Royer MOD + DALE's M7 capsule - possible multi pattern DIY ?

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Purusha

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I am just about to start the MIC DIY project with Dale's M7 capsules and Royer MOD circuit inside Ioaudio's mic bodies.

I have all the parts together, just don't know exactly how to make the Royer MOD circuit multipattern.

Anyone tried this before?


Mic2.jpg
 
Piece of cake :razz:

The multipattern switch is usually done inside the PSU box and all it does switches bias voltages on the capsule.
Look at the G7 on Jakob's site. IIRC, it has a well written description. I think 60V would be good for M7, so your PSU should have at least 120V.

Best, M
 
[quote author="Purusha"]I have all the parts together, just don't know exactly how to make the Royer MOD circuit multipattern. Anyone tried this before?[/quote]

I have a schematic and PCB designed that is the Royer mod with the G7 switching setup if you're interested.
 
[quote author="bigugly"][quote author="Purusha"]I have all the parts together, just don't know exactly how to make the Royer MOD circuit multipattern. Anyone tried this before?[/quote]

I have a schematic and PCB designed that is the Royer mod with the G7 switching setup if you're interested.[/quote]

Hey! If you want, just post it with no reverences like "if you want it"!
I mean... I am way too lazy to start making drawings... :twisted:
 
ok guys, here it is.




I have the gerbers also. if anyone wants 'em just PM me with your email and I'll send them over.

have fun,
James

I forgot, the 3 large holes at the top are for teflon insulated pins that I have. if anyone wants some for their mics I can send some to ya.
 
I guess you have tested this idea in real life, right? :razz:

Looking at your photos I am still not sure I understand how to control the "pattern" thing in the PSU box.

Do you have the PCB layout, too?
 
The psu voltage control works in that way that you make a voltage divider in the psu derived from the B+ for example with the necessary voltages for the patterns you like.

The front of the diaphragm is always polarised with the same voltage. At ground potential if i remember correctly.

The backplate is constantly polarised with half of the B+ voltage (look at at the 470k voltage divider).

That makes the front have a potential difference in regards to the backplate of half B+

If you send 0v to the back diaphragm you get an omni pattern because both the front and back diaphragms are polarised with the same voltage.
half B+ to the back means cardiod.
B+ means figure8

And then theres alot of other patterns inbetween. But i dont remember the formula for calculating them.

You should probably read the info about the g7 on gyrafs homepage. Its all very nicely explained there.



Oh yeah i almost forgot. If you have a couple of those teflon washers left bigugly, id like some if possible. Id like to try this circuit sometime soon.

/J
 
Purusha, I've built or modded almost a dozen mics using this circuit and PCB. It works fine. I do have a couple of PSU layouts. When I get back to my computer at home I'll post 'em.

Jonkan, PM me your address and I'll send some. (How many do you need?)
 
Okay, here is the PSU.



I have gerbers for this also. R1 on the schem should be adjusted to get the right voltage under load. A JAN5840 tube has a max anode voltage of 165 volts. I usually run my B+(measured at the PSU) at 120v under load.

Purusha, the washers are teflon insulated pins. They go into the 3 large holes at the top of the mic PCB. The capsule leads get connected to them on one side and some components get soldered to the other.
 
I understand that Royer no longer sells the mod kits for the MXL 2001. I would LOVE to try this mod but I have never taken on PCB making or breadboarding. Is there a possibility of some PCB's being made for this, or am I just shit out of luck? I'd be willing to buy a couple of PCB sets.

Adam
 

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