Igo Primo Voice German
Christian Erdmann
I was going to put out an article for all voice types at once, but this turned out to be much heavier reading, so I have split this into two articles. This week, I have released the following article on male voice type and next week I will release an article on female voice type. Richard Miller, considered to be one of the most respected writers on voice for the last 100 years, created an interesting system where it is possible to identify vocal fach based on the location of the primo (lower) and secondo (upper) passaggii.
Dramatic baritones may find themselves having high tenor notes when they finally access their head range. Rather than training towards becoming a tenor, it may be more prudent to revel in having a rarer voice type and training particularly in Verdi roles.
This baritone is commonly misfached as a tenor. The distinguishing factor of a lyric baritone is that B3-E4 is a particularly impressive part of the voice, with a considerable amount of groundedness and power. It could be said that at this point, the lyric baritone is the perfect example of a marriage between the laser-like sound quality of a spinto tenor, but with more ovular depth of the dramatic baritone.
The bari-tenor is a unique vocal fach where the singer has very distinct, darker colours similar to the lyric baritone, but they have the ability to sing far into the range of a normal tenor. I find that the bari-tenor is a warmer voice than the typical dramatic tenor. When you listen to someone like Jonas Kaufmann (classical) or Ramin Karimloo (Musical Theatre), there does seem to be a very distinct baritonal quality in the lower part of the range, while there is a distinctly tenorial cut in the upper part of the range. I believe it is important for me to use a musical theatre example here as the bari-tenor is commonly found in this genre.
If you are a male singer and you are not entirely sure about your fach, ultimately one of your best steps is to go to a teacher who is well respected and gets good results. Do not be saddened if it takes a while to find your true fach. As I have stated in part 1 of this series, try to begin with songs that do not demand tremendous amounts of vocal weight or the extremities of your range. The natural laryngeal tilt that must occur in order to sing through the entire voice without any breaks is best achieved with material that does not demand as much from you as a singer.
This is the last in a four part series about powering the Primo EM172 microphone capsule. Part 1 outlined the problem of how to provide 5-10v to the capsule and predicted some results. Part 2 shared some results and pointed out that the gain differences between inputs on my recorder invalidated my predictions. Part 3 discussed my reasons for going with XLR connectors on all my microphones, and some of the details of that. This last part puts it all together into a step-by-step DIY for building microphones with Primo EM172 capsules, powered by 48v phantom power on an XLR plug.
EDIT: Akira also pointed out that my value for R (120k) resulted in something like 1.3-1.5V at the capsule. I experimented with a number of resistors to see what value of R would produce 7.5V at the capsule on my recorder, and for a Tascam DR-70D, R=40k produces just over 7.5V. When you do this build, you will have to find what works best for your equipment.
The first step is to strip one end of the cable, trim back the red and white wires to a workable length, and still leave plenty of shield exposed. The red and white wires are then soldered onto the appropriate pads on the capsule.
Be sure to account for every strand in the shield as you bring it up and over the heat shrink. Wrap with foil tape and trim back the shield so no wires protrude. Be sure no wires cross over the heat shrink and touch the front of the capsule.
Solder a leftover component lead from pin 1 to the ground tab. Next, solder one end of the resistor to the ground tab as well. Next, solder the (+) end of the capacitor to pin 2. Finally, tie the two free ends of the capacitor and resistor together.
This is a good time to test the mic to make sure nothing went wrong. Plug it into your recorder, turn on phantom 48v power, and dial up the gain. If all went well you should have a low noise microphone ready to be installed in its mic body. If not, go back and check each step to find out what went wrong.
Funny you should ask! Just yesterday I built a pair around some EM184 caps I picked up from micbooster.com. Everything worked fine. If you grab the datasheet for the EM184 and the datasheet for the EM172, you can see the hot and ground pads on each of the mics. The red wire goes on the hot, and the white (black in the diagram) goes on the ground pad. Do the same on the EM184 and you should be good to go.
To strain relieve the cables I applied umpteen zillion layers of heat shrink tubing to the cable to bring it up to the right diameter. By using different lengths it made a tapered strain relief sleeve.
This sort of solved the rattling capsule issue as well. I left a bit of length on the wires where they solder onto the back of the capsule. Once the cable was pulled down into the mic body, I still had to compress the wires to get the capsule into the body. When the front cap was screwed on, the mic was under some spring pressure from the back because of the wires. That pushed it up against the cap enough to keep it from rattling.
If your recorder takes a 3.5mm input and provides plug-in-power rather than phantom power, those typically are wired for stereo. There are some really good references out there for building stereo pairs of EM172 mics with 3.5mm inputs. These are the two I based my original pair off of:
At that point the SimpleP48 circuit can be wired into the XLR shell: Pin 3 goes to Drain on the capsule, and the wire coming off of the resistor and capacitor goes to the ground side of the 2.2k resistor at the back of the capsule.
Thank you Tom, I adapted my 172 to XLR following your post but I have some problems. The inner noise is really low but the mics are super-silent (I used them with Tascam HD-P2). Instead of 4.7uF 25v aluminum electrolytic capacitor I used 4.7uF 50v, so I have no idea if there is the problem or I just burn them during soldering (I used unregulated iron). Can you tell me what I am doing wrong? Thx a lot!
Hi Tom, at first thank you for your quick response. I am still kinda lost. The recorder is sending out 48V. When I put in the recorder just the XLR with soldered capacitor, resistor and the joint (without microphone cable and microphone) is sending something around 8,5-9V. But when I solder the microphone cable and microphone it is something around 0,3-0,5V. I have no idea what is wrong.
Thank you for your help.
Ian
Another interesting discovery for me was that the R value of 120k ohm suggested for EM172 in naturerecordists/micbuilders Yahoo forums was clearly too high, at least for my samples of EM172 capsules and Fostex FR2LE. (48.8V phantom voltage, measured.)
Anyhow, thanks Akira, I am actually rather happy with that mistake because of your second discovery, which I might not have read without this cap issue. Will definitively change those resistors as well!
So far, the M10 has been enough for me with the pluginpower. Probably getting the F4 (Zoom) in the very near future. The 4-6 channels would make it easy to testdrive different set ups and mics side by side in a total sync. The preamps seem very nice despite the reputation that brand has in the past regarding preamps and plastic feeling.
I gutted one of my mics, wired in a 100k potentiometer, dialed it up to 95k, plugged it in, and measured the voltage across the capsule. Then I tuned it until I got 7.5v. It wound up being right around 40k.
I think the value depends on the actual P48 voltage supplied by the recorder and the amount of current it can source. One thing I learned about my Tascam DR-70D is that both of those dip if the battery level is low. First time I did the potentiometer trick I wound up with something closer to 30k. Then I realized my batteries were almost dead. I plugged in an external battery pack, powered everything back in, and just about fried one of my mics. (I thought I had, but even though I put over 10V through it it somehow survived.) Lesson learned: Use fresh batteries when doing that test, and test on the recorder you intend to use. Even so, the value I came up with was a far cry from the 120k I started with.
Since both factors could theoretically interfere with the signal quality in some way I ordered some mini jacks as well as some XLR connectors.
My plan was to (more or less directly) fix the capsules to a 3.5mm socket each so I can plug in various extensions just when I need them. The first option would be a XLR P48 cable for my interface, the second a XLR P24 cable for the recorder (due to battery life) and maybe a third one with a simple 3.5mm TRS connection for testing the 5V plugin-power of the recorder.
What made that possible was that Homero Leal pointed out that precision resistor assortments show up on Ebay all the time at reasonable prices. I think I got mine for under $20, and it has tons of sizes to choose from. If I use up too many of on size, I tack that onto the next order from Mouser or Digikey.
As for the technical aspects, my DR-60D recorder works with about 45.5V on the 48V rail, with 23.5V on the 24V rail.
First of all I tried the P48 XLR build with a 41.2K resistor and hit a voltage peak of 9.0V just at the first attempt ?
After deciding to work with XLR I tried to solder another pair of XLR cables for 24V phantom power. Finding the right value for R was quite easy as well since I ordered a large variety of different resistors between 10k and 50k. I ended up with a 25.5kOhm resistor resulting in just about 9.9V at the loaded capsule. You can see a chart with a few reistor values I have tried out in the imgur gallery linked above.
So finally I ended up with a pair of P24 and P48 cables, both giving me about 10V of power at the capsules. To keep the system fully modular I used some 3.5mm TRS male and female jacks with threaded couplings by Hicon connecting the XLR cables with the capsule cables.
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