I made this PCB for the Shoeps / Dorsey circuit....

[tv]

@Silvas:

If you're really going to re-work the pcb, and use my advice for the part flipping @input (i.e. aroud the fet gate and the 10gig resistors), then I should add this as well:

When you finally get to the ground-pour around the fet gate traces, don't fill the ground as close to the traces as it is now - better leave some space around (perhaps similar to what you have around the two 100k resistors in the original layout) - so that when the circuit is soldered and assembled, you can use a toothbrush and alcohol and really clean-up the spot around the fet gate, so that there are practically no chances for any parasitics or residues.

 

[bernbrue]

Hi,
I appreciate Silva´s effort to do the pcb layout. Lots of experts chimed in an gave good hints to improve the design. Wouldn´t it be a good idea to have a pcb that is as close as possible to an existing schoeps or neumann mic circuit? Max´s MK7 project made lots of people enthusiastic about building once own mic. Wouldn´t it be better/easier/cheaper for beginners to start with a transformerless solid state circuit? In another thread GUS mentioned that he has something up his sleeve. I think, now is the time.
kind regards
Bernd

 

[livingnote]

Ah, pcb, right - yeah. Sure. Distracted I was with me litany.

What are the dimensions?

 

[bernbrue]

Hi Lukas,
there are some changes suggested here in the thread. Maybe someone of the experts (Rossi, GUS, TV et al) comes with a completely different/better design and is willing to share it.
regards
Bernd

 

[livingnote]

They know what they're doing. I'll be around if you need me.

 

[tv]

Forgot to add this:

Regarding EBC vs BCE, SGD vs GDS transistors - you don't have to add additional pads or even think about it, because it is actually very simple to accomodate f.e. a BCE part into a EBC layout: flip the transistor for 90deg (top view), B lead goes into Bpad, and with just a little twist, C and E leads fit into their corresponding pads. Similar goes for FETS.

In my book, fitting BCE into EBC layout is easier, but I'm from BC108 era.


I think that this circuit should work pretty OK even if 2N3819 and BC560 were used... however, I wonder what would happen if somebody swapped the Zener for a 12V one. Any experimenters out there?

 

[Silvas]

Ah, pcb, right - yeah. Sure. Distracted I was with me litany.

What are the dimensions?

Don´t have the exact dimensions at hand. You just print the PDF on lazertran or something like that, then iron it.

Forgot to add this:

Regarding EBC vs BCE, SGD vs GDS transistors - you don't have to add additional pads or even think about it, because it is actually very simple to accomodate f.e. a BCE part into a EBC layout: flip the transistor for 90deg (top view), B lead goes into Bpad, and with just a little twist, C and E leads fit into their corresponding pads. Similar goes for FETS.

In my book, fitting BCE into EBC layout is easier, but I'm from BC108 era.

You are right. Just wanted the pcb to be "neat" and easy to use. Don´t like bending transistors. At the expense of longer traces and some pads.

I might do a revision incorporating all the suggestions (including the ommited caps but maybe not the DC-DC converter...), when i have some time in my hands (i´m going to be very busy in the studio for quite a while) but this idea is very cool. I wanted to use this PCB with a peluso K47 copy and put it in front of a 26" kick drum. Sort of a poor man FET47, something like that

This thread is very educational, btw.

Thanks for all the suggestions...That´s why i love this place !

 

[reanimatorstudio]

http://www.groupdiy.com/index.php?topic=42836.msg534430#msg534430

 

[vizcities]

Resurrecting this to see if anyone has an equivalent PCB for sale - or, even better, the Gerber files to upload to Oshpark.  This seems like a very useful circuit to make easily available.

 

[homero.leal]

I Think you should PM mr. silva. He is available at this group, and also in facebook.

A few weeks ago, I contacted him and he kindly sent me the Eagle (.sch and .brd) of this PCB.

Cheers!