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Post by amanajoe on Nov 16, 2022 19:08:19 GMT -5
For me they have been an obsession covering over 30 years. My microphone locker can be broken down into 4 basic types: Dynamics Ribbons Large Diaphragm Condensers Small / Medium Diaphragm Condensers Of the 4, I make and design my own of the last three types. Why no dynamics you might ask? Well, it is all about the capsule with dynamics, buy the capsule and you are pretty much done. Ribbon microphones have been a more recent thing for me (as in the last 20 years or so, ever since I saw what Royer was charging for his mics). The ribbon microphone is quite frankly both the simplest and hardest microphone to build. It takes a steady hand and patience but really has only 3 major components. A body (generally just a tube), a transformer (37:1) from one of many sources and a “ribbon motor”. The ribbon motor is a thin piece of aluminum foil that has been crenelated and suspended between two very strong magnets with a low impedance path to connect each end to the transformer. The difficult part is the crenelating and setting the tension of the foil. Once you get good at that, you can whip out a new mic in about an hour.
I'm currently working on an active version to eliminate the need for high gain preamps that can get a little noisy.
They sound great on just about everything. If you have never used one, they sound (to most) the closest to what everyone really does hear. They are warm and can handle very loud sounds. The cons of them is that they can be very dangerous to use for vocals with an untrained person, generally a pop filter is a must for vocals. Plosives can blow out the foil and you are back to making and setting tension on another piece. Phantom power is another no-no as that can damage them too. They are also finicky about how you store them (the foil can go slack under it's own weight and need to be changed or re-tensioned if not stored upright or in the correct orientation). Ask questions as we go, I'll try to answer when I can. I'll continue large diaphragms in the next installment.
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Dub
Administrator
I'm gettin' so the past is the only thing I can remember.
Posts: 19,888
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Post by Dub on Nov 16, 2022 19:23:41 GMT -5
Excellent. I’m really looking forward to this.
As you may know, I came to Cedar Rapids in 1976 from Chicago to work for the Turner Microphone Co.
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Post by John B on Nov 16, 2022 19:44:44 GMT -5
I have one of Joe's mics. I am not as eloquent as Marshall, but suffice to say I like it. I look forward to hearing more about Joe's mics (amybe someday I can try my hand at inadvertently destroying a ribbon mic).
And Mark's turn at Turner would be something nice to hear about, too.
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Post by amanajoe on Nov 16, 2022 21:04:19 GMT -5
Excellent. I’m really looking forward to this. As you may know, I came to Cedar Rapids in 1976 from Chicago to work for the Turner Microphone Co. Ooh, I’ve been wanting to ask this from somebody knowledgeable, years ago a buddy brought me a Turner mic and asked me how to hook it up. It had 4pins and my answer was a solid, I dunno. What was the 4th pin for? I thought maybe a hi-z / low-z thing, but didn’t want to take it apart to find out. We never used it.
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Dub
Administrator
I'm gettin' so the past is the only thing I can remember.
Posts: 19,888
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Post by Dub on Nov 16, 2022 21:35:44 GMT -5
Excellent. I’m really looking forward to this. As you may know, I came to Cedar Rapids in 1976 from Chicago to work for the Turner Microphone Co. Ooh, I’ve been wanting to ask this from somebody knowledgeable, years ago a buddy brought me a Turner mic and asked me how to hook it up. It had 4pins and my answer was a solid, I dunno. What was the 4th pin for? I thought maybe a hi-z / low-z thing, but didn’t want to take it apart to find out. We never used it. Oh, man. I'm sorry but I have no idea. The Turner mics I had were the white stage mics and they used XLR cables as far as I can remember. I sold that stuff, mics, stands, & related probably 25 or 30 years ago when I thought I'd never be using sound equipment again. The white mics were the ones endorsed by the Doobie Brothers. I think they were designed by Steve Armstrong's dad.
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Post by gbacklin on Nov 16, 2022 23:53:56 GMT -5
This is great, thank you !
Moderators: can we pin this for a while ?
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Post by gbacklin on Nov 17, 2022 11:09:19 GMT -5
Thank you for the pin ! Of all the mics I have, the AKG C414 stereo pair, has been my workhorse. For orchestra and large choir ensembles, I have a tripod that will sit about 10 feet behind the conductor in a left/right placement up high. This gives me the full sound and room ( mostly churches) sound that basically is the recording. It will be supplemented by various spot mics for instruments and vocalists. AKG C414My question is what is done to two mics to produce a matched pair ? Thank you in advance.
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Post by RickW on Nov 17, 2022 16:32:46 GMT -5
I keep thinking that I want to get a better mic. I have an Audio-Technica AT2020, not expensive. But I really like the sound I get on both vocals and my acoustic with it. Not to mention, if I’m going upgrade, I’d probably want to spend a lot more money.
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Post by amanajoe on Nov 17, 2022 17:05:55 GMT -5
Large Diaphragm Condensers Part Uno So, back in the 80's when I traipsed around various studios in the Chicago area I ran across my first Large Condenser Tube Microphones. I wanted one or two really bad, until I found out how much they cost. Most were more expensive than the car I was driving. Right now, an AKG C12 Reference will run you about $7000. I decided I'd try to build something similar. I could get a hold of actual C12 capsules from AKG as “a repair item” for about $400 (the actual thing from AKG is now about $1800) but you had to give them a local repair depot location to ship it to. I had a friend that was hot rodding / doing depot repair for Fender in Chicago, so he got it shipped to him and I was off to the races. www.akg.com/Microphones/Tube%20Microphones/C12VR.htmlwww.telefunken-elektroakustik.com/microphones/ela-m-251eThe ELAM (as they are affectionately known) are actually a kind of copy of the C12 using the same capsule with a few other parts. That makes them easy to replicate as well if you can make a C12. The interesting thing about tube mics is that the circuitry isn't that complex. It just requires picking a few of the right parts (about 7 or 8 is all that is in the mic) and knowing enough not to get killed by the power supply you needed to run them. I got an old busted supply from one of the studios, fixed it and figured out how to make a better one. The most expensive parts (besides the capsule) are the transformers (one in the power supply and one in the microphone). So if you are gutsy and don't mind taking chances with high voltages, you too can make a really nice mic. About 12 years ago, a bunch of low cost copies of the C12 started to come out. They were junk and didn't sound anything like the real thing, but they were sub-$300 and had something perfect for guys like me. A nicely made mic body, a nice multi-pin XLR cable, and a power supply! All you had to do was gut it and make your stuff fit. About 9 years ago several other people out in the world noticed too and now there is a whole hobby industry making top notch C12 and ELA-M-251 clones for dirt cheap. They've become so popular that the cheap import mics have gone up in price too, just to support the market. The neat thing about the whole design is that you can adjust front to back bias on the capsule so instead of just Omni, Cardoid, or Figure8, you can create multiple patterns (9 in the case of my most recent one). If anyone is interested I can share places you can buy the parts and make your own. Most of mine are very similar with little tweaks (there's not much you can do with so few parts) and better quality C12 replica capsules (although my favorite, made by an acquaintance in Chicago) are now long lead time and significantly more than the $425 I used to pay. A newer head basket design, etc. All up, I used to build these mics for myself for about $700 in parts. Nothing else sounds like one. Virtually every video you see in the studio of vocalists performing it is into one of these tube mics or a Neumann. Next up, my inborn need for Neumann mics, also known as, if they give you a schematic without all the values on it, can you still make a good copy?
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Post by amanajoe on Nov 17, 2022 17:10:16 GMT -5
I keep thinking that I want to get a better mic. I have an Audio-Technica AT2020, not expensive. But I really like the sound I get on both vocals and my acoustic with it. Not to mention, if I’m going upgrade, I’d probably want to spend a lot more money. Absolutely nothing wrong with the AT2020, for the price it is a sturdy mic for the first time buyer of a recording mic.
It does emphasize the bass side of things a bit, so it shouldn't be used on bass heavy stuff and has a definite proximity effect, so back up from the mic a bit. It is quite good at guitar recording, just don't have it too close and it will sound good.
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Post by amanajoe on Nov 17, 2022 17:19:13 GMT -5
Thank you for the pin ! Of all the mics I have, the AKG C414 stereo pair, has been my workhorse. For orchestra and large choir ensembles, I have a tripod that will sit about 10 feet behind the conductor in a left/right placement up high. This gives me the full sound and room ( mostly churches) sound that basically is the recording. It will be supplemented by various spot mics for instruments and vocalists. AKG C414My question is what is done to two mics to produce a matched pair ? Thank you in advance. They were the first Large Condensers that broke the $1000 barrier and were a very hot commodity when they first came out. I've used the C12 capsule from them for a few mics (the guys a full compass in Madison are great for such things and have them in stock usually). They run the C12 capsules through a test suite and the ones that don't make it for the actual C12's go into the C414's. Not that they are bad, but there has to be some kind of magic for a $7000 mic.
Most people don't understand that much of the cost of a mic is wrapped up in name, marketing, and lore. My latest multi-pattern LDC mic (which is unique in that it requires 2 mic inputs and was really design for use with interfaces and digital audio workstations, but can be used live with the right mixer) cost about half of the latest variant of the C414.
The are great mics and the fact that you can get parts for them for repair if something stupid happens makes them a great buy.
Pair matching is all about labor and trade-offs. If I buy 20 capsules, run them through a sweep (literally they go into a box facing a reference monitor and then a sweep of frequencies is sent through them) the curve that comes out will indicate how the mic hears things. Running through all 20 mics, I might find two or three that have their curves match within 1 dB across the entire sweep (some say 1.5dB is good enough). Once that is done, the same is done for the circuits (head amp) that they are going into. The final test is back into the box again when completed.
I generally don't have to match the circuits due to my penchant for 0.1% resistors and matching the transistors before assembly, but capacitors are not as easy and therefore, may need to be matched as well (only the ones in the audio chain).
So out of 40 mics you might get 2 pairs, so that is why they cost more to make.
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Post by gbacklin on Nov 17, 2022 18:14:15 GMT -5
I keep thinking that I want to get a better mic. I have an Audio-Technica AT2020, not expensive. But I really like the sound I get on both vocals and my acoustic with it. Not to mention, if I’m going upgrade, I’d probably want to spend a lot more money. The 2020's and the old Studio Projects C1's are my live large condenser mics. They are inexpensive, but a very good mics. The C1's I have recorded guitar, vocal and even a brass ensemble and they handled it all. The placement is key and in a live situation, you just do not want to get too close as the performers do move around a bit. This recording had the C414's as elevated main pair and C1's as spot mics.
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Post by gbacklin on Nov 17, 2022 18:14:39 GMT -5
Thank you for the pin ! Of all the mics I have, the AKG C414 stereo pair, has been my workhorse. For orchestra and large choir ensembles, I have a tripod that will sit about 10 feet behind the conductor in a left/right placement up high. This gives me the full sound and room ( mostly churches) sound that basically is the recording. It will be supplemented by various spot mics for instruments and vocalists. AKG C414My question is what is done to two mics to produce a matched pair ? Thank you in advance. They were the first Large Condensers that broke the $1000 barrier and were a very hot commodity when they first came out. I've used the C12 capsule from them for a few mics (the guys a full compass in Madison are great for such things and have them in stock usually). They run the C12 capsules through a test suite and the ones that don't make it for the actual C12's go into the C414's. Not that they are bad, but there has to be some kind of magic for a $7000 mic. Most people don't understand that much of the cost of a mic is wrapped up in name, marketing, and lore. My latest multi-pattern LDC mic (which is unique in that it requires 2 mic inputs and was really design for use with interfaces and digital audio workstations, but can be used live with the right mixer) cost about half of the latest variant of the C414. The are great mics and the fact that you can get parts for them for repair if something stupid happens makes them a great buy. Pair matching is all about labor and trade-offs. If I buy 20 capsules, run them through a sweep (literally they go into a box facing a reference monitor and then a sweep of frequencies is sent through them) the curve that comes out will indicate how the mic hears things. Running through all 20 mics, I might find two or three that have their curves match within 1 dB across the entire sweep (some say 1.5dB is good enough). Once that is done, the same is done for the circuits (head amp) that they are going into. The final test is back into the box again when completed. I generally don't have to match the circuits due to my penchant for 0.1% resistors and matching the transistors before assembly, but capacitors are not as easy and therefore, may need to be matched as well (only the ones in the audio chain).
So out of 40 mics you might get 2 pairs, so that is why they cost more to make.
Thank you so much !
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Post by RickW on Nov 17, 2022 22:19:55 GMT -5
I keep thinking that I want to get a better mic. I have an Audio-Technica AT2020, not expensive. But I really like the sound I get on both vocals and my acoustic with it. Not to mention, if I’m going upgrade, I’d probably want to spend a lot more money. Absolutely nothing wrong with the AT2020, for the price it is a sturdy mic for the first time buyer of a recording mic. It does emphasize the bass side of things a bit, so it shouldn't be used on bass heavy stuff and has a definite proximity effect, so back up from the mic a bit. It is quite good at guitar recording, just don't have it too close and it will sound good. About 8 to 10 inches out, pointed at the 12th fret, angled slightly at the fretboard. I’ve tried a bunch of different stuff, but that always works. For vocals I put it just to the side, so I’m not popping right into it, and seems to work very well.
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Post by RickW on Nov 17, 2022 22:23:25 GMT -5
I keep thinking that I want to get a better mic. I have an Audio-Technica AT2020, not expensive. But I really like the sound I get on both vocals and my acoustic with it. Not to mention, if I’m going upgrade, I’d probably want to spend a lot more money. The 2020's and the old Studio Projects C1's are my live large condenser mics. They are inexpensive, but a very good mics. The C1's I have recorded guitar, vocal and even a brass ensemble and they handled it all. The placement is key and in a live situation, you just do not want to get too close as the performers do move around a bit. This recording had the C414's as elevated main pair and C1's as spot mics. Man that sounds fantastic. Pretty incredible mix for live, but I guess classical players are used to fitting in their volume and tone, but I assume the spot mics help with that. The french horn player using her fist as a mute.
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Post by gbacklin on Nov 18, 2022 0:22:11 GMT -5
The 2020's and the old Studio Projects C1's are my live large condenser mics. They are inexpensive, but a very good mics. The C1's I have recorded guitar, vocal and even a brass ensemble and they handled it all. The placement is key and in a live situation, you just do not want to get too close as the performers do move around a bit. This recording had the C414's as elevated main pair and C1's as spot mics. Man that sounds fantastic. Pretty incredible mix for live, but I guess classical players are used to fitting in their volume and tone, but I assume the spot mics help with that. The french horn player using her fist as a mute. I received a number of suggestions, from the ensemble, on how to set up my gear and just politely thanked them and set it up in a way that I knew I would get what I wanted. With brass and percussion, you just have to make sure the levels are not too high or the signal will clip. That is a casualty of the digital world. In the analog tape days, you to tried to get as much volume onto tape to reduce the hiss.
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Post by RickW on Nov 18, 2022 0:46:05 GMT -5
Man that sounds fantastic. Pretty incredible mix for live, but I guess classical players are used to fitting in their volume and tone, but I assume the spot mics help with that. The french horn player using her fist as a mute. I received a number of suggestions, from the ensemble, on how to set up my gear and just politely thanked them and set it up in a way that I knew I would get what I wanted. With brass and percussion, you just have to make sure the levels are not too high or the signal will clip. That is a casualty of the digital world. In the analog tape days, you to tried to get as much volume onto tape to reduce the hiss. When I was in my twenties I got to do some recording in some really nice local studios, and then built one with a couple of friends. 8 tracks, a teac machine. I sure like recording on my MacBook with logic a lot better.
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Post by gbacklin on Nov 18, 2022 1:44:28 GMT -5
I received a number of suggestions, from the ensemble, on how to set up my gear and just politely thanked them and set it up in a way that I knew I would get what I wanted. With brass and percussion, you just have to make sure the levels are not too high or the signal will clip. That is a casualty of the digital world. In the analog tape days, you to tried to get as much volume onto tape to reduce the hiss. When I was in my twenties I got to do some recording in some really nice local studios, and then built one with a couple of friends. 8 tracks, a teac machine. I sure like recording on my MacBook with logic a lot better. Oh, don’t get me wrong. For the money, I could not do in tape and pure analog, what I do digitally. No way possible. I was just mentioning the sound level approach with digital vs tape. By the way, I still have my TEAC 3340s 4 track, 3300 half track and 3300 quarter track. I had them recalibrated about 10 years ago and honestly, they sound better now than they did back in 1974 when I purchased them. They guys did a phenomenal job. Occasionally I will bounce my master tracks to tape for get that saturation, then re import them to digital.
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Post by coachdoc on Nov 18, 2022 10:19:06 GMT -5
Wow. What a sound and what a performance.
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Post by amanajoe on Nov 18, 2022 16:48:30 GMT -5
Large Condensers Part Duex At the same time as I was messing around with tube mics, several people started hanging out on the newly formed micbuilders yahoo group. We discussed things like the tube mics I was building and the want to build FET based mics like the Neumann. Neumann actually published the schematics of the mics (without a few key components needed to make them work well, but that just upped the challenge of making them, it was like waving a red cape at a bull). en-de.neumann.com/u-87-aiWe dissected the schematics and came up with what seemed like it would be a great design. There was only one problem. Nobody outside of Neumann made the capsules needed and also, while these used solid state electronics instead of tubes, you still needed a transformer (one we didn't have the spec for) to complete the mic. The capsule issue got taken care of through a fellow that was doing re-skinning (replacing the gold sputtered mylar diaphragms) of the capsules for various people after they had been damaged. He took apart the K87 (multi-pattern) and K67 (dual sided) capsules of a Neumann, measured them, and started to make replicas. They are literally brass with holes drilled in it and a chamber to resonate at certain frequencies. At the same time, the Chinese manufacturers got into the game and started selling versions of the mics (many marketed by MXL). We couldn't initially figure out why they sounded so bad though. It was back to the Neumann circuits to give us a clue. The original capsule (cardiod) that Neumann produced was the K47 (cardiod). It has a very nice sound, but a pretty strong proximity effect (bass increases the closer you get). To solve that, the resonant chamber of the K87 and even more so the K67 have an exaggerated high frequency peak. In the audio (and electronics world) it is called pre-emphasis. The circuit you need to hook it up to must have de-emphasis to account for it to balance things out. The Chinese copies (virtually all of them right up to this day) are really K67ish even the ones that are supposed to be K47s. None of the circuits in the mics account for the pre-emphasis and therefore, they all sound sibilant and hyped. After quite a bit of work, the folks at micbuilders figured out the actual circuit and we determined that the missing data on the schematic were parts that had to be adjusted to match the chosen transistors used in the circuit. Through a lot of smart people testing a lot of variations we arrived at the current versions of the circuits used by many today. In the intervening years, several manufacturers have teamed up with Chinese and other Asian makers to create low cost but very serviceable capsules of all three types. The transformers turned out to be made by Lundahl and we found other versions that worked just as well from AMI and Cinemag (the ones I use). Bodies were a bit of a challenge, but several of the cheaper makers solved that by making terrible copies of the U87 that were cheap but had all the switches for pattern selection, pad, and low roll off. Then an enterprising guy on the west coast got some bodies made overseas and now (while they aren't always available) I can get really nice ones relatively quickly. So, a capsule, board, body and $150 in parts (all told about $700 again) gets me a mic that has been hand tuned (a necessity unfortunately) rivaling a $3200 mic. I've built a couple and even have a B-Stock one as I call it. It was a venture into a lower cost body that works fine, just that I touched one of the plastic slider switches (all my other ones use metal) with the soldering iron so it is slightly deformed. If anyone is interested, I'd part with that one. If anyone wants to take a whack at learning how to do any of this, you know, build your own microphone, I'd be glad to give you pointers on how to get it done. By the way, if you're are getting tired of my bloviating on this feel free to say so and I'll shut up!
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