S*E*5000 tube mic schem

I reversed this circuit that came out of the body I now use for my G7.
I think I've traced it right, but if you want, I'll check anything you doubt.

What are your thoughts on this circuit?
I have a good 6072 in it but it came with a 12at7.

I plan on trying this circuit with a better transformer and a lollypop M7. Before my G7 was assembled I tried out the Gefell MT711 M7 capsule with it. It was smoother but I think a good transformer might help it a great deal.

www.geocities.com/pepperplace/se5000

EDIT 270M resistors should be 270K

Lance

http://www.groupdiy.com/index.php?topic=633

I heard Apex came out with an S.E. 5000 clone.

hey Gus ,
thanks for the link, lots of food for thought there. Nady is the same cicuit. I had two of these SE mics. One has mega bottom. I just let a friend have it. The one I'm messing with has OK ottom . Maybe they have different capsule than the Nady's. also...(edit) R8 is not in my mic, tube pin 8 to grnd and output is off pin 1. Low mid are too much and the high end is harsh/tinny.

cheers,
Lance

I noticed the SE5000 takes the output from pin one of the tube as Scott
Humphrey suggested as a mod to try...




10:1 is not intelligent to cathode follower output transformer,
use 1:1 - 4:1.
xvlk[/quote]

Isn't that why these companies are using a cathode follower circuit--to make up for the cheap, low ratio output transformer? If you have a good 10:1 transformer, you might try disconnecting the cathode follower part of the circuit (the second half of the tube). Run a wire directly from the first half of the tube at the plate (pin 1) to the output capacitor (c8). This makes the circuit very similar to a ela m251.scott_humphrey[/quote]


I guess that is why the SE5000 has decent low end.

CJ , I bet you are right about the Apex. It seems like many of these chinese mics are using a variation on the same circuit. Kinda funny.

cheers,
Lance

lookin at the very similar tube mic schematic recently posted I
realized that the schem I posted here has errors. The resistors marked 270M should read 270K.

Lance

it looks like they just ground out the whole second half of the tube
when they could have at least wired them in parallel !
I have been trying to find the apex 460 schematic [ ANYONE ? ]which
apparently uses both halves of the tube [ the classic AKG C-12
only uses one half for a cathode follower , the c-24 then uses
both ]

Regards Greg

parallel is not what you want. Remember the old gefells used a tube that is 1/2 of a 12at7.

http://www.groupdiy.com/index.php?topic=7759


The nady 1050 is the same circuit and I get rid of the CF change the tube and operating points etc..... That stock china circuit is very "broken"

I should be working with someone on this china microphone circuit. I have a few different mods for that china microphone, that I have developed in my two nadys.

One is a low cost (labor only) one that I have not seen anyone do but me.

I think the mods will be sound documented so maybe in a few weeks there will be some news.

There are a few different things that can be done

The power supply has design problems.