OPEN SOURCE DIY Mic Project - ORS 87 - Stripped Down u87

[elskardio]

Haven't really noticed a difference between 24v and 33v, but I'm fairly certain that all my PCB builds have been 33v, so that could be why.
Gain overall is about the same as my u87ai. I have a couple that have lower gain, but I've just been pulling FETs out of a bag of them without testing first.

Thanks

I'm currently using an old RK-87 capsule from Micparts. Did you compare this capsule with the TSC-2?
I'm wondering if it would be a good $40 investment or not...

 

[Wordsushi]

Using a higher voltage, so 33V Zenner, will get a bigger headroom, allows higher SPL before distortion.

Since I'm just mumbling into them, I haven't really noticed any headroom issues with the way I'm using it. I haven't tested the mic any other way yet.

Thanks

I'm currently using an old RK-87 capsule from Micparts. Did you compare this capsule with the TSC-2?
I'm wondering if it would be a good $40 investment or not...

I have not tried the MicParts RK-87. I've only heard the TSC-2 in the AKG Perception 420. The only capsules I've used with this build are the 797 audio ones, the 3u, some of the unknown brand ones that came out of BaiFei Li mics, which were surprisingly decent, a couple of $20 cheapies from Aliexpress which weren't that great and 32mm pulled from an old MXL years ago, which wasn't really to my liking but someone else who I put that one together for really loves it. So, it's hard to know unless you have it in front of you.

 

[elskardio]

TBH the RK-87 sounds pretty decent!
but curiosity pushes me to spend $40 on the TSC-2

 

[micolas]

TBH the RK-87 sounds pretty decent!
but curiosity pushes me to spend $40 on the TSC-2

I bought the WarmAudio WA-87r2 when it came out, for this money you can't find a complete kit with quality parts. 3U capsule, Fairchild NOS jFET, Cinemag 13113 transformer, big body, solid as a tank. Inspired by the vintage U87i. Sounds excellent. Who can't make it sound good, stop mixing.
Years ago I bought an AKG P420 used but in mint condition, at a very good price from a friend.
When I compared the WA-87r2 and the modded P420, I noticed how close the AKG came to the sound of the U87. The only problem is the body, the headbasket which does not help to obtain the U87 character. His capsule, TSC-2 was analyzed and highly appreciated by valuable members of the group.
Now I want to buy a new P420 and transplant it into the HL-95 body, de-emphasize it in several stages with a rotary switch (or DIP inside).
If you're looking for the 87 sound and can't afford an Arienne capsule, then it's worth spending $40. Unfortunately, we in Europe have to pay more, so we are looking for other solutions.
I specify that I have many microphones of all kinds, from all price ranges, DIY, stock or modified, including Neumann. Each sounds good on some sources.
But I can say that the P420 impressed me, it feels like a natural extension of my voice and what's more, it's very versatile, sounds good in almost any scenario.

 

[cholmes777]

Completely off topic but curious, since you like the WA 87r2, what do you think about their wa8000/ c800g clone?
I know it doesn't sound exactly the same, and that i don't mind. But does it sound good and is the price worth the parts and
how it is built? Im thinking about getting this mic one day maybe..

 

[micolas]

Completely off topic but curious, since you like the WA 87r2, what do you think about their wa8000/ c800g clone?
I know it doesn't sound exactly the same, and that i don't mind. But does it sound good and is the price worth the parts and
how it is built? Im thinking about getting this mic one day maybe..

WA87 and WA8000 have different characters,jFET vs Tube, even though they both have 67-type capsules. While the 87 is more neutral, more towards the TLM67, the other has a Smile-type response.
It is a fashion in rap to use C800g, and as a budget solution WA8000, for intelligibility, impact. Of course WA doesn't have the refinement of Sony,
I don't even think it's a faithful clone.
I haven't had a chance to open a WA8000 so I can't say anything about the build quality.Some complain about the inconsistency of Warm products, maybe that's something they fixed.
Personally, I like it on some female fuller voices - soul, gospel, rhythm and blues.
Below: I notice that there is a closeness in FR between AKG and Sony. The graphic is exaggerated vertically on smartphone.
I wonder how the AKG P820 and C800g would compare, both with tubes, similar headbasket, etc

 

[Wordsushi]

Quick prototype build of a board that my buddy, Duffy over at Hula Cow Studios, designed to stuff the whole ORS 87 circuit onto a tiny PCB that fits inside a TLM-103 style body. Sounds great.

 

[micolas]

View attachment 129687
Quick prototype build of a board that my buddy, Duffy over at Hula Cow Studios, designed to stuff the whole ORS 87 circuit onto a tiny PCB that fits inside a TLM-103 style body. Sounds great.

Is the one you tested on YouTube in the shockmount designed by you and 3D printed?

 

[Wordsushi]

Is the one you tested on YouTube in the shockmount designed by you and 3D printed?

Actually no. The one in the shockmount video has an Alice circuit and an edge terminated capsule, but it's the same style body. This ORS Nano 87 was just built yesterday and I'll probably pop out a YouTube short with it in the next day or two.

But here's a short sample of it.
View attachment Hula Cow Nano ORS 87 Prototype.wav

 

[micolas]

Actually no. The one in the shockmount video has an Alice circuit and an edge terminated capsule, but it's the same style body. This ORS Nano 87 was just built yesterday and I'll probably pop out a YouTube short with it in the next day or two.

But here's a short sample of it.
View attachment 129689

I like the Nano87 , but the headbasket is smaller than the 103/87 and on my smartphone seems to have less lows/low-mids and more mids.
A higher value of C5 / 33nF would
help it sound fuller, you've already tested that IIRC.
I also have 2 similar bodies waiting.
View attachment 87 vs ORS87 level check.wav

 

[Wordsushi]

Thanks! Definitely not as girthy down there. Currently using 100nf on C5, but I'm not sure I really want to make the low end bigger on this one.

I find that my ORS 87 experiments are pivoting away from trying to closely match the u87 to more of an overall exploration of what I like about the overall 87-ish tonality of an upper mid-forward mic on my voice and the tighter sound of the smaller headbasket really intrigues me as something different but still very much in the realm of what I'd use for stuff.

 

[untamedfrontier]

Just ordered some boards for this project and now am starting to assemble a list of parts needed which aren't already in my guitar pedal part inventory.

I think for 1 board I'm going to use sockets so I can easily swap in and out different values for the components that contribute to the tonality of the mic, basically treating it like a PCB breadboard (but without having to think the layouts). As a DIY mic n00b, this thread is fascinating and hopefully I'll have something to contribute eventually.

 

[micolas]

Thanks! Definitely not as girthy down there. Currently using 100nf on C5, but I'm not sure I really want to make the low end bigger on this one.

I find that my ORS 87 experiments are pivoting away from trying to closely match the u87 to more of an overall exploration of what I like about the overall 87-ish tonality of an upper mid-forward mic on my voice and the tighter sound of the smaller headbasket really intrigues me as something different but still very much in the realm of what I'd use for stuff.

I do the same, I often get different flavors with some builds and keep most of them, I like them all. Does this mean we are soundaholics?

 

[micolas]

Just ordered some boards for this project and now am starting to assemble a list of parts needed which aren't already in my guitar pedal part inventory.

I think for 1 board I'm going to use sockets so I can easily swap in and out different values for the components that contribute to the tonality of the mic, basically treating it like a PCB breadboard (but without having to think the layouts). As a DIY mic n00b, this thread is fascinating and hopefully I'll have something to contribute eventually.

Good luck in the exciting adventure that is microphone DIY! And don't abandon guitar effects pedals either!

 

[micolas]

@Wordsushi +1
Ok! The Hula Cow ORS87 Nano Prototype sounds great.
It's the right thing for commercials, well-defined, contoured mid-highs, intelligibility, penetrating, pleasant, positive sound, compliments the voice nicely.
In the end what value did you use for C5?

 

[Wordsushi]

@Wordsushi +1
Ok! The Hula Cow ORS87 Nano Prototype sounds great.
It's the right thing for commercials, well-defined, contoured mid-highs, intelligibility, penetrating, pleasant, positive sound, compliments the voice nicely.
In the end what value did you use for C5?

In the end, I went with 68nf for C5 on the Nano. 100nf felt too woofy and 68 better matched the u87. I'm going with 100nf for C5 in my larger body builds and that seems to feel right, but with both Nano builds I've done, 68nf was best for me, both with the Neutrik 10/3 (w/3u audio K87) and a second with the Ali T-13 (w/Bai Fei Li black ring k87) and the low end presented the same with each.

 

[micolas]

In the end, I went with 68nf for C5 on the Nano. 100nf felt too woofy and 68 better matched the u87. I'm going with 100nf for C5 in my larger body builds and that seems to feel right, but with both Nano builds I've done, 68nf was best for me, both with the Neutrik 10/3 (w/3u audio K87) and a second with the Ali T-13 (w/Bai Fei Li black ring k87) and the low end presented the same with each.

Hi! As usual very useful detailed information for us!
And most importantly, we can hear and analyze the differences produced by the various components.
Thanks a lot!

 

[Wordsushi]

Need some help diagnosing this noise issue.
I built a second "Nano" ORS 87 in a TLM-103 style body and when I plug it in from the booth, it makes this noise.
View attachment ORS Nano Noise issue.wav
There's a ferrite bead on the mic cable just below the XLR connector. I don't detect this noise outside of the booth when I use this mic at my desk with a Zoom F3, just inside the booth. I went back and cleaned the board with isopropyl and reflowed all the solder joints, added RF capacitors in at the XLR jack on the mic, all to no effect. When I switch inputs to a different preamp, the issue remains, so it's definitely happening inside the mic.
The first Nano ORS87 I built in the same style body is fine, no noise issue. The only differences between them are the affected one has an Ali T-13 transformer and a Bai Fei Li K87. The good one has a Neutrik 10/3 and a 3u capsule.
I have the same transformer combo in larger body ORS87 build and that one is fine with no noise issue through the same input.

Does anyone recognize what could be causing this?

 

[soliloqueen]

Need some help diagnosing this noise issue.
I built a second "Nano" ORS 87 in a TLM-103 style body and when I plug it in from the booth, it makes this noise.
View attachment 129963
There's a ferrite bead on the mic cable just below the XLR connector. I don't detect this noise outside of the booth when I use this mic at my desk with a Zoom F3, just inside the booth. I went back and cleaned the board with isopropyl and reflowed all the solder joints, added RF capacitors in at the XLR jack on the mic, all to no effect. When I switch inputs to a different preamp, the issue remains, so it's definitely happening inside the mic.
The first Nano ORS87 I built in the same style body is fine, no noise issue. The only differences between them are the affected one has an Ali T-13 transformer and a Bai Fei Li K87. The good one has a Neutrik 10/3 and a 3u capsule.
I have the same transformer combo in larger body ORS87 build and that one is fine with no noise issue through the same input.

Does anyone recognize what could be causing this?

this is 2.4ghz wifi. the clicks are the beacon and the pops every 10 or so are the network name. if the board layout and shielding isn't perfect, you'll pick it up to some degree depending on the parts you use w the u87 circuit. where and how are you grounding?

 

[Wordsushi]

this is 2.4ghz wifi. the clicks are the beacon and the pops every 10 or so are the network name. if the board layout and shielding isn't perfect, you'll pick it up to some degree depending on the parts you use w the u87 circuit. where and how are you grounding?

Normal grounding stuff. Tie pin1 to the chassis via the little notch thing on the front of the XLR jack. I'll definitely take a look at it and maybe the inside of the xlr barrel on the body has paint in it or the screw hole that holds the xlr jack in place? I'll dig around inside to see what the grounding situation is. Thanks!!