DIY mic questions

[nacho459]

I'm looking at the G7 project and have several questions.

1) I want the end project to look really clean. I want my clients to feel like they are using a really expensive mic rather than a weird home made pipe thing. After all, for many people it has to look good to sound good. I would love to use the http://www.microphoneclones.com/indexUS.htm U47 body, but I ain't gonna drop a grand any time soon! Many people have suggested using the studio projects C3 and rebuilding it. Does any one have any other cosmetic ideas?

2) I own an NT1 that I am not too fond of. It is a later model that just doesn't sound as good as the first batch. I have to use EQ to keep it from sounding harsh, and I see that as a sign of a bad mic. Does any one know of a good mod for this mic, or is it the diaphragm? Would this be a good body for the G7? Just gut the whole thing, PCB and diaphragm? I saw the NT2 mod, has anyone built a G7 in an NT1?

3) I noticed in the G7 that the heater voltage was rectified to DC, is this a requirement of the tube, or just to keep the 6.3vAC from interfering with the audio signal in the cable?

4) What kind of cable do you use for the mic cable? does it have a separate shielded twisted pair for the audio to isolate it from the power lines?

Thanks :wink: :guinness:

 

[alk509]

*BUMP*

 

[zebra50]

3) I noticed in the G7 that the heater voltage was rectified to DC, is this a requirement of the tube, or just to keep the 6.3vAC from interfering with the audio signal in the cable?

You could do AC if you prefer, although I would argue that is is simpler to get DC to be quiet than AC. AC vs DC has been discussed here before and different people have different opinions. I have some old tube mics with AC heating. Personally I like DC with an adjustable regulator so I can play with underheating regulator

4) What kind of cable do you use for the mic cable? does it have a separate shielded twisted pair for the audio to isolate it from the power lines?

Mogami and Gotham make tube mic cable, and a twisted pair is good. there is some discussion of cables in another thread. Look at the microphone meta thread under G7 project.
hope that helps.
Stewart

 

[Rob Flinn]

has anyone built a G7 in an NT1?

I suspect it would be a little tight if you used the Gyraf circuit board, as from memory the NT1 is smaller than the NT2. It may be possible to shoe horn it into the body if you designed your own circuit board or point to point wired it.

 

[Gus]

Nt1 or Nt1a?

 

[Tim Campbell]

You could always try your hand at building something unique following this technique http://www.timcampbell.dk/micfab.htm

 

[nacho459]

It's an NT1, I got it about 4 years ago before the NT1a came out.

Tim, I like your technique, but I'm not really into the brass look.

 

[Tim Campbell]

You should know that many mic bodies are brass that are then enameled, painted or chromed. If you're going to chrome one of these you must use silver solder to assemble it.

 

[Gus]

An NT1 should fit a royer circuit with no problem. A jensen 12:1 might be the biggest transformer you could fit without more work. The Royer mod should help that microphones high end. The 797 capsules in the Rodes seem to be tuned different in the high end. The voltages and operating points of the royer circuit can have a "warming" sound. If you build the Royer circuit I would suggest a reg heater supply.

 

[ChumpitO]

[quote author="Tim Campbell"]You should know that many mic bodies are brass that are then enameled, painted or chromed. If you're going to chrome one of these you must use silver solder to assemble it.[/quote]

What about powder coating, has anyone seen this on a mic grill?

 

[toby]

if you wanted to use an NT1 (imho a decent mic for the price) you could mount the transformer in the psu if the cable to the psu was pretty short. i think those old sony tube mics(c37?) do this.

 

[nacho459]

:idea: I finally figured out what IMHO stood for...

Yeah. I'm gonna look into getting the royer circuit into my NT1. Right now it is just collecting dust. So I might as well mod it into something useful or use it to crack open walnuts. A while back a buddy of mine sold me a Groove Tubes FET-1b for $84 and it destroys my NT1. Since then it has sat in the bottom of my mic box next to my BLUE Ball.

At first I thought the Royer mod was for the Royer ribbon mics, not David Royer. I saw a TUBE Royer ribbon mic at NAMM, but the rep said it was just a prototype, and they weren't planing to produce them because they would have to sell them for like five grand. That's what I imediately thought of. :shock: