I use a copper foil tape to sheild them then I put the mics in a brass tube and fill that with epoxy and heat shrink over that. You then end up with a very nice looking mic that will handle all kinds of abuse.. Just heat shrinking the capsule alone does not decrease the noise floor you must have good shielding at the back of the capsule imo...If you really want to sheild the capsule well I also use a fine brass mesh screen over the front of the capsule this further eliminates inducted RF and EMI from getting into the capsule...
Chris
PS... I am not trying to sell anything here this is simply just how I make a omni panasonic mic...
Chris - Unless Bruce Bartlett had a time machine to zoom forward to learn your mod and then zoom back to 1998 in time to get it in his book, Practical Recording Techniques it is not your mod. It sure looks like your mod.
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wow those dont sound bad at all!
but isnt the Panasonic WM61A - cards?
They are omni and when you do my 4.7k mod to them look out :) they sound great.. Thats a good capsule still available at digikey... I cut the trace between the ground and the negative pad then solder a 4.7k 1/8th watt resistor I then connect the output to the + terminal and the ground to the case side of the resistor you have a reduction in distortion from 1.5% @ 114db to just under 0.3% @ 114db @ 1k.
The key to my mod is making sure the resistors you use are exactly 4.7k.. if they are not your distortion figures will suffer.. I also make sure both capsules are matched at 1k. for output and distortion then I measure the resistors and match them.. After all that's done you have a well matched set of mics with high spl handling good frequency response.. I then coat the back of the capsule in epoxy because any air leak in the back of the capsule will cause low end distortion to increase. After that I heat shrink the capsule wires to the back of the capsule, then I use a copper foil tape to sheild them then I put the mics in a brass tube and fill that with epoxy and heat shrink over that. You then end up with a very nice looking mic that will handle all kinds of abuse.. Just heat shrinking the capsule alone does not decrease the noise floor you must have good shielding at the back of the capsule imo...If you really want to sheild the capsule well I also use a fine brass mesh screen over the front of the capsule this further eliminates inducted RF and EMI from getting into the capsule...
Chris
PS... I am not trying to sell anything here this is simply just how I make a omni panasonic mic...
Chris - Unless Bruce Bartlett had a time machine to zoom forward to learn your mod and then zoom back to 1998 in time to get it in his book, Practical Recording Techniques it is not your mod. It sure looks like your mod.
Um this is where "a little" knowledge is dangerous... this is not my mod actually this is a modification for a mic pad.. I guess your trying to say I did not come up with my 4.7k mod? lol... Well I did... this is not it..
See where it says the word PAD -12 DB.... this is a simple resistive pad.. That's not what my mod is... actually so I guess Bruce did not have to travel in the time machine after all... ::) I dont understand why some people such as your self are so hell bent on trying to discredit me. Strange does it have to do with the fact that I would not sell you any of my gear since you were so rude to me? I wonder.....
Chris.....
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I made my DIY mics and BB following those greenmachine instructions. I cut up a bic
pen for the housing, next time I'm trying some 9mm brass casing.
of course, when I get my act together, I'm buying Chris's stuff.
Fine Brass screen? you mean like those found with some smoking pipes?
The brass screen I am talking about is much finer then the pipe screen its made by a company called K&S Engineering.. Out of Chicago.
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It's not the same mod. Chris is disconnecting the ground connection from the internal FET amp (inside the mic capsule) and placing a 4.7k resistor between the FET amp and ground. What you have shown is just a signal attenuator that provides enough resistive isolation that you can (usually) connect balanced and unbalanced equipment without a transformer. The only thing similar between the two circuits is the resistor value, 4.7k.
wow those dont sound bad at all!
but isnt the Panasonic WM61A - cards?
They are omni and when you do my 4.7k mod to them look out :) they sound great.. Thats a good capsule still available at digikey... I cut the trace between the ground and the negative pad then solder a 4.7k 1/8th watt resistor I then connect the output to the + terminal and the ground to the case side of the resistor you have a reduction in distortion from 1.5% @ 114db to just under 0.3% @ 114db @ 1k.
The key to my mod is making sure the resistors you use are exactly 4.7k.. if they are not your distortion figures will suffer.. I also make sure both capsules are matched at 1k. for output and distortion then I measure the resistors and match them.. After all that's done you have a well matched set of mics with high spl handling good frequency response.. I then coat the back of the capsule in epoxy because any air leak in the back of the capsule will cause low end distortion to increase. After that I heat shrink the capsule wires to the back of the capsule, then I use a copper foil tape to sheild them then I put the mics in a brass tube and fill that with epoxy and heat shrink over that. You then end up with a very nice looking mic that will handle all kinds of abuse.. Just heat shrinking the capsule alone does not decrease the noise floor you must have good shielding at the back of the capsule imo...If you really want to sheild the capsule well I also use a fine brass mesh screen over the front of the capsule this further eliminates inducted RF and EMI from getting into the capsule...
Chris
PS... I am not trying to sell anything here this is simply just how I make a omni panasonic mic...
Chris - Unless Bruce Bartlett had a time machine to zoom forward to learn your mod and then zoom back to 1998 in time to get it in his book, Practical Recording Techniques it is not your mod. It sure looks like your mod.
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Brothers!
Where is this thread going to?
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Brothers!
Where is this thread going to?
Actually I was just trying to help some people out here at T.S with some "inside" info on how I do things.. The greenmachine DIY method would work if you wanted to build some mics that worked "ok" but if you want to build something that will really handle the high SPL my method has been tested and proven.. And I wanted to simply share it.. But one of the users in this forum has seen fit to call me out on my 4.7k mod... and the simple truth of the matter is this user has a "hidden agenda" so that's all carry on..
Chris
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Brothers!
Where is this thread going to?
Actually I was just trying to help some people out here at T.S with some "inside" info on how I do things.. The greenmachine DIY method would work if you wanted to build some mics that worked "ok" but if you want to build something that will really handle the high SPL my method has been tested and proven.. And I wanted to simply share it.. But one of the users in this forum has seen fit to call me out on my 4.7k mod... and the simple truth of the matter is this user has a "hidden agenda" so that's all carry on..
Chris
no problem..that user got *pawned*
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Brothers!
Where is this thread going to?
Actually I was just trying to help some people out here at T.S with some "inside" info on how I do things.. The greenmachine DIY method would work if you wanted to build some mics that worked "ok" but if you want to build something that will really handle the high SPL my method has been tested and proven.. And I wanted to simply share it.. But one of the users in this forum has seen fit to call me out on my 4.7k mod... and the simple truth of the matter is this user has a "hidden agenda" so that's all carry on..
Chris
no problem..that user got *pawned*
How much did we get for him :P
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Brothers!
Where is this thread going to?
Actually I was just trying to help some people out here at T.S with some "inside" info on how I do things.. The greenmachine DIY method would work if you wanted to build some mics that worked "ok" but if you want to build something that will really handle the high SPL my method has been tested and proven.. And I wanted to simply share it.. But one of the users in this forum has seen fit to call me out on my 4.7k mod... and the simple truth of the matter is this user has a "hidden agenda" so that's all carry on..
Chris
Chris --
Just what is my hidden agenda??? And how can you claim credit for something which is in the public domain?
Ad hominum attacks (aqainst the person) happen when there is no way to defend yourself against the question. Again, how can you claim credit, and you do it often, for something in the public domain? If you charge me with something you better be ready to back it up. 8)
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boojum, can you build the mics and audio equipment Chris does? I don't have to say anything about the stuff he makes. There are TONS of recordings out there that show the quality of his product. If you cna do what he does you have a right to argue. If you can't you have no say in anything.
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Brothers!
Where is this thread going to?
Actually I was just trying to help some people out here at T.S with some "inside" info on how I do things.. The greenmachine DIY method would work if you wanted to build some mics that worked "ok" but if you want to build something that will really handle the high SPL my method has been tested and proven.. And I wanted to simply share it.. But one of the users in this forum has seen fit to call me out on my 4.7k mod... and the simple truth of the matter is this user has a "hidden agenda" so that's all carry on..
Chris
Chris --
Just what is my hidden agenda??? And how can you claim credit for something which is in the public domain?
Ad hominum attacks (aqainst the person) happen when there is no way to defend yourself against the question. Again, how can you claim credit, and you do it often, for something in the public domain? If you charge me with something you better be ready to back it up. 8)
Its public f'ing domain because I MADE IT SO.... actually.. Because I am the one that thought of it, and I am the one that came up with the idea. In the first place. Other then that I guess I dont have any rights.. Your hidden agenda is plain as the nose on your face. You got rejected from me because you were very rude. You asked if I had a return policy if you "did not like the mics" I said NO, Your not shopping at Walmart here these are HANDMADE items, I dont take off the shelf gear and repackage it. Out of all the 4,000 + customers I have had in the last 3 years 0 of them have ever asked for the money back on a product I have built. Your exact response was "I must have something to hide" as if my products must be shit or something how did you expect me to treat you when you insult me?.. Look at the 1000's of users I have ask them what they think dont ask me.. lol. I told you to take a walk because you were a condescending rude ass.. Plain and simple, When you get to own your own company you can get to decide who gets to own your gear and who does not. You do have a hidden agenda. You are 100% incorrect in assuming I did not come up with this, you know nothing about electronics.. And yet you insist on challenging me on a subject you actually know nothing about?
I guess your just trying to make me look bad that's ok. I think your the one that is starting to look bad here.. I have done nothing wrong I have done more then most vendors have done simply by disclosing what I do to my microphones to get them to handle the high spl that they handle. I did not read up on the Internet on how to do it. I invented it...
Say what you will but in this case your dead wrong.
PS... any one can look things up on the Internet and say hey this has a 4.7k resistor it must be the same mod Chris Church does! lol..
Here's a tip before you go digging up things on the Internet, schematics and such maybe you should learn how to read them? It helps to strengthen your argument when you actually know what the hell your talking about..
Chris
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Ad hominum attacks (aqainst the person) happen when there is no way to defend yourself against the question. Again, how can you claim credit for something which is in the public domain?
Again, how can you claim credit, and you do it often, for something in the public domain?
Dude, it's only in the public domain because Chris put it there. Have you seen it somewhere else? That other thing you posted isn't even close to the same thing. If you're going to attack someone, be prepared to back it up with relevant facts.
And by the way, if you're going to boldly use Latin, at least spell it right. (It's ad hominem (http://en.wiktionary.org/wiki/Ad_hominem) and it's more effective if you use the correct spelling.)
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I would just like to thank Chris Church for everything he has given to this community. He makes exceptional products and sells them at very reasonable prices. He very well could of kept his 4.7k resistor mod in the dark. He is also telling everyone how he manufactures one of his products, not many businesses do that.
Thank you.
Now back to the topic, I have heard many recordings made in the sweet spot with the "stock" panasonic capsules and they have turned out terrific. I've also listened to Chris's mics in a loud environment and they definitely hold their ground when comparing to mics that cost hundreds more.
This is just my opinion, my ears are still young.
-trenton
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Just a quick note to say thanks to Chris for contributing a little more hard earned knowledge to the group..... and for what? Oh , goodwill.
Joe Holland
By the the way, Does any one have any firsthand knowledge about th Transound replacement for the Pana 60 capsule?
http://www.jlielectronics.com/transsound/electrets/ts-60a.htm
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Just a quick note to say thanks to Chris for contributing a little more hard earned knowledge to the group..... and for what? Oh , goodwill.
Joe Holland
By the the way, Does any one have any firsthand knowledge about th Transound replacement for the Pana 60 capsule?
http://www.jlielectronics.com/transsound/electrets/ts-60a.htm
I have used them both I like the TS-62 and TS-60 both are good choices and both will work very well the TS-62 Can handle very high spl unmodded! I am talking very similar performance to my 4.7k mod.. I also think the TS-60 is very easy to mod with my 4.7k mod just cut the traces and solder to the resistor across the "happy face" and the ground pad :) you will see the happy face when you get the capsule in your hand.. :)
Chris
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Chris don't let the ramblings of someone distract you from what you are doing on this board. You are a very valuable source for all of us. I learned a long time ago when you argue, do it from a point of strength ie: know what your talking about before you open your mouth, if you don't shut up and listen. Appearntly some have yet to learn this fact. I find the knowledge you have to be refreshing and wanting me to learn more....And to have fun while doing it.
Its like being king of the hill, everyone wants to try and take a swat and knock you off. Again don't let it get you down. Those of us who have been around the board for a while know the truth and will back you up 100%...................
Now back to the fun stuff....( insert thread hijack) Where is that preamp your building? its almost july and please no pictures of wires with duct tape..LOL...eager minds want to know and SEE!
Keep up the excellent work...OTheroneK
Oh yeah I almost forgot T+
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Mr Church, you are a good dude.
I have actually looked at every single article on the internet regarding 4.7k and audio circuits. You are indeed the first person documented using this mod. This boojum dude is oviously has some personal bias against you.
I understand why you are pissed at Sound Pros for not giving you credit. I know about how that all went down, and they didn't intend to steal your thunder....
take care dude!
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Chris... i'll back you up even though you laid into me for ripping on coresounds...
you mod is indeed unique. The diagram pictured is in no way your mod, it merely uses a 4.7k resistor.
I cannot verify your mod was published somewhere unofficial, say a micdiyer forum, however your intense defense leads me to believe you are not lying that you invented it. If you didn't, you've just opened the flood gates.
You make a good product at a great price. Keep up the good work.
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The truth need only be spoken quietly. It need not be shouted. It defends itself. 8)
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The truth need only be spoken quietly. It need not be shouted. It defends itself. 8)
You have made a mistake here be a man and say you made a mistake. I will be a gentleman and accept your apology and we can move on..
Chris
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When Matsushita put the caps out they also put out an application whitepaper which described uses and model circuits.
The rest is a bit of trial and error and/or an understanding of the application and its design and customizing it to your particular use.
Those inclined to experiment probably should.
Those who want a finished product should see Chris or the other vendors who put the pieces together and make it work.
Its what make this system great, we have choices.
Peace
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The truth need only be spoken quietly. It need not be shouted. It defends itself. 8)
You have made a mistake here be a man and say you made a mistake. I will be a gentleman and accept your apology and we can move on..
Chris
Chris - this is quite different from what you sent me in a private note. Post what you sent me. 8)
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Chris - this is quite different from what you sent me in a private note. Post what you sent me. 8)
Heck with that. Chris, post the email that boojum sent to you. (Did it have any misspelled Latin phrases? Come on. Spill.)
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Chris, on second thought, let it drop. We all know that boojum is just pissed because you wouldn't agree to let him return your mics if he didn't like them. If he'd been paying attention, he could have taken advantage of the set that you had in the loaner program.
And boojum, quit being such a whiner. I want to be able to like all of the other members of team old farts and you are really making it hard for me to do so. Act your age. Chris is not your local WalMart. He's delivering a hand-built product that has a good reputation. If he sells something to you, his only obligation is to deliver a working product. The fact is that he goes well beyond that with after-the-sale support that is not offered by any of the other merchants on here that sell mics. He shouldn't have to agree to a no-questions-asked return policy and if that's what you require in a merchant, then buy your mics at WalMart. Or Best Buy. And again, act your age. You're embarrassing the rest of us that have been around the sun more than 50 times.
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The truth need only be spoken quietly. It need not be shouted. It defends itself. 8)
You have made a mistake here be a man and say you made a mistake. I will be a gentleman and accept your apology and we can move on..
Chris
Chris - this is quite different from what you sent me in a private note. Post what you sent me. 8)
Humm the part where I said you could "suck me" after you made a threat to basically contact ebay and report me and publish my emails here in an attempt you get me to be quiet? that email??
Lets drop this.. you have made your point you are a no-mind.. Lets move on now shall we? and for God sakes use spell check its saved me plenty of times.. When your spelling is correct your threats seem to have more weight behind them.. And better serves your intimidation tactics.
I did extend the olive branch here, but I can see I am not dealing with a 67 year old man but a 67 year old baby.
So stick that pacifier in your mouth or find me the article that has my 4.7k mod on it with someone else's name attached. Ether way you can stop emailing me, and forget about a Christmas card this year! 8)
Chris
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WAIT JUST ONE MINUTE! Off the Christmas card list.... Better think carefully here.
Some people are beyond reason, though. By the way, Canada Post sent me some email, Thanks Chris.
Joe
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Chris, when someone steps over the line into that space of public discredit, squash him/her.
your god given right to do so.
spare no one.
g
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and please no pictures of wires with duct tape..LOL...eager minds want to know and SEE!
If you go to the Greenmachine website (link is in my original post) you can find a zillion pix of the batt-pack without tape. I wanted to show you how the 'mini-rig' looked like, when I take it out in the field. ;)
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They are omni and when you do my 4.7k mod to them look out :) they sound great.. Thats a good capsule still available at digikey... I cut the trace between the ground and the negative pad then solder a 4.7k 1/8th watt resistor I then connect the output to the + terminal and the ground to the case side of the resistor you have a reduction in distortion from 1.5% @ 114db to just under 0.3% @ 114db @ 1k.
The key to my mod is making sure the resistors you use are exactly 4.7k.. if they are not your distortion figures will suffer.. I also make sure both capsules are matched at 1k. for output and distortion then I measure the resistors and match them.. After all that's done you have a well matched set of mics with high spl handling good frequency response.. I then coat the back of the capsule in epoxy because any air leak in the back of the capsule will cause low end distortion to increase. After that I heat shrink the capsule wires to the back of the capsule, then I use a copper foil tape to sheild them then I put the mics in a brass tube and fill that with epoxy and heat shrink over that. You then end up with a very nice looking mic that will handle all kinds of abuse.. Just heat shrinking the capsule alone does not decrease the noise floor you must have good shielding at the back of the capsule imo...If you really want to sheild the capsule well I also use a fine brass mesh screen over the front of the capsule this further eliminates inducted RF and EMI from getting into the capsule...
Chris
PS... I am not trying to sell anything here this is simply just how I make a omni panasonic mic...
Is this what you are doing? http://sound.westhost.com/p93-f8.gif Seems that the output impedance gets very high.
Roger Gustavsson
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They are omni and when you do my 4.7k mod to them look out :) they sound great.. Thats a good capsule still available at digikey... I cut the trace between the ground and the negative pad then solder a 4.7k 1/8th watt resistor I then connect the output to the + terminal and the ground to the case side of the resistor you have a reduction in distortion from 1.5% @ 114db to just under 0.3% @ 114db @ 1k.
The key to my mod is making sure the resistors you use are exactly 4.7k.. if they are not your distortion figures will suffer.. I also make sure both capsules are matched at 1k. for output and distortion then I measure the resistors and match them.. After all that's done you have a well matched set of mics with high spl handling good frequency response.. I then coat the back of the capsule in epoxy because any air leak in the back of the capsule will cause low end distortion to increase. After that I heat shrink the capsule wires to the back of the capsule, then I use a copper foil tape to sheild them then I put the mics in a brass tube and fill that with epoxy and heat shrink over that. You then end up with a very nice looking mic that will handle all kinds of abuse.. Just heat shrinking the capsule alone does not decrease the noise floor you must have good shielding at the back of the capsule imo...If you really want to sheild the capsule well I also use a fine brass mesh screen over the front of the capsule this further eliminates inducted RF and EMI from getting into the capsule...
Chris
PS... I am not trying to sell anything here this is simply just how I make a omni panasonic mic...
Is this what you are doing? http://sound.westhost.com/p93-f8.gif Seems that the output impedance gets very high.
Roger Gustavsson
No thats not it....
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I posted that one too Roger - not it - explained in another thread...
And for the record - I wasnt trying to participate in discrediting Chris - but I have been reading about DIY mics since the USENET days and the 4.7 mod rang a few bells - I thought back to the Linkwitz mod as well...
Not it...
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I posted that one too Roger - not it - explained in another thread...
And for the record - I wasnt trying to participate in discrediting Chris - but I have been reading about DIY mics since the USENET days and the 4.7 mod rang a few bells - I thought back to the Linkwitz mod as well...
Not it...
YES YOU ARE! :P
Just kidding :) How did the EV lavs work out??
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Here's the link to Chris comparing his mod to Linkwitz...the devil is in the details...
http://taperssection.com/index.php/topic,85208.msg1145083.html#msg1145083
The EVs lavs worked OK - but I used a shitty DAT deck for the show that had drop outs here and there - so I need to try again - plus it was piano music...I need some loud rock and roll to test those babies out!
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Here's a funny story - I once made a set of mics to stealth with - tried them out at the HORDE tour in 94-95?
I must have used some info similar to the Linkwitz mod - but didn't pay attention as carefully as should...
I had the capsules and some 9V batteries - went to Radio Shack and bought two of these...
(http://www.allproducts.com/ee/lingin/04-electrolytic_capacitor.jpg)
Yeah - they worked - but super bassy...
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Here's a funny story - I once made a set of mics to stealth with - tried them out at the HORDE tour in 94-95?
I must have used some info similar to the Linkwitz mod - but didn't pay attention as carefully as should...
I had the capsules and some 9V batteries - went to Radio Shack and bought two of these...
(http://www.allproducts.com/ee/lingin/04-electrolytic_capacitor.jpg)
Yeah - they worked - but super bassy...
That's a lot of storage 250 volts :) I think that 4.7uf is good for cardioid mics but for Omni mics 1uf or 2.2uf is a better choice for a coupling cap. And besides these caps are huge :)
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Here's a funny story - I once made a set of mics to stealth with - tried them out at the HORDE tour in 94-95?
I must have used some info similar to the Linkwitz mod - but didn't pay attention as carefully as should...
I had the capsules and some 9V batteries - went to Radio Shack and bought two of these...
(http://www.allproducts.com/ee/lingin/04-electrolytic_capacitor.jpg)
Yeah - they worked - but super bassy...
well - not those exactly - whatever Radio Shack would have - I thought I had just exchanged the words "resistor" and "capacitor" - but maybe I did follow the directions - Whats a coupling cap do?
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Here's a funny story - I once made a set of mics to stealth with - tried them out at the HORDE tour in 94-95?
I must have used some info similar to the Linkwitz mod - but didn't pay attention as carefully as should...
I had the capsules and some 9V batteries - went to Radio Shack and bought two of these...
(http://www.allproducts.com/ee/lingin/04-electrolytic_capacitor.jpg)
Yeah - they worked - but super bassy...
well - not those exactly - whatever Radio Shack would have - I thought I had just exchanged the words "resistor" and "capacitor" - but maybe I did follow the directions - Whats a coupling cap do?
Its the cap that blocks the dc voltage the capsule operates on and allows just the signal out of the capsule to connect to the next stage with out passing DC :) So the value of the coupling cap is important. if its too low of a value it will reduce bass if its too hi it will allow to much to pass...
it sounds like what you created was a low pass filter :) on the output of your mic :) lopping off all the top end :)
Chris
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it sounds like what you created was a low pass filter on the output of your mic lopping off all the top end
Well that sure is what it sounded like!!! No amount of Eq could tame the bass!
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Seems that the output impedance gets very high.
Roger Gustavsson
In fact on the Linkwitz site, he has posted a following opamp-based circuit that buffers and balances the capsule output. That is less of a concern with relatively high input impedance portable recorders. I believe there is also merit in operating the capsule in common drain rather than source, but it is less convenient with low-voltage 2-wire configurations.
Regards
Jon
But again what I do is not the linkwitz mod..
Chris
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I have not seen your schematic, but I think this may be correct based upon your description. If so, I believe has the same impedance as the linkwitz capsule.
That schematic is correct.
Chris
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chris: whats the best resistor to use in a DIY batt box for use with the 4.7k mod mics?
thanks for all the knowledge! :D
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chris: whats the best resistor to use in a DIY batt box for use with the 4.7k mod mics?
thanks for all the knowledge! :D
According to Spark'e a 4.7k but when I did the distortion tests originally I was using a 10k I will do some tests this week and show you guys the difference between the two..
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WM61A seems to like to draw 0.4mA or so, so 10k would drop 4V. Also in theory that would create gain in common source configuration. I did that in one circuit, and if I recall distortion can be worse as you increase the drain resistor too high (too high being 15 or 22k). Again it depends on the voltage supply; I was doing that with regulated 12V, 9V would probably be OK, until the battery started to drop. Maybe 6k8 would be reasonable, but 10k is worth a try. It will be interesting to hear Chris' results.
For anybody using a recorder with a balanced input, one benefit of using 4k7 is you can create a balanced output with a 3-wire configuration.
All I did was simply measure the distortion at 1k at 114db and changed the value of the resistor until I got the least amount of distortion.. There was no math involved or theories :) Just me changing a resistor until it worked.. It came about because I ordered my capsules I use for my cardioid mics sight unseen :) I did some tests and I started to freak out... The distortion was hideous.. I though there is no way I can sell my mics with such poor performance so I just started changing resistors until I got what I wanted.. Then all was good :) I will do the tests with 6.8 and 10k and 4.7 and a few other values if anyone can suggest any other values. and I will post the results with graphs.
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I thought we were talking about the battery box supply resistor ??? I would concur with 4k7 for WM61A source resistor.
Sorry! I was talking about how I came to choose the 4.7k... I was using a 10k when I tested the 4.7k lol if that makes any sense.. So I will do some tests with different bias resistors.
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very interesting thread indeed, thank's a lot Chris for sharing your knowledge, T+!
though I am curious of your resistor/distortion finds, I have two somewhat other questions:
1: how does the Panasonic WM55 capsule compare to the WM61 resp. the mentioned TS60 and TS62 ( WM55 I can gethands on easily here, the others not )
2: what exactly means 'heat shrinking'?
thank's a lot for any input to clarify,
kuuan
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1: how does the Panasonic WM55 capsule compare to the WM61 resp
That's actually a good question. I noticed those while browsing around DigiKey, and they look pretty decent on paper (20Hz-16kHz response), though the capsules are almost 10mm across. I'll probably buy a few in my next order.
I found this, which has a sample that sounds very good.
http://www.mp3forkidz.com/mic/phantxy.html
2: what exactly means 'heat shrinking'?
Heat shrink tubing. Special kind of tube that you put over something (often wires that you have connected), then use a heat gun to shrink it down to 1/2 or 1/4 of its original diameter.
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thank's nasarius, T+!
I believe that the WM55 are not very different from the WM61, the later being somewhat favoured by some micbuilders it seems. Please post if you find out more!
The site you found is very good, the author member of the yahoo group 'micbuilders': http://tech.groups.yahoo.com/group/micbuilders/
thank's for explainingheat shrinking.. I have been doing that but did not know that it was the same which is refered to by 'heat shrinking'.
good luck for anybody building his own mics, it is easy and fun!
kuuan
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Well, the WM55 is a cardioid and the frequency response drops a lot, about 20 dB at 20 Hz and 1 meter. The WM61 is linear to at least 10 Hz.
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Well, the WM55 is a carioid and the frequency response drops a lot, about 20 dB at 20 Hz and 1 meter. The WM61 is linear to at least 10 Hz.
Hm, I misstated the response...it's 100Hz-16kHz, and that's all the datasheet shows as well. I'm not sure where you're getting those numbers, but the point is valid; the WM-55A loses 10dB at 100Hz, up to a few dB at 250Hz.
They should be better than the Giant Squid cardioids at least (which, given their size and advertised 100Hz - 12kHz response, are most likely WM-65As).
http://rocky.digikey.com/scripts/ProductInfo.dll?Site=US&V=10&M=WM-55A103
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Panasonic WM55 and WM61, tested here:
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thank you very much Roger, and BTW welcome to the forum, you are a very valuable new member.
I know too little, is to say close to nothing about technical specs so I must admit that the test don't tell me much.
I do understand that you say that the WM61 is better....
However i believe that this dhould not discourage poeple do try out the WM55 in case they cannot get hold of WM61, like me. Many mic DIY did use the WM55 also:
http://www.prodigy-pro.com/FORUM/viewtopic.php?p=270393&sid=c0677291ae69a16269e98b4c980bd378
http://www.scotthelmke.com/stereo-mic.html
http://www.mp3forkidz.com/mic/phantxy.html
http://homepage.ntlworld.com/henry01/cheap_soundfield/cheap_soundfield.htm
http://www.mp3forkidz.com/mic/msmicV2.html
I guess you have seen those sites, but I hope somebody might find them interesting,
In noticed that the the WM55 had been modified for 'source follower operation' using a 2,2 k resistor. Please excuse my innocence, maybe I am wrong, but: Is this a similar mod Chris is doing but using a different value for the resisitor?
thank you,
cheers,
kuuan
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Incidentally, I have found that all three Pana capsules are happiest with 4k7 source resistors, but other brands of capsules, especially in the 10mm size, generally like higher values. It's always worth experimenting.
This got me curious. Are there any good capsules (equal or better than the Panasonics) available to the general public? That is, no more than 10 or so as a minimum purchase from some distributor.
Answering my own question a little...from this (http://www.scotthelmke.com/alice-mic.html) DIY site I found Transound capsules:
http://www.jlielectronics.com/transsound/electrets/tsb-165a.htm
But they're 16mm, which is probably too large for most stealth taping purposes. Maybe these, which are about the same size as the WM-55A:
http://www.jlielectronics.com/transsound/electrets/tsb-99a.htm
Or these, which are rather pricey and require an external FET:
http://www.jlielectronics.com/transsound/electrets/tsb-120a.htm
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nasarius I am sure the TSB-165 are really good, I don't know about the others. A quote from Scott Helmke from the micbuilders:
> The TS capsules that are similar to the Panasonic series are basically
> about as noisy. If you go with the ones that require an external FET and
> 1Gohm resistor then there's a huge difference - the TSB-160, TSB165 are
> both this way. The sound of those capsules is a bit on the bright side,
> but you can build a fully professional mic with them.
seen here: http://tech.groups.yahoo.com/group/micbuilders/message/4759
nasarius, if you want to buy some, need to take 10 Pcs and don't want them all, I'd like to take...let's say, 4 pcs, or half of them?
cheers,
kuuan
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New to all of this as I am, I'm still constantly surprised by the quality of recordings possible from a pair of mics as tiny as these Greenmachine mics.
I'd love to build a pair of my own mics one of these days, but since I've never even considered picking up a soldering iron I think I'll be sticking to other people's work for the time being!
;D
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Quite new to all of this I am too, and very surprised at the quality of recordings from a pair of binaural mics as tiny and cheap as the ones I made with two 0,60 USD capsules simply soldered to 1USD earphones. That hardly needs knowledge of soldering, and if you take capsules for 1,50 each and better cables, OK, don't spend 3 USD but 5.
I'd love to have real good mics, but if it is just entry level mics, why spend 50 or 100 USD if I can get the same quality for just 3 or 5 USD!
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Yep, I understood. Chris is providing some DIY tips, or at least a way to evaluate any Panasonic WM6x mics other people are selling out there.
Keep the tips coming, we call always learn more tricks...
Richard
Brothers!
Where is this thread going to?
Actually I was just trying to help some people out here at T.S with some "inside" info on how I do things.. The greenmachine DIY method would work if you wanted to build some mics that worked "ok" but if you want to build something that will really handle the high SPL my method has been tested and proven.. And I wanted to simply share it.. But one of the users in this forum has seen fit to call me out on my 4.7k mod... and the simple truth of the matter is this user has a "hidden agenda" so that's all carry on..
Chris
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> quote: 'illconditioned will now replace poorlyconditioned hopefully things will go better this time'
why?
what happened to poor poorlyconditioned?