[BUILD] 1108 DIY project and PCB layout

[Stagefright13]

I posted the board size earlier in the thread. Hope ya read in American inches over there! LOL

And scale to that size in your program.

I haven't etched anything in YEARS! But I used to.

John

 

[juanjovincenzo]

Thanks John, I think the board fit in 2 inches (with) Je je I love etch my boards!
So in the other hand please you can explain me how I can add the PAD, Phantom Power and the Fase or if you have some schematics or circuit to do this  ;D
regards

 

[ilfungo]

I just finished 2 x 1108
sounds wonderful
a question:
I used CM-2511
I have to connect pins 6 and 7 to case ground?
or just the 7 pin?
thanks

 

[ilfungo]

???

 

[Echo North]

Pin 6 is the Faraday shield.  It needs to be grounded to circuit ground.

Pin7, the can should go to case ground.

Mike

 

[ilfungo]

Thanks Echo North
last question:
it's normal that i have more less gain with 8k2 resistor ( pin 5 -E)?
What happens if I leave out  8.2k (E-5)?
Thanks


Thanks

 

[ilfungo]

???

 

[ilfungo]

I finished 2 of 1108 channels
wonderful sound!!
I don't use Vactrol
I must omit R2 or can leave  in place?
Thanks

 

[ilfungo]

???

 

[Stagefright13]

WOOHOO! Finally got back to this 1108 project and finished it! NO HUM and sounds great. It was on the shelf for so long I am embarrassed!!!

I fixed my Mnats power supply and added a resistor. (270 Ohm 5watt) at the AC input for the 48 volt side to drop the voltage down some. I had 35 volts going in... from my 30/30 transformer. The resistor put all the voltages within the ratings of my caps. After that it was a simple matter of installing the new power supply. That cured all the hum problems is perfectly quiet now. Thanks Mnats!! Can't wait to start making music with it. Will be using it later this week on a session.

Thanks everyone for all the help. It was greatly appreciated as usual!!! 

Here's a final pic:

 

[ilfungo]

sorry Stagefright13
If I don't use Vactrol
I must omit R2 or can leave  in place?
Thanks

 

[Stagefright13]

I remove R2 ilfungo.

 

[tomas1808]

Looking good Stagefright! About to finish mine also.

Does anybody know which pot I need when using the vactrol?

 

[Stagefright13]

This pre kicks some butt you should hear it on A snare drum with an 1176 chasing it! Perfect Match. Top and bottom mic. Had some gigs to use mine on. I haven't tried it on vocals yet just drums. But in A couple days I will get to work it thru the ringer so to speak...

Sounds great on guitar as well!! Coolass Pre Mnats! TYVM!

Just add A little reverb to it and whammo! Classic sound.

John

 

[Stagefright13]

That EQ would definitely put it over the top if anyone could work that out!! It would be really baddass if I could have A 2 band eq like 60 to 100 sweepable and 10k to 15k sweepable. Even if wasn't the original design...

Any ideas???

Or A sidechain so I could control the Vactrols?? If I put them back in???


EDIT: forget the Vactrols... Needs that EQ!!!! Prolly enough info on here to do it. But will check with friends to see how that was done and the values for it. Any help would be cool!! Still may be able to squeeze that eq in the box. Don't know much about inductors and such. Need help.

Actually 100hz and 10k bell shape would be plenty eq!! Like a wideband boost at those frequencies, Or cut in some circumstances...


Thanks,
John

 

[Stagefright13]

OK here is the Mnats 1108 in this song. Doing all the heavy guitars and snare.

http://stagefrightrecords.com/Lynny.mp3

 

[Stagefright13]

I used this schematic to wire up the inputs. http://www.eisenaudio.com/products/diy500mkii/images/diy500mkii_schematic2008_web.jpg

But any pre schematic will have something similar so just copy that part.

John

 

[ilfungo]

Sorry I have a strange trouble...
I haven't used vactrol
1 M pot and no R2

All the gain is in the first 1/4 of the pot
Why?
Thanks

 

[Harpo]

You probably have used a lin taper 1M pot.
You want a 1M log taper pot for a more usable response.

 

[AdoreaRecordingStudio]

So I've self-etched 2 channels of the MNATS 1108's and tirelessly read through EVERY groupDIY  forum that has anything to do with 1108's before posting but I am admitting defeat - at least for the night lol  - I've got the first of two "solo" style units built.. Cinemag 2511 input / EA-5002 output. - Thanks Hairball*** I've chosen to not include 48v phantom in this first unit so that is not where the issue stems from. I am getting a hum/buzz that is just too loud for me to be okay with. I am assuming this is a grounding issue. However any thoughts would be greatly appreciated.

I am using insulated wire to go to the volume pots* / grounded my power supply at 0v / and grounded all shields to chassis from IN/OUT xlr's.

I'd gladly post pictures if anyone has any thoughts?

Ps - i've already successfully built 2 "1176" style bluestripe boxes with great success, and since the circuit  is very similar I am perplexed as to what I am screwing up??

Thanks !

Travis