D-EF47 Tribute To Oliver Archut U47 Build Thread.

[JeffKall]

Hello,
Can anyone tell me if vintagemicrophonepcbkit.com is still selling this PCB? It has said out of stock for some time. Maybe I am years too late?

Thank you!

I recently built 2 of these kits … and I just rechecked Dan’s vintagemicrophonepcbkit.com site and the D-EF47 PCB’s are still available on his Orders page …

https://www.vintagemicrophonepcbkit.com/orders.html

Also … you can email Dan directly for current availability …

He is very responsive !

 

[pjproby]

I recently built 2 of these kits … and I just rechecked Dan’s vintagemicrophonepcbkit.com site and the D-EF47 PCB’s are still available on his Orders page …

https://www.vintagemicrophonepcbkit.com/orders.html

Also … you can email Dan directly for current availability …

He is very responsive !

Thank you Jeff! I did write to Dan, who did respond, and it seems the trouble was caused by the relay, which is out of stock— and no longer being made. I removed it from the order and it went through. Thank you again.
PJ

 

[koki]

Is it possible to find somwhere that relay since it no longer being made ?

 

[JeffKall]

Is it possible to find somwhere that relay since it no longer being made ?

The 48v version is available directly from RS Electronics (formerly Allied Electronics)

https://us.rs-online.com/?gad_source=1&gclsrc=ds

Hopefully this helps !

 

[Silas]

The 48v version is available directly from RS Electronics (formerly Allied Electronics)

https://us.rs-online.com/?gad_source=1&gclsrc=ds

Hopefully this helps !

Yes good shout, I bought this one when building one recently, all good!

 

[Hibernate Audio]

Finished my PSU the other day! Collective cases chassis, pretty tight fit but not too bad with a lot of planning.

Calibrated with 150k and 30 ohms, B+ looked good and H+ was a little high. We'll see how it looks with the mic once I get it built up.

Does anyone have a recommendation for where to buy a nice quality tube?

 

[Cgaines]

Hey guys, I have kind of half assed my way through this build, and have done ok so far. I’m still learning the ropes obviously, but I did run into an issue. How do I wire my M7 capsule? I’ve been through the thread and it isn’t specifically mentioned. My Thiersch capsule has three wires, so where does each wire go? There are two small solder points at the top of the PCB where I thought they should go, but since the back plate is labeled, I feel like one should go there. Please send help, thank you in advance.

 

[Silas]

That’s the photo in the first page of this thread which shows you. There are on the capsule two wires that connect to the diaphragms and one which connects to the mount (on the theirsch capsules - that I have anyway) the mount wire is backplate - connect the diaphragms as front and back depending on how you orientate it in the microphone.

Whilst soldering I usually cover the capsule with something (clean plastic etc) to stop solder spitting near it.

I also where vinyl gloves (ones without powder in..)

Hope that helps

 

[Cgaines]

…oh good lord

 

[craigmorris74]

Just finished my mic with Ari flat 47 capsule, Telefunken ef802, and Moby transformer. Sounds great and is super quiet. TLRT’s grounding diagram is super helpful.

 

[rock soderstrom]

Just finished my mic with Ari flat 47 capsule, Telefunken ef804, and Moby transformer.

EF804 in a U47 style mic? Any changes to the schematic?

Sounds great and is super quiet. TLRT’s grounding diagram is super helpful.

Can you post this grounding diagram? Can not find it...thanks!

 

[craigmorris74]

EF804 in a U47 style mic? Any changes to the schematic?

Brain fart, meant ef802

Can you post this grounding diagram? Can not find it...thank

Check post 656.

 

[rock soderstrom]

Check post 656.

 

[Cgaines]

Ok, I got everything setup and ready to test, so I powered it on. No explosion, so it was great. I checked my H+, great. Checked B+, and it’s 200v… what did I do wrong!? Also, can this voltage hurt the capsule? I’m in the US, so I’m on 120v mains. Also, just to make sure I’m testing correctly, I have a lead from my DMM clamped to the ground on the IEC. Then I’m using, what I assume are test points, on the PCB labeled “H+” and “B+” to measure the values. In DC on the DMM. Is this correct? Where can I start? Should I throw up?

 

[mrgrooves666]

use dummy resistor or plug the mic while setting up b+. PSU on its own with no load will give you higher b+

 

[Cgaines]

use dummy resistor or plug the mic while setting up b+. PSU on its own with no load will give you higher b+

I had the mic plugged in when I was trying to setup the values. The 200v was with the mic load

 

[mrgrooves666]

I had the mic plugged in when I was trying to setup the values. The 200v was with the mic load

Then review your transformer wiring and drop resistor.

 

[Silas]

I had the mic plugged in when I was trying to setup the values. The 200v was with the mic load

Worth checking for dry solder joints on the PSU, there are points where the voltage is dropped but if they’re not quite connected it will stay high

 

[Cgaines]

Then review your transformer wiring and drop resistor.

Ok with everything plugged in, I get 360V at R1 and then 260v at R3. From the transformer, I have the yellow and black going to the 230v section, the blue and violet tied together at the hot side of my switch and the orange and red are soldered together and set aside. I used the drawing at the beginning of the thread for my wiring. Any thoughts?

 

[rock soderstrom]

Any thoughts?

Don't take offense, but what you're doing is too dangerous. You have no idea what you're doing and you're fiddling around with things that could easily kill you.

That's why no one likes to help you kill yourself, the danger is totally real.

Don't you know anyone you can at least do the power supply with? You could learn and then do it yourself later on. This is really too dangerous, your mains connection knows no mercy and even if you don't get a direct electric shock, you can put yourself and your family/friends in real danger later with a faulty power supply--> fire hazard!

Don't get me wrong, but the questions you're asking clearly show that you're beyond your capabilities and it's just too dangerous for that here. Seek help locally...