[BUILD] 1176LN Rev D DIY

[Harpo]

.. output transformer ..
output measurements (input pot and output pot fully CW) - 0,3V on blue(pin2) 0V on
red(pin3)

as you see i dont get proper levels (sound is also very very thin and output unbalanced)

measure across xlr-pins 2/3. transformer balanced output is floating, not referenced to 0V.

 

[uzak33]

can you wire a rev d like the rev a? refering to mnats new wiring plan? is it similar!

thanks

 

[college101]

Uzak...have you been to mnats website for the wiring detail? They are very similar..

 

[college101]

OK GUYS>>>HELP HELP HELP....I am at my breaking point...I re-checked everything, and then installed my new 2k trimmer into r44, and geuss what!!!??? It still does not work...I have gone back threw, everything test's correctly, all of my parts are receiving and reading at the correct voltages...

what do I do now?  I can set the step before in the calibration process, but once I go inside to adjust r44, nothing, no amount of turning effects the needle movement twoards -10

CAN some previous builders please respond and give me an idea of where to go from here...Im on my 4th trimmer that does nothing!!

 

[college101]

OK GUYS>>>HELP HELP HELP....I am at my breaking point...I re-checked everything, and then installed my new 2k trimmer into r44, and geuss what!!!??? It still does not work...I have gone back threw, everything test's correctly, all of my parts are receiving and reading at the correct voltages...

what do I do now?  I can set the step before in the calibration process, but once I go inside to adjust r44, nothing, no amount of turning effects the needle movement twoards -10

CAN some previous builders please respond and give me an idea of where to go from here...Im on my 4th trimmer that does nothing!!

SO this is whats happening...I am setting the front controls, but compared to the video, I feel like my input is super high, and my output it super low...went back threw AGAIN...my wiring detail...everything matches mnats site picture diagram...

I move in to adjust R44, and nothing happens, I have reflowed the joints and nothing happens...what Do I Do now...?

I can get it to go to -10...but I have to turn my signal up on mt audio generator...the problem is, if I do get the needle to swing to the correct point, I CANT adjust R44 to the correct setting to hold the adjustment...what do i do...is there a way to jump the tracks?

 

[college101]

Re: 1176LN Rev D DIY
« Reply #1612 on: February 10, 2011, 02:33:55 pm »Quote You shouldn't be touching the input pot when making the adjustment.

I haven't done the calibration in a while, but sometimes it helps to use a 5K trim pot instead of a 2K in the tracking adjust position.  Found this on page 81...for all the builders on here...

Since some of the original spec parts are switched out, the tracking adjust pot has to be a 5K to adjust it correctly...

After trial and error last night, I could only get it to compress to -8...and that was as far as I could get it to adjust to...Ordering a 5K right now!!!!!!

 

[college101]

I installed my new 5k Trimmer, and nothing...no amount of adjustments will adjust r44 to correct the needle movement from -8 to -10

Anysuggestions~!!  come on people!!!

 

[Harpo]

not a previous builder of this board, so just wild guessing, but looking at the schematic and silcscreen, you put in the jumper at TP1 (right next to R44), else any whatever value trimmer will be one side connected only, doing nothing ...

 

[college101]

Hey Harpo..Thanks for some input..

Yes...I have tried both settings with it connected to jumper and with jumper out of circuit...

Nothing makes r44 workin the circuit...  I also measured the out put, and I am getting audio at the xlr output pins 2/3..Im able to watch the voltage differences.... Just not able to set the needle to -10 to show the -10 compression level

What should I do next guys?????????????

 

[college101]

I keep going back through the archived pages...and I have found multiple people with the same problem I am having...

I did find something where people were stating that after reversing the black and green wires from the ratio board to the attack knob!?

I am going to try that, but what worries me, is that all my voltages are reading correctly....I measured everything...and no one seems to have a clue on where to go with this problem....


I also noticed that none of the people who have had problem, found a solution....

 

[spase]

anyone can tell me the series of edcor transformers(LL1540 clone) ?Thanks

 

[college101]

I keep going back through the archived pages...and I have found multiple people with the same problem I am having...

I did find something where people were stating that after reversing the black and green wires from the ratio board to the attack knob!?

I am going to try that, but what worries me, is that all my voltages are reading correctly....I measured everything...and no one seems to have a clue on where to go with this problem....


I also noticed that none of the people who have had problem, found a solution....

BUMP..help guys

 

[college101]

Q12 has to be the problem!  I made the mistake and resolder'd my output wires backwards...fixed that, but now, I cant adjust the input to get -10....I cant get it to show zero with compression off, and then when compression is ON durring +4

Checking q12 and q13 when I get home

 

[college101]

Does anybody have any input? OK..when I have the compression ON via the ATTACK switch, I cant adjust with r44...in VU mode or in +4  !!!!!!!  I have found that I am getting 4 volts over the 9.28 and 9.75 needed near r44

I need some input guys..I went back threw my build...everything is correct, and everything is set the same as mnats build pics and matches the schematic...

 

[skidmorebay]

Hello,
I recently completed my Rev D 1176. It's working wonderfully. I've been able to complete the first two steps of calibration per the MNATS videos, but I don't have the signal generator needed for completing the meter calibration. I used the signal generator in my DAW for the earlier steps.
Does anyone know how a DAW can be used to create the 0dbm tone required for the last step in meter calibration? Is there a specific voltage I can look for at the input terminals of the 1176, etc, while using a 1khz tone from my computer, or any other method?
thanks!

 

[college101]

Do you know what Dbm means skidmorebay? Check it on on wikipedia

I just got a wide range oscillator, the same one as used in mnats videos and they work great...If your gonna build gear, I highly recommend picking one up...I got mine for a hundred bucks

Harpo...when R44 is in the circuit, meaning the pole is connected, it does nothing to adjust needle movement...  thats in +4 or GR mode...I know cause I tried both meter settings....

 

[Harpo]

Harpo...when R44 is in the circuit, meaning the pole is connected, it does nothing to adjust needle movement...  thats in +4 or GR mode...I know cause I tried both meter settings....

Only GR mode is of interest here. The +4dB or +8dB modes are only connecting the meter thru 3K6 or 8K2 to X/Y, further going to output XLR-pins2/3.
When R44 doesn't operate, something is preventing current flow. I'd double check R70, R71, R73 and maybe R68, R69, R72 as well for parts values and being conducting, including solder joints and a check for broken traces in between. Good luck.

 

[college101]

Harpo..thanks mate...

I will definitly check traces first,check to make sure those joints are re-flowed,and then and pull those rsistors next tonight

 

[erjos]

Sory For asking maybe someone has allready but i could find this question somewere.
In the Mnats Revision D transistor Q6 can be safely substituted with a tip 120 or tip 122 without losing anything?its impossible to find in my country the 2n3053 specified in the Bom.Other possibilities that i have are the BC107 metal can and 2n2222A metal can.Pls advise what should be the best.It seems that Tip 120 has better power handling,but im not shure for the rest.
Thanks in advance

 

[college101]

GOOD NEWS!!  I got my 1176 Rev D to meet the specs of step 3...It compress's to -10 with compression ON, and with compression OFF shows 0 VU....

BUT, once I go back into +4 mode, I was expecting to see the 1kHz signal show zero again, but it does not? Has anybody else found this to be the same with there's?

I cant wait to take it to my friends studio and try it out!!