[BUILD] 1176LN Rev D DIY

[Brotastic]

So the n is for nanofarad?  I just want to make sure.  I know caps are measured in farads and I usually see nF for the nanofarad.  In the Mnats website for the psu it is just an "n" and on the board it is just an "n".  Just want to make sure it is the right measurement. 

 

[Ilya]

So the n is for nanofarad?  I just want to make sure.  I know caps are measured in farads and I usually see nF for the nanofarad.  In the Mnats website for the psu it is just an "n" and on the board it is just an "n".  Just want to make sure it is the right measurement.

Yes. n=nF (nano), p=pF (pico), u=uF (micro)

 

[Brotastic]

cool, thanks.  I thought so, but I am just so worried I am going to mess something up I wanted to make sure. 

How would I go about figuring out the recommended voltage for the .1uf (100nF) cap? 

The 10uf cap is 35v and the 1000uf cap is 50v. 

I really appreciate everyone's help. 

 

[Ilya]

How would I go about figuring out the recommended voltage for the .1uf (100nF) cap? 

I doubt you'll find ceramic caps with voltage rating less than 50V. 50V is plenty enough, but you can go higher if you have problems sourcing the particular part.

 

[sr1200]

Yep, what Ilya said... all other cap values voltages are listed on the BOM. (ie 35V for 47uf electro...)

 

[Brotastic]

Thanks for putting up with my questions.  You guys have been a big help.  Ill just get a 50v cap

 

[pittsburgh]

  I just noticed a few unterminated connections at the bottom of the VU meter board. I'm looking at connections marked 22, Black, and GRN. I'm wondering if this is possibly the reason why I haven't been able to get any compression, or visual compression from the meter. Do these connections terminate, and if so where do they connect to? I didn't see any multiple connections put to a single point in the wiring guide. I guess I have a good guess for where 22 and GND go, but I'm not sure where black is supposed to run to. The black wires on the attack pot/ ratio board maybe?

  Thanks again,

  -P

 

[Stagefright13]

Brotastic I use this chart when choosing Caps. Example .0047 UF = 4.7 NF

http://www.justradios.com/uFnFpF.html

If those wires aren't connected Pittsburgh it WILL not compress! You'll need to consult the wiring guide or schematic. There are NO unused connections. 2 of those wires turn on and off the compression. Look here:

http://mnats.net/1176_reva-d_hairball_wiring_power.html

John

 

[Stagefright13]

And here: http://www.hairballaudio.com/docs/FET%20Compressor%20PCB%20Board%20Info%20V3.pdf

If ya download the schematic you will see straight away where those wires go.

John

 

[Brotastic]

Brotastic I use this chart when choosing Caps. Example .0047 UF = 4.7 NF

http://www.justradios.com/uFnFpF.html

If those wires aren't connected Pittsburgh it WILL not compress! You'll need to consult the wiring guide or schematic. There are NO unused connections. 2 of those wires turn on and off the compression. Look here:

http://mnats.net/1176_reva-d_hairball_wiring_power.html

John

Cool thanks, I will put that in my favorites.  I usually just do the math, but that is easier. 

 

[pittsburgh]

Stagefright13, I'm confused. The meter board wiring guide states not to use the BLK, GRN, and 22 Pads, located on the meter PCB board, unless I'm using an alternate wiring for the meter, which I'm not. Should I be using a different configuration?

 

[Ilya]

Stagefright13, I'm confused. The meter board wiring guide states not to use the BLK, GRN, and 22 Pads, located on the meter PCB board, unless I'm using an alternate wiring for the meter, which I'm not. Should I be using a different configuration?

Unless you're going to put bypass instead of +8 button you should forget about blk, grn and 22 pads on the meter switch assy PCB forever. Don't use them.

 

[pittsburgh]

In the paragraph where it talks about the classic meter board wiring guide it references the 25K attack pot. I'm assuming that the attack pot gets connected another way then?

-P

 

[sr1200]

Pitts, are you using the rotary switch or the hairball kit?  And im sure most people on here dont have the entire MNATS wiring guide committed to memory, give us a page or a link or something as reference.

If you follow along from step one, the AC wiring, its spelled out step by step and even gives color guides to follow.  The only confusing thing would be the wiring for the power transformer if you're not using the hairball power transformer (and even then, you just have to know which wires are which on the transformer and that should be labeled on it)

This is one guide where you can't afford to skim over ANY part, there are little links and things hidden all throughout the guide that will get you from a to z. 

If you didn't follow the guide to do the wiring from the beginning, I would suggest removing them all, and starting over with the guide so nothing is missed.  If after that, there's still issues give me a shout, ill help however i can.

 

[pittsburgh]

  Thanks SR, I'm using the Hairball kit. I'm just trying to figure out why I'm not compressing here, and thought that those points on the meter board switch PCB, which the compressor board build guide says not to use, might have something to do with it. I'll run back through the kit and let you know.

-p

 

[fazeka]

Hi all,

Finally got around to building my 1176 Rev D using mnats' PCBs and hairball's pushbutton kit/PCBs. Only took me three years...!

Regarding calibration, I followed mnats' first two video steps to a "T" and everything is perfect.

I got to the GR Meter tracking adjustment (step 3 video) and have some problems.

In short, in part 1 of this adjustment (i.e., VU mode) I can't seem to get 10dB of GR when setting up the input and output controls. I get 7dB. Of course when I switch to GR, it's the same (7dB).

I searched through the group DIY pages, but it seems like a few of those problems tie to the previous step 2's calibration errors by a few people. I can't see any reason why I didn't follow those instructions properly because it was very clear and everything in that step worked well for my compressor. Maybe someone else has experienced something similar before and can point out where my mistake is? Specifically, here's what I am doing:

What I found whilst performing the GR Meter tracking adjustment: I set input and output at 1/2-way with GR disabled and then I raise output to 0 and then upon turning on GR, I "turn the input down" to reflect -10dB (because the meter stays at 0 when I turn on GR). But when I disable GR again, output needs to be turned up to get to 0 and then I run out of "pot" (output is maxed). So what I end up doing is starting all over again by turning the input all the way up and output down (instead of both 1/2-way) and then I get close, but only get down to -7dB when it's all said and done.

I know it's only a 3dB difference but my hope is that my compressor is not compromised in some way either in its build or its calibration because of this "issue".

So again hoping someone's heard of this or experienced it and can shed some light.

Best regards,
Chris

 

[pittsburgh]

Is there a wiring layout for the ratio board? I accidentally ripped off a pad from one of the wires and need to jump it from another point.

 

[sr1200]

Pitts: the scematic should help with that.  Mnats site pdf.
Faze: instead of doing the 50/50 thing with the knobs, try bringing the input to 100% and then bringing to output up till you get to zero,  see what kind of a drop you get there. If its still above 10, adjust the input lower till you hit -10, switch back and readjust the OUTPUT knob to get back to 0.

 

[fazeka]

Faze: instead of doing the 50/50 thing with the knobs, try bringing the input to 100% and then bringing to output up till you get to zero,  see what kind of a drop you get there. If its still above 10, adjust the input lower till you hit -10, switch back and readjust the OUTPUT knob to get back to 0.

I tried this.

With GR disabled and meter in +4 with the 1k tone at 0.775 feeding the input, I bring the input all the way up and bring output up so VU reads 0. When I switch GR on, I have to lower input again to get to -10. Then I disable GR again and have to increase the output to get to 0. I go through this dance once more on the lowering of the input and when I go back to disabling the GR again, I can't get to 0 VU as the output pot at this point is "maxed out".

If I set it up for 7dB of GR instead of 10dB, I don't have this problem. But then something's telling me that all my calibration procedures are wrong or my unit is wired incorrectly.

It's almost as if once the input is (set) too low, it will never calibrate for 10dB GR...

 

[Ilya]

Faze: instead of doing the 50/50 thing with the knobs, try bringing the input to 100% and then bringing to output up till you get to zero,  see what kind of a drop you get there. If its still above 10, adjust the input lower till you hit -10, switch back and readjust the OUTPUT knob to get back to 0.

I tried this.

With GR disabled and meter in +4 with the 1k tone at 0.775 feeding the input, I bring the input all the way up and bring output up so VU reads 0. When I switch GR on, I have to lower input again to get to -10. Then I disable GR again and have to increase the output to get to 0. I go through this dance once more on the lowering of the input and when I go back to disabling the GR again, I can't get to 0 VU as the output pot at this point is "maxed out".

If I set it up for 7dB of GR instead of 10dB, I don't have this problem. But then something's telling me that all my calibration procedures are wrong or my unit is wired incorrectly.
It's almost as if once the input is (set) too low, it will never calibrate for 10dB GR...

Looks like there's something wrong with your output amp. Check resistor values, especially in the feedback loop.