Re: [BUILD] New FET/RACK Official Help Thread - Please read first post!
« Reply #20 on: September 08, 2016, 04:11:07 PM »
I don't really see anything too bad.

Check the continuity with the Ω setting.  When you touch each end of the trace, is the reading less than 1Ω?

Mike

Hey Mike,

I'm getting a reading between 0.7 to 0.8 Ω, that's a good thing I suppose?

Yup...most of that resistance is probably in your leads.  You should be good.

Sweet! Thanks for the awesome help!

Gonna need to purchase a new slimmer screw driver -_-

I scratched the trace while screwing the silver pans because my current screw driver is a fat one...


Hairball Audio

Re: [BUILD] New FET/RACK Official Help Thread - Please read first post!
« Reply #21 on: September 08, 2016, 04:13:15 PM »
I don't really see anything too bad.

Check the continuity with the Ω setting.  When you touch each end of the trace, is the reading less than 1Ω?

Mike

Hey Mike,

I'm getting a reading between 0.7 to 0.8 Ω, that's a good thing I suppose?

Yup...most of that resistance is probably in your leads.  You should be good.

Sweet! Thanks for the awesome help!

Gonna need to purchase a new slimmer screw driver -_-

I scratched the trace while screwing the silver pans because my current screw driver is a fat one...

Most likely just scratched the solder mask over the trace. Old school gear doesn't generally even have solder mask.
Hairball Audio, LLC
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Re: [BUILD] New FET/RACK Official Help Thread - Please read first post!
« Reply #22 on: September 13, 2016, 06:01:50 PM »
Hey Guys,

So I just finished calibrating my Hairball 1176 Rev D and gave it a test run by compressing a Bass D.I.

I noticed something weird...

When I had a ratio of 20:1, the GR meter was reading around -3 to -5 db reduction.

When I had a ration of 4:1, the GR meter was reading -10db to -20db + of reduction.

Even when I would switch between both ratios, I noticed the 20:1's output was louder than the 4:1's output.

They both had the exact same settings as I was A/B-ing them during the process.

My Ratio Buttons are properly soldered to the ratio PCB and the PCB is aligned with the front panel ratio texts.

I'm not sure why my 4:1 ratio is behaving like a 20:1 ratio and vice versa...

Some pictures to help out:

4:1 Ratio


20:1 Ratio


DAW Waveforms


PCB | Buttons


I also noticed that my T-Pad makes a crackling noise to the signal every time I rotate between Negative Infinity to 18 db, anything above doesn't add mechanical noise.

I don't mind the noise as I never ride compression on analog gear, but it would be nice to fix it anyway so it feels clean and tidy.

Thanks!
« Last Edit: September 13, 2016, 06:05:53 PM by Hxcplayer »

Hairball Audio

Re: [BUILD] New FET/RACK Official Help Thread - Please read first post!
« Reply #23 on: September 13, 2016, 07:29:23 PM »
Hey Guys,

So I just finished calibrating my Hairball 1176 Rev D and gave it a test run by compressing a Bass D.I.

I noticed something weird...

When I had a ratio of 20:1, the GR meter was reading around -3 to -5 db reduction.

When I had a ration of 4:1, the GR meter was reading -10db to -20db + of reduction.

Even when I would switch between both ratios, I noticed the 20:1's output was louder than the 4:1's output.

They both had the exact same settings as I was A/B-ing them during the process.

My Ratio Buttons are properly soldered to the ratio PCB and the PCB is aligned with the front panel ratio texts.

I'm not sure why my 4:1 ratio is behaving like a 20:1 ratio and vice versa...

Some pictures to help out:

4:1 Ratio


20:1 Ratio


DAW Waveforms


PCB | Buttons


I also noticed that my T-Pad makes a crackling noise to the signal every time I rotate between Negative Infinity to 18 db, anything above doesn't add mechanical noise.

I don't mind the noise as I never ride compression on analog gear, but it would be nice to fix it anyway so it feels clean and tidy.

Thanks!

The 1176 threshold lowers as you move down the ratios. So the 4:1 threshold is way lower than the 20:1 ratio, so you'll see more OVERALL compression at 4:1.  Ratio is a totally different thing that has nothing to do with a single point compression.  Checkout the UREI manual for more info. However, your unit is working as expected.

We use the BI T-Pads because they tend not to suffer from end of track noise like other pots.  Sounds like maybe you have some EOT noise. It's really hard to get rid of in these Tpads because to Tpad sits before the amp stages so any little noise in the pot get's amplified.  We can send you another one if you like to see if you get any better results, but keep in mind the desoldering can be a little tricky.

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

Top secret stuff and upcoming releases:
http://facebook.com/hairballaudio
http://twitter.com/HairballAudio/

Re: [BUILD] New FET/RACK Official Help Thread - Please read first post!
« Reply #24 on: September 13, 2016, 07:49:24 PM »
Hey Guys,

So I just finished calibrating my Hairball 1176 Rev D and gave it a test run by compressing a Bass D.I.

I noticed something weird...

When I had a ratio of 20:1, the GR meter was reading around -3 to -5 db reduction.

When I had a ration of 4:1, the GR meter was reading -10db to -20db + of reduction.

Even when I would switch between both ratios, I noticed the 20:1's output was louder than the 4:1's output.

They both had the exact same settings as I was A/B-ing them during the process.

My Ratio Buttons are properly soldered to the ratio PCB and the PCB is aligned with the front panel ratio texts.

I'm not sure why my 4:1 ratio is behaving like a 20:1 ratio and vice versa...

Some pictures to help out:

4:1 Ratio


20:1 Ratio


DAW Waveforms


PCB | Buttons


I also noticed that my T-Pad makes a crackling noise to the signal every time I rotate between Negative Infinity to 18 db, anything above doesn't add mechanical noise.

I don't mind the noise as I never ride compression on analog gear, but it would be nice to fix it anyway so it feels clean and tidy.

Thanks!

The 1176 threshold lowers as you move down the ratios. So the 4:1 threshold is way lower than the 20:1 ratio, so you'll see more OVERALL compression at 4:1.  Ratio is a totally different thing that has nothing to do with a single point compression.  Checkout the UREI manual for more info. However, your unit is working as expected.

We use the BI T-Pads because they tend not to suffer from end of track noise like other pots.  Sounds like maybe you have some EOT noise. It's really hard to get rid of in these Tpads because to Tpad sits before the amp stages so any little noise in the pot get's amplified.  We can send you another one if you like to see if you get any better results, but keep in mind the desoldering can be a little tricky.

Mike

Cheers Mike!

You always have the most informative answers.

I would love to get another t-pad if that would be possible!

Hairball Audio

Re: [BUILD] New FET/RACK Official Help Thread - Please read first post!
« Reply #25 on: September 13, 2016, 07:51:09 PM »
Send me an email to the "[email protected]" address for the t-pad.

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

Top secret stuff and upcoming releases:
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twentys7ven

Re: [BUILD] New FET/RACK Official Help Thread - Please read first post!
« Reply #26 on: September 13, 2016, 10:16:27 PM »
Hi guys,

I posted a couple of days ago in the Rev A thread but figured I'd ask here too, I'm currently working on my second FET/Rack kit and it appears I've run into some trouble. I'm able to complete the Q bias calibration but I'm unable to complete step 2 as my VU meter won't budge no matter what I do, it stays all the way to the left. Any ideas of where potential trouble could be? I'm relatively new to DIY so I'm unsure how to check the voltages against the schematic or if that would even help narrow it down.

Hairball Audio

Re: [BUILD] New FET/RACK Official Help Thread - Please read first post!
« Reply #27 on: September 13, 2016, 10:20:09 PM »
Hi guys,

I posted a couple of days ago in the Rev A thread but figured I'd ask here too, I'm currently working on my second FET/Rack kit and it appears I've run into some trouble. I'm able to complete the Q bias calibration but I'm unable to complete step 2 as my VU meter won't budge no matter what I do, it stays all the way to the left. Any ideas of where potential trouble could be? I'm relatively new to DIY so I'm unsure how to check the voltages against the schematic or if that would even help narrow it down.

which version of the PCB do you have? I want to keep things in the proper thread. Let me know and I'll answer in the appropriate thread.

Thanks!
Hairball Audio, LLC
DIY Parts and Kits
http://hairballaudio.com/shop

Top secret stuff and upcoming releases:
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twentys7ven

Re: [BUILD] New FET/RACK Official Help Thread - Please read first post!
« Reply #28 on: September 13, 2016, 10:30:01 PM »
which version of the PCB do you have? I want to keep things in the proper thread. Let me know and I'll answer in the appropriate thread.

Thanks!

v1.12 I believe, from the most recent batch of Rev As that got sent out about a month ago.

Hairball Audio

Re: [BUILD] New FET/RACK Official Help Thread - Please read first post!
« Reply #29 on: September 13, 2016, 10:37:06 PM »
which version of the PCB do you have? I want to keep things in the proper thread. Let me know and I'll answer in the appropriate thread.

Thanks!

v1.12 I believe, from the most recent batch of Rev As that got sent out about a month ago.

Then this is the correct thread.

Does the meter work in +4 or +8? 

Get a good signal going through it...like at least 0dbu (0.775VAC) on the output.  Does the meter react in +8 or +4?
Hairball Audio, LLC
DIY Parts and Kits
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Top secret stuff and upcoming releases:
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Re: [BUILD] New FET/RACK Official Help Thread - Please read first post!
« Reply #30 on: September 14, 2016, 05:21:18 PM »
Hey Mike,

When i purchased my rev d kit, i also ordered with it the orange drop caps.

If i were to replace the film caps with the drops, would I then have to re-calibrate my 1176?

Hairball Audio

Re: [BUILD] New FET/RACK Official Help Thread - Please read first post!
« Reply #31 on: September 14, 2016, 05:42:13 PM »
Hey Mike,

When i purchased my rev d kit, i also ordered with it the orange drop caps.

If i were to replace the film caps with the drops, would I then have to re-calibrate my 1176?

Nope.
Hairball Audio, LLC
DIY Parts and Kits
http://hairballaudio.com/shop

Top secret stuff and upcoming releases:
http://facebook.com/hairballaudio
http://twitter.com/HairballAudio/

twentys7ven

Re: [BUILD] New FET/RACK Official Help Thread - Please read first post!
« Reply #32 on: September 14, 2016, 11:57:59 PM »
Then this is the correct thread.

Does the meter work in +4 or +8? 

Get a good signal going through it...like at least 0dbu (0.775VAC) on the output.  Does the meter react in +8 or +4?

Nope, not at all. Just fed it a signal and the meter won't budge at all regardless of how loud of a signal is passed through or what the meter is set to display.

Hairball Audio

Re: [BUILD] New FET/RACK Official Help Thread - Please read first post!
« Reply #33 on: September 15, 2016, 11:01:42 AM »
Then this is the correct thread.

Does the meter work in +4 or +8? 

Get a good signal going through it...like at least 0dbu (0.775VAC) on the output.  Does the meter react in +8 or +4?

Nope, not at all. Just fed it a signal and the meter won't budge at all regardless of how loud of a signal is passed through or what the meter is set to display.

Hmmmm. Sounds like a damaged meter maybe. You have the signal wire harness on there? (Metal Spades).
Hairball Audio, LLC
DIY Parts and Kits
http://hairballaudio.com/shop

Top secret stuff and upcoming releases:
http://facebook.com/hairballaudio
http://twitter.com/HairballAudio/

Re: [BUILD] New FET/RACK Official Help Thread - Please read first post!
« Reply #34 on: September 15, 2016, 11:37:25 AM »
Hi

This is my first time here. I've just completed building 2 Rev As and I'm having a bit of trouble with the Q bias calibration.
Before I go on, I've re-verified all components correctly placed, DC voltages correct, calibration parameters set per the Q bias instructions on the site, exact same problem on both units.

Here's what I've got-
1K signal reads 0dbu (0.775VAC) at the input and that signal reaches the primary of the input transformer->
with the input knob at 24, the signal after the tranny reads 0.120 VAC at TP1 and the signal voltage tracks with the knob from 0-0.360VAC which seems correct->
but there are 0.0 volts on the Q1 side of R5 (27Kohm).

The signal drops to zero volts after R5.
Henceforth, there is no signal anywhere down the chain and my calibration stops there.

I've tested Q1 and it has many mega ohms across it on both units, solder joints and component values all good.

I'm obviously missing something. Any help would be much obliged.


Hairball Audio

Re: [BUILD] New FET/RACK Official Help Thread - Please read first post!
« Reply #35 on: September 15, 2016, 11:41:56 AM »
Hi

This is my first time here. I've just completed building 2 Rev As and I'm having a bit of trouble with the Q bias calibration.
Before I go on, I've re-verified all components correctly placed, DC voltages correct, calibration parameters set per the Q bias instructions on the site, exact same problem on both units.

Here's what I've got-
1K signal reads 0dbu (0.775VAC) at the input and that signal reaches the primary of the input transformer->
with the input knob at 24, the signal after the tranny reads 0.120 VAC at TP1 and the signal voltage tracks with the knob from 0-0.360VAC which seems correct->
but there are 0.0 volts on the Q1 side of R5 (27Kohm).

The signal drops to zero volts after R5.
Henceforth, there is no signal anywhere down the chain and my calibration stops there.

I've tested Q1 and it has many mega ohms across it on both units, solder joints and component values all good.

I'm obviously missing something. Any help would be much obliged.

Short somewhere around Q1 I would say. What happens if you remove Q1? Then can you get signal to the output?

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

Top secret stuff and upcoming releases:
http://facebook.com/hairballaudio
http://twitter.com/HairballAudio/

Re: [BUILD] New FET/RACK Official Help Thread - Please read first post!
« Reply #36 on: September 15, 2016, 11:56:00 AM »
I've not tried that yet. Will pull it later today and let you know what I find.
Thanks for the quickness...

twentys7ven

Re: [BUILD] New FET/RACK Official Help Thread - Please read first post!
« Reply #37 on: September 15, 2016, 02:02:00 PM »
Then this is the correct thread.

Does the meter work in +4 or +8? 

Get a good signal going through it...like at least 0dbu (0.775VAC) on the output.  Does the meter react in +8 or +4?

Nope, not at all. Just fed it a signal and the meter won't budge at all regardless of how loud of a signal is passed through or what the meter is set to display.

Hmmmm. Sounds like a damaged meter maybe. You have the signal wire harness on there? (Metal Spades).

If those are the terminals underneath the meter then yep.

Re: [BUILD] New FET/RACK Official Help Thread - Please read first post!
« Reply #38 on: September 15, 2016, 08:15:38 PM »
K.
Removed Q1. And yes, the signal now makes it to the gate of Q2.
But it stops there because there is no DC voltage on the power rail to Q2 and Q3.
There are however, 30 VDC on both sides of R17.

I guess there is a short somewhere around Q2 or Q3 or both or dang.
I'm confused.  Kids calling.

Re: [BUILD] New FET/RACK Official Help Thread - Please read first post!
« Reply #39 on: September 16, 2016, 01:21:05 AM »
Alright, I got the first one calibrated. R17 was missing a pad so no power on the rails downstream of it.

Fixed that and on to my second Rev As problems.
Again, can't perform the Q bias calibration this time because R59 produces no change in output signal when adjusted. It stays at its full output regardless of how many ccw turns. Verified components and reflowed joints. No change.

Thanks for the help.