stagnant and a solid state follower circuit

[Gus]

Why do people build clones and not expand, adjust microphone circuits?

A number of tube microphones are simple circuits

Plate/anode out cap to transformer. This is simple in principle but harder because of imperfections  of components. You need to understand the interactions.
Followers, except for  direct coupled grid to charge the capsule C60 etc Why?
Possible microphonics is this what people want?


Now solid state is more interesting
The TLM170 is an interesting circuit.
A few companies have worked with the 87 like circuit and changed things for an different adjustment
Transformerless is fun to work with.
If I was to build a follower I would make it solid state unless it was something like the C60 input
Hybrid circuits can be fun working on one now.

Solid state and DIY you can now buy a lot of different parts to build a microphone.

It surprises me that people have not DIY built focused microphones for certain uses.
Here is one cut and paste type build
AKG first stage low parts count and it bootstraps the drain
No DC to DC.
low voltage capsule charge can be adjusted lower.
Try different ratio and size and lam and winding transformers.
Other things to try, adjust the biasing and transistor numbers and operating currents


Think loud sources like drums yes the SN might not be the best but it is only a small amount of parts.
I like other followers circuit better but this should have some distortion and it is two transistors and not many other parts

I have not built it yet it is in the list of things to build and try.

 

[rockinrob86]

I think it is because different people diy for different reasons.

I am 33, and enjoy electronics and enjoy learning about how things work - to a point.  I am a songwriter/musician first, and a recording engineer next because I want to have the control over my sound.  I diy because I can trade my time while learning some things for high end performing gear, without paying high end cash.

I build clones instead of designing new mics because a) I don't really know what I'm doing.  b) I do all of this to write and record my songs, record parts for other people's songs and to record my friends, so I don't really need to reinvent the wheel here.  c) I've read a ton from engineers who made my favorite records, and I generally know what mics were used on what. 

Let's use a U47 for an example, because it is nearly ubiquitous.  I know the terms people use for this mic and the general uses - "huge" "Detailed but never harsh" "Velvet", blah blah.  The point is, I know what to expect.  I built one, with a well documented project, easily found parts and choices for components.  My mic sounds fantastic, and I completely understand the terms I have heard used to describe this mic.  I have a thinner more midrangey voice with sibilance issues, and the mic I built fits me VERY well, as expected.  I plug it into one of many preamps I have built, and I get a great sound in minutes - I'm very happy, no need to change anything here.

I've also built clones of 251, u87, u67, u47fet and km84, and I installed new transformers and 1.8 micron ribbons in several chinese ribbon bodies.  All of these mics work as expected, blow any commercial offerings at similar prices out of the water, and beat or equal mics for multiples of the prices I have into them.

I don't know if my U47 sounds identical to a real one.  I spent maybe $1K on the parts - poctop m7 capsule, ioaudio body  and transformer (bought used), gotham cable, zayance power supply.  I don't know if it is 80% there, 95% there, 99% there.  I don't particularly care even - it sounds fantastic and there is almost no way I can imagine ever spending $10K on a mic. 

Could I do a lot more studying and start designing mics?  Yes.  Is it an interesting project to me at this time?  Not really.  I'm very happy with what I have?  Could I continue on the DIY path and end up working on my own designs in the future?  Based on my progression over the last 10 years since I picked up a soldering iron, it actually wouldn't surprise me if I devote time to this at some point.  But for now, I want to spend that time on other things.

 

[midwayfair]

I built or breadboarded several pedals before I started making modifications to all but the most simple circuits. It took me about a year and close to 50 pedals before I came up with something cool and unique.

Guitar pedals are CHEAP. And you can breadboard them easily. I was able to easily transport that knowledge to a couple rack compressors and especially preamps. But microphones are much, much harder to do anything with. Because the circuits are so simple, parts that can be really hard and expensive to play with (capsules) play a much bigger role. I don't even own the tools to experiment with capsules. Hell, I can't even measure anything except their capacitance with what I have on hand. What good does modifying a circuit do me if I can't empirically pinpoint its real-world effect on the sound? It was expensive enough for me to build several FET microphones so I could hear the difference between a few transformers. And that's before I get to physical modifications like the headbasket mesh!

 

[Winston OBoogie]

A lot of people who want to build their own stuff maybe don't feel qualified to do a from scratch design of a microphone?

Very possible that, for what they're doing, a  U87, U47, C12 et al. type works really well for the stuff they record.

Solid state follower with, maybe, its own dedicated 60V power supply rail for capsule and elec. would be cool.  I'd like to try a few things one day.
It's possible that the benefits of a super-duper design on that type of thing may only be of much benefit to the guys who need/want to chase that top extra 5-10% ?  of performance.  Classical recordists etc.

Why not do a design you think is  worthy and offer it up, you're more than qualified to make it a great one.

 

[RuudNL]

I think most DIY builders trust that the manufacturer of a proven design has optimized the circuit as much as possible.
"If it could have been better, the manufacturer would have done it"...

 

[Winston OBoogie]

I think most DIY builders trust that the manufacturer of a proven design has optimized the circuit as much as possible.

Yes, there's that.  Even if it's optimised within a certain price point, it's maybe good enough for what they want to do.

 

[Gus]

Myself and others have posted circuit ideas in the past.
The square microphone circuit  and pictures
Attached is a picture of the side view of the square. EF86, 200VDC B+, LED bias with helper current, direct to grid input, cardiod only switch, HBHO CK12 like capsule, tapered grill,  pattern control on body.
Grill build is a little ugly it is a prototype

I did post a solid state follower cut and paste in this thread. The AKG 414 EBs and Sony C38B circuits look like good DIY follower circuits to build and learn from and you might like them the nice thing is it looks like you can adjust for JFETS.

Something that might make people hesitant about posting a circuit is that someone will take it and start a company. That makes sense why some people don't post.

 

[RuudNL]

Are there separate connectors for audio and supply/polarisation voltages?
The V-shaped headbasket looks interesting.
I didn't see this shape before in commercial microphones, but there may be a lot of advantages.

 

[Gus]

Separate 3 pin XLR and power pattern control cables. This is not new I believe other microphones have this.

Attached is a back view

The grill was due to something I read about a trademark. The grill could be made nicer looking and I will change the capsule grill environment when I get back to working on this microphone.
Funny thing, people sometime react in a positive way to how this  microphone and some guitar effects I built(I have built effects in soup and coffee cans when I did not have a nice "standard" effect box and I want to finish the build) they like the homemade/crude look.

 

[rogs]

Something that might make people hesitant about posting a circuit is that someone will take it and start a company......

I wondered that when I posted both my  'Schoeps' style  project notes here:  http://www.jp137.com/lts/LDCX2.notes.pdf  -- and even more with my RF project here:  http://www.amx.jp137.com

But I think it's unlikely -- and even if they did, I think I should probably just be flattered

I'm much more interested to see how others get on  - and perhaps modify and improve on my  circuits ideas?..

We are, after all, primarily a DIY hobby forum...

 

[Winston OBoogie]

Cool, thanks Gus. 
Yeah I like  the idea of isolated audio and power.  If I were to do a solid-state mic for myself, I'd most likely  forget about using P48 and just use a dedicated power supply and use a 4 pin XLR on the mic.  Or 5 pin if it was bi-polar voltages. 

I've done lots of other audio designs but I'm new to having this urge to design/build a good mic so I'll search through past posts from you guys. 

I get it on being wary of someone stealing new circuits posted on here for profit.  I know there've been a few that were basically re-hashes of clone/vintage circuits (I believe a couple have been sold commercially from schems I've posted) but I don't know of anything that come from a complete new idea on here.  I was away from the forum for some time though so ?

Anyway, cheers Gus, time to do some thinking and reading.

Oh, P.S.  Nice one on the LED bias for your tube mic, that's exactly what I would do myself, even if it was just basically another  U-47/M49 type build. 

 

[Winston OBoogie]

I wondered that when I posted both my  'Schoeps' style  project notes here:  http://www.jp137.com/lts/LDCX2.notes.pdf  -- and even more with my RF project here:  http://www.amx.jp137.com

Nice work Rogs.  I hadn't seen those before, thank you.

 

[Winston OBoogie]

I didn't see this shape before in commercial microphones, but there may be a lot of advantages.

It reminds me of that shaver looking Milab Mic (I forget the model number) but it's not really the same and I like idea of Gus' V shape too

 

[Gus]

Looking on the web for stuff about the C800g clones Some of what I read makes me wonder if I should post about what I think the designer of the C800G was thinking with the design.

An idea came to me on how to work with the stock tube and adjust some of the circuit for possible longer tube life and something else

I drew up a circuit adjustment and started simming things. Thinking I might have found something a little different for a microphone, I phoned a member to talk about the circuit and they said they had a similar idea. 
I then remembered NewYorkDave posted a microphone  similar circuit some years ago. Unfortunately the image is no longer in the NYD thread.  Anyone hear from NYD?

So if this circuit is interesting to two other people and myself why have I not seen a microphone schematic based on it?
Maybe I will post it after I finish installing it in a microphone using a 6AU6  I built.

I am posting this because to me this place is more fun when people are not just copying circuits.

Anyone look at the solid state follower circuit? I was thinking drum microphone when I did the cut and paste.

 

[Gus]

Something simple and easy to build for a drum microphone etc and hardly any replies?

Maybe the microphone forum should be renamed "build "clones" of circuits"

 

[Moby]

Most of the DIY  guys are just musicians or producers who want to have "vintage sounding" microphones for less  money. So, they stick to well known designs because it's "vintage" or because it's simple. On the top of that nowdays big mic manufacturers went to SMD and transformerless and mostly avoid rare tubes (hard or impossible to find large batch of tubes) so there is a chance for individuals to build clones of those "good old mic's". Maybe I'm wrong, but that's how I see the situation

 

[Gus]

I will try one more time

Do people "get" what shared with the schematic?

You can use that  transformer you removed from the China N channel PNP circuit you find.

 

[abbey road d enfer]

I will try one more time

Do people "get" what shared with the schematic?

You can use that  transformer you removed from the China N channel PNP circuit you find.

Is it purposedly that the xfmr in your schemo is a 3:1?

 

[Gus]

Is it purposedly that the xfmr in your schemo is a 3:1?

It was posted as a circuit starting point

Just some random >= 1.88:1 or what ever the China transformer is in a N channel PNP circuit.
One can drive a higher ratio for a pad and to get more distortion from the circuit for the same output level.

DIYers should experiment you are building a microphone, how hard is it this change parts to test ideas?

I make the capsule voltage variable on some of my builds.
A way to think about this is the gain and master volume interaction on a guitar amp.

More capsule voltage more drive to circuit pad it down with the transformer.
Same capsule voltage move the microphone close to say a guitar cab speaker lower the voltage and/or increase the transformer ratio.

The circuit is a low parts count one, should be an easy build