DIY Mic Amp- Clean, Transformerless, Battery Powered, Discrete, Sonosax-esque.

[Jarno]

Note that if you're thinking about actually using the THAT 1570 / 1580, that is a tiny QFN package that is only 4mm across total. You'd have to be Ant-Man to solder that.

Not sure if you are up for the learning curve, and, I am not sure how QFN relates to SOT363, but Seeedstudio now has metal stencils with their PCB's for little money.
I couldn't hand solder those BCM847bs's anymore, so I ordered a stencil with my latest PCB's and tried my hand at reflowing.
Works pretty well, I am using a manually operated toaster oven, with a cheap temperature sensor and a stopwatch.
Getting an appropriate layer thickness of paste with a squeegee is a bit of trial and error (as are the switching points when to turn oven off and on). But I am getting the hang of it.
It is not quicker when verifying boards (so for a single, first, board), but you can do 3-5 instead of just one.

 

[Newmarket]

damn, thats not happening. I guess 1510 it is, or discrete.
Re-reading my copy of The Art of Electronics to try and figure out how to make a BJT based mic preamp.
I could actually go unbalanced out, possibly further simplifying the design..
How do I make a really high quality BJT based mic preamp with modest gain that only needs to serve known impedance condenser mics? Any links or books?

The Horowitz & Hill book is great. But to get more directly into the audio side of things read the relevant sections of Douglas Self's Small Signal Audio Design book. And there's loads of schematic info out there to consider.
That's assuming you want the challenge of the electronics.
If you simply want to DIY a hi fi, linear, low distortion and low noise solution then the THAT or similar solutions are your best bet.

 

[PRR]

> How do I make a really high quality BJT based mic preamp

Is the "BJT" a vital specification?

And FWIW the THAT chips are BJT based. (Study of their innards might be entertaining.)

 

[L´Andratté]

Also check Samuel Groner´s site for high quality preamp designs, that are not "THAT"...!
http://www.nanovolt.ch/resources/microphone_preamplifiers/index.html

 

[JohnRoberts]

damn, thats not happening. I guess 1510 it is, or discrete.
Re-reading my copy of The Art of Electronics to try and figure out how to make a BJT based mic preamp.
I could actually go unbalanced out, possibly further simplifying the design..
How do I make a really high quality BJT based mic preamp with modest gain that only needs to serve known impedance condenser mics? Any links or books?

Modest gain(how much?), known impedance condenser (what impedance?).

The off the shelf ICs are BJT and proven technology. If compelled to roll your own, you might make a passable low gain, high impedance pre using some of the modern low noise JFETs.  I am not a big fan of reinventing wheels. Back in the day we used discrete BJT (with op amps wrapped around them) because they were better than we could make using off the shelf solutions. Today this is no longer the case.

JR

 

[dlozanothornton]

> How do I make a really high quality BJT based mic preamp

Is the "BJT" a vital specification?

And FWIW the THAT chips are BJT based. (Study of their innards might be entertaining.)

No, BJT, FET, whatever! I can probably put together a THAT schematic, but I'd like to learn a little bit more and maybe I could adapt and change this project over time as my understanding grows, so that's what I'm trying to find out. The Art of Electronics is a not very geared towards audio. I just picked up Douglas Self's Power Amplifier book (might be interesting even though it won't entirely help me with this project), unfortunately the provincial library system doesn't seem to have many audio circuits books.

 

[dlozanothornton]

Also check Samuel Groner´s site for high quality preamp designs, that are not "THAT"...!
http://www.nanovolt.ch/resources/microphone_preamplifiers/index.html

Thank you! and everyone!

 

[Newmarket]

No, BJT, FET, whatever! I can probably put together a THAT schematic, but I'd like to learn a little bit more and maybe I could adapt and change this project over time as my understanding grows, so that's what I'm trying to find out. The Art of Electronics is a not very geared towards audio. I just picked up Douglas Self's Power Amplifier book (might be interesting even though it won't entirely help me with this project), unfortunately the provincial library system doesn't seem to have many audio circuits books.

Self's 'Small Signal Audio Design' book would be more relevant. Good coverage of mic pre design detail.
Also THAT have some excellent material on their site whether you use their chips or not - AES presentaions etc.