[BUILD] 1176LN Rev D DIY

[college101]

not holding r44

 

[Biasrocks]

That looks like that trimmer is fried, your fingers are providing some resistance when you hold it. Does it measure any resistance out of circuit?

What happens when you put a 1K resistor in place of the trimmer?

Regards,
Mark

 

[college101]

TONIGHT, after class, I will try a 1k in r44...oh wait..its wednesday...I can do it in a bit...thought it was thursday

It measures out of circuit...1.68K to get me to -10

but for some reason, if I let go of the trimmer, then it falls to the -15 area...

Just order'd a new trim pot from mouser...hope it gets here quick!

 

[tandri79]

I´m little bit puzzled over the capacitor on the attack pot/switch that is supposed to go with the 25k resistor
what is the correct value ? is there a formula to find this out ?

Sorry for the noob question.

 

[tandri79]

;D figured it out

edit: No secret. sorry for that

I forgot about the pcb´s that where suplied for the rotarie switches and all the right values where printed on there

Attack pot: Capacitor 22nf with 470ohm resistor
Release pot: 270k resistor

 

[s2udio]

;D figured it out

Must be A Top military Secret then .
This thread is getting some really some skilled paint by number experts !
Shame really but following the usual present internet diy trend.....???

 

[college101]

I think I figured out my problem as well! I some how have lifted the trace between the trimmer side and the middle terminal of R44.. so when I was connecting R44 with the dip socket...I was getting the false readings...tomorrow I will repair and hopefully my new trimpot comes in the mail from mouser...

Im excited to say the least...Biasrocks ..you rock again!

 

[tandri79]

For rev D ratioboard it goes:
R1=150 1/2w
R2=470
R3=560
R4=1.5K
R5=10M
R6=56K
R7=56K
R8=68K
R9=47K
R10=56k

The other boards are for if you build it using rotary switches for the ratio and metering.

 

[cybergolio]

http://hairballaudio.com/docs/FET_Compressor_PCB_Board_Info_V2.pdf
findable here :
http://hairballaudio.com/shop/product_info.php?cPath=22&products_id=31

 

[college101]

OK guys..

IM back with bad news

Got my new bourns 2k trim pot, and it does not fix the problem..YET AGAIN, it seems as soon as I put it into the dip socket...the needle drops past -20 and no amount of adjusting causes the needle to move...

IF I bread board out the new pot...and hold it with my hands, this allows me to move the needle, but this is wrong!

HELP! Im so close...

There is no coninuity between the trim pad and center pad on R44..so I connected them with a piece of wire trim to join the two dip socket joints...coninuity then passes...but once I add in the new 2 k trimmer...with my 1k signal tone, it drops the needle to -20..

HELP

 

[college101]

Well..I have given up on the current board I have...Order'd a new one from Mnats, and will try again....considering the first one as my initial epic failure

Plan on taking the slow speed and careful soldering iron along on my next journey...
geuss I can use the old board for spare parts

***Another thing I have recently been wondering about the 1176! On mnats site and on Hairball audio, they have a disclaimer about the parts list currently being used, that they have not verified those lists... By now, I would of thought they would have verified those lists and confirmed if certain parts were not meant to be used in this current rev D configuration...or some explanation of what should be changed...

I have read every post and gone threw multiple pdf's and other people's 76 site info...

 

[Biasrocks]

OK guys..

IM back with bad news

Got my new bourns 2k trim pot, and it does not fix the problem..YET AGAIN, it seems as soon as I put it into the dip socket...the needle drops past -20 and no amount of adjusting causes the needle to move...

Have you traced the circuit around the trimmer to make sure it's going where it's supposed to?

Do you have the Jumper next to the trim pot shorted out or open?

Mark

 

[sr1200]

***Another thing I have recently been wondering about the 1176! On mnats site and on Hairball audio, they have a disclaimer about the parts list currently being used, that they have not verified those lists... By now, I would of thought they would have verified those lists and confirmed if certain parts were not meant to be used in this current rev D configuration...or some explanation of what should be changed...

This is the reason I gave up on my Rev J.  I've found you just have to pick ONE BOM and go with it ignoring anything else you might come across.  Which is why I stuck with doing the Rev D.  Go with the MNATS BOM, and only follow the hairball directions for the parts you get from hairball (push buttons, meter).  The wiring manual on MNATS site is VERY VERY good if you follow it to a TEE.  I also suggest using the different colored wires, as one wire in the wrong spot can get all sorts of confusing REALLY fast. (I originally tried with 3 colors and tore it all out and re-did it with the full rainbow... was way easier to see if something was wrong)

A couple of dumb questions for ya... im hoping the answer is yes to all of them:
1) did you look at the calibration page on mnats site that listed the current "errors" for the revision BOM
2) if you're using the rotary switch instead of the hairball kit, are you shorting pad 22 to ground when you're adjusting
2B) if you're using the hairball kit, are you turning the GR off (fully counter clockwise till it clicks) when adjusting

 

[college101]

bias rocks...I will re-check BUT based on my notes from my last check...

the jumper was connected .....meaning, R44 was in circuit..
From the tracing, everything is going to where it is supposed to go....with compression on via the attack know...and R44 not connected but JUMPER installed, signal is moving the needle...

As soon as I add R44, the needle falls to the left and does nothing

sr1200
BELIEVE ME...I have read all those pages up and down, and I used the corrected values for parts

I went with originally with Kato's parts list for REV D... I didnt think anything was wrong with the parts list BUT-
  I had to modify the clip on heatsink for the Voltage regulator
  I had to add dip sockets for some of the transistors
  I had to add white paste to the output transistor, and voltage regulator for heat dissapation

In terms of the questions you asked...
  1)YES
  2)YES-when the attack switch is off, you are shorting to ground
 

 

[David R.]

Just wanted to share the good news, I now have two beautifully working units.  I completed my second build this time without a hitch.  Found a few things I did wrong on the first build, corrected them.  Then the first one would not pass audio.  Searched everywhere, finally found the culprit. The connection on the attenuator board just came off of the board, no idea why, but I soldered a jumper and all is good.

 

[erjos]

College101
Don't give up. I had similar problems during my builds. In the second one I put on a wrong resistor from 4.7 to 47k it's very easy to be wrong in resistor values. Only one color diference. Have you really really checked all values carefully?

 

[college101]

Yes I have gone back threw my build..I took a day off work a month or so ago and went back threw every resistor... verified everyone...and everyone was correct...

I seriously just going to start over...

 

[edanderson]

college101,

i hope you'll eventually be able to finish this project.  it seems like you've put a lot of work into it so far.  there are a lot of little details, and if you've never done a project this complicated before, it can be really difficult.

you may be sick of it, but i would spend some time checking your wiring, etc against the original schematics.  the wiring guides, parts lists, and so on are helpful, but it is possible to mis-interpret them.  if you understand what the different parts are supposed to do and why they are connected that way, it is a lot easier to figure out why things aren't working.

good luck,

ed

 

[David R.]

College 101,

It actually helped building the second box.  The build was much faster, I learned what I screwed up on in the first build, and was able to compare the two when troubleshooting the first one.  Hope you can figure out what is wrong. 

 

[college101]

Once i get the new PCB, I will begin again...Honestly, I think I just got solder gun happy and messed up something in the R44 area , and I have to start over...

Everything I have checked, has checked out...I just cant get R44 to adjust the needle while in GR mode...and I am a perfectionist, so making this work drives me nuts... Once I get the new board, I will take even greater care to do it right the first time, and then be happy...

Once I get one fully working...Im gonna get a bunch more