Gauging Interest in Microphone Circuits

Hey folks love this community. Some very creative people! I know this is mostly a guitar pedal focused kinda place but was wondering if anyone had knowledge on mic pre / compressor circuits etc. I'd love to build a relative budget channel strip type thing for podcasting etc but really lack the design expertise to do so. I figured I would put the feelers out to see if there would be any collaborators interested before putting up more in depth design ideas that we could turn into a community design.

Edit: Also interested in converting pedal PCBs to line level / post mic pre if anyone wants to weigh in on that.


Cheers!
 
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I’d be interested in muc projects if they were available, but I don’t have any expertise that I could offer— the most I’ve done is restoring some old dynamic mics
 
The most I have delved into it is replacing broken mics with micparts.com stuff and then building a seventhcircleaudio rack for myself. Great stuff but gets pricey fast.
 
It'd be cool if there were some DIY Mic projects here.

These are some of the ones I've looked into, but haven't acted upon... (cut n paste from my DIY studio doc)

BUMBLEBEE DIY PRO AUDIO
Uncategorized, Ribbon Mic DIY Kits, Ribbon Mic DIY, Parts, Pro Audio DIY Kits, Accessories, Tools
Mic Pres, DI s, mics...
BUMBLEBEE PRO RIBBON MIC RM5
www.bumblebeepro.com/rm-5-diy-ribbon-mic-full-kit/

DIYRE
https://www.diyrecordingequipment.com Home of the colour
500 RACK:
OLA5 Opto Compressor From $300.00
EQP5 Passive Equalizer From $200.00
PR502 2-Slot 500-Series Chassis Kit From $150.00
Colour 500-Series Palette mkII From $150.00
CP5 Colour Mic Preamp From $150.00
500EXT 500 Series Extender Kit $20.00
OLA5 Horizontal Front Panel $15.00
500-Series Aluminum Blanking Panel $5.00
COLOUR PLUGINS
DIYRE
RM-5 Ribbon Microphone Kit $299.00 sale $250.00
RM-6 Ribbon Microphone Kit $350.00
SM-28 Shock Mount $35.00
SB-30 Stereo Blumlein Bar $25.00
L2A, L4A
[some of the above pricing may be out of date]


www.vintagemicrophonepcbkit.com/
Vintage U87i






Other studio related DIY:
DIY BASS TRAPS/ACOUSTIC TREATMENT



SOUND SKULPTOR 
500 series mic-pres, comps, eq, tape-sim


HAIRBALL AUDIO
Looks like GOOD STUFF! Seattle-based Co focusing on quality components/builds.

500 series & rackmount


GYRAF DIY
http://gyraf.dk/diy-projects/
GYRATEC G9 – DUAL MICROPHONE PREAMP

GYRATEC G10: STEREO VARI-MU COMPRESSOR

GYRATEC G14: STEREO PARALLEL-PASSIVE EQUALIZER

GYRATEC G21: MAGNETO-DYNAMIC INFUNDIBULUM [PARALLEL/PASSIVE EQ]
The G21 is kinda an elaboration on our G14 parallel-passive eq – the parallel topology enables multi-band control without running into the traditional problems in multi-banding.

GYRATEC G22: STEREO/DUAL/MS VARI-MU COMPRESSOR
G22 is an elaborated and dualified version of our venerable G10 vari-mu compressor. It can be set to dual-mono, but still keeps a backwards-compatibility “G10 mode” where one set of knobs controls real stereo, like you’d want most of the time in mastering.

GYRATEC G23: “AMBLER” TILT EQUALIZER (DISCONTINUED, see G-23s below) 
 The G23 was a Tilt-type Equalizer aimed mainly at mix and mastering – for the situations where you had a mix that’s already nearly-perfect balanced, but you wanted it a tad darker or brighter without messing up the overall definition.

GYRATEC G23-S: “AMBLER” TILT EQUALIZER W/ SOLID-STATE OPTION
 The G23-S is an elaboration of our G23 Tilt-type Equalizer, where we added a selectable option for either solid-state or tube audio path.
 Like the standard G23, it’s aimed at the situations where you have a mix that is already nearly-perfect balanced, but you want it a tad darker or brighter without messing up the overall definition. This unique tilt equalizer works by distributing the uneven phase response associated with filtering across the whole audio spectrum in stead of having it all within one octave like on ordinary first-order tilt filters.



GYRATEC G24: “PASSIVE/AGGRESSIVE” CADMIUM COMPRESSOR stereo
 The G24 is an entirely new type of stereo compressor – aimed at mix and mastering functions. Like it’s sister and predecessor, the G23 EQ, it’s for those situations where you have a mix that is already nearly-perfect balanced, but you want to control some part of its dynamic without messing up the overall definition.




CAVEAT EMPTOR
I ordered a couple of EQ PCBs from PCBGrinder and never received them (in Hong Kong). Contacted the guy, said he is reluctant to ship a replacement set to China because he's lost parcels a few times. I wanted the PCBs so I told him to send them to my Canadian address, but after 2+ years and still no PCBs I'll be happy if I could just get my money back.
 
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The most I have delved into it is replacing broken mics with micparts.com stuff and then building a seventhcircleaudio rack for myself. Great stuff but gets pricey fast.

I think that's what I'm interested in here. A lot of the DIY projects available are trying to replicate expensive LA studio gear. But a lot of people who are podcasting or live streaming etc just need a solid circuit that does the job. I'm wondering if even some of the existing guitar circuits could be altered for line level impedance etc.
 
I've built some of the DIYRE stuff. Easier than a pedal but way more expensive. I really want to mod one of my mics but can't get my brain around a $150 capsule
 
I'd add JLM audio to the above list of suppliers.

Some really handy utility PCBs, cool projects, good prices, excellent support.
As mentioned above, this stuff gets pricy REALLY fast when you start looking at transformers and cases and PSUs etc etc. You're not going to stumble onto a way to make a Neve pre for $50.

GroupDIY is probably the main forum for that kind of stuff, but I've never been able to figure out how to get a join request approved. There's tonnes of info and schematics and troubleshooting/build threads over there (and also it's incredible what people are able to build) to dig through. That said, it has a... vibe.

Anyway, here's a cool mic pre.

$5_Preamp.png
 
I think that's what I'm interested in here. A lot of the DIY projects available are trying to replicate expensive LA studio gear. But a lot of people who are podcasting or live streaming etc just need a solid circuit that does the job. I'm wondering if even some of the existing guitar circuits could be altered for line level impedance etc.

Apologies in advance for rambling, but this is basically my day job and I've had too much coffee this am...

I guess the main question would be, as always, what are you trying to accomplish?

Do you want to a fun DIY project? Is there an issue with your recordings that you're trying to solve? Are you trying to save money on gear? What do you already have on hand? What are you trying to do that you can't get done with what you have? What are the needs of the project?
 
I have one little nugget of wisdom to add, the best piece of gear purchased for my studio was the materials to build acoustic panels.

It changed my recordings for the better and was really easy to build and upholster. No matter what you decided to do to build to record with make sure you have it somewhat treated.
 
I have one little nugget of wisdom to add, the best piece of gear purchased for my studio was the materials to build acoustic panels.

It changed my recordings for the better and was really easy to build and upholster. No matter what you decided to do to build to record with make sure you have it somewhat treated.
Absolutely!
 
Apologies in advance for rambling, but this is basically my day job and I've had too much coffee this am...

I guess the main question would be, as always, what are you trying to accomplish?

Do you want to a fun DIY project? Is there an issue with your recordings that you're trying to solve? Are you trying to save money on gear? What do you already have on hand? What are you trying to do that you can't get done with what you have? What are the needs of the project?
I want to build some for my podcast collaborators essentially.

I actually own a Presonas Studio Channel and a DBX 286s. They're both great and I use the Presonas Studio Channel for all my vocal work. Even those are probably better quality than a lot of podcasters / streamers need. Basically I think a PCB that would allow a project where a mic pre, compressor and EQ to fit in a 1/2U Box would be a good DIY project as long as the circuits are relatively simple. Most people don't need a Neeve, just a solid input channel.

I trawl GroupDIY a lot but never seem to find how you actually get in on projects either. But yeah, I know a good transformer and case will be almost $100 by itself. But that's ok. Part of the fun is the build.

I found these that seem like a good compliment to a mic pre.

Simple Compressor.

compressor---limiter-circuit.jpg
(https://www.circuitlib.com/index.ph...simple-compressor-limiter/category_pathway-29)

4 band EQ.PNG
(https://circuitszone.com/4-band-equalizer-circuit/)
 
I know how much work would be involved in developing something like this. I'd love to learn how to design PCBs, been messing around with Dip Trace a little bit.
 
Man, if there was a PCB of a Cloudlifter type thing out there I'd be so stoked. Those things seem way overpriced for what they are yet they are such a great gadget. I see the Bumblebee kit, but looking for something stateside.
 
I'd add JLM audio to the above list of suppliers.

Some really handy utility PCBs, cool projects, good prices, excellent support.
As mentioned above, this stuff gets pricy REALLY fast when you start looking at transformers and cases and PSUs etc etc. You're not going to stumble onto a way to make a Neve pre for $50.

GroupDIY is probably the main forum for that kind of stuff, but I've never been able to figure out how to get a join request approved. There's tonnes of info and schematics and troubleshooting/build threads over there (and also it's incredible what people are able to build) to dig through. That said, it has a... vibe.

Anyway, here's a cool mic pre.

View attachment 13752
Yo, just realised. I live in the same city where JLM is based!
 
Apologies in advance for rambling, but this is basically my day job and I've had too much coffee this am...

I guess the main question would be, as always, what are you trying to accomplish?

Do you want to a fun DIY project? Is there an issue with your recordings that you're trying to solve? Are you trying to save money on gear? What do you already have on hand? What are you trying to do that you can't get done with what you have? What are the needs of the project?

If that's rambling, then my posts must often look like huge tomes, but ones without the scholarly bits... 😸
 
Replying to show my interest in some generally microphone-related PCBs! I'd put a pair of FetHead things in an enclosure for sure.
 
@ryan z here's the schematic for the triton fethead; it's about as simple as a circuit as you could imagine, and you could easily put it together on vero. The XLR connectors are probably 10x the cost of the components.

View attachment 13764
I am an idiot when it comes to jfet. It seems the 2SK170BL is hard to find. What is a suitable replacement here?
 
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