Hairball Audio

Re: [BUILD] New FET/RACK Official Help Thread - Please read first post!
« Reply #1840 on: August 20, 2020, 12:39:31 AM »
JMan check your attack/release PCB super closely.  Make sure the values are good and everything is soldered well and the release legs are ok.

Make sure those 6.8 tantalums are in correctly.

Make sure all your wire headers are in correctly.

Make sure you release and output pots are not swapped.  Release is blue, output is grey.

Mike
Hairball Audio, LLC
DIY Parts and Kits
https://hairballaudio.com

Top secret stuff and upcoming releases:
http://instagram.com/Hairballaudio
http://facebook.com/hairballaudio


JMan

Re: [BUILD] New FET/RACK Official Help Thread - Please read first post!
« Reply #1841 on: August 20, 2020, 02:29:16 AM »
Oh brother, I totally have the output and release pots swapped!

I’ll switch them tomorrow and try again.  Will report back!

JMan

Re: [BUILD] New FET/RACK Official Help Thread - Please read first post!
« Reply #1842 on: August 21, 2020, 09:30:32 PM »
Okay, so I got the pots in the correct places.  I also found that R57 on the attack/release board was the wrong value by several orders of magnitude, so I put in the correct value.  I went through the entire circuit and triple checked my resistor color codes and other component values, and everything else checks out, including ratio and meter boards and now the attack/release board.

This mostly fixed the issue.  However...

In step 3 of calibration (where I was having trouble), turning on the attack pot does drop the voltage from 2.44v now that I've corrected those components, but not all the way back down to 0.775 -- only to 1.025.  If I adjust that down with the output control, then the "attack off" voltage drops accordingly.  In other words, I'm not getting the full 10dBu attenuation. 

Additionally, my voltages at TP22, Q7-10, and CR2 went further out of whack.  Most everything there shot high, particularly at the higher ratios (which it was already doing, but more so now -- for example, I've got 0.450v at Q7 as opposed to the expected 0.377v).  I've also still got a higher-than-expected voltage at Q5.

Having said all that, the unit does pass audio and compresses, and on a fun little test running bass guitar through it and then some drums, it sounds fabulous!  I'm just wondering what I'm still missing to get it all the way to where it's supposed to be.

Hairball Audio

Re: [BUILD] New FET/RACK Official Help Thread - Please read first post!
« Reply #1843 on: August 23, 2020, 11:46:59 AM »
Okay, so I got the pots in the correct places.  I also found that R57 on the attack/release board was the wrong value by several orders of magnitude, so I put in the correct value.  I went through the entire circuit and triple checked my resistor color codes and other component values, and everything else checks out, including ratio and meter boards and now the attack/release board.

This mostly fixed the issue.  However...

In step 3 of calibration (where I was having trouble), turning on the attack pot does drop the voltage from 2.44v now that I've corrected those components, but not all the way back down to 0.775 -- only to 1.025.  If I adjust that down with the output control, then the "attack off" voltage drops accordingly.  In other words, I'm not getting the full 10dBu attenuation. 

Additionally, my voltages at TP22, Q7-10, and CR2 went further out of whack.  Most everything there shot high, particularly at the higher ratios (which it was already doing, but more so now -- for example, I've got 0.450v at Q7 as opposed to the expected 0.377v).  I've also still got a higher-than-expected voltage at Q5.

Having said all that, the unit does pass audio and compresses, and on a fun little test running bass guitar through it and then some drums, it sounds fabulous!  I'm just wondering what I'm still missing to get it all the way to where it's supposed to be.

Those voltages are not crazy out.  They seem fine.

Not sure what's happening with your calibration step.  Have you looked at some of the calibration videos on you tube?  You might be doing it wrong?

Mike
Hairball Audio, LLC
DIY Parts and Kits
https://hairballaudio.com

Top secret stuff and upcoming releases:
http://instagram.com/Hairballaudio
http://facebook.com/hairballaudio

JMan

Re: [BUILD] New FET/RACK Official Help Thread - Please read first post!
« Reply #1844 on: August 23, 2020, 09:05:23 PM »
Well, whatever I was doing wrong before, I got it right this time.  Unit is fully calibrated and racked up, and it looks and sounds fabulous!  Thanks Mike for such a fun build.  I look forward to doing a few more of these units in the near future.

andow

Re: [BUILD] New FET/RACK Official Help Thread - Please read first post!
« Reply #1845 on: November 03, 2020, 04:37:25 PM »
Any update on the partial kits?  :-\

Re: [BUILD] New FET/RACK Official Help Thread - Please read first post!
« Reply #1846 on: November 11, 2020, 11:05:03 PM »
Hi there,
 
I have just built a Rev A.
The unit will be working well passing audio normally but  will randomly shut down and turn back on or it will shut down and not turn on again for another 24 hrs or so.

It's like it has over heated and shut down. I'm not really quite sure what the problem is.

Any help would be appreciated

Re: [BUILD] New FET/RACK Official Help Thread - Please read first post!
« Reply #1847 on: November 15, 2020, 02:23:01 PM »
Hello guys,need a lil bit of help here
So, I've built an 1176 rev F, calibration went well (checked it twice), when I set the ratio 8 ,12 or 20 everything works fine, but there is something wrong with ratio 4, meter hardly moves even when i crank the input to max, it shows me only 3 db of gr max. 

To give you more information I don't know if i've done something wrong or the issue was already, but after the calibration I did onlye these things :
1) Run some audio through it with ratio 8 -> worked well
2)Run audio with ratio 12 --> worked well
3) Then I've tried the all button setting --> meter went crazy all to the right in red, i've got scared by this weird response so I've turnt it off
4)Turn it back on, checked if all works fine, all good but 4 ratio issue, so at this point i'm not sure if the problem was already there or i've done something wrong (on point 3 maybe), it would be nice if someone can help me

Kind regards

Re: [BUILD] New FET/RACK Official Help Thread - Please read first post!
« Reply #1848 on: December 06, 2020, 05:30:33 PM »
Hi Team.

Just starting into a Rev. A build.

I have completed the first build guide for Step 1: Building the Power Supply.

Starting to check the power supply:

I have 0.2-0.4Ω between chassis and IEC ground. Good.

Turned on - no smoke. Good.

Checking the voltage on the cathode of CR8.

This should read 30VDC +/- 5%.

I am getting 47.5 VDC here fluctuating up to 49 VDC. I am going to turn this off and drain the caps because I’m reading that same voltage across my 40V caps.

At -10V DC test point on CR9 I have -9.65 VDC. Good.

My mains voltage is 122.9 VAC is that high enough to throw this off? Naw.

Wouldn’t the Zener clamp the voltage at 30 VDC regardless? Isn’t that the point of one of those little dudelingers?

Re: [BUILD] New FET/RACK Official Help Thread - Please read first post!
« Reply #1849 on: December 07, 2020, 11:45:08 AM »
I am going to check the grounds on the L-brackets. Maybe I put one of those in the wrong way and am not getting a good connection. The build guide mentions that they're longer on one side than the other but boy oh boy it's pretty close eh?

I will as well read the resistance from the bottom of anode of the diode to ground and take a look there.


Re: [BUILD] New FET/RACK Official Help Thread - Please read first post!
« Reply #1850 on: December 07, 2020, 08:44:38 PM »

3) Then I've tried the all button setting --> meter went crazy all to the right in red, i've got scared by this weird response so I've turnt it off

That's what happens when you push all the buttons in on any 1176. It's a good practice to set the meter to read output level instead of gain reduction when all buttons are in so that the meter isn't pegged for hours on end.

Re: [BUILD] New FET/RACK Official Help Thread - Please read first post!
« Reply #1851 on: December 08, 2020, 11:03:34 AM »
Okay.

Checked the anode of the stud diode to ground. Reading 0.2 ohm

Double checked all of the L brackets with a set of Vernier calipers and they were all installed correctly and are making good contact with the case.

My soldering iron is set somewhere between 600-650 Fahrenheit.

I have a reasonable skill with soldering. Not a pro, but I have been soldering for nearly 20 years and worked on my technique throughout the years.

I feel like such a dummy. I will pull the diode and test it out of circuit and if anyone can give me a solid lead on ordering another one from a reliable place that would be great. Not having much luck sourcing one through Mouser or Digikey.

JMan

Re: [BUILD] New FET/RACK Official Help Thread - Please read first post!
« Reply #1852 on: December 08, 2020, 03:11:59 PM »
3) Then I've tried the all button setting --> meter went crazy all to the right in red, i've got scared by this weird response so I've turnt it off

When I built my Rev D a few months ago, I had this same experience.  I had never used a real 1176 before, so I didn’t know to expect it (the plugins sure don’t model this aspect of the unit  ;D ), and I freaked out!  The suggestion above to switch the meter to output mode is a good one.  I’m in such a habit of always leaving all my meters in GR that this had never even occurred to me!

Re: [BUILD] New FET/RACK Official Help Thread - Please read first post! New
« Reply #1853 on: April 01, 2021, 09:04:08 PM »
Hi, I got the FET/RACK Revision D kit to build for a review we are doing, then we will implement into our studio.  I went through the calibration procedure, but I think the directions can use a lot of clarification.  Any tips on how to know if I got the Q bias correct, and clarification of the Null Adjust and Meter Tracking adjustments?

Thanks!
« Last Edit: April 10, 2021, 05:30:20 PM by Derrick »
I love the smell of solder in the morning.