[BUILD] 1176 Rev A - Back to the beginning...

scott2000 said:

Regardless of Gain reduction switched  on/off?


Is the ground from meter board showing connection to main pcb??? and all the other ground points in circuit??

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yes, regardless of bypass setting. Does it have to be connected to ground??

The ground from meter board shows continuity to all ground connections and chassis, i guess that's alright.

weiss said:

yes, regardless of bypass setting. Does it have to be connected to ground??

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I believe it does while gain reduction  is off...??...need to look more

how do you disable gain reduction?? The meter switch?

Do your shared attack and release pot pins show up at pad 7 on main pcb???

scott2000 said:

I believe it does while gain reduction  is off...??...need to look more

how do you disable gain reduction?? The meter switch?

Do your shared attack and release pot pins show up at pad 7 on main pcb???

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Put it into BP mode, yes.
They both show up at Pad 7.

weiss said:

Put it into BP mode, yes.

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pad 22 should be grounded when bypassed.....I guess something is up???? You can't calibrate it until you bypass if I'm correct??


wonder if you can jump 22 to ground to see if you can calibrate...sounds scary

that's true. but my unit is always bypassed. there is no compression going on. so i'm not sure it would help.
but in the calibration guide, they say i have to short it to ground OR turn the attack pot all the way ccw so the inbuilt switch turns off. but it's not even connected in my unit (i wouldn't know where). So i'm not sure i'm even trying the right thing..

The rotary meter board has the bypass in it so you don't need the attack switch type.....

.And, you'll never get compression until the unit is calibrated I think so, it may not be in "bypass" right now, just not compressing because it's not set up yet.......

I just don't know what's going on with the meter board not switching to ground 22...maybe it doesn't.. I don't think it'll hurt anything to try jumping 22 to ground to see if you can calibrate it to find out if you can get compression but, I can't say for certain because I don't know what is going on.... I'd probably try but, I'm crazy and have broken things by experimenting...lol

If it did work, you wouldn't have bypass available after removing the jumper...... There's a way to work around this and maybe use the attack switch for bypass I suppose.....

Do you have that particular attack pot with the switch???

surprised nobody else is chiming in ???  Maybe they're too busy getting a good laugh...lol     

ahh okay i get you! yes i got that switch installed actually. you want me to connect those additional 3 cables ?  or just put a jumper somewhere? where exactly? i'm really sorry for spamming this thread and beeing such a noob but i just can't help it..

I would probably try jumping first just to see what happens with calibrating....... but, don't take that as good advice.....

oh.....just short 22 to ground on the pcb or meter board should have same effect........ i think....

I guess , if you know how to rearrange the set up, it would be better? I'll see what goes where and try as well.......

Just curious why the meter switch isn't working...maybe it doesn't switch there.......and if it'll have other issues when trying to go further......


just saw this.....  #1143

https://groupdiy.com/index.php?topic=20058.1140

should be able to figure out how to redo the bypass ..... Still seems like a band aide....need to read more..... definitely getting closer I'd imagine.....

that schematic just got me more confused 

maybe also the switch is broken.. i'm gonna order a new one in the meantime

yeah....better safe than sorry I guess before messing around

switches go bad I guess??? seems weird....
..... I'm still going to look around to see what's up..... ..


so I'm guessing the meter board  doesn't show continuity from it's ground pad to it's pad 22 regardless of how it's switched.....??


EDIT/////I think this video shows that you have to short 22 to ground.....when calibrating.... That would make sense.....??? so you leave the meter gr on to calibrate.....???? but you have to bypass gr circuit to do this.....and that's why you jump 22 to ground temporarily.......????

still not sure though....but seems to be what he's saying

still wonder if that the meter gr off should bypass the compression once calibrated???? not sure if that will be all good or if there is an issue....


https://www.youtube.com/watch?time_continue=83&v=WuDdVY1R__w

you could try it.......

Okay i am gonna try that. But still. Shouldnt i hear some difference when bypassing? Shouldnt i see meter movement. After all strange but i‘m gonna try shorting and do the basic calibration steps

Meter too??? I don't know what it will do now....Please update with your findings.... Pretty sure you have it wired up correctly from your progress??

Says in the guides that the unit doesn't work until it's calibrated.....???

scott2000 said:

Meter too??? I don't know what it will do now....Please update with your findings.... Pretty sure you have it wired up correctly from your progress??

Says in the guides that the unit doesn't work until it's calibrated.....???

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It doesnt work, thats what i wanted to say . And yes it has to be calibrated before using

weiss said:

It doesnt work, thats what i wanted to say . And yes it has to be calibrated before using

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have you tried jumping 22 and ground and calibrating yet???

How's it going weiss???

Any progress?

I have to admit, I'm pretty stumped on this whole bypass thing and how it relates to the rotary version. The schematic points out the separate bypass switch if I'm not mistaken and, the more I try to read, the more confused I get as to how the rotary meter does the bypassing. There's a ground and a pad 22 on the meter board so, I am guessing it shorts them on the meter board, but you saying that this doesn't happen is confusing.

I'm pretty green on this stuff too so, I'm not surprised I can't figure it out but, it shouldn't be impossible to understand.....

The rotary meter has GR off, GR on, and +4 for output monitoring.........

so , when it is off, is it supposed to short pad 22 to ground or doesn't it? I can't imagine it just shuts off the meter and that's it??

Have you found out any direction on this?

Maybe your switch is hokey?

Could sneak this in another build thread to see if anyone knows???? I'm pretty sure it's got to be something in this section of your build.....

scott2000 said:

How's it going weiss???

Any progress?

I have to admit, I'm pretty stumped on this whole bypass thing and how it relates to the rotary version. The schematic points out the separate bypass switch if I'm not mistaken and, the more I try to read, the more confused I get as to how the rotary meter does the bypassing. There's a ground and a pad 22 on the meter board so, I am guessing it shorts them on the meter board, but you saying that this doesn't happen is confusing.

I'm pretty green on this stuff too so, I'm not surprised I can't figure it out but, it shouldn't be impossible to understand.....

The rotary meter has GR off, GR on, and +4 for output monitoring.........

so , when it is off, is it supposed to short pad 22 to ground or doesn't it? I can't imagine it just shuts off the meter and that's it??

Have you found out any direction on this?

Maybe your switch is hokey?

Could sneak this in another build thread to see if anyone knows???? I'm pretty sure it's got to be something in this section of your build.....

Click to expand...

okay now i really give up.
it is literally impossible to calibrate this thing.. i'm absolutely in the dark what else there could be wrong.

so first i put on the 1k signal like in the video, turn up the input. at first it wouldn't even go over -10db on the meter. Only when i turn input and output completely cw i am able to read 1 dB. but then the funny things begin.... the meter doesn't stay at 1 db. it is constantly moving. subtile little movements (i tried to capture that in the video but it's not that obvious). also when the unit is warm after some minutes. so as soon as i try to set 1 db and move the input knob, it is constantly moving, which makes it impossible for me to calibrate. next thing: IF it stays at 1dB and i try to set the 1db drop with q bias adjust, the stupid trimmer doesn't do anything. i can't even make it move into the right direction, the meter it just goes up and down almost as if it wants to say f* u .

Also if i listen closely to the sound of the returning signal, i see changes in the analyzer. The sine wave is changing over time without me doing anything... what is wrong with that unit ????
in the beginning i was able to make it slightly move towards 0dB but halfway there i felt a resistance in the trimmer which probably indicates that i shouldn't continue trimming.... so i really don't know what's going on here. and that's only the first step  :-[

okay sorry for flipping out but that stupid thing really gets me angry....! 

i uploaded a video of the first seconds. i know it sounds stupid but i can't make this 1dB drop happening... something is really off!

here the link: https://www.youtube.com/watch?v=LTEFPepm6xM

Oh no! :-\


You're absolutely positive you didn't miss a step or anything???

I'll look over everything here in a little bit to see if I can't get you more lost from here...lol.........

It has to be something simple we're not catching.......
Somebody HELP!

Please??

yeah... probably wiring issue ??? switch works fine as far as i can tell.
but why does the vu meter play games?

weiss said:

so first i put on the 1k signal like in the video,

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I'll try to follow along....piece by piece as I can since we are alone here we should be able to figure it out within all of the guides and videos although there are differences I'd guess.......


the unit is warmed up first???

so there is .775vac at the + and  -pins of your input xlr inside to make sure there isn't an impedance loss?

http://library.hairballaudio.com/images/fetrack/input_test_points.jpg


are you setting your qbias resistor to o or to wide open????? are you testing it to make sure????

one thing too that seems to be noted is the importance of the tant caps at c19 and 20..........?? I forgot what brand/type you used here.....guessing low esr?? maybe swapping those places wouldn't be a bad idea......


are you following the older version calibration on the Hairball site???? Seems the Hairball method is slightly different than the mnats video version...... doesn't really talk about the meter until that next step in the calibration......just the voltage drop.....??

scott2000 said:

I'll try to follow along....piece by piece as I can since we are alone here we should be able to figure it out within all of the guides and videos although there are differences I'd guess.......


the unit is warmed up first???

so there is .775vac at the + and  -pins of your input xlr inside to make sure there isn't an impedance loss?

http://library.hairballaudio.com/images/fetrack/input_test_points.jpg


are you setting your qbias resistor to o or to wide open????? are you testing it to make sure????

one thing too that seems to be noted is the importance of the tant caps at c19 and 20..........?? I forgot what brand/type you used here.....guessing low esr?? maybe swapping those places wouldn't be a bad idea......


are you following the older version calibration on the Hairball site???? Seems the Hairball method is slightly different than the mnats video version...... doesn't really talk about the meter until that next step in the calibration......just the voltage drop.....??

Click to expand...

unit is completely warmed up. i checked my input voltage, it was relatively high with 2,8vac. i lowered it to .775 but now i don't get only veeeery little meter movement and i can't even get to zero db by using the adjust trimmer. is there something wrong with the 2k trimmer i use instead of the trim pot which would be located at the front panel? i just assumed i could choose either way..

before i was even able to to do q bias adjust but now that's not possible any more. i also found out, that the oszillations of the meter result from me touching ground... that's weird ??? and also noise from the unit disappears as i touch cables..

no i didn't test the trimmer.. 

good question, just normal 6.8uF 100V caps by nichicon... why? you think they bad?

i was just referring to the mnats videos.. i don't know any other calibration guides..