Gyraf g7, a DIY tube microphone | part.1 ordering stuff

As I was waiting for my cases to rack my latest projects I thought about starting yet a new project. I had some PCB laying around that I bought a while ago in frenzy of "I want moooore PCB" and dug in my treasure chest to find a g7 tube mic.

A word about the g7: it's a tube mic designed by Jakob Erland, the guy at Gyraf Audio in Denmark. His contribution to the audio DIY community is invaluable, and beside offering some high end audio tools, Jakob has a nice DIY page. The mic is an original design based on the famous Neumann U47, AKG C12, with the Neumann U67 tube (EF86). That's quite a pedigree...
As with all the tube mics, you need an external power supply because tubes need high voltage to work. No phantom power for those. And as a reminder, those high voltages are lethal, so don't die building a mic...

The starting point is that I bought 2 of them, one had already quite a few components soldered and the second is just the bare PCB. So I started to complete the one already soldered. And the starting point is to order everything that is needed. And I suddenly remembered that a PCB and components are mostly cheap, but it gets expensive real fast with metal work, transformers, tube, connectors and so on... And you need to find a capsule...

The capsule

I bought a C12 capsule from microphone parts. Fast shipping, unbeatable price. It's not the best on the market, chinese product but with high standards. A lot of people report that their capsules just work really well.

The PSU,

I bought the parts from Conrad as they have cheap shipping costs. Still they managed to break this little order in 4 different parcels, one I'm still waiting for...

The transformer

I bought the expensive Lundahl 1538 as proposed by Gyraf. OEP is also fine, but I wanted a high quality build this time. The don audio shipped the transformer really fast, thank you.

The tube

I bought 4 used ef86 on eBay. Let's see if they are as good as the seller claims. At least they look clean and fairly unused

Let's build the thing!

DIY Monitoring controler from IJ Research | update

After a really long time, I finally got into debugging my monitoring controler from Igor (IJ research).
It didn't work for quite long and I eventually found 2 mistakes:
- wrong power connection... (OK, shame on me, this shouldn't happen)
- some pins of my test VGA cable were shorted to the shield so the power supply was not working anymore. I changed the cable and it's working.
Here a quick'n dirty video
It's moving! and it blinks!

Well I should be cautious with saying this, because it just responds as expected, display, LEDs and buttons. I need to make a custom db25 cable to test the input-output with audio. And then I can say if it's really working and passing audio.

And then I just need my brother in law to CNC a nice case for this one and integrate it in my setup.

As chunger says: human wins

Yeah, power supply is working!

Hi there,
I'm pleased to announce that I managed to have the power supply for the innersonix lucidity preamp work.
As I had a bit of respect for 220V, a friend helped me wire the transformer and explained roughly how such a supply is working. After that I got power but the 3,3V was missing and the LED wasn't working. After a message to Alex from Innersonix he told me I should cut pin 7 from one of the regulator. It was written in the groupdiy forums but I somehow missed it ( or forgot about it). so I cut the pin and it worked...

I just need to wire everything now and let you know