Topic: Greetings... my new mic preamp.

[fivefishdiy]

Okay... been busy this afternoon...    

... trying to rack a 1-channel SC-1 Solo version.... so if you want to imagine the 2-channel TS-2 version, well just double what you see here.

Designed the front and rear panels, setup hole dimensions and locations... then created the CNC Gcodes.

This is the front panel layout. You can see the holes for the brackets, gain, trim, switch and LED.


Before I can even mill the aluminum panel, I need to create a jig out of MDF. Then I drop the panel inside the pocket I created and screw it to the board.

If you want to see how my panels are milled, see this related video: http://www.youtube.com/watch?v=uA0xwIE4xdI

And this is the finished CNC-milled panel.

Just look at that XLR hole... it's perfect!


I told you the fit is perfecto-mundo!

[skip the boring stuff, screwing holes, etc...]


And here's the finished 1-channel preamp... powered by a Tekkeon battery.


Closeup shots of the back.


And here's another beauty shot...

That's all folks.

Next.... I'll try to finish the (2) channel prototype... but I need to wait first on the VU meter boards from the factory. I need to verify clearances on the switchboard PCB. If everything's good, we send out the switchboard PCB for manufacturing while we start design on the main motherboard.

[Colin Liston]

Awesome stuff.  Love the progress, keep up the good work.  We really do appreciate it.

[jerryfreak]

my only other suggestion is some sort of locking switchraft power connector (ala v3), or a retainer clip for the power cable (ala minime)

Awesome stuff.  Love the progress, keep up the good work.  We really do appreciate it.

[fivefishdiy]

my only other suggestion is some sort of locking switchraft power connector (ala v3), or a retainer clip for the power cable (ala minime)

Awesome stuff.  Love the progress, keep up the good work.  We really do appreciate it.

Hey jerry, I do have the locking switchcraft jack. I just didn't use it for this prototype. (I don't have a corresponding power source to use with that jack.)

[illconditioned]

my only other suggestion is some sort of locking switchraft power connector (ala v3), or a retainer clip for the power cable (ala minime)

Awesome stuff.  Love the progress, keep up the good work.  We really do appreciate it.

Hey jerry, I do have the locking switchcraft jack. I just didn't use it for this prototype. (I don't have a corresponding power source to use with that jack.)

FWIW, I've had great luck just using a hot melt glue gun and some gaffer's tape and putting at the point where the (right angle) power connector meets the wire.  I've done this on any rig I've used, Edirol UA5, R4, R09, and lots of other stuff.  More or less permanently attaches the plug.  Not elegant, but works with any gear.

By the way, will those locking connectors work with standard power supply connectors?  Are they like the ones on the Dmic20?  If so, putting a locking jack on the gear would satisfy all of us.

  Richard

[fivefishdiy]

Not sure what the Dmic20 looks like.... but the ones I got are the Switchcraft DC jacks 2.5mm with nut.

Yes, they work with plain-vanilla, normal DC jacks.



These are panel mount so it's easy to add it anytime, or even do it as a mod by the user.

[rowjimmy]

That's the stuff.
The Sound Devices MP-2 has that same jack/plug combo.

[Chilly Brioschi]

my only other suggestion is some sort of locking switchraft power connector (ala v3), or a retainer clip for the power cable (ala minime)

Awesome stuff.  Love the progress, keep up the good work.  We really do appreciate it.

Hey jerry, I do have the locking switchcraft jack. I just didn't use it for this prototype. (I don't have a corresponding power source to use with that jack.)

How about a four-pin XLR for power?
Cheap, bomber, and easy to get:

[fivefishdiy]

I think that 4-pin XLR jack will be overkill. Since we only need 12V and a ground.  The locking Switchcraft DC jack does the job.

Now, if you're building a remote PSU that needs to supply +18, -18, +48 and GND... that 4-pin XLR jack is perfect. 

[Gutbucket]

Not sure what the Dmic20 looks like.... but the ones I got are the Switchcraft DC jacks 2.5mm with nut.

Yes, they work with plain-vanilla, normal DC jacks.



These are panel mount so it's easy to add it anytime, or even do it as a mod by the user.

That Switchcraft DC jack is a good screw-on, locking connection, but the problem for our applications is that it is not available as a right angle connection.  That's the one used on the V3 which ends up sticking out the back farther than anything else and can end up crushing the power cable entry to the connector.  Again, not as big a problem if used on the side of the unit, but even on the side, many would prefer a connector that has a right angle option.  That's the only real advantage of the 4-pin xlr that I can see.

[willndmb]

might i suggest the poss of putting some of those black "U" on the back too
it would give people something to rest on instead of the cables when running upright

looks good

[moooose]

I love this thread!

Thank you all.

[drpro]

Actually right angle Switchcraft locking type connectors are available from Remote audio and nonlocking right angle are available from Mouser.

David

[fivefishdiy]

might i suggest the poss of putting some of those black "U" on the back too
it would give people something to rest on instead of the cables when running upright

looks good

I tried the above suggestion.  Photo here:



You can also see the locking Switchcraft DC jack that I installed.

Re: the brackets at the back. I find that they interfere with right-angle XLR jacks. Not unless you turn the jacks so the cable come out of the top or bottom, instead of the side.

Plus, beside... if you use a right-angle XLR jack, the depth of the XLR jack already provides protection to the DC jack.

Now, if you use a straight XLR jack, the jack is longer than the brackets anyway so the brackets at the back are really of no practical use.

So I'm not sure if I'm going to go for that on the final product. Good suggestion though, and I did gave it a try... but I'm not fully convinced it's useful.

Added LED panel mount indicator for the front panel and replaced all bracket screws with Stainless steel ones. The PCB is also attached to the case with spacers and screwed to the bottom with recessed stainless head screws. This PCB ain't going anywhere... considering the fact it's also bolted to the front panel via the Gain and Trim pots screws.

It's solidly built.




Tekkeon Battery:
On a different matter, I've been playing with this Tekkeon Battery with the adjustable outputs and I find that they give a fairly good amount of RF interference.... I noticed this when I laid the battery on top of the input mic cables, with volume set at max and gain at max 72db. I can hear RF noise.  It's not noticeable though at lower gains, 60dB and below.

The RF noise is not there if I use a DC wall wart adapter or plain 9V battery. It's definitely coming from the Tekkeon battery pack.

[shaggy]

I noticed this when I laid the battery on top of the input mic cables, with volume set at max and gain at max 72db. I can hear RF noise.  It's not noticeable though at lower gains, 60dB and below.

Can you describe the noise?  A ticking or something with a regular period of repetition?