U47 with Phaedrus VF14 M tube

[TLRT]

Hello Do you sell this microphones?

Yes,now out of stock,but I sell when all parts are available.

 

[ZHOUJUN]

Here is the clip for my U47.

Could you tell me what the U47 capsule, thank you!

 

[JW]

Would the D EF47 power supply be a good place to start for a point to point EF12/EF13 setup?

 

[Purplenoise]

Would the D EF47 power supply be a good place to start for a point to point EF12/EF13 setup?

Yes why not? I just did the same thing with the D49. Changed it to p2p and kept the psu from D49

 

[elstongunnn]

Hi Oscar

I'm planning to also build a u47 with tiersch m7, BV8c and phaedrus VF14m. I'm noticing there's no polarity switch on the mic, so I guess you put it on the PSU ? Did you adapt Oliver Archut alternate schematic ?

thanks

 

[abbey road d enfer]

Hi Oscar

I'm planning to also build a u47 with tiersch m7, BV8c and phaedrus VF14m. I'm noticing there's no polarity switch on the mic, so I guess you put it on the PSU ?

I assume you mean the directivity pattern switch. Fitting it in the PSU allows almost infinite choice of directivity patterns.

 

[elstongunnn]

I assume you mean the directivity pattern switch. Fitting it in the PSU allows almost infinite choice of directivity patterns.

Indeed , seems like the best choice
I'm trying to see how much modifications I need to do from Oliver's schematics that are adapted for an ef800 and not a vf14m

 

[abbey road d enfer]

I'm trying to see how much modifications I need to do from Oliver's schematics that are adapted for an ef800 and not a vf14m

The indication on the schemo indicates that an EF800 can be used without modification to the schematic.
However, with an EF800, the ratio of R2/R3 may need to be adjusted for setting the optimum operating current, which should be around 0.5 mA.

 

[Potato Cakes]

Indeed , seems like the best choice
I'm trying to see how much modifications I need to do from Oliver's schematics that are adapted for an ef800 and not a vf14m

When I built my U47 with those exact same specs I had asked one of the guys at Tab-Funkenwerk about doing a remote polar pattern switch with a VF14M and his response was that he never saw Oliver use one with a VF14M so I just used the traditional switch on the head basket scheme.

Thanks!

Paul

 

[abbey road d enfer]

When I built my U47 with those exact same specs I had asked one of the guys at Tab-Funkenwerk about doing a remote polar pattern switch with a VF14M and his response was that he never saw Oliver use one with a VF14M

That is not a good reason for not doing it. One may question the real benefit of having the switch in the PSU, but there is nothing wrong with it.
Guru's opinions should always be challenged.

 

[oscarhuang]

Hi Oscar

I'm planning to also build a u47 with tiersch m7, BV8c and phaedrus VF14m. I'm noticing there's no polarity switch on the mic, so I guess you put it on the PSU ? Did you adapt Oliver Archut alternate schematic ?

thanks

I only used one side capsule, cardioid

 

[TLRT]

Just don't derive the reed relay voltage from B+, as those relays break sometimes and without the reed relay's fixed load your B+ will double, say goodbye to you capsule in some cases.

 

[Potato Cakes]

That is not a good reason for not doing it. One may question the real benefit of having the switch in the PSU, but there is nothing wrong with it.
Guru's opinions should always be challenged.

I agree. I believe the reason was not so much for the sake of being a purist but that there was no good way to incrementally change the polarization of both sides of the capsules using the schematic as is, which is what I think TLRT is saying. And with the minimal knowledge I had years ago when I build the microphone, I didn't know what need to be altered and/or added to achieve remote pattern control. And those parts were expensive so it would have been doubly sad to destroy them with my ignorance. And in the end, I really only used it in cardiod.

That being said, I would welcome someone figuring out how to do a remote polar pattern with the VF14 schematic.

Thanks!

Paul

 

[abbey road d enfer]

I agree. I believe the reason was not so much for the sake of being a purist but that there was no good way to incrementally change the polarization of both sides of the capsules using the schematic as is, which is what I think TLRT is saying.

No. The circuit as is, is ready for remote setting of directivity pattern, controlled by the voltage on pin 1 of the 7-way connector.
Actually, for correct cardioid operation with a dual-diaphragm capsule, this pin must be elevated at about 63V.
That is what TLRT should have said.
Now if you're using a single-diaphragm capsule, you don't have to.

That being said, I would welcome someone figuring out how to do a remote polar pattern with the VF14 schematic.

It just takes feeding pin 1 with a variable voltage. 0V makes omni, +126V makes it fig-8. *
This is usually done either with a rotary switch and a chain of voltage dividers or a potentiometer.

* That is if the values of R6 & R7 are correct...