[BUILD] 1176LN Rev D DIY

[blackwaterstudios]

Ok - figured it out.  I have some of the strangest things happen to me!!  Sounding great - Moving on to the 3rd one!

 

[adrenalin1982]

Hi folks,

I start to measure my 1176 Rev D and found out, that it have hum about 50 hz. (with some Harmonics) with the Output-knob set to 24.  Here is a Picture from the Spectragraph.
The compressor works and sounds great at all. The Attack-Knob is wired as On/off switch.

Hope somebody could help.

Kindregards

http://img33.imageshack.us/i/bildschirmfoto20110307uo.png

 

[SaMpLeGoD]

Did you have the CT from the power transformer's secondaries connected to the star ground? if not, try that...
Cheers,

Eddie

 

[adrenalin1982]

hi eddie, try it and check the ct but unfortunately it doesn't work and nothing happens. still the hum on 50 hz

any other idea?

 

[guitarwill]

hey question guys, i was calibrating my rev d and got to the tracking adjust stage in GR Mode and all of a sudden it just stops compressing.

now it's not showing compression in +4 mode and GR mode the needle wont move from all the way left.  also having to crank the input and output to get to 0 in +4.  The only way i can get compression and gain back to normal is to go all buttons in, but still nothing is moving in GR mode.

any advice, think i need a new ratio board? 

 

[Stagefright13]

adrenalin1982 did you follow Mnats wiring scheme and grounding tutorial? You shouldn't have any hum. It should be very quiet.

John

 

[Echo North]

hey question guys, i was calibrating my rev d and got to the tracking adjust stage in GR Mode and all of a sudden it just stops compressing.

now it's not showing compression in +4 mode and GR mode the needle wont move from all the way left.  also having to crank the input and output to get to 0 in +4.  The only way i can get compression and gain back to normal is to go all buttons in, but still nothing is moving in GR mode.

any advice, think i need a new ratio board? 

Are you sure your Q-Bias is set right?

Sounds like maybe your Q-Bias is off.  If you switch GR off (short pad 22 to ground) does your output go up?

 

[jandoste]

hey question guys, i was calibrating my rev d and got to the tracking adjust stage in GR Mode and all of a sudden it just stops compressing.

now it's not showing compression in +4 mode and GR mode the needle wont move from all the way left.  also having to crank the input and output to get to 0 in +4.  The only way i can get compression and gain back to normal is to go all buttons in, but still nothing is moving in GR mode.

any advice, think i need a new ratio board? 

Are you sure your Q-Bias is set right?

Sounds like maybe your Q-Bias is off.  If you switch GR off (short pad 22 to ground) does your output go up?

I had exactly this problem and I searched 40 days  ;D what was it !

Now it works ! rock it !

Cheers,

 

[guitarwill]

it was working right, now when i switch attack knob switch on and off it does nothing

 

[Echo North]

Maybe a broken switch?

Removing the wires from the switch and twist 22 and GRN* together for GR on and then 22 and BLK (Ground) together for GR off.

*Please note GRN on the ratio board stands for "Green" which was the color of wire they used, not ground.  BLK is ground.

Mike

 

[adrenalin1982]

adrenalin1982 did you follow Mnats wiring scheme and grounding tutorial? You shouldn't have any hum. It should be very quiet.

John

Hi John, will start to wire my clone with  shielded cable in the next days. Maybe it will help to reduce the hum!? Do you mean this grounding tutorial on http://mnats.net/1176-wiring.html ?

 

[guitarwill]

i replaced the q bias trim and the ratio board and it's showing compression again.  however in the last calibration step i can get the 10db swing in +4 mode but when i goto GR and move the jumper for tracking adjust the needle just goes all the way left and the trim adjust doesn't move the needle at all.  any advice?

 

[Stagefright13]

This one here: http://mnats.net/1176_reva-d_hairball_wiring_power.html

 

[jordan s]

I recently made a Mouser order using the Hairball cart and C1 (Wima, 1uF, 100v, 5%) was out of stock so I substituted a Wima 1uF, 63v, 10% cap. I am going to be ok using this or do I need to order the the original cap which is now in stock?

 

[Echo North]

I recently made a Mouser order using the Hairball cart and C1 (Wima, 1uF, 100v, 5%) was out of stock so I substituted a Wima 1uF, 63v, 10% cap. I am going to be ok using this or do I need to order the the original cap which is now in stock?

You'll be fine!

 

[Biasrocks]

(Wima, 1uF, 100v, 5%) was out of stock so I substituted a Wima 1uF, 63v, 10% cap. I am going to be ok using this or do I need to order the the original cap which is now in stock?

While I respect what Mike is trying to do with creating a ready to go BOM, has it really come to this?

Please guys, do some reading, use your brains, learn something and build something cool.

Mark

 

[Echo North]

Especially considering this is on the same page:
http://hairballaudio.com/docs/SubGuide.pdf

 

[jordan s]

Sorry guys, I'm a fool. I was just worried about substituting a lower voltage capacitor, especially since the file you linked says, "you can always use a higher voltage capacitor but never a lower voltage." I guess that's incorrect?

 

[Echo North]

The original capacitor was a 50 or 63V cap.  They were out of stock, so I substitute the larger 100V value in the BOM.  

Mike

 

[Biasrocks]

The schematic is your ultimate reference.

Mark