D-EF47 Tribute To Oliver Archut U47 Build Thread.

[EarthTone]

Yes Thank you, a low volume comes out, no low frequencies, only highs
Grazie

Are your voltages coming off of the power supply correct? Did you try any different tubes to rule out a bad tube? Does the behavior happen on all the different polar patterns? Are you sure you have the transformer wired correctly? Assuming the PSU is working correctly, are you sure the 7-pin cable & joining connectors are wired correctly, and that your solder joints on the mic are clean and working correctly with no bridges? Also- Check for bad/cold solder joints, and please check to make sure you have not created any solder bridges between components. Check for problems at the capsule- Either the capsule wiring or maybe the capsule itself has a defect and you can try a different capsule to rule it out as a problem. It could be as simple as one of those problems listed above, which are easy to check for and basic troubleshooting I’d look for first. It could be something more complicated than that, but check there first. Check to make sure that all of the values of the components you have installed are correct. Without more information provided and pictures, we will only be shooting in the dark like this in order to try and help you.

 

[Robby1970]

Thank you very much for the reply, the power supplies are ok, the Ef 800 valve is a Telefunken, I had it tested, Ok, I checked that the soldering was ok, the M7 capsule is new, even if I bought it on Aliexpress, I don't know how to test it, the BV8 transformer always on Aliepress, perhaps it was connected incorrectly, unfortunately I have limited availability. I'll do more tests tomorrow.
Thanks Infinite

 

[Robby1970]

Since I am not a specialized technician how the transformer should be positioned, perhaps that is precisely the problem

 

[Robby1970]

A courtesy, do the 2 Jumpers go on the microphone?

 

[donivan]

Has anyone else experienced large voltage spikes when switching patterns
I've changed the switch
I've got the correct resistor for the 48vdc relay
thanks

 

[donivan]

spikes at the audio out

 

[shabtek]

yes mute channel before switching pattern

 

[JeffKall]

A quiet, respectful cry for help …
I have built 2 of Dan’s D-EF47’s … and I am using Matador’s Universal Tube Power Supply to power them …

They work perfect … I am able to achieve all the proper voltages (I changed R1 and R2 in Matador’s PSU to 82K 1W to achieve 105V B+ … my Heater is +5.05V … I left Bias disconnected …

I used Marador’s 7 pin XLR pinouts:

1 B+
2 Heater
3 POLAR
4 Bias (not used)
5 Audio +
6 Audio -
7 GRND (tied to SHIELD)

Everything is fine with B+ and Heater dialed in to the required voltages …

I used Matador’s PSU 9 position Pattern Selector switch … which feeds the 7 pin XLR Pin 3 POLAR and PTRN (via the microphone 7 pin XLR Pin 3) on the D-EF47 PCB …

I used the RS 48V reed relay …

With a dummy load … when the Omni pattern is selected on Matador’s PSU … OV is sent to the POLAR output (Pin 3) … when I select the position one click counterclockwise from CARDIOD 54V is sent to the POLAR output (Pin 3) …

But when I connect Matador’s PSU to the D-EF47 … B+ and Heater are PERFECT … but the POLAR (PTRN) leg pulls to 0V … regardless of Polar Pattern Selector switch position …

So … the D-EF47 is pulling the Matador Universal Tube PSU to OV on the POLAR (PTRN) leg for reasons
I don’t understand …

But the D-EF47 is essentially “stuck” in CARDIOD … and I have to say … it sounds GREAT !!!

Can anyone tell me what the OLD Norwegian Newbie is doing WRONG ???

BTW … BOTH of my D-EF47’s exhibit the exact same behaviors !

Thank you all in advance for your insights, patience and tolerance with my limited understanding !!!

Best Regards !

 

[Bonnie1]

A quiet, respectful cry for help …
I have built 2 of Dan’s D-EF47’s … and I am using Matador’s Universal Tube Power Supply to power them …

They work perfect … I am able to achieve all the proper voltages (I changed R1 and R2 in Matador’s PSU to 82K 1W to achieve 105V B+ … my Heater is +5.05V … I left Bias disconnected …

I used Marador’s 7 pin XLR pinouts:

1 B+
2 Heater
3 POLAR
4 Bias (not used)
5 Audio +
6 Audio -
7 GRND (tied to SHIELD)

Everything is fine with B+ and Heater dialed in to the required voltages …

I used Matador’s PSU 9 position Pattern Selector switch … which feeds the 7 pin XLR Pin 3 POLAR and PTRN (via the microphone 7 pin XLR Pin 3) on the D-EF47 PCB …

I used the RS 48V reed relay …

With a dummy load … when the Omni pattern is selected on Matador’s PSU … OV is sent to the POLAR output (Pin 3) … when I select the position one click counterclockwise from CARDIOD 54V is sent to the POLAR output (Pin 3) …

But when I connect Matador’s PSU to the D-EF47 … B+ and Heater are PERFECT … but the POLAR (PTRN) leg pulls to 0V … regardless of Polar Pattern Selector switch position …

So … the D-EF47 is pulling the Matador Universal Tube PSU to OV on the POLAR (PTRN) leg for reasons
I don’t understand …

But the D-EF47 is essentially “stuck” in CARDIOD … and I have to say … it sounds GREAT !!!

Can anyone tell me what the OLD Norwegian Newbie is doing WRONG ???

BTW … BOTH of my D-EF47’s exhibit the exact same behaviors !

Thank you all in advance for your insights, patience and tolerance with my limited understanding !!!

Best Regards !

Which xlr pin are you using to engage/disengage the relay? Are you using a double pole polarity pattern switch or separate toggle switch for cardioid?

 

[JeffKall]

Which xlr pin are you using to engage/disengage the relay? Are you using a double pole polarity pattern switch or separate toggle switch for cardioid?

The 9 position pattern selector switch … which I intend to replace with a double pole pattern switch when I understand what is pulling my POLAR (PSU) /PTRN (D-EF-47) voltage to OV …

The D-EF47 “defaults” to CARDIOD when the reed relay is not energized … so the pattern switch only needs to supply 48V - 57.5V to energize and add the Back Capsule for OMNI …

Thank you for your response !!!

 

[Bonnie1]

The 9 position pattern selector switch … which I intend to replace with a double pole pattern switch when I understand what is pulling my POLAR (PSU) /PTRN (D-EF-47) voltage to OV …

The D-EF47 “defaults” to CARDIOD when the reed relay is not energized … so the pattern switch only needs to supply 48V - 57.5V to energize and add the Back Capsule for OMNI …

Thank you for your response !!!

What is your mechanism to de-energize the relay?
You may find this information useful, Polar Pattern Madness

 

[JeffKall]

What is your mechanism to de-energize the relay?
You may find this information useful, Polar Pattern Madness

Thank you, Bonnie 1 …
I appreciate your advice !

In theory … the reed relay should energize when it receives voltage by switching the Pattern Selector switch from CARDIOD (0V) to OMNI (48-57.5V) via the POLAR/PTRN leg (Pin 3 of the 7 pin XLR) … and the relay should de-energize when the Pattern Selector switch selects CARDIOD (0V) and removes the POLAR/PTRN voltage from the relay …

With a dummy load (180K 1W resistor) the PSU works perfectly … supplying 54V when switched (OMNI) and then 0V when switched back (CARDIOD) …

The problem occurs when the D-EF47 is connected to the supply, which pulls the POLAR/PTRN leg to 0V regardless of Pattern Selector switch position on the PSU … effectively “locking” the D-EF47 in CARDIOD, which is not a completely terrible situation !

There is obviously “something” pulling (shorting) the POLAR/PTRN voltage to 0V in BOTH of my D-EF47’s when they are connected to the Universal Tube PSU … which works flawlessly with my other 47 style microphones …

I should also reiterate that aside from this pattern selector issue … my D-EF47’s work perfectly and sound amazing (thank you, Dan!) !

Truly Twilight Zone WEIRD !

 

[Bonnie1]

Thank you, Bonnie 1 …
I appreciate your advice !

In theory … the reed relay should energize when it receives voltage by switching the Pattern Selector switch from CARDIOD (0V) to OMNI (48-57.5V) via the POLAR/PTRN leg (Pin 3 of the 7 pin XLR) … and the relay should de-energize when the Pattern Selector switch selects CARDIOD (0V) and removes the POLAR/PTRN voltage from the relay …

With a dummy load (180K 1W resistor) the PSU works perfectly … supplying 54V when switched (OMNI) and then 0V when switched back (CARDIOD) …

The problem occurs when the D-EF47 is connected to the supply, which pulls the POLAR/PTRN leg to 0V regardless of Pattern Selector switch position on the PSU … effectively “locking” the D-EF47 in CARDIOD, which is not a completely terrible situation !

There is obviously “something” pulling (shorting) the POLAR/PTRN voltage to 0V in BOTH of my D-EF47’s when they are connected to the Universal Tube PSU … which works flawlessly with my other 47 style microphones …

I should also reiterate that aside from this pattern selector issue … my D-EF47’s work perfectly and sound amazing (thank you, Dan!) !

Truly Twilight Zone WEIRD !

Hello JeffKall,
Re-read that link again, and again until you have a Aha moment. (Your voltages with dummy load are not correct)

Polar patterns in this circuit are created by adjusting the voltage on the rear diaphragm 0-120v

A completely different conductor needs to be used to complete the circuit to energize/ de-energize the relay.

Based upon the information you have provided, If you remove the relay from the circuit your Polar patterns will work correctly. (you won't get +3db s/n in cardioid)

 

[JeffKall]

Hello JeffKall,
Re-read that link again, and again until you have a Aha moment. (Your voltages with dummy load are not correct)

Based upon the information you have provided, If you remove the relay from the circuit your Polar patterns will work correctly. (you won't get +3db s/n in cardioid)

Aha !!!

I will happily try removing the reed relay … and routing the PTRN voltage directly to the back capsule !

Thank you !!!

 

[Friedemann]

Hey!

Is the PCB Kit still available?

Thanks and bye Friedemann

 

[Thegoldenlockedlamb]

Hello everyone !



Sorry to bother you with what are probably dumb questions , but this is my first ever tube mic build .



First off I attached a photo of the 7 pin xlr connector, in the diagram Dany attached in post 78 of this thread mentions attaching pin 3 to cable shield and pin 1 also , I was wondering if the pin/tab I circled in red is what he is referring to as a cable shield?



Second question, the diagram Dany posted mentioned pin 3 goes to pin 1 and the cable shield also , then pin 1 goes to A- on the mic pcb , so is it as it sounds that the wire goes from pin 1 to A- on the pcb ? Which means pin 3 doesn’t go to anything on the pcb except by going through pin 1 correct ? Again I’m sure this is a dumb question and i apologize if I missed this being answered somewhere in this thread already . Thanks again !



Ethan

 

[Silas]

Hi Ethan,

I have built the DEF47s a few times:

The pinouts for the 7 pin XLR and 3 pin are different so yes you are correct shield is pin1 for audio (as standard) and pin3 for tube cable (7pin)
You can simply wire the connectors on the PSU as the pinout says - the board has the 7pin connections and 3 pin and routes shield and ground correctly (as well as the rest, audio etc) I have not needed to route the pins 1 & 2 of tube mic directly to XLR 2&3 - leaving these run on the board.

(you can link the ground shield lift permanently on the board as this does not need to be disconnected ever)

The XLR tab is to connect the shield to the connector assembly - you can link this to pin 3 on the 7pin XLRs (which is for shield on the pinout)

Note: Ground and shield are separate lines on the tube mic cable and should be wired as such, you can link them in the connector if you like though.

For the tube mic cable you should have two heavier gauge cables and a copper shield (as well as the other five cables) - these heavier gauge will be for the heater (pin 4) and ground (pin 7 - centre pin on XLR) and the copper shield for the pin 3 shield connection.

I hope this helps,

Silas

Another note: if you have issues with ground noise my experience was to not ground the mic PCB on the rails but at one single point at the connector, this avoids a loop and maintains good safety shield. My ground and shield lines are linked at the mic end - they are also linked at the PCB by default.

 

[Thegoldenlockedlamb]

Hi Ethan,

I have built the DEF47s a few times:

The pinouts for the 7 pin XLR and 3 pin are different so yes you are correct shield is pin1 for audio (as standard) and pin3 for tube cable (7pin)
You can simply wire the connectors on the PSU as the pinout says - the board has the 7pin connections and 3 pin and routes shield and ground correctly (as well as the rest, audio etc) I have not needed to route the pins 1 & 2 of tube mic directly to XLR 2&3 - leaving these run on the board.

(you can link the ground shield lift permanently on the board as this does not need to be disconnected ever)

The XLR tab is to connect the shield to the connector assembly - you can link this to pin 3 on the 7pin XLRs (which is for shield on the pinout)

Note: Ground and shield are separate lines on the tube mic cable and should be wired as such, you can link them in the connector if you like though.

For the tube mic cable you should have two heavier gauge cables and a copper shield (as well as the other five cables) - these heavier gauge will be for the heater (pin 4) and ground (pin 7 - centre pin on XLR) and the copper shield for the pin 3 shield connection.

I hope this helps,

Silas

Another note: if you have issues with ground noise my experience was to not ground the mic PCB on the rails but at one single point at the connector, this avoids a loop and maintains good safety shield. My ground and shield lines are linked at the mic end - they are also linked at the PCB by default.

Hey Silas,

I very much appreciate you getting back to me . I am pretty new to building these so hopefully you don’t pull your hair out with my questions , as I may ask you to explain this like I’m a kindergartner! Haha

Also to clarify , the connector I attached the picture of is the one that goes in the bottom of the mic body and goes to the mic pcb . So the tab on the connector in the picture is what they call the the cable shield ? Or is the cable shield something different ? So If I understand correctly I would run the cables as follows :

Pin 1 of the connector goes to the A- pad on the mic body pcb

Pin 2 goes to the A+ pad on the mic body pcb

Pin 3 i would run a wire from it to pin 1 and the. Another wire from pin 3 to the tab i circled in red in the pic , this I assume is the cable shield

Pin 4 goes to the H+ Pad on the mic body pcb.

Pin 5 goes to the B+ pad on the mic body pcb.

Pin 6 goes to the Ptrn pad on the mic body pcb .

Pin 7 goes to ground pad on the mic body pcb.

Am I correct on the routing of the pin 3 to that tab on the xlr and also to pin 1? Or is something else the cable shield that I’m not familiar with ?

Also I will attach. A photo of the wire I bought based on what a member in here recommend , hopefully I got the right stuff . I got two colors ( black and red ) in 22 gauge and the rest in 28 gauge. So pin 4 and pin 7 get the thicker gauge wire ? If I understand correctly the wire from pin 3 to that xlr tab should be the thicker wire too? Does the wire from pin3 to pin 1 need to be thicker wire too? Do you think the 22 gauge wire is thick enough?

Thank you for your help and time. I apologize for my noobness/dumbness . I just want to not screw this up! Haha

Thanks again !

Best,

Ethan

 

[Silas]

Hi Ethan,

Okay gotya!

- for your mic body here is what I would suggest in terms of pins:

Pin 1 of the connector goes to the A- pad on the mic body pcb

Pin 2 goes to the A+ pad on the mic body pcb

Pin 3 i would run a wire from it to pin 1 and the. Another wire from pin 3 to the tab i circled in red in the pic , this I assume is the cable shield Wire directly to the mic body - this is the shield (shield being the metal shell and so shielding you from electrocution, as it is shielded to the electronic earth via the cable shield [which also surrounds all the inner wires of the cable] and then PSU then IEC - making this the easiest route to ground instead of potentially yourself when touching the mic - this is essential for safety in case of HT components touching the mic body). Also wire this to pin 7 of the XLR in the mic connector. (thicker wire for this)

Pin 4 goes to the H+ Pad on the mic body pcb - (thicker wire for this)

Pin 5 goes to the B+ pad on the mic body pcb.

Pin 6 goes to the Ptrn pad on the mic body pcb .

Pin 7 goes to ground pad on the mic body pcb - (thicker wire for this)

Am I correct on the routing of the pin 3 to that tab on the xlr and also to pin 1? Or is something else the cable shield that I’m not familiar with ? - You can connect the tab to pin 3 but not pin 1 (as this is for audio)

Thicker wire for anything high current - being: heater connection and ground/shield connections - the rest you can use your thinner wire. I personally use multicoloured wires so that all lines are of a different colour to make troubleshooting easier.

Cheers!

S

 

[Thegoldenlockedlamb]

Hi Ethan,

Okay gotya!

- for your mic body here is what I would suggest in terms of pins:

Pin 1 of the connector goes to the A- pad on the mic body pcb

Pin 2 goes to the A+ pad on the mic body pcb

Pin 3 i would run a wire from it to pin 1 and the. Another wire from pin 3 to the tab i circled in red in the pic , this I assume is the cable shield Wire directly to the mic body - this is the shield (shield being the metal shell and so shielding you from electrocution, as it is shielded to the electronic earth via the cable shield [which also surrounds all the inner wires of the cable] and then PSU then IEC - making this the easiest route to ground instead of potentially yourself when touching the mic - this is essential for safety in case of HT components touching the mic body). Also wire this to pin 7 of the XLR in the mic connector. (thicker wire for this)

Pin 4 goes to the H+ Pad on the mic body pcb - (thicker wire for this)

Pin 5 goes to the B+ pad on the mic body pcb.

Pin 6 goes to the Ptrn pad on the mic body pcb .

Pin 7 goes to ground pad on the mic body pcb - (thicker wire for this)

Am I correct on the routing of the pin 3 to that tab on the xlr and also to pin 1? Or is something else the cable shield that I’m not familiar with ? - You can connect the tab to pin 3 but not pin 1 (as this is for audio)

Thicker wire for anything high current - being: heater connection and ground/shield connections - the rest you can use your thinner wire. I personally use multicoloured wires so that all lines are of a different colour to make troubleshooting easier.

Cheers!

S

Hey Silas!

Man thank you for trying to explain this to me like a kindergartener like I asked! So am I understanding you correctly that pin 3 will just be wired to the thing I circled in red on the connector and then also pin 7 ? Or when you said directly to the mic body /metal shell were you referring to the mic’s actual body like the body shell that slides off ? I’m assuming not since this needs to be removed sometimes , but I want to make sure . I suppose also the metal chassis like the pcb is mounted to could be used for this instead also? Again this is assuming you’re talking about the actual mic body and not the thing on the cable I circled in red in the pic .Again I apologize for being a bit of a moron .hopefully you haven’t pulled all of your hair out yet!

I do have all different colours of wire except the two thicker wires are black and red , maybe I should have added a third colour of those also in hind sight !

Thank you again for your help and time .

Best,

Ethan