A new Earthworks product..

[Svart]

surface mount or through hole? standard sized through hole will make this bigger than can fit in the mic. i can bunch the stuff up and make odd sized through hole arrangements to make it fit.

any opinions?

 

[Svart]

ok finished a through hole version, most of the Resistors will stand up, same for the diode. I don't know what kind of caps I'll use yet so I might need to tweak some spacing and move some things around. I left space for the larger electrolytics to lie down on the board.

It's in Circuitmaker2k

anybody want to host the .pcb and .ckt files?

 

[Bear]

Ok, I must be outta tweak practice. I've unscrewed the little guys retaining the xlr plate in my ECM-8000's, pulled out the circuit boards from the bottom (interestingly wrapped in some semi-rigid clear plastic), but they're tethered in and can't be fully extracted. Do the "stalk" or the "nose cone", if you will, disassemble so I can complete the extraction? I assume I need to snip some wires somewhere, but right now I can't even get at the wires to snip.

(I've got one of the non-transformer versions, btw.)

Bear

 

[Svart]

i accidentally pulled the wires loose from the capsule, that's how i got it out. however i since learned that the nose of the mic where it looks like a seam is actually a seam and the nose is GLUED on. I buggered the nose up getting it off but i think some gentle heat will release the glue and allow it to come off. the nose is brass and very soft so any pressure from pliers or the like will cause scratches!

both of mine have the electronic boards too, not the trafo boards. i think the concensus was that the trafos were cheap china made and likely not very good. a redesign of the electronics was easier. If i can find a host I'll be posting the PCB file next tuesday when i get back into the office.

:guinness:

 

[adrianh]

My 2 commits;

MCM does sell the Toshiba fets but they are very poor and need to be reprimanded. They have been bad and they need to know it.
There is no such part number as 2SK170 or 2SK389 !!!!!!!!!!!!!
They do not specify the Idss grades of the fets they sell. The suffix is either GR, BL ,V.
So it is
2SK170GR
2SK170BL
2SK170V
and the same for the 2SK389(suffix)

Every time you order from them they ship out a different one.
The fets Idss (transconductance) varies greatly and you must
use the correct part for the right application.

*************
How do you take the ECM8000 apart. I though the capsule part unscrewed?

 

[Svart]

the 2sk170s from MCM are BL suffix.

the FET in the capsule is: 2sk3372
http://www.semicon.panasonic.co.jp/ds/eng/SJF00032BED.pdf

just an update. still stuffing my new boards, got the capsules modded and installed.

 

[Svart]

ok the ECM8000 rebuild are finally done and working better than expected!

actually with the new capsule w/linkwitz mod, the circuit by Marik and my new PCBs, these things rock! I've found a secret weapon for a few things in these mics...

I have the finished and tested Circuitmaker and Traxmaker files for the circuit and PCB. i'm going to be making a few more of these from scratch, body and all, so I'll be documenting the build with pictures and maybe an autocad layout of the body of the mic...

so i need a host for a couple of files and an MP3 of the mics in action.. any takers?

:thumb:

 

[Marik]

Here is my ECM8000 schematics and layouts, drawn by Svart:

 

[Svart]

If you want/need the original Circuitmaker/Traxmaker files, PM me with your email addy and I'll send them to you.


just some info/tips about the layout:

the Jfet througholes are spaced for either two single 2sk170 or one 2sk389(which i used).

all resistors should be 1/8w and all parts stand up.

I used Nichicon VZ series caps because they are the smallest diameter and length i could find in a regularly availiable cap. they are mounted parallel with the pcb.

for the 1uf coupling cap i ended up using a polyester and mounting it on the trace side of the board.

the body of the ecm8000 has 3 small ridges that stick out into the board cavity. try as i did, I couldn't get everything to fit in there without reaming those out. a 5/8" drill bit worked fine.

thanks again to Marik for his circuit and for hosting!

:thumb:

 

[Marik]

Here is the sound clip:

http://home.comcast.net/~markfuksman/drums.mp3

 

[Svart]

it's just the "ECM8000s" as overheads, a kick mic and a snare mic.

 

[Bear]

Lots of tom through those overheads - probably better than a lot of mics at removing the need for separate tom mics, just to judge by the clip.

Bear

 

[Svart]

yeah i was astounded by the toms in the overheads. i'm going to build a few more to try as tom mics.. :green:

 

[Bear]

Is there a compelling reason not to do the mod on the original boards? Or has it evolved past that point?

And which capsule is now recomended? The WM60 is gone, WM61 is what you used, and what's the deal w/ the WM64?

Bear

 

[Svart]

i just found it easier to make a new board than to run jumpers all over the old board. I'm pretty anal about my DIY.. :green:

I haven't tried the WM64, which panasonic lists as a replacement for the wm60. I have a baggie full of wm61's which i doubt I will use up so it's not likely i'll try the wm64. if you do let us know how it works!

:thumb:

 

[Marik]

[quote author="Bear"]Is there a compelling reason not to do the mod on the original boards? Or has it evolved past that point?

And which capsule is now recomended? The WM60 is gone, WM61 is what you used, and what's the deal w/ the WM64?

Bear[/quote]

I made this circuit on original boards--too much pain cutting traces, installing jumpers, and figuring out layout. Svart has a nice art work and it will be much easier (and faster) to use it.

I like WM61 better than WM60--less noise and more sensitive. With this circuit and WM60 sensitivity will be low. Don't have any experience with WM64.

 

[Svart]

I have some buildup pics of the board and parts on it if anyone is interested, maybe if I ask Marik nicely he'll host those for me too.. :green:

 

[Marik]

[quote author="Svart"]I have some buildup pics of the board and parts on it if anyone is interested, maybe if I ask Marik nicely he'll host those for me too.. :green:[/quote]

Sure...


what's the heck...



send them my way.

 

[Marik]

Here are some Svart's populated boards:

 

[Svart]

shameless bump.


thanks again marik!